Solid Waste Management

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Sustainability sustainability	3.9	5.8	2009	18.8 Days	CHF 2400
Energies energies	3.2	5.5	2008	16.1 Days	CHF 2600
Resources resources	3.3	7.7	2012	23.8 Days	CHF 1600
Recycling recycling	4.3	5.4	2016	20 Days	CHF 1800
Environments environments	3.7	5.9	2014	23.7 Days	CHF 1800

18 pages, 2585 KiB

Open AccessArticle

The Relationship between Knowledge, Attitudes, Values, and Technology in Promoting Zero-Waste Pro-Environmental Behaviour in a Zero-Waste Campus Framework

by Mayawi Baba-Nalikant, Nor Athiyah Abdullah, Mohd Heikal Husin, Sharifah Mashita Syed-Mohamad, Mohamad Saifudin Mohamad Saleh and Asyirah Abdul Rahim

Recycling 2023, 8(2), 40; https://doi.org/10.3390/recycling8020040 - 05 Apr 2023

Cited by 2 | Viewed by 3313

Abstract

This study aimed to investigate the relationships between knowledge, attitudes, and values in promoting zero-waste, pro-environmental behaviour among the university campus community and how technology plays its role. A survey instrument was developed from the findings of earlier focus group discussions and in-depth [...] Read more.

This study aimed to investigate the relationships between knowledge, attitudes, and values in promoting zero-waste, pro-environmental behaviour among the university campus community and how technology plays its role. A survey instrument was developed from the findings of earlier focus group discussions and in-depth interviews, which were based on the adaptation and adoption of previous studies, especially Kollmuss and Agyeman’s 2002 Model of Pro-Environmental Behaviour and a modified Knowledge-Attitude-Practises Model. Three hundred ninety-three respondent samples from Universiti Kebangsaan Malaysia, Universiti Putra Malaysia, and Universiti Sains Malaysia were analysed for their insights regarding their vision of a Zero-Waste Campus using the Structural Equation Modelling approach. The results show positive relationships between the five studied variables and the proposed hypotheses. Knowledge and attitudes serve as moderating variables, enhancing the strength of the causal effects of the related relationships. As the results show good significance, proper planning for integrating the studied variables and the proposed zero-waste campus framework can be used by university management, other institutions, or national-level agencies to develop an environment-specific plan to promote zero-waste, pro-environmental behaviour. Full article

(This article belongs to the Topic Solid Waste Management)

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16 pages, 4262 KiB

Open AccessArticle

Soil Improvement Using Blends of Coal Ash and Plantain Peel Ash as Road Pavement Layer Materials

by Isaac Akinwumi, Manuela Onyeiwu, Promise Epelle and Victor Ajayi

Resources 2023, 12(3), 41; https://doi.org/10.3390/resources12030041 - 22 Mar 2023

Cited by 2 | Viewed by 2121

Abstract

The management of waste and its environmental impact remains an issue. Thus, various strategies are being explored to mitigate this problem. For this research case, the ash of plantain peel and coal was harnessed to enhance soil for usage in designing road pavements. [...] Read more.

The management of waste and its environmental impact remains an issue. Thus, various strategies are being explored to mitigate this problem. For this research case, the ash of plantain peel and coal was harnessed to enhance soil for usage in designing road pavements. The form of the soil, as regards its plasticity and grain assortment, positions it as a sandy lean clay material. Geotechnical parameters of the natural soil were established before being treated with coal ash (CA) and plantain peel ash (PPA), and subjected to tests for the Atterberg limits, California bearing ratio (CBR) and compaction, as well as investigations pertaining to its crystallinity and morphology. These assessments showed that strength parameters of soil increased on adding CA and PPA. However, the inclusion of these admixtures should be conducted until optimal strength is achieved as seen in 9% CA + 6% PPA. The use of soil stabilised with CA and PPA is suitable for general fillings and embankments. These findings revealed that integrating CA and PPA together would have the potential of stabilising soil as pavement layer material while also eliminating the pollution that emerges from the improper disposal of coal and plantain peels from the environment. Full article

(This article belongs to the Topic Solid Waste Management)

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18 pages, 2703 KiB

Open AccessArticle

Optimization of Municipal Waste Streams in Achieving Urban Circularity in the City of Curitiba, Brazil

by Aarthi Aishwarya Devendran, Brijesh Mainali, Dilip Khatiwada, Farzin Golzar, Krushna Mahapatra and Camila H. Toigo

Sustainability 2023, 15(4), 3252; https://doi.org/10.3390/su15043252 - 10 Feb 2023

Cited by 3 | Viewed by 2034

Abstract

The municipal solid waste (MSW) remains a great challenge in most cities of developing countries, as the majority of the generated waste is either not collected or is dumped in open uncontrolled non-engineered landfill sites, creating significant pollution due to the leakage of [...] Read more.

The municipal solid waste (MSW) remains a great challenge in most cities of developing countries, as the majority of the generated waste is either not collected or is dumped in open uncontrolled non-engineered landfill sites, creating significant pollution due to the leakage of landfill leachate in the surrounding environment. In developing countries, a complete transition to a zero-landfill scenario is less likely to happen in the near future due to various socio-economic challenges. Therefore, the existing landfills in developing countries need holistic waste management thinking with more efforts on waste to energy conversions. This study highlights the challenges with existing MSW management practices of Curitiba, Brazil, and suggests some holistic and sustainable landfill management techniques. This is accomplished through the (i) identification of the suitable sites for setting up transfer stations (TSs), (ii) route optimization for MSW transportation, and (iii) analysis of the life expectancy of the existing landfill with waste valorization techniques for enhancing circularity of MSW of the city. The study has identified six potential TSs, making use of various geological criteria and constraints as suggested by the United States Environmental Protection Agency using GIS-based spatial analysis, which could save fuel cost of approximately 1.5 million Brazilian Real (BRL) per year for the solid waste transportation (from the source to the landfill site). This research has also made a value addition in this specific field with the preparation of a digitized road network map of the study region. Further, the sensitivity-based scenario analysis highlights that the lifespan of the existing landfill (until 2030) might be extended to 2058 if the city achieves the targeted recycling rate of 85% compared with the current rate of 23%. The results would be useful for policy-makers to adopt the crucial MSW scenario to achieve a circular economy in the waste management of the city of Curitiba. Full article

(This article belongs to the Topic Solid Waste Management)

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22 pages, 1592 KiB

Open AccessArticle

A Zero-Waste Campus Framework: Perceptions and Practices of University Campus Community in Malaysia

by Mayawi Baba-Nalikant, Sharifah Mashita Syed-Mohamad, Mohd Heikal Husin, Nor Athiyah Abdullah, Mohamad Saifudin Mohamad Saleh and Asyirah Abdul Rahim

Recycling 2023, 8(1), 21; https://doi.org/10.3390/recycling8010021 - 06 Feb 2023

Cited by 7 | Viewed by 5221

Abstract

This paper will explore the university campus community’s perspective towards the realization of a zero-waste campus. A qualitative approach is employed to identify the factors influencing the campus community’s awareness and participation in solid waste management (SWM). Perceptions, attitudes, beliefs, opinions, and ideas [...] Read more.

This paper will explore the university campus community’s perspective towards the realization of a zero-waste campus. A qualitative approach is employed to identify the factors influencing the campus community’s awareness and participation in solid waste management (SWM). Perceptions, attitudes, beliefs, opinions, and ideas of Universiti Sains Malaysia (USM) campus community members are explored in focus group discussions (FGD) to determine the main factors influencing their zero-waste pro-environmental behaviour (PEB). The in-depth interview (IDI) is used to learn more about the university campus community’s perspectives on the themes defined by the FGD. The instruments were developed based on the adaption and adoption of previous studies, especially in reference to Kollmuss and Agyeman’s 2002 Model of Pro-Environmental Behaviour and a modified Knowledge-Attitude-Practices model. The findings show that environmental goals, environmental education, personal waste-related experience, environmental policy, environmental self-awareness, reinforcement contingencies, community engagement, social responsibilities, exemplary leadership, and social media influence the campus community’s zero-waste PEB. A framework based on an adaptation of Kollmuss and Agyeman’s model of pro-environmental behaviour is proposed to promote sustainable pro-environmental behaviour towards a Zero-Waste Campus. Full article

(This article belongs to the Topic Solid Waste Management)

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36 pages, 13482 KiB

Open AccessArticle

Modify the Injection Machine Mechanism to Enhance the Recycling of Plastic Waste Mixed with MHD Nanoparticles

by Ahmed M. Abed, Ali AlArjani, Laila F. Seddek and Samia ElAttar

Sustainability 2023, 15(3), 2641; https://doi.org/10.3390/su15032641 - 01 Feb 2023

Cited by 1 | Viewed by 1402

Abstract

Recycling plastic waste (RPW) benefits the ecological footprint. Therefore, the authors test its mixing by magnetic hydrodynamic MHD nanofluid materials such as alumina in two sizes (

β_{c o r e}, β_{s k i n}

) prepared into a [...] Read more.

Recycling plastic waste (RPW) benefits the ecological footprint. Therefore, the authors test its mixing by magnetic hydrodynamic MHD nanofluid materials such as alumina in two sizes (

β_{c o r e}, β_{s k i n}

) prepared into a new device called the incubator installed in the desktop injection machine to enhance its solubility by taking advantage of the mixture’s heat via defining the oblique stagnation-point slip flow (OSPSF) of a nanofluid in two dimensions. The paper has been innovative in mathematically identifying the operating parameters’ values for the injection flow mechanism (IFM) via controlling in Riga magnetic field and piston orifice pressure using a meta-heuristic algorithm called WSA. The proposed (IFM) is used to experimentally enhance the mixture properties via parameters’ control to meet the output quality and predict the control equation for the Riga plate. IFM controls the amount of pushed nanoparticles in the mixture with a ratio of plastic to aluminum approximate by 96.1%: 3.9%. The defects were reduced by approximately 23.21%, with an increasing system performance of 70.98%. Full article

(This article belongs to the Topic Solid Waste Management)

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18 pages, 6591 KiB

Open AccessArticle

Synthesis of Floral-Shaped Nanosilica from Coal Fly Ash and Its Application for the Remediation of Heavy Metals from Fly Ash Aqueous Solutions

by Virendra Kumar Yadav, Abdelfattah Amari, Shivraj Gangadhar Wanale, Haitham Osman and M. H. Fulekar

Sustainability 2023, 15(3), 2612; https://doi.org/10.3390/su15032612 - 01 Feb 2023

Cited by 13 | Viewed by 2196

Abstract

Every year a large amount of coal fly ash (CFA) is generated and dumped in fly ash ponds. Fly ash has numerous toxic heavy metals, which leads to water pollution due to the percolation of these heavy metals. Heavy metal toxicity has become [...] Read more.

Every year a large amount of coal fly ash (CFA) is generated and dumped in fly ash ponds. Fly ash has numerous toxic heavy metals, which leads to water pollution due to the percolation of these heavy metals. Heavy metal toxicity has become a major issue for the whole globe. Moreover, CFA has several value-added minerals, such as silica, alumina, and ferrous in large amounts. Therefore, the synthesis of silica nanoparticles from CFA and their application for the removal of toxic heavy metals from fly ash aqueous solution will prove to be an economical and efficient approach. Here, in the present research work, investigators synthesized nanosilica from CFA by alkali dissolution and sol-gel methods and applied them for heavy metal removal. Firstly, CFA was treated with high molar NaOH, along with stirring and heating. Further, the sodium silicate leachate from CFA was treated with dilute HCl till the formation of a white gel at neutral pH. Purification of the nanosilica was achieved by treating with 1M HCl along with stirring followed by calcination at 400 °C for 4 h. The synthesized nanosilica was characterized by UV-Vis, Fourier transform infrared (FTIR), particle size analyzer (PSA), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), electron diffraction spectroscopy (EDS), and high-resolution transmission electron microscope (HR-TEM). The sizes of the floral-shaped nanosilica particles were 20–70 nm, and the purity was 90–95%, as confirmed by microscopy and EDS, respectively. The XRD and FTIR revealed the amorphous nature of nanosilica. Finally, the potential of the nanosilica was assessed for the removal of heavy metals from 20% CFA aqueous solutions in batch experiments. The nanosilica showed about 40–90% removal of heavy metals (Al, Pb, Cd, Cu, Cr, Ni, Co, Zn, Mn) from the fly ash aqueous solution. Full article

(This article belongs to the Topic Solid Waste Management)

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19 pages, 1866 KiB

Open AccessReview

The Role of Informal Waste Management in Urban Metabolism: A Review of Eight Latin American Countries

by Beatriz Espinosa-Aquino, Xavier Gabarrell Durany and Roberto Quirós Vargas

Sustainability 2023, 15(3), 1826; https://doi.org/10.3390/su15031826 - 18 Jan 2023

Cited by 1 | Viewed by 2632

Abstract

Social and spatial segregation structures in Latin America are perceived as processes for the selective concentration of social or demographic groups in geographic sectors of the city. This voluntary or forced segregation creates poor, wealthy, and marginal areas, leading to the territory’s marginalization [...] Read more.

Social and spatial segregation structures in Latin America are perceived as processes for the selective concentration of social or demographic groups in geographic sectors of the city. This voluntary or forced segregation creates poor, wealthy, and marginal areas, leading to the territory’s marginalization and fragmentation, destroying the symbolic and territorial urban continuity. To understand the behavior of waste pickers in a Mexican city, we sought to know the conditions of the informal collection activity in eight Latin American countries with similar conditions. Therefore, the goal was to carry out a bibliographic evaluation that included the environmental contribution of waste pickers, their organizations, and their link with urban metabolism. The tasks performed by informal waste pickers in the cities of the eight selected Latin American countries, their organizations, and their way of working were studied. Their role in reducing environmental impact and improving the quality of life of city dwellers was evaluated. Web sites, web searches, and face-to-face meetings created electronic communication channels with this community were analyzed. In some cases, they are well organized and become microentrepreneurs with salary, social security, and economical insurance by starting an ecological business. In contrast, marginal groups seeking economic support collect, separate, sort, and group recoverable waste daily and sell it at waste distribution points. This link in the urban metabolism reintroduces valuable solid waste into the production chain. In addition, materials with commercial value, such as metals, plastics, paper, cardboard, and wood, can re-enter the production chain as secondary materials for industry. Thus, a collective of well-organized waste pickers contributes to the city’s sustainability and provides better living conditions for the waste pickers. In Mexico, there is a lack of official information regarding the number of waste pickers, organizations, activities, and their environmental contribution. Therefore, a directory with that information is highly relevant to designing public policies to recognize the essential contributions of this sector. Full article

(This article belongs to the Topic Solid Waste Management)

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15 pages, 3124 KiB

Open AccessArticle

Municipal Solid Waste Collection: Challenges, Strategies and Perspectives in the Optimization of a Municipal Route in a Southern Mexican Town

by Viridiana Del Carmen-Niño, Ricardo Herrera-Navarrete, Ana Laura Juárez-López, María Laura Sampedro-Rosas and Maximino Reyes-Umaña

Sustainability 2023, 15(2), 1083; https://doi.org/10.3390/su15021083 - 06 Jan 2023

Cited by 3 | Viewed by 3196

Abstract

Solid waste management represents a challenge for municipalities, particularly at the collection stage. The high costs involved in its operation make it difficult to provide the service in all its communities, which results in bad practices (burning, burying, or dumping into a river) [...] Read more.

Solid waste management represents a challenge for municipalities, particularly at the collection stage. The high costs involved in its operation make it difficult to provide the service in all its communities, which results in bad practices (burning, burying, or dumping into a river) and the proliferation of open dumps. Collection efficiency is aggravated by poor route planning, narrow road networks, and irregular scheduling. This research proposes and develops the following objectives: (1) an analysis of the technical and logistical conditions of a town, (2) an improved municipal route for waste collection, and (3) the practical implications identified in the optimization of the service (challenges, strategies, and perspectives). During the study period (2018, 2019 and 2021), the following steps were carried out: (1) field trips to monitor the formal and informal routes, georeferencing each stop with a global positioning system, (2) semi-structured interviews to route personnel to learn about technical and logistical aspects, (3) the downloading of cartographic data for digitization, and (4) a network analysis aimed at designing an optimal route for formal collection and the spatial scope of the informal routes. The current technical and logistical analysis detected inefficiency in collection due to weak municipal operational planning and the irregular frequency of visits to the locality. The locality produces an average of 2.8 tons per day and its largest volume is organic waste (68.3%), followed by non-recyclable inorganic waste (21.2%), and recyclable waste (10.5%). In terms of results for the optimization of the municipal collection route, it is estimated that there will be an improvement in the time of the day of approximately 2 h less, going through 95 points when its schedule is 60 collection points, while the distance factor does not suffer changes due to the fact that there are no alternate routes between the departure and destination route. Among the main challenges faced by the municipalities are the limited budgets for basic sanitation services, which is why technological strategies and trained human resources are required for better municipal solid waste management. From a technical perspective, geographic information systems are a current trend to model and optimize service routes, with which a better scenario can be proposed. From a social perspective, community participation works as a key factor to carry out activities focused on finding solutions to the problems related to municipal solid waste management. Full article

(This article belongs to the Topic Solid Waste Management)

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8 pages, 925 KiB

Open AccessArticle

Biological Pretreatment Effects on the Bioconversion of Brewer Spent Grain with Hermetia illucens Larvae

by Martha Sumba-Zhongor, Eduardo Álava, Luis Galarza, Johana Ortiz-Ulloa, Eduardo J. Chica, Omar Ruiz-Barzola, Julia Nieto-Wigby, Maria Isabel Jiménez-Feijoo and Malena Torres-Ulloa

Recycling 2023, 8(1), 3; https://doi.org/10.3390/recycling8010003 - 27 Dec 2022

Viewed by 1937

Abstract

Hermetia illucens is an important species for waste management and the circular economy. The aim of this study was to analyze the effects of Trichoderma reesei C2A and Pleurotus sp. as pretreatments of brewer spent grain (BSG). BSG was inoculated with fungal solution [...] Read more.

Hermetia illucens is an important species for waste management and the circular economy. The aim of this study was to analyze the effects of Trichoderma reesei C2A and Pleurotus sp. as pretreatments of brewer spent grain (BSG). BSG was inoculated with fungal solution or distilled water (control). After seven days, this was used for H. illucens larvae cultivation. At the end of bioconversion process, parameters of substrate reduction and H. illucens larval development were evaluated. Chemical properties of BSG, frass and larvae were also analyzed. With T. reesei C2A pretreatment, highest substrate reduction (46.3 ± 0.9%) was achieved, but larval growth rate was lower (1.0 ± 0.1 mg/d) than that of control (2.8 ± 0.2 mg/d). Larvae of Pleurotus sp. pretreatment had limited development, reflected in their negative growth rate (−0.6 ± 0.2 mg/d). In conclusion, cultivation of H. illucens larvae (six day old) on BSG pretreated with Pleurotus sp. is not recommended. On the other hand, T. reesei C2A pretreatment enhance BSG reduction, and its potential use for lignocellulosic waste management should be more explored. Full article

(This article belongs to the Topic Solid Waste Management)

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18 pages, 4167 KiB

Open AccessArticle

Recycling of Post-Use Bioprocessing Plastic Containers—Mechanical Recycling Technical Feasibility

by Duc-Nam Luu, Magali Barbaroux, Gaelle Dorez, Katell Mignot, Estelle Doger, Achille Laurent, Jean-Michel Brossard and Claus-Jürgen Maier

Sustainability 2022, 14(23), 15557; https://doi.org/10.3390/su142315557 - 23 Nov 2022

Viewed by 3308

Abstract

Most of the plastic-based solutions used in bio-manufacturing are today incinerated after use, even the not “bio-contaminated”. Bioprocessing bags used for media and buffer preparation and storage represent the largest amount today. The aim of this work was to technically assess the feasibility [...] Read more.

Most of the plastic-based solutions used in bio-manufacturing are today incinerated after use, even the not “bio-contaminated”. Bioprocessing bags used for media and buffer preparation and storage represent the largest amount today. The aim of this work was to technically assess the feasibility of the mechanical recycling of bioprocessing bags. Materials from different sorting and recycling strategies have been characterized, for their suitability of further use. Quantitative physical and mechanical tests and analysis (FTIR, DSC, TGA, density, MFI, color, tensile, flexural, and Charpy choc) were performed. The data show that these recycled plastics could be oriented towards second use requiring physical properties similar to equivalent virgin materials. A comparative life cycle assessment, based on a theoretical framework, shows that mechanical recycling for end of life presents the advantage of keeping material in the loop, without showing a significant statistical difference compared to incineration with regards to the climate change indicator. Full article

(This article belongs to the Topic Solid Waste Management)

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11 pages, 2397 KiB

Open AccessArticle

Assessment of the Energetical and Biological Characteristics of Municipal Solid Waste from One of the Largest Landfills in Kazakhstan

by Arlan Z. Abilmagzhanov, Nikolay S. Ivanov, Oleg S. Kholkin and Iskander E. Adelbaev

Recycling 2022, 7(5), 80; https://doi.org/10.3390/recycling7050080 - 20 Oct 2022

Cited by 5 | Viewed by 2281

Abstract

Solid waste management is one of the main problems in large cities. The determination of the quantitative and qualitative composition of municipal solid waste is necessary for proper planning in the processing of such waste. This article presents the results of studies of [...] Read more.

Solid waste management is one of the main problems in large cities. The determination of the quantitative and qualitative composition of municipal solid waste is necessary for proper planning in the processing of such waste. This article presents the results of studies of the morphological composition, physico-chemical parameters and energetical potential of municipal solid waste (MSW) from the landfill of the city of Shymkent. Waste samples were taken from 10 different points of the landfill. The volume–mass parameters of the samples and their average density were determined. The combined waste samples mainly consisted of food waste, paper and cardboard, polymers and plastic, glass, metal, textiles, wood, leather, bones and rubber. Most of the waste, more than 30%, contains plastic products. The moisture of the combustible fraction of the samples is low and varies from 0.3% to 2.3%. The average ash content of the combustible fraction of the samples was determined and its average value is 18.4%. The yield of the volatile substances was determined and the average value per dry state is 78.7%. To determine the energetical potential of municipal solid waste, the gross calorific value was determined and the net calorific value was calculated, the average value of which is 24.15 MJ/kg. This shows the possibility of using solid waste as an energy source. Full article

(This article belongs to the Topic Solid Waste Management)

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20 pages, 1889 KiB

Open AccessArticle

Identifying the Leverage Points in the Household Solid Waste Management System for Harare, Zimbabwe, Using Network Analysis Techniques

by Phyllis Rumbidzai Kwenda, Gareth Lagerwall, Sibel Eker and Bas van Ruijven

Sustainability 2022, 14(19), 12405; https://doi.org/10.3390/su141912405 - 29 Sep 2022

Cited by 4 | Viewed by 1605

Abstract

Managing household solid waste (HSW) has gone beyond what the Harare local government can handle. Inadequate knowledge of the interactions existing between issues that affect the efficient running of waste management systems is one of the major hindrances in waste management planning in [...] Read more.

Managing household solid waste (HSW) has gone beyond what the Harare local government can handle. Inadequate knowledge of the interactions existing between issues that affect the efficient running of waste management systems is one of the major hindrances in waste management planning in developing countries like Zimbabwe. The complexity of the waste management system for a given municipal area needs to be identified and understood to generate appropriate and efficient waste management strategies. Network analysis (NA) is a methodology extensively used in research to help reveal a comprehensive picture of the relationships and factors related to a particular phenomenon. The methodology reduces the intricacy of large systems such as waste management to smaller and more understandable structures. In this study, NA, which was done mainly using the R software environment, showed a result of 1.5% for network density, thus signifying that for Harare, waste management strategies need to be ‘seeded’ in various parts of the system. The Pareto principle and the 3Rs (Reduce, Reuse, Recycle) concept were applied to suggest the issues to prioritize and generate strategies that could potentially affect significant change to the city’s waste management system. The key issues identified, in their order of importance, are an increase in uncollected waste, low waste collection efficiency, increase in illegal waste dumping, the deteriorating country’s economy, reduced municipal financial capacity, reduced municipal workforce capacity, inadequate or unreliable waste data, increase in waste volume, increase in the number of street vendors, no waste planning and monitoring unit, no engineered landfills in the city, increase in waste collection pressure, low waste collection frequency, increase in the unemployment rate, reduced municipal technical capacity, few waste collection vehicles, limited vehicles maintenance, distinct socio-economic classes, high vehicles breakdown, and increase in population. Full article

(This article belongs to the Topic Solid Waste Management)

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17 pages, 1931 KiB

Open AccessArticle

Environmental Performance of Semi-Aerobic Landfill by Means of Life Cycle Assessment Modeling

by Anna Mazzi, Michela Sciarrone and Roberto Raga

Energies 2022, 15(17), 6306; https://doi.org/10.3390/en15176306 - 29 Aug 2022

Cited by 1 | Viewed by 1230

Abstract

The potential impacts and the environmental performance of the semi-aerobic landfill technology were assessed through the Life Cycle Assessment (LCA) methodology. Project data that referred to a hypothetical Italian plant design were used and ISO 14040/14044 standards were applied. All the life cycle [...] Read more.

The potential impacts and the environmental performance of the semi-aerobic landfill technology were assessed through the Life Cycle Assessment (LCA) methodology. Project data that referred to a hypothetical Italian plant design were used and ISO 14040/14044 standards were applied. All the life cycle phases were considered, from landfill construction to filling, aftercare, closure and conversion for future use. All the landfill processes and the inflow of materials, energy and rainwater, and the outflow of biogas and leachate, were included in the system boundaries. The results show that the overall environmental impacts associated to semi-aerobic landfill are primarily due to the filling and aftercare phases, but the impacts related to construction and closure phases are not negligible. The contribution analysis underlines the processes with major responsibility within the environmental profile, while the normalization of results demonstrates what are the environmental categories on which the landfill impacts fall most. Important lessons emerging from this research can support practitioners and scientists in optimizing semi-aerobic landfill design and management. Full article

(This article belongs to the Topic Solid Waste Management)

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21 pages, 4713 KiB

Open AccessArticle

Bibliometric Analysis of Municipal Solid Waste Management Research: Global and South African Trends

by Vhuthu Ndou and Isaac Tebogo Rampedi

Sustainability 2022, 14(16), 10229; https://doi.org/10.3390/su141610229 - 17 Aug 2022

Cited by 7 | Viewed by 3178

Abstract

Municipal solid waste management has become one of the most important environmental management issues around the world. In this study, a bibliometric analysis of the literature related to municipal solid waste management from a global and South African perspective was performed using the [...] Read more.

Municipal solid waste management has become one of the most important environmental management issues around the world. In this study, a bibliometric analysis of the literature related to municipal solid waste management from a global and South African perspective was performed using the software, VOSviewer. Relevant scientific literature was sourced from the Scopus database. Results showed that, globally, articles based on this topic started during the 1968–1969 period, whereas in South Africa such articles only appeared in 1996. The keyword analysis showed that most studies were related to waste-to-energy technologies, waste treatment, and other management aspects. Globally, emerging keywords representing new research areas were COVID 19-related waste streams, life-cycle assessments, and the role of municipal solid waste management in the circular economy. In contrast, South Africa’s prominent keywords were municipal solid waste, developing country, landfills, waste treatment, waste-to-energy technologies, pollution, greenhouse gas emissions, and others. Based on these results, and possible solutions to reduce the amounts of MSW generation rates, recommendations are made to bring South African research on par with international trends. Full article

(This article belongs to the Topic Solid Waste Management)

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18 pages, 7346 KiB

Open AccessArticle

An Emerging Solution for Medical Waste: Reuse of COVID-19 Protective Suit in Concrete

by Tao Ran, Jianyong Pang and Jiuqun Zou

Sustainability 2022, 14(16), 10045; https://doi.org/10.3390/su141610045 - 13 Aug 2022

Cited by 3 | Viewed by 1496

Abstract

With the continuous spread of COVID-19 (coronavirus disease 2019), a large number of medical protective suits (PS) have been used and discarded, causing great damage to the ecological environment. The main component of PS is polypropylene plastic, which will enter the oceans, rivers, [...] Read more.

With the continuous spread of COVID-19 (coronavirus disease 2019), a large number of medical protective suits (PS) have been used and discarded, causing great damage to the ecological environment. The main component of PS is polypropylene plastic, which will enter the oceans, rivers, and animals with groundwater and will not decompose for hundreds of years. Therefore, this global health crisis not only affects the health and economy of the world’s population now but will also continue to disrupt our daily lives after the pandemic ends. The main objective of this study is to explore an effective method to reduce the biological and environmental hazards of medical waste by combining PS with concrete. Due to the excessive size of the PS, protective suit fibers (PSF) were obtained from PS by cutting. To investigate the possibility of using PS in concrete, a series of experiments were conducted, including a physical parameter test, compression test, split tensile test, ultrasonic pulse velocity test, scanning electron microscope (SEM), and finite element simulation. The results indicated that the introduction of PSF significantly enhanced the mechanical properties of concrete, and the maximum compressive strength and splitting tensile strength increased by 7.3% and 43.6%, respectively. The ultrasonic pulse velocity and density of concrete containing PSF decreased compared with the control group. The images of SEM show that PSF binds tightly to the cement matrix and hinders the propagation of micro-cracks. The introduction of PS into the concrete material leads to the improvement of the mechanical properties of concrete and the improvement of the overall quality of the concrete, which is of great significance for reducing the damage of medical waste to the environment. The originality of this work is that polypropylene fibers acquired from PS were put into concrete for the first time for performance testing. Full article

(This article belongs to the Topic Solid Waste Management)

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21 pages, 18340 KiB

Open AccessArticle

Evaluation of Landfill Site Selection by Combining Fuzzy Tools in GIS-Based Multi-Criteria Decision Analysis: A Case Study in Diyarbakır, Turkey

by Kasım Şimşek and Selçuk Alp

Sustainability 2022, 14(16), 9810; https://doi.org/10.3390/su14169810 - 09 Aug 2022

Cited by 9 | Viewed by 2183

Abstract

Solid waste disposal is one of the important environmental and socioeconomic problems faced by city managers with the increase in urban population. To overcome this problem, landfilling is a common and effective solution used by municipalities frequently. This study aims to assess and [...] Read more.

Solid waste disposal is one of the important environmental and socioeconomic problems faced by city managers with the increase in urban population. To overcome this problem, landfilling is a common and effective solution used by municipalities frequently. This study aims to assess and identify suitable potential areas for municipal solid waste disposal. For this purpose, a criteria determination and evaluation commission consisting of experts from various institutions and disciplines was established. Fourteen criteria, including environmental, economic and sociocultural sensitivities, were selected via the experience of an expert team and a wide literature search. The criteria used in this study were standardized by using fuzzy membership functions and feature values turned into continuous values. The Stepwise Weight Assessment Ratio Analysis (SWARA) method, in which expert opinions are effective, was used to determine the criterion weights. A site suitability map was obtained by using the Weighted Linear Combination (WLC) method with standardized thematic maps and the criterion weight variables. As a result of this study, 3.44% of the total study area was determined suitable for a solid waste storage area. These determined areas were found in different locations of study and numbered on the map and each of them was selected as an alternative storage area candidate. Developed methodology was validated via exploration and observation of candidate areas by the expert team. The proposed methodology can be used for similar scale cities with its ease of use, flexibility and expert opinion. Full article

(This article belongs to the Topic Solid Waste Management)

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15 pages, 564 KiB

Open AccessArticle

Factors Influencing Household Waste Separation Behavior: Cases of Russia and Finland

by Anna Zaikova, Ivan Deviatkin, Jouni Havukainen, Mika Horttanainen, Thomas Fruergaard Astrup, Minna Saunila and Ari Happonen

Recycling 2022, 7(4), 52; https://doi.org/10.3390/recycling7040052 - 28 Jul 2022

Cited by 13 | Viewed by 4138

Abstract

This paper investigates the factors influencing the behavior of individuals in source-separation of municipal solid waste in an immature system for collection of recyclable waste (Saint Petersburg, Russia) and a more mature waste system (selected urban areas, Finland). Online questionnaires were applied to [...] Read more.

This paper investigates the factors influencing the behavior of individuals in source-separation of municipal solid waste in an immature system for collection of recyclable waste (Saint Petersburg, Russia) and a more mature waste system (selected urban areas, Finland). Online questionnaires were applied to collect data from citizens of Saint Petersburg and the Finnish urban population. The data were examined within an extended theory of planned behavior using structural equation modeling for the identification of factors affecting waste source-separation behavior. The findings indicate that the factors differed significantly in the two waste systems. In Russia, the inconvenience of waste collection limited waste source-separation behavior, while intentions of individuals and information availability had an almost equal positive effect. In Finland, waste source-separation behavior was mostly affected by people’s intentions. Based on the findings, recommendations for the development of recycling practices were made for practitioners in Russia and possibly other early-stage systems for the collection of recyclable waste. Limitations of the study pinpointed the possibilities for future research. Full article

(This article belongs to the Topic Solid Waste Management)

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15 pages, 1371 KiB

Open AccessArticle

Waste Bank Policy Implementation through Collaborative Approach: Comparative Study—Makassar and Bantaeng, Indonesia

by Fatmawati Fatmawati, Nuryanti Mustari, Haerana Haerana, Risma Niswaty and Abdillah Abdillah

Sustainability 2022, 14(13), 7974; https://doi.org/10.3390/su14137974 - 30 Jun 2022

Cited by 19 | Viewed by 3697

Abstract

The purpose of this study is to determine the dynamics of implementing waste management policies through the waste bank innovation program in national policies. It also aims to determine the factors that influence it through a collaborative approach based on communication between community [...] Read more.

The purpose of this study is to determine the dynamics of implementing waste management policies through the waste bank innovation program in national policies. It also aims to determine the factors that influence it through a collaborative approach based on communication between community stakeholders, entrepreneurs, and the government in Makassar City and Bantaeng Regency. This is a qualitative-exploratory research study that uses a case study approach to delve into the research topic. The data collected were analyzed using the software Nvivo 12 pro to provide a systematic, factual, accurate, and in-depth picture of the implementation of waste bank program policies in eastern regions in Indonesia. The results of this study explain that the implementation of the Waste Bank Management Policy in Makassar City and Bantaeng Regency has not been run optimally, especially in the aspect of communication between stakeholders, including community participation. Although stakeholders and implementing agents have understood the intent and purpose of the waste bank program, socialization in the community is still considered less than optimal. Therefore, this research encourages local governments to implement effective and efficient waste bank program policies, with collaboration for every stakeholder in the area, to increase public and private participation. Full article

(This article belongs to the Topic Solid Waste Management)

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12 pages, 806 KiB

Open AccessArticle

Economic–Environmental Performance of Reverse Logistics of Disposable Beverage Packaging

by Marcela Malindzakova, Jana Štofková and Milan Majernik

Sustainability 2022, 14(13), 7544; https://doi.org/10.3390/su14137544 - 21 Jun 2022

Cited by 5 | Viewed by 2087

Abstract

The aim of this article is to provide analysis and description of deposit and recycling system of disposable beverage packaging, which started in the Slovak Republic in 2022. The article provides the review of relevant literature with a focus on circular economy and [...] Read more.

The aim of this article is to provide analysis and description of deposit and recycling system of disposable beverage packaging, which started in the Slovak Republic in 2022. The article provides the review of relevant literature with a focus on circular economy and Deposit Refund System (DRS), where analysis of refund systems was performed for this work. The proposed model involving reverse logistics describes how such deposit and collection system can work in practice, highlighting potential disadvantages, mainly the high investment costs. Therefore, the article also includes a financial analysis exploring potential cost of establishing said deposit and collection system. The number of necessary collection point for Slovakia has been determined and the total investment costs for the vending machines installations and service in Slovakia has been calculated. Full article

(This article belongs to the Topic Solid Waste Management)

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15 pages, 5786 KiB

Open AccessArticle

Development and Optimization of a Sustainable Process Assisted by Microwave Energy to Dye Cellulosic Fabrics by Juglans regia Barks Residues Extract

by Nourhene Slama, Manel Ben Ticha, Wiem Skhiri, Chedly Boudokhane and Hatem Dhaouadi

Sustainability 2022, 14(13), 7534; https://doi.org/10.3390/su14137534 - 21 Jun 2022

Cited by 3 | Viewed by 1198

Abstract

Juglans regia barks contain a diversity of phenolic compounds. Two of the most important groups of phenolic compounds are tannins, and flavonoids. These latter, possess different antioxidant, anti-inflammatory, and antibacterial properties. This paper explores the usefulness of dyeing cellulosic fabrics, namely cotton, with [...] Read more.

Juglans regia barks contain a diversity of phenolic compounds. Two of the most important groups of phenolic compounds are tannins, and flavonoids. These latter, possess different antioxidant, anti-inflammatory, and antibacterial properties. This paper explores the usefulness of dyeing cellulosic fabrics, namely cotton, with Juglans regia barks residues extract. The dyeing process proposed was assisted by microwave energy. The impact of the main dyeing conditions (percentage of cationizing agent, pH, dyeing duration, and microwave power) on the color strength (K/S) and the L*, a*, b*, C*, and h* coordinates were studied. Optimization experiments were carried out using a definitive screening type plan (MINITAB 19). It was found that the best conditions to achieve the dyeing of cellulosic fabrics were: a pH of 6.23; a percentage of cationizing agent of 6.5%; a microwave power of 690 W, and a dyeing duration of 4.5 min. Full article

(This article belongs to the Topic Solid Waste Management)

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19 pages, 514 KiB

Open AccessReview

Environmental and Economic Life-Cycle Assessments of Household Food Waste Management Systems: A Comparative Review of Methodology and Research Progress

by Na Yang, Fangling Li, Yang Liu, Tao Dai, Qiao Wang, Jiebao Zhang, Zhiguang Dai and Boping Yu

Sustainability 2022, 14(13), 7533; https://doi.org/10.3390/su14137533 - 21 Jun 2022

Cited by 11 | Viewed by 3195

Abstract

Household food waste (HFW) is the main component of municipal solid waste (MSW). Appropriate HFW management strategies could reduce the environmental burdens and economic costs to society. Life-cycle thinking is an effective decision-making tool for MSW management. This paper compares the three main [...] Read more.

Household food waste (HFW) is the main component of municipal solid waste (MSW). Appropriate HFW management strategies could reduce the environmental burdens and economic costs to society. Life-cycle thinking is an effective decision-making tool for MSW management. This paper compares the three main environmental and economic assessment methodologies, i.e., societal life-cycle costing (societal LCC), environmental cost-effectiveness (ECE) analysis, and multicriteria analysis (MCA) in terms of the definitions, method frameworks, and their advantages/disadvantages. Most reviewed studies applied the environmental life-cycle costing (ELCC) method, a simplified ECE, which does not involve interactive quantitative comparisons between environmental and economic benefits. Further attention should be paid to the coordination between life-cycle assessment (LCA) and life-cycle costing (LCC), the monetization coefficient in external cost calculation of societal LCC, and the standardization and evaluation approaches of ECE. HFW prevention is rarely considered in the reviewed literature but was demonstrated as the best route over treatment or utilization. Anaerobic digestion is environmentally preferable to composting and landfilling; it is comparable to biodiesel production, feeding conversation, and incineration. From the perspective of economic costs (including societal LCC), the ranking of treatment technologies varied a lot from one study to another, attributable to the diverse evaluation methods and different data sources. To improve the environmental and economic assessment approaches to HFW management, an inventory database (e.g., food waste properties, technical treatment parameters, material flow, and fund flow data) suitable for HFW should be constructed. When establishing the system boundaries, the processes of source sorting, collection and transportation, and by-product handling should be coherent with the investigated treatment technology. Full article

(This article belongs to the Topic Solid Waste Management)

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15 pages, 3894 KiB

Open AccessArticle

Woodland for Sludge Disposal in Beijing: Sustainable?

by Bingchen Wu, Shi Qi, Yishui Hu, Yutong Li and Jinxing Zhou

Sustainability 2022, 14(12), 7444; https://doi.org/10.3390/su14127444 - 17 Jun 2022

Cited by 2 | Viewed by 1570

Abstract

The sludge products of urban sewage treatment plants in Beijing are increasing year by year, and there is a large amount of stagnation, which requires scientific and reasonable disposal strategies. Currently, the woodland in the mountainous area of Beijing is considered the main [...] Read more.

The sludge products of urban sewage treatment plants in Beijing are increasing year by year, and there is a large amount of stagnation, which requires scientific and reasonable disposal strategies. Currently, the woodland in the mountainous area of Beijing is considered the main means for sludge disposal; however, because the heavy metals in the sludge may cause potential pollution to the soil and groundwater, it is unclear how much sludge can be applied per unit area. To ensure the sustainable disposal of sludge, it is necessary to measure the risk of heavy metals on soil and groundwater under different sludge application rates to determine the most scientific disposal plan. In this study, the undisturbed soil columns obtained from the field were used to clarify the migration behaviors and accumulation of eight hazardous heavy metals under simulated rainfall conditions, and three sets of tests (the application rates of sludge products were 30 t·ha⁻¹·a⁻¹, 60 t·ha⁻¹·a⁻¹ and 120 t·ha⁻¹·a⁻¹ respectively) were set based on the supply–demand relationship between Beijing’s annual sludge output and the woodland area available for sludge disposal. The results showed that there were significant differences in the migration rules of heavy metals under different application rates, which were mainly reflected in the differences in accumulation in each layer of the soil. In terms of the leaching efficiency of heavy metals, except for Cadmium, the leaching rates of other heavy metals did not exceed 0.1%, indicating that most heavy metals accumulated in the soil. During the application process of sludge products, Arsenic and Cadmium posed a greater potential risk to groundwater than other heavy metals, to which should be paid sufficient attention. Based on the accumulation of heavy metals in soil, Arsenic was the main factor limiting the amount and frequency of sludge product application. The application rate of 60 t·ha⁻¹·a⁻¹ was preferred compared with the other two tests because it presented minimal risk to groundwater and soil in the short term, while the total amount of sludge disposal can be maximized. Full article

(This article belongs to the Topic Solid Waste Management)

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18 pages, 4663 KiB

Open AccessArticle

Waste Classification for Sustainable Development Using Image Recognition with Deep Learning Neural Network Models

by Meena Malik, Sachin Sharma, Mueen Uddin, Chin-Ling Chen, Chih-Ming Wu, Punit Soni and Shikha Chaudhary

Sustainability 2022, 14(12), 7222; https://doi.org/10.3390/su14127222 - 13 Jun 2022

Cited by 25 | Viewed by 7080

Abstract

The proper handling of waste is one of the biggest challenges of modern society. Municipal Solid Waste (MSW) requires categorization into a number of types, including bio, plastic, glass, metal, paper, etc. The most efficient techniques proposed by researchers so far include neural [...] Read more.

The proper handling of waste is one of the biggest challenges of modern society. Municipal Solid Waste (MSW) requires categorization into a number of types, including bio, plastic, glass, metal, paper, etc. The most efficient techniques proposed by researchers so far include neural networks. In this paper, a detailed summarization was made of the existing deep learning techniques that have been proposed to classify waste. This paper proposes an architecture for the classification of litter into the categories specified in the benchmark approaches. The architecture used for classification was EfficientNet-B0. These are compound-scaling based models proposed by Google that are pretrained on ImageNet and have an accuracy of 74% to 84% in top-1 over ImageNet. This research proposes EfficientNet-B0 model tuning for images specific to particular demographic regions for efficient classification. This type of model tuning over transfer learning provides a customized model for classification, highly optimized for a particular region. It was shown that such a model had comparable accuracy to that of EfficientNet-B3, however, with a significantly smaller number of parameters required by the B3 model. Thus, the proposed technique achieved efficiency on the order of 4X in terms of FLOPS. Moreover, it resulted in improvised classifications as a result of fine-tuning over region-wise specific litter images. Full article

(This article belongs to the Topic Solid Waste Management)

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13 pages, 4416 KiB

Open AccessFeature PaperArticle

Processing of Gypsum Construction and Demolition Waste and Properties of Secondary Gypsum Binder

by Girts Bumanis, Jelizaveta Zorica, Aleksandrs Korjakins and Diana Bajare

Recycling 2022, 7(3), 30; https://doi.org/10.3390/recycling7030030 - 17 May 2022

Cited by 11 | Viewed by 3624

Abstract

The waste amount coming from construction and demolition (CDW) has significant volume and potential to provide the backbone of a secondary material bank. Up to now, little attention is paid to waste gypsum recycling from CDW while a shift in global attitude toward [...] Read more.

The waste amount coming from construction and demolition (CDW) has significant volume and potential to provide the backbone of a secondary material bank. Up to now, little attention is paid to waste gypsum recycling from CDW while a shift in global attitude toward waste management brings motivation to use CDW gypsum as secondary raw material. The present research investigates the properties of gypsum binder obtained from secondary raw materials originating from CDW. Three types of drywall boards and cast monolithic gypsum from interior walls, treated in the laboratory, and a gypsum binder was obtained. Comparison has been studied and the most effective solutions regarding CDW treatment are represented. Separation, crushing, and milling were done. DTA/TG, XRD, SEM, and particle size distribution were characterized by CDW gypsum. The heat treatment temperature was selected at 130 °C for 4 or 24 h and 180 °C for 4 h. Consistency, set time, and mechanical properties were characterized. Results indicate that a gypsum binder with a strength up to 3.7 MPa can be obtained. Low strength is associated with fineness of CDW gypsum and a high water/gypsum ratio (from 0.6 to 1.396). Gypsum content in CDW (38 to 92 wt.%) should be considered as an important factor during gypsum CDW recycling. Full article

(This article belongs to the Topic Solid Waste Management)

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13 pages, 2660 KiB

Open AccessArticle

Sustainable Utilization of Waste Oyster Shell Powders with Different Fineness Levels in a Ternary Supplementary Cementitious Material System

by Shanglai Liu, Yuan Wang, Bonan Liu, Zhen Zou, Yina Teng, Yidi Ji, Yubo Zhou, Lei V. Zhang and Yannian Zhang

Sustainability 2022, 14(10), 5981; https://doi.org/10.3390/su14105981 - 14 May 2022

Cited by 12 | Viewed by 2578

Abstract

As cement manufacturing accounts for 8% of global CO₂ emissions, there is an urgent need to tackle the environmental impacts of cement production and address the decarbonization of construction materials. Adopting supplementary cementitious materials (SCMs), including fly ash, slag, silica fume, etc., [...] Read more.

As cement manufacturing accounts for 8% of global CO₂ emissions, there is an urgent need to tackle the environmental impacts of cement production and address the decarbonization of construction materials. Adopting supplementary cementitious materials (SCMs), including fly ash, slag, silica fume, etc., can be used as a partial replacement for ordinary Portland cement (OPC) to reduce CO₂ emissions related to the OPC industry, while providing benefits for waste valorization. This study aims to explore the sustainable utilization of a waste oyster shell powder (OSP)–lithium slag (LS)–ground granulated blast furnace slag (GGBFS) ternary SCM system in green concrete. The effect of OSP fineness on compressive strength, hydration products, pore structure, and transport properties in ternary SCM-based mortars was studied using a wide array of experimental techniques, including thermogravimetric analysis (TGA), scanning electron microscopy (SEM) analysis, Mercury intrusion porosimetry (MIP), the water absorption test and the rapid chloride penetration test (RCPT). The results revealed that the concrete with the ternary SCMs showed equivalent compressive strength compared to reference specimens. The water absorption and chloride ion charge of the RCPT in the concrete containing the ternary SCMs decreased by up to 30% and 81.4%, respectively. It was observed that the specimens incorporating the OSP with a mesh size of 3000 exhibited the highest compressive strength and the most refined microstructure. Full article

(This article belongs to the Topic Solid Waste Management)

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13 pages, 2069 KiB

Open AccessArticle

Heavy Metals/Metalloids in Soil of a Uranium Tailings Pond in Northwest China: Distribution and Relationship with Soil Physicochemical Properties and Radionuclides

by Yu Mao, Jinlong Yong, Qian Liu, Baoshan Wu, Henglei Chen, Youhua Hu and Guangwen Feng

Sustainability 2022, 14(9), 5315; https://doi.org/10.3390/su14095315 - 28 Apr 2022

Cited by 4 | Viewed by 1575

Abstract

Uranium tailings ponds have a potential impact on the soil ecological environment and human health. In this study, the measurement and spatial distribution characteristics of soil physicochemical properties (pH, EC, TN, TOC, and TP) and heavy metals/metalloids (Cd, Pb, Zn, Cr, and As) [...] Read more.

Uranium tailings ponds have a potential impact on the soil ecological environment and human health. In this study, the measurement and spatial distribution characteristics of soil physicochemical properties (pH, EC, TN, TOC, and TP) and heavy metals/metalloids (Cd, Pb, Zn, Cr, and As) in two different profiles (0–5 cm, 5–15 cm) were completed and visualized in a decommissioned uranium tailings pond in Northwest China. The results showed that almost all measured values in the study area were within the background values of China and other countries or regions around the world. The visual spatial distribution map showed that the spatial distribution characteristics of the EC, TP content, Pb content, and Cr content of the soil in the tailings pond and its adjacent area increased with the increase in depth of the vertical profile. The visual correlation heatmap analysis found that, in general, there were significant positive correlations among heavy metals and radionuclides and significant negative correlations among heavy metals, radionuclides, and physicochemical properties. The cluster tree divided environmental factors into two clusters; pH, TP, ⁴⁰K, Cd, and Zn formed one cluster, which could be related to the similar structures and physicochemical properties of Cd and Zn, and Pb, Cr, ²³²Th, TN, EC, TOC, As, ²³⁸U, and ²²⁶Ra formed another cluster of lithophile elements with similar geochemical properties. Based on the analysis results, the uranium tailings pond is in good operation, and no migration and diffusion of heavy metals/metalloids to the surrounding soil ecological environment was found. Full article

(This article belongs to the Topic Solid Waste Management)

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15 pages, 5964 KiB

Open AccessArticle

Experimental Study on the Use of Iron Tailings-Based Multicomponent Solid Waste as SCMs

by Yannian Zhang, Houqi Sun, Xiaowei Gu, Wenjie Zhang and Bonan Liu

Sustainability 2022, 14(9), 5124; https://doi.org/10.3390/su14095124 - 24 Apr 2022

Cited by 3 | Viewed by 1510

Abstract

A considerable amount of carbon dioxide is released during the preparation of traditional Portland cement, which is not in conformity with the sustainable road. Developing supplementary cementitious material (SCMs) and reducing cement consumption are safe ways to solve this problem. Iron tailings (IOTs), [...] Read more.

A considerable amount of carbon dioxide is released during the preparation of traditional Portland cement, which is not in conformity with the sustainable road. Developing supplementary cementitious material (SCMs) and reducing cement consumption are safe ways to solve this problem. Iron tailings (IOTs), a type of mining waste from the beneficiation process of iron ore concentrate, can be used as SCMs in concrete. In order to tackle the problem of low compressive performance of IOTs as SCMs in concrete, this study develops a multi-SCMs system based on IOTs. Mechanical properties and microstructure of samples with different activator contents and ratios were analyzed by compressive strength, differential thermal–thermal gravimetric analysis (DTA-TG), and scanning electron microscopy (SEM). The results show that the compressive strength of the composite gel blocks in different gel systems changed as follows: ternary SCMs system > binary SCMs system > unary SCMs system. The ternary SCMs system (IOTs: Steel slag(SS):Phosphorus slag(PS) = 1:2:2) without activator was added so that it resulted in the highest compressive strength in multi-SCMs system. With the increase in the content of activators, the compressive strength with ternary SCMs system shows a decreasing trend. It is well known from DTA-TG, as well as SEM, that NaOH and Na₂SiO₃ have an inhibitory effect on the secondary hydration reaction and inhibit the formation of C-S-H gel. Full article

(This article belongs to the Topic Solid Waste Management)

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17 pages, 3665 KiB

Open AccessArticle

Analysis of the Effectiveness of Green Waste Composting under Hyperbaric Conditions

by Jerzy Bieniek, Błażej Gaze, Bernard Knutel, Krzysztof Rać and Sara Góraj

Sustainability 2022, 14(9), 5108; https://doi.org/10.3390/su14095108 - 23 Apr 2022

Viewed by 1675

Abstract

Increasing global population growth has a significant impact on waste production. The European Union (EU) focuses on waste recycling, biological treatment, and reuse. In the case of biodegradable waste, a significant problem is the long process of material decomposition so that the product [...] Read more.

Increasing global population growth has a significant impact on waste production. The European Union (EU) focuses on waste recycling, biological treatment, and reuse. In the case of biodegradable waste, a significant problem is the long process of material decomposition so that the product meets the requirements of national regulations and EU directives. The search for a way to accelerate this process is still ongoing. This study presents the composting process of green waste under hyperbaric conditions. Eight experiments, four with air exchange frequency t_AE = 4 h and four experiments with t_AE = 8 h were established. The experiments were conducted in four variants: 0 (atmospheric pressure) and overpressures 50, 100, and 200 kPa. They were carried out on the same input material characterized by the initial moisture content of 60% and a mass of 2000 g. During the composting of green waste, all parameters of the obtained product (moisture content, pH, loss on ignition (LOI), C:N ratio, nutrient content (P, K), and the respiratory activity of microorganisms (AT₄)) were also evaluated. The most significant weight loss of the composted material was observed in the variant of an overpressure of 200 kPa (t_AE = 4 h). The compost weight in relation to the original material decreased by 23.7%. The highest organic matter removal efficiency was obtained for the overpressure variants of 50 and 100 kPa (t_AE = 4 h). Full article

(This article belongs to the Topic Solid Waste Management)

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25 pages, 3863 KiB

Open AccessArticle

Estimation for Potential of Agricultural Biomass Sources as Projections of Bio-Briquettes in Indian Context

by Sunny Vaish, Gagandeep Kaur, Naveen Kumar Sharma and Nikhil Gakkhar

Sustainability 2022, 14(9), 5077; https://doi.org/10.3390/su14095077 - 23 Apr 2022

Cited by 16 | Viewed by 3714

Abstract

Energy is an indicator of the socio-economic development of any country and has become an indispensable part of modern society. Despite several renewable sources of energy generation, biomass sources are still under-utilized due to the absence of standard policies of estimation of resources [...] Read more.

Energy is an indicator of the socio-economic development of any country and has become an indispensable part of modern society. Despite several renewable sources of energy generation, biomass sources are still under-utilized due to the absence of standard policies of estimation of resources at the country level. This paper attempts to estimate the gross crop residue and surplus residue potential for all provinces of the agricultural country, India. In India, the total area under crop production is 94,305 thousand hectares and the yield from all significant crops is 309,133 kg per hectare. It is estimated that total gross crop residue generation in the country is 480 million tonnes. Subsequently, after consumption of crop residues for numerous applications, the surplus crop residues are 121 million tonnes. The bioenergy potential from the surplus residues is estimated as 1988 PJ, which offers a huge potential energy source, from materials otherwise treated as waste. The Indian province Punjab, rich in agricultural sources and covering only 7% of the total cropping area of the country, generates 11% of the total surplus crop which could be used for further efficient use as bio briquettes. Full article

(This article belongs to the Topic Solid Waste Management)

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22 pages, 2658 KiB

Open AccessArticle

Studying Waste Separation Behaviors and Environmental Impacts toward Sustainable Solid Waste Management: A Case Study of Bang Chalong Housing, Samut Prakan, Thailand

by Pavinee Pongpunpurt, Pakornkeat Muensitthiroj, Pat Pinitjitsamut, Pavisorn Chuenchum, Pisut Painmanakul, Nattawin Chawaloesphonsiya and Thaksina Poyai

Sustainability 2022, 14(9), 5040; https://doi.org/10.3390/su14095040 - 22 Apr 2022

Cited by 6 | Viewed by 5313

Abstract

This study aims to develop more inclusive and sustainable waste management practices to be implemented in Bang Chalong Housing, a model community with unsatisfactory waste separation and recycling rate. The extended theory of planned behavior was employed to investigate the effect of attitude, [...] Read more.

This study aims to develop more inclusive and sustainable waste management practices to be implemented in Bang Chalong Housing, a model community with unsatisfactory waste separation and recycling rate. The extended theory of planned behavior was employed to investigate the effect of attitude, subjective norm, perceived behavioral control, knowledge, and situational factors on household waste separation intention and behavior, using structural equation modeling as a tool. Based on the questionnaire responses of 321 residents, the house owner’s status exhibited a considerable impact on waste-sorting behavior. Knowledge (β = 0.653; p < 0.001) and subjective norm (β = 0.160; p < 0.05) were two significant predictors of the respondents’ intention, which showed a strong influence on household waste separation behavior (β = 0.804; p < 0.001). Various waste management scenarios were also evaluated through material flow analysis and life cycle assessment. Installing a waste-sorting plant in addition to the current approach (recycling and landfilling) could annually reduce 26.4 tons of solid waste from being landfilled and mitigate GHG emissions by up to 47.4 tons CO₂ equivalent. Finally, the implications of these results on designing interventions and amending waste management schemes were discussed. Full article

(This article belongs to the Topic Solid Waste Management)

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25 pages, 2281 KiB

Open AccessArticle

Potential of Using Selected Industrial Waste Streams in Loop-Closing of Material Flows—The Example of the Silesian Voivodeship in Poland

by Karolina Jąderko-Skubis, Mariusz Kruczek and Magdalena Pichlak

Sustainability 2022, 14(8), 4801; https://doi.org/10.3390/su14084801 - 16 Apr 2022

Cited by 3 | Viewed by 1639

Abstract

Every year, the industrial sector produces a significant amount of waste. Bearing in mind the need to improve resource efficiency and reduce the impact of industrial plants on the environment, an attempt was made to identify and determine the processing potential of selected [...] Read more.

Every year, the industrial sector produces a significant amount of waste. Bearing in mind the need to improve resource efficiency and reduce the impact of industrial plants on the environment, an attempt was made to identify and determine the processing potential of selected waste streams with respect to the circular economy, along with an indication of sectoral connections. The subject of the study was industrial waste, which is the dominant stream of waste generated in the Silesian Voivodeship—the area of research. The paper presents the results of quantitative and qualitative analysis of the selected industrial waste streams and provides a visual representation of the flow. The study was based on available statistical data covering quantities of industrial waste. The article also includes the characteristics and possibilities of closing their circulation in the economy. The conducted SWOT analysis identified factors that strongly affect the possibility of implementing the circular economy model. The research allowed us to indicate possible waste flows and identify sectors closing their loop according to the assumptions of industrial symbiosis. The research path carried out on the example of Silesia shows the potential of the model and thus the possibility of implementation in other locations. This study showed that the strongest connection exists between mining-related plants, industrial power plants and combined heat and power plants, cement plants, and construction plants, especially road construction. Full article

(This article belongs to the Topic Solid Waste Management)

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22 pages, 3705 KiB

Open AccessArticle

Predicting Possible New Links to Future Global Plastic Waste Trade Networks

by Changping Zhao, Xinli Qi, Jin Wang, Fengyang Du and Xiaolan Shi

Sustainability 2022, 14(8), 4692; https://doi.org/10.3390/su14084692 - 14 Apr 2022

Cited by 5 | Viewed by 2257

Abstract

China’s waste plastic ban has sparked a discussion about how the global plastic waste trade (GPWT) will develop in the future. To answer this question, this article uses the link forecasting and QAP method to predict and analyze the possible development trend of [...] Read more.

China’s waste plastic ban has sparked a discussion about how the global plastic waste trade (GPWT) will develop in the future. To answer this question, this article uses the link forecasting and QAP method to predict and analyze the possible development trend of the GPWT in the future. The research results show that GPWT has certain stability and sustainability; although plastic waste trade has narrowed under the ban, it still has the potential trend of reconnecting the same type of links. Specifically, from a regional perspective, the future trade of new plastic waste trade will be dominated by cross-regional trade. Plastic waste may continue to flow to countries in the Asian–Pacific, Middle East, and African regions, while European countries will strengthen the internal recycling and processing of plastic waste. From the perspective of the national income level, the establishment of the new relationship will show an evolutionary trend in which high-income countries are dominated and the scale of trade between non-high-income countries expands. In addition, the differences in the level of economic development, liner transport connectivity, and the proportion of mismanagement of plastic waste among countries has a positive effect on the establishment of a new relationship in the GPWT, while tariff rates have an inhibitory effect. In general, the GPWT will still exist in the future, which requires the international community to guide the GPWT to promote the recycling and reuse of plastic waste in a real sense and adjust the unreasonable trade model. Full article

(This article belongs to the Topic Solid Waste Management)

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14 pages, 507 KiB

Open AccessReview

A Revision for the Different Reuses of Polyethylene Terephthalate (PET) Water Bottles

by Rahaf Ajaj, Wisam Abu Jadayil, Hamna Anver and Eman Aqil

Sustainability 2022, 14(8), 4583; https://doi.org/10.3390/su14084583 - 12 Apr 2022

Cited by 11 | Viewed by 5196

Abstract

According to studies on global plastic manufacturing and the resulting pollution, plastic wastes have been identified as a serious environmental concern. The impact of plastic garbage on marine species, humans, and the environment is a source of public concern, necessitating the need to [...] Read more.

According to studies on global plastic manufacturing and the resulting pollution, plastic wastes have been identified as a serious environmental concern. The impact of plastic garbage on marine species, humans, and the environment is a source of public concern, necessitating the need to save ecosystems and the lives that depend on them. Polyethylene terephthalate (PET) water bottles have a significant carbon footprint and represent tremendous waste. In the United Arab Emirates (UAE), PET water bottles are widely utilized, with yearly consumption reaching 450 water bottles per person. This study aims to review the literature on using PET water bottles in the UAE. A systematic literature search was conducted on journal articles, peer-reviewed journal articles, etc., published in the last 12 months. The main aspects of this systematic literature review include information on how plastic wastes are managed in the UAE and worldwide. In addition, it discusses the public health effects caused by plastic wastes, how the consumers of plastic bottles responded to the environmental policies, and so on. The article selection criteria included studies related to plastic water bottles in the UAE, waste management, environmental consequences, etc. A total of 30 articles were selected by initial screening, and 20 met the selection criteria and were included in the final review. To establish the credibility of this research, we understood that it was necessary to survey the UAE population to see the best approach to deal with PET water bottles. Full article

(This article belongs to the Topic Solid Waste Management)

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34 pages, 7866 KiB

Open AccessEditor’s ChoiceReview

Plastic Waste Management in India: Challenges, Opportunities, and Roadmap for Circular Economy

by Rumana Hossain, Md Tasbirul Islam, Riya Shanker, Debishree Khan, Katherine Elizabeth Sarah Locock, Anirban Ghose, Heinz Schandl, Rita Dhodapkar and Veena Sahajwalla

Sustainability 2022, 14(8), 4425; https://doi.org/10.3390/su14084425 - 08 Apr 2022

Cited by 25 | Viewed by 24391

Abstract

Plastic waste (PW) is one of the most rapid-growing waste streams in municipal solid waste all over the world. India has become a global player in the plastic value chain. Despite low consumption, domestic generation and imports create a significant burden on the [...] Read more.

Plastic waste (PW) is one of the most rapid-growing waste streams in municipal solid waste all over the world. India has become a global player in the plastic value chain. Despite low consumption, domestic generation and imports create a significant burden on the overall waste management system, which requires in-depth understanding of the scenario and pathways that can mitigate the crisis. Although Indian researchers have widely researched technology-related issues in academic papers, a substantial knowledge gap exists in understanding the problem’s depth and possible solutions. This review article focuses on current plastic production, consumption, and waste generation in India. This review article mainly analyzes data and information regarding Indian PW management and highlights some critical issues such as reverse supply chain, effective PW management, source-specific recovery, and PW rules in India. Comprehensively, this review will help to identify implementable strategies for policymakers and research opportunities for future researchers in holistic PW management and recycling in India, focusing on the circular economy and sustainable development goals. Full article

(This article belongs to the Topic Solid Waste Management)

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11 pages, 6628 KiB

Open AccessArticle

Valorization of Juglans regia. L Bark Residues as a Natural Colorant Based on Response Surface Methodology: A Challenging Approach to a Sustainable Dyeing Process for Acrylic Fabrics

by Manel Ben Ticha, Nourhene Slama, Nedra Dhouibi, Chedly Boudokhane and Hatem Dhaouadi

Sustainability 2022, 14(7), 4134; https://doi.org/10.3390/su14074134 - 30 Mar 2022

Cited by 1 | Viewed by 1684

Abstract

The dyeing industry is considered one of the most polluting industries. Thus, several researchers have focused on studying the possibilities of natural textile dyeing. The objective of this paper was to optimize the microwave extraction process for Juglans regia bark residues in order [...] Read more.

The dyeing industry is considered one of the most polluting industries. Thus, several researchers have focused on studying the possibilities of natural textile dyeing. The objective of this paper was to optimize the microwave extraction process for Juglans regia bark residues in order to dye acrylic fabrics. Hence, at first, the following extraction conditions were studied: microwave power, pH, extraction duration and concentration of dry mass. Flavonoid and tannin content was measured each time. Moreover, the obtained extracts were used for dyeing acrylic fibers with microwave assistance, and the corresponding color yield (K/S) was measured. Then, the microwave extraction process already developed was optimized; a response surface design was established using Minitab 19 software. The optimal extraction conditions were found to be: microwave power = 850, pH = 3 and extraction time = 4 min. Finally, dyed and undyed acrylic were characterized by infrared (FTIR) spectroscopy in order to distinguish the effect of this natural dye on the external layer of the acrylic fiber. Full article

(This article belongs to the Topic Solid Waste Management)

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20 pages, 5097 KiB

Open AccessArticle

Study on the Effect of Amorphous Silica from Waste Granite Powder on the Strength Development of Cement-Treated Clay for Soft Ground Improvement

by Joyce Nakayenga, Mutsuko Inui and Toshiro Hata

Sustainability 2022, 14(7), 4073; https://doi.org/10.3390/su14074073 - 29 Mar 2022

Cited by 2 | Viewed by 2209

Abstract

Granite powder (stone powder), a waste product generated from stone quarries, is increasingly being reused in cement-treated clays. The particle size of stone powders affects the cement-clay reaction by either increasing or reducing the unconfined compressive strength (UCS). This study investigated this phenomenon [...] Read more.

Granite powder (stone powder), a waste product generated from stone quarries, is increasingly being reused in cement-treated clays. The particle size of stone powders affects the cement-clay reaction by either increasing or reducing the unconfined compressive strength (UCS). This study investigated this phenomenon by separating stone powder from the same batch at the quarry into five particle sizes (A, B, C, D and E: 106–75 µm, 40–75 µm, 20–40 µm, <20 µm and 106–<1 µm, respectively). Flow value, fall cone, UCS and thermogravimetry-differential thermal analysis (TG-DTA), X-ray fluorescence, electrical conductivity and NaOH digestion tests were conducted. It was discovered that stone powder had an amorphization rate of up to 1.45% (14.5 mg/g of amorphous silica); hence, it was pozzolanic. However, the amorphousness varied with the particle size of the material in the order of D > E > C > B > A, which translated into UCS variation in the same order. Stone powders D and E played two roles in UCS development, i.e., nucleation of cementitious products and reaction with Ca(OH)₂ to increase the UCS higher than the control sample. Linear regression equations determined the minimum concentration of amorphous silica for a UCS increment as 9.4 mg/g. Full article

(This article belongs to the Topic Solid Waste Management)

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25 pages, 3427 KiB

Open AccessReview

A Review of Medical Waste Management Systems in the Republic of Korea for Hospital and Medical Waste Generated from the COVID-19 Pandemic

by Cheol-Woo Yoon, Min-Jung Kim, Yoon-Su Park, Tae-Wan Jeon and Min-Yong Lee

Sustainability 2022, 14(6), 3678; https://doi.org/10.3390/su14063678 - 21 Mar 2022

Cited by 25 | Viewed by 7468

Abstract

With the increasing generation of medical waste worldwide, managing medical waste has become crucial, given its potential environmental and public health risks. Previously in the Republic of Korea, medical waste was often mixed with municipal waste and disposed of in residential landfills or [...] Read more.

With the increasing generation of medical waste worldwide, managing medical waste has become crucial, given its potential environmental and public health risks. Previously in the Republic of Korea, medical waste was often mixed with municipal waste and disposed of in residential landfills or unsuitable treatment facilities (e.g., improperly managed incinerators). Environmental regulators and waste producers have made extensive efforts in recent years to improve waste management at healthcare facilities. This study presents an overview of the status of medical waste management in Korea and discusses information on the generation, composition, separation, transportation, and treatment of medical waste. Incineration was confirmed to be the most preferred treatment method for medical waste and was the only one used until late 2005. Large-scale medical waste incinerators are used for treating medical waste from most medical facilities in Korea; however, with increasing regulations on toxic air emissions (e.g., dioxins and furans), air emission standards are being tightened for all existing small-scale incineration facilities without air pollution control. Since medical waste usually contains various plastic materials such as polyvinyl chloride, these incinerators are highly likely to emit toxic air pollutants if improperly operated and managed. Waste minimization and recycling, control of toxic air emissions from medical waste incinerators, and alternative treatment methods to incineration are seen as major challenges. Incineration capacity cannot be expanded as quickly as the rising quantities of medical waste in Korea; thus, there is a growing need to reconsider the overall management system. Accordingly, we examined various medical waste treatment policies and methods that are being implemented in other countries, in addition to the main strategy of waste management. To determine preferable directions for the improvement of the medical waste management system, we investigated and compared the status of domestic and foreign waste management and proposed directions for improvement, focusing on several issues related to the current medical waste management system in Korea. Full article

(This article belongs to the Topic Solid Waste Management)

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20 pages, 6233 KiB

Open AccessArticle

A Multi-Commodity Mathematical Modelling Approach—Hazardous Waste Treatment Infrastructure Planning in the Czech Republic

by Radovan Šomplák, Jiří Kropáč, Jaroslav Pluskal, Martin Pavlas, Boris Urbánek and Petra Vítková

Sustainability 2022, 14(6), 3536; https://doi.org/10.3390/su14063536 - 17 Mar 2022

Cited by 1 | Viewed by 1985

Abstract

This paper presents an analysis of infrastructure for the processing of Czech hazardous waste and pays attention to predictions of waste management development in the upcoming years. For this purpose, a unique complex approach to modelling future waste management changes is applied. The [...] Read more.

This paper presents an analysis of infrastructure for the processing of Czech hazardous waste and pays attention to predictions of waste management development in the upcoming years. For this purpose, a unique complex approach to modelling future waste management changes is applied. The method uses a multi-commodity network flow model with reverse flows between treatment facilities to consider complete waste management of hazardous waste. The future outlook (2030) for the forecasted generation of different types of hazardous waste in the Czech Republic requires decisions on waste treatment facility infrastructure. The uniqueness lies in using real data for such a wide scope of a task, further enhanced by concurrent analysis of more types of waste interconnected through limited processing capacities. The results indicate the insufficiency in hazardous waste thermal treatment and stabilization. A suggestion is to extend the incineration capacity because it influences the stabilization units, which must process the remaining waste. The recommended increase is 100% with different proportions in individual regions. Full article

(This article belongs to the Topic Solid Waste Management)

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13 pages, 1948 KiB

Open AccessArticle

Quest for the Co-Pyrolysis Behavior of Rice Husk and Cresol Distillation Residue: Interaction, Gas Evolution and Kinetics

by Na Xu, Mifen Cui, Zhuxiu Zhang, Jihai Tang and Xu Qiao

Energies 2022, 15(6), 2130; https://doi.org/10.3390/en15062130 - 14 Mar 2022

Viewed by 1739

Abstract

With the tremendous prosperity of industry, more and more hazardous waste is discharged from industrial production processes. Cresol distillation residue is a typical industrial hazardous waste that causes severe pollution without proper treatment. Herein, the co-pyrolysis of rice husk and cresol distillation residue [...] Read more.

With the tremendous prosperity of industry, more and more hazardous waste is discharged from industrial production processes. Cresol distillation residue is a typical industrial hazardous waste that causes severe pollution without proper treatment. Herein, the co-pyrolysis of rice husk and cresol distillation residue was studied using thermogravimetry–mass spectrometry and kinetic studies. The Coats and Redfern method was employed to calculate the activation energy. The results indicated that the pyrolysis process of cresol distillation residue and RH/CDR (Rice Husk and Cresol Distillation Residue) blends can be divided into four stages and three stages for RH. The introduction of RH not only improved the thermo-stability of cresol distillation residue at a low temperature but also reduced the activation energy of the blends. The activation energy was the lowest when the proportion of rice husk in the blend was 60%. The main gaseous pyrolysis products included CH₄, H₂O, C₂H₂, CO₂, C₃H₆ and H₂. There existed an unusual combination of synergistic and inhibitive interactions between RH and cresol distillation residue, respectively, within different temperature ranges. The synergistic interaction decreased the reaction’s activation energy, whereas the inhibitive interaction reduced the emission of main gaseous products, such as CH₄ and CO₂. It was concluded that the addition of RH was conducive to improving the pyrolytic performance of cresol distillation residue and the resource utilization of cresol distillation residue. Full article

(This article belongs to the Topic Solid Waste Management)

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21 pages, 2074 KiB

Open AccessArticle

Life Cycle Assessment of Existing and Alternative Options for Municipal Solid Waste Management in Saint Petersburg and the Leningrad Region, Russia

by Anna Zaikova, Natalia Vinitskaia, Ivan Deviatkin, Jouni Havukainen and Mika Horttanainen

Recycling 2022, 7(2), 19; https://doi.org/10.3390/recycling7020019 - 14 Mar 2022

Cited by 5 | Viewed by 5381

Abstract

A waste reform was recently introduced in Russia to divert waste from landfills. To help advance the reform, this paper presents a life cycle assessment of the municipal solid waste management system in Russia’s second largest city—Saint Petersburg—and its neighboring Leningrad region. Five [...] Read more.

A waste reform was recently introduced in Russia to divert waste from landfills. To help advance the reform, this paper presents a life cycle assessment of the municipal solid waste management system in Russia’s second largest city—Saint Petersburg—and its neighboring Leningrad region. Five scenarios were evaluated: the current state of the system (S0), its expected post-reform state in 2024 (S1), and its state improved by increased landfill gas collection (S2), by increased waste incineration (S3), and by separate collection of waste (S4). The environmental impact was assessed in terms of climate change, acidification, eutrophication, and abiotic resource depletion (fossil fuels). The results showed an overall reduction in the environmental impact of the waste management system across all impact categories and all scenarios studied. The largest reduction in all impact categories (except abiotic resource depletion) was achieved through source separation of municipal solid waste. Particularly, global warming potential was reduced from 0.328 kg CO₂-eq./kg waste generated in S0 to 0.010 kg CO₂-eq./kg waste in S4. Regarding abiotic resource depletion potential (fossil fuels), the incineration scenario is the most beneficial, since it reduces the impact by 573%. Full article

(This article belongs to the Topic Solid Waste Management)

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13 pages, 1295 KiB

Open AccessArticle

Household Solid WasteManagement in the Dominican Republic: Case of the Municipality of Puñal, Santiago

by Edian F. Franco, Wilfredo Padrón Iglesia and Karina Pérez Teruel

Sustainability 2022, 14(6), 3149; https://doi.org/10.3390/su14063149 - 08 Mar 2022

Cited by 2 | Viewed by 3588

Abstract

One of the biggest problems that the Dominican Republic has had in recent decades is the efficient management of solid domestic waste. This problem has worsened in recent years due to the decrease in available areas for the construction of sanitary landfills, the [...] Read more.

One of the biggest problems that the Dominican Republic has had in recent decades is the efficient management of solid domestic waste. This problem has worsened in recent years due to the decrease in available areas for the construction of sanitary landfills, the lack of recycling culture in the population, the deficiency in waste collection, and the scarce legal controls aimed at preserving water, air and soil among other factors. The objective of this study is to explore the management of solid waste by the population and the municipality of Puñal, province of Santiago, to evaluate and analyze the situation and generation of solid waste, municipal solid waste management services, and the attitudes of the population regarding recycling projects and waste management. A total of 275 households from 29 localities in the municipality of Puñal were surveyed, which allowed for a significant population sample. According to the results, the most significant type of waste produced by families is organic waste, followed by plastic waste and paper. Of the total organic waste produced in the municipality, 53% of solids wastes are handled through the municipal waste collection system, while 47% is used as plant fertilizers or animal feed. On the other hand, most households receive the municipal waste collection service and pay for this service, through which the municipal government collects, processes, and deposits the waste in different landfills. However, a more efficient waste collection system and the development of programs and projects that allow households to manage the solid waste efficiently they produce would be necessary. Full article

(This article belongs to the Topic Solid Waste Management)

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18 pages, 4222 KiB

Open AccessArticle

Bacterial Community Structure and Predicted Metabolic Function of Landfilled Municipal Solid Waste in China

by Han Ke, Jinghang Li, Xuanqi Zhang and Jie Hu

Sustainability 2022, 14(6), 3144; https://doi.org/10.3390/su14063144 - 08 Mar 2022

Cited by 7 | Viewed by 2048

Abstract

The biodegradation behavior of municipal solid waste (MSW) depends on the diversity and metabolic function of bacterial communities, which are affected by environmental factors. However, the diversity of the bacterial communities and metabolic functions in MSW, as well as their influencing factors, remain [...] Read more.

The biodegradation behavior of municipal solid waste (MSW) depends on the diversity and metabolic function of bacterial communities, which are affected by environmental factors. However, the diversity of the bacterial communities and metabolic functions in MSW, as well as their influencing factors, remain unclear. In deep-aged MSW, the abovementioned deficiencies are more significant, and will effectively hamper landfill disposal. In this study, high-throughput sequencing was performed to examine the bacterial community structure and metabolic function from depths of 10 m to 40 m, of two large MSW landfills on the southeast coast of China. Thermotogota (1.6–32.0%), Firmicutes (44.2–77.1%), and Bacteroidota (4.0–34.3%) were the three dominant phyla among the 39 bacterial phyla identified in aged MSW samples. Bacterial genera associated with the degradation of many macromolecules, e.g., Defluviitoga, Hydrogenispora, and Lentimicrobium were abundantly detected in MSW samples, even in aged MSW. Redundancy analysis (RDA) showed that bacterial diversity in the landfills was most strongly correlated with electrical conductivity, age, and moisture content of the MSW. Tax4fun2 analysis predicted that there were abundant metabolism functions in aged MSW, especially functional enzymes (e.g., glycine dehydrogenase and cellulase) related to amino acids and cellulose degradation. This study increases our understanding of the bacterial diversity and functional characteristics in landfilled MSW. Full article

(This article belongs to the Topic Solid Waste Management)

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11 pages, 4108 KiB

Open AccessArticle

Concentration of Microplastics in Road Dust as a Function of the Drying Period—A Case Study in G City, Korea

by Heejun Kang, Saerom Park, Bokjin Lee, Ilho Kim and Seogku Kim

Sustainability 2022, 14(5), 3006; https://doi.org/10.3390/su14053006 - 04 Mar 2022

Cited by 16 | Viewed by 3577

Abstract

Microplastics (MPs) are plastic particles < 5 mm in diameter, which are detected in air, soil, and water, causing various environmental problems. In total, 37.3% of MPs are generated from point pollution sources and 62.7% from non-point sources; most of the non-point-source MPs [...] Read more.

Microplastics (MPs) are plastic particles < 5 mm in diameter, which are detected in air, soil, and water, causing various environmental problems. In total, 37.3% of MPs are generated from point pollution sources and 62.7% from non-point sources; most of the non-point-source MPs are from vehicles tires, road-marking paint, and bitumen used in road pavements. In this study, the concentrations of MPs generated from roads in Goyang city, South Korea, were examined in terms of the drying period (0, 1, 2, or 3 d). Road dust sampling was performed at the kerb and quantitative and qualitative analyses were conducted for each sample. The MP concentrations were 552 (±39) MPs g⁻¹ for a 0 d drying period and 1530 (±602) MPs g⁻¹ for a 3 d drying period, confirming that the MP concentration in road dust increased with the increase in drying period. Among the detected substances, black particles accounted for the highest proportion (72%) and were found to be bitumen and tyre particles. This study also confirmed that the MPs accumulated on roads were washed away when rainfall exceeded a certain amount. Full article

(This article belongs to the Topic Solid Waste Management)

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14 pages, 1362 KiB

Open AccessArticle

Impact of China’s National Sword Policy on the U.S. Landfill and Plastics Recycling Industry

by Aditya Vedantam, Nallan C. Suresh, Khadija Ajmal and Michael Shelly

Sustainability 2022, 14(4), 2456; https://doi.org/10.3390/su14042456 - 21 Feb 2022

Cited by 17 | Viewed by 8850

Abstract

This paper analyzes the impacts of China’s Green Fence and National Sword Programs, under which strict contamination limits were imposed on recyclable materials, besides prohibiting imports of low quality recyclables. Specifically, this study investigates the impacts of this policy on landfills, and the [...] Read more.

This paper analyzes the impacts of China’s Green Fence and National Sword Programs, under which strict contamination limits were imposed on recyclable materials, besides prohibiting imports of low quality recyclables. Specifically, this study investigates the impacts of this policy on landfills, and the risks to the U.S. plastics secondary materials market and material recovery facilities (MRFs). A hierarchical regression analysis reveals the significant impacts of China’s Green Fence and National Sword polices on the amount landfilled plastic. Controlling for oil prices, producer price index (PPI), and amount of plastic scrap exported, our findings show that the Green Fence had no statistically significant impact on the amount of plastic landfilled in the U.S. However, the quantity of plastic landfilled in the U.S. increased by 23.2% following the implementation of National Sword. Furthermore, analysis of the annual reports submitted by registered MRFs in New York (NY) state reveals that the total amount of plastic recovered by them has decreased. We suggest that demand creation and investments that improve the quality of bales are needed to help solve this economic dilemma. Full article

(This article belongs to the Topic Solid Waste Management)

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17 pages, 966 KiB

Open AccessArticle

The Potential Determinants for Smartphone Recycling Behaviour Sustainability in UAE

by Taher Ben Yahya, Noriza Mohd Jamal, Balan Sundarakani and Siti Zaleha Omain

Sustainability 2022, 14(4), 2282; https://doi.org/10.3390/su14042282 - 17 Feb 2022

Cited by 6 | Viewed by 2851

Abstract

Repeated actions and behaviours are characteristic of people’s daily lives. However, there is a dilemma when this repeated action is associated with mobile phone recycling since convincing mobile users to recycle sustainably is challenging. This study analysed the four factors (i.e., actual knowledge, [...] Read more.

Repeated actions and behaviours are characteristic of people’s daily lives. However, there is a dilemma when this repeated action is associated with mobile phone recycling since convincing mobile users to recycle sustainably is challenging. This study analysed the four factors (i.e., actual knowledge, salience, environmental constraints, and habits) adopted from the Integrated Behavioural Model (IBM) theory and examined their impact on behavioural sustainability. A partial least squares structural equation modelling (PLS-SEM) approach was applied to evaluate 601 responses from a self-administered online survey collected from mobile user participants based in the United Arab Emirates (UAE). The survey findings indicated that habit has the strongest and statistically significant positive influence on behaviour; followed by knowledge and skills. Additionally, the salience of behaviour has a considerably negative influence on behaviour sustainability unaffected by environmental constraints. This study serves as a springboard for future research examining the IBM model to understand recycling behaviour in general and smartphone recycling sustainability in particular. Additionally, this research can assist smartphone manufacturers in understanding the factors that will maintain the recycling behaviour continuity, increasing the number of returned devices. Full article

(This article belongs to the Topic Solid Waste Management)

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18 pages, 2119 KiB

Open AccessReview

Bibliometric Analysis; Characteristics and Trends of Refuse Derived Fuel Research

by Khadija Sarquah, Satyanarayana Narra, Gesa Beck, Edward A. Awafo and Edward Antwi

Sustainability 2022, 14(4), 1994; https://doi.org/10.3390/su14041994 - 10 Feb 2022

Cited by 9 | Viewed by 3091

Abstract

Among the sustainable ways of municipal solid waste management (MSW) is energy recovery, particularly into refuse derived fuel (RDF). However, the potential, application, and research of RDF in existing cases is not exhausted. Additional analysis of literature is needed to provide further insights [...] Read more.

Among the sustainable ways of municipal solid waste management (MSW) is energy recovery, particularly into refuse derived fuel (RDF). However, the potential, application, and research of RDF in existing cases is not exhausted. Additional analysis of literature is needed to provide further insights into the area. The evolution of RDF research over the past 30 years is analyzed and presented in this paper. Using a statistical approach, a bibliometric analysis was conducted for research on RDF from the SCOPUS database to assess perspectives and trends and gain a better understanding of the scope of RDF research. The bibliometric analysis tools, co-citation, keyword occurrence, co-authorship, and bibliometric coupling network, were utilized in VOSviewer to map out keywords, collaborations, and citations. The result from the analysis indicated that scholarly works around RDF were largely written in English (92.7%). Journal articles were the most frequently occurring document type, representing 68.5% of the records, followed by conference papers (24.9%). Out of a total of 1184 documents analyzed, the number of publications rose steadily from 26 in 2003 to 102 in 2021. Most publications on RDF were in the subject area of Environmental Science (648), Energy (483), and Engineering (441). Waste Management, Fuel, Waste Research and Management, and the Journal of Cleaner Productions were the sources that contained most of the publications on RDF research. The contributions (number of publications) in the RDF research were largely from the US (176), Italy (97), Japan (90), Germany (86), China (79), and the UK (74), among others. Collaborations were notable between the US, Europe, and the Asian regions (China, India, and Thailand). Conspicuously missing were research contributions from the African region, comparatively, thus emphasizing the need for contributions from such perspectives. The keyword analysis result further showed studies were within knowledge areas of conversion processes, applications, and management. Thermochemical conversion pathways were highly applied to RDF and thus combustion/co-combustion/incineration (717), gasification (224), and pyrolysis (115). Additionally, research on RDF applications was mostly in the cement industry (150) and electricity generation (55). The time incident analysis outlined recent interest and emerging trends in optimization of valorization processes, towards a circular economy and sustainability. Cross-cutting areas of environmental focus (emissions) were observed along the years analyzed. There is a rising focus on indicators for commercialization, environmental impacts, and optimum production from the analysis. This is useful especially for the emerging regions/territory of research contributions. These discussions would potentially maximize the co-benefits of energy generation and eco-environment sustainability via cost benefits deployments suggested for future research. Analyzing the RDF research trends, these findings are useful for the future endeavor of researchers and developers. Full article

(This article belongs to the Topic Solid Waste Management)

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32 pages, 2866 KiB

Open AccessReview

The Recycling of Coal Fly Ash: A Review on Sustainable Developments and Economic Considerations

by Amanda Qinisile Vilakazi, Sehliselo Ndlovu, Liberty Chipise and Alan Shemi

Sustainability 2022, 14(4), 1958; https://doi.org/10.3390/su14041958 - 09 Feb 2022

Cited by 29 | Viewed by 5581

Abstract

The recycling and utilization opportunities for coal fly ash (CFA) have increased in the past two decades. However, limited commercialization of the material is still reported, while disposal and management remain major concerns. CFA utilization is currently commercially feasible in the building and [...] Read more.

The recycling and utilization opportunities for coal fly ash (CFA) have increased in the past two decades. However, limited commercialization of the material is still reported, while disposal and management remain major concerns. CFA utilization is currently commercially feasible in the building and construction industry. Other alternative uses that are being explored involve the extraction of valuable metals and the purification of wastewater. The CFA-produced adsorbent material utilized in wastewater purification processes should be able to generate water that meets the legal quality requirements for reutilization in alternative applications. On the other hand, in the recovery of metallic components such as smelter-grade alumina, high recovery and high purity products are only achievable through the processing of CFA using expensive and energy—intensive processes. Furthermore, most of the current CFA recycling processes tend to generate secondary solid residues (SSR), which can cause environmental pollution, thus requiring further downstream processing. In this context, this paper reviews and discusses current research on CFA recycling methods, challenges and opportunities associated with resource recovery from CFA, and the acceptability of the value-added products, and it therefore proposes sustainable processes for CFA utilization. This review further suggests that to successfully compete with bauxite for production of smelter-grade alumina, other saleable value-added products such as Ti, Fe and the REEs should be recovered by engineering an integrated process design. The generated SSR in each process must also be characterized, recycled and re-used to reduce waste production and advance the circular economy concept. The review concludes that for CFA to become considered as a more attractive commercial resource, there is need for its complete and holistic utilization in high volumes and in different applications to offset its low value. Full article

(This article belongs to the Topic Solid Waste Management)

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16 pages, 4532 KiB

Open AccessArticle

Evaluation of the Melting Gasification Process for Recovery of Energy and Resources from Automobile Shredder Residues

by Heung-Min Yoo, Sang-Yeop Lee, Sung-Jin Cho, Yong-Chil Seo and Ha-Na Jang

Energies 2022, 15(3), 1248; https://doi.org/10.3390/en15031248 - 08 Feb 2022

Cited by 3 | Viewed by 2017

Abstract

In this study, we investigated the applicability of an automobile shredder residue (ASR) as an energy and recycling resource. First, ASR gasification was conducted in a fixed-bed reactor (throughput = 1 kg/h) at different temperatures (800, 1000, and 1200 °C) and an equivalence [...] Read more.

In this study, we investigated the applicability of an automobile shredder residue (ASR) as an energy and recycling resource. First, ASR gasification was conducted in a fixed-bed reactor (throughput = 1 kg/h) at different temperatures (800, 1000, and 1200 °C) and an equivalence ratio of 0.1–0.5. Clay bricks were prepared with the solid residue obtained from the gasification process to address the issue of solid-residue production in pyrolysis. The syngas (H₂ + CO) from ASR gasification had maximum and minimum yields of approximately 86 and 40 vol.%, respectively. Furthermore, the yield of syngas increased with the temperature and equivalence ratio (ER); therefore, the optimum conditions for the ASR gasification were determined to be a temperature of 1200 °C and an ER of 0.5. In addition, solid residues, such as char and ash, began to melt due to thermal heating in the range of 1300–1400 °C and were converted into melting slag, which was subsequently used to manufacture clay bricks. The absorption ratios and compressive strengths of the clay bricks were compared to those set by Korean Industrial Standards to evaluate the quality of the clay bricks. As a result, the manufactured clay bricks were estimated to have a compressive strength of over 22.54 N/mm² and an absorption ratio of less than 10%. Additionally, greenhouse gas (GHG) emissions from the melting–gasification process were estimated and compared with those from ASR incineration, calculated using the greenhouse gas equations provided by the Korean Ministry of Environment. As a result, it was revealed that the GHG emissions from the combined melting–gasification process (gasification, melting system, and clay-brick manufacturing) were approximately ten times higher than those from the ASR-incineration process. Thus, in terms of operation cost on the carbon capture process for GHG reduction, the combined melting–gasification process would be a more efficient process than that of incineration. Full article

(This article belongs to the Topic Solid Waste Management)

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15 pages, 3960 KiB

Open AccessArticle

Theoretical and Experimental Analysis on Influence of Natural Airflow on Spent Fuel Heat Removal in Dry Cask Storage

by Ratiko Ratiko, Raden Sumarbagiono, Aisyah Aisyah, Wati Wati, Kuat Heriyanto, Mirawaty Mirawaty, Pungky Ayu Artiani, Yuli Purwanto, Dwi Luhur Ibnu Saputra, Jaka Rachmadetin, Risdiyana Setiawan, Arifin Istavara and Abdullah Ahmad Rauf

Sustainability 2022, 14(3), 1859; https://doi.org/10.3390/su14031859 - 06 Feb 2022

Cited by 3 | Viewed by 1768

Abstract

A key issue contributing to the success of NPP technology is the safe handling of radioactive waste, particularly spent nuclear fuel. According to the IAEA safety standard, the spent fuel must be stored in interim wet storage for several years so the radiation [...] Read more.

A key issue contributing to the success of NPP technology is the safe handling of radioactive waste, particularly spent nuclear fuel. According to the IAEA safety standard, the spent fuel must be stored in interim wet storage for several years so the radiation and the decay heat of the spent fuel will decrease to the safe limit values, after which the spent fuel can be moved to dry storage. In this study, we performed a theoretical analysis of heat removal by natural convection airflow in spent nuclear fuel dry storage. The temperature difference between the air inside and outside dry storage produces an air density difference. The air density difference causes a pressure difference, which then generates natural airflow. The result of the theoretical analysis was validated with simulation software and experimental investigation using a reduced-scale dry storage prototype. The dry storage prototype consisted of a dry cask body and two canisters stacked to store materials testing reactor (MTR) spent fuel, which generates decay heat. The cask body had four air inlet vents on the bottom and four air outlet vents at the top. To simulate the decay heat from the spent fuel in the two canisters, the canisters were wrapped with an electric wire heater that was connected to a voltage regulator to adjust the heat power. The theoretical analysis results of this study are relatively consistent with the experimental results, with the mean relative deviation (MRD) values for the prediction of air velocity, the heat rate using natural airflow, and the heat rate using the thermal resistance network equation are +0.76, −23.69, and −29.54%, respectively. Full article

(This article belongs to the Topic Solid Waste Management)

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24 pages, 2180 KiB

Open AccessArticle

Towards a Sustainable Bioeconomy through Industrial Symbiosis: Current Situation and Perspectives

by Nicolas Bijon, Tom Wassenaar, Guillaume Junqua and Magali Dechesne

Sustainability 2022, 14(3), 1605; https://doi.org/10.3390/su14031605 - 29 Jan 2022

Cited by 10 | Viewed by 3105

Abstract

The concepts of industrial symbiosis (IS) and bioeconomy (BE) both focus on ways to reduce dependence on non-renewable resources. However, these two frames of reference have rarely been considered as part of a joint strategy to achieve sustainability. Here, we describe how they [...] Read more.

The concepts of industrial symbiosis (IS) and bioeconomy (BE) both focus on ways to reduce dependence on non-renewable resources. However, these two frames of reference have rarely been considered as part of a joint strategy to achieve sustainability. Here, we describe how they inter-operate, in well documented IS case studies, to identify current synergy patterns of organic by-products, their limits, and promising pathways towards integrated initiatives that pursue the respective goals of each framework. We first evaluated the nature of synergies in current practices, and how they contribute to sustainability. Second, we focused on the role of agriculture in these symbioses, due to its fundamental role in circular bioeconomy. We used three main dimensions to analyze our case studies: IS emergence, governance of synergies, and actor serendipity. We identified three main patterns of organic matter use within IS, which we termed metabolic resources, metabolic biorefinery, and global biorefinery. Our observations suggest that synergies with agriculture are undervalued, by both internal and external practitioners. We conclude that while the combination of BE and IS can bolster sustainability, it requires a dedicated implementation strategy that has yet to be conceived. Full article

(This article belongs to the Topic Solid Waste Management)

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13 pages, 1416 KiB

Open AccessArticle

Using Wood-Based Waste from Grapevine Cultivation for Energy Purposes

by Grzegorz Maj, Kamila Klimek, Magdalena Kapłan and Edyta Wrzesińska-Jędrusiak

Energies 2022, 15(3), 890; https://doi.org/10.3390/en15030890 - 26 Jan 2022

Cited by 3 | Viewed by 2421

Abstract

This paper presents the possibility of the energetic utilization of biowaste in the form of lignified one-year shoots from the cultivation of grapevines of the Seyval Blanc (WSBL), Solaris (WSOL), Regent (WREG) and Rondo (WRON) varieties, grown in temperate climate zones. A technical [...] Read more.

This paper presents the possibility of the energetic utilization of biowaste in the form of lignified one-year shoots from the cultivation of grapevines of the Seyval Blanc (WSBL), Solaris (WSOL), Regent (WREG) and Rondo (WRON) varieties, grown in temperate climate zones. A technical analysis, an elemental analysis and the determination of the highest heat value and lowest heat value were performed to define the quality parameters of waste as fuel. In addition, the emission factors of SO₂, NO_x, CO, CO₂ and dust were estimated to demonstrate the impact of potential biowaste from combustion. Based on the stoichiometric equations, the exhaust gas composition, the theoretical oxygen demand and the total flue gas volume were evaluated. The study showed that the material with the highest energy potential was WREG (LHV-16.19 MJ·kg⁻¹), with an ash content of 3.68%, while the lowest potential was found for WRON (LHV-15.88 MJ·kg⁻¹), with an ash content of 4.21%. The study showed that the use of the studied viticulture waste instead of hard coal could reduce CO emissions by 26–27%, CO₂ by 24–26%, NO_x by 55–56%, SO₂ by 96–97% and dust by 77–80%. Full article

(This article belongs to the Topic Solid Waste Management)

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20 pages, 790 KiB

Open AccessArticle

What Influences Consumers to Recycle Solid Waste? An Application of the Extended Theory of Planned Behavior in the Kingdom of Saudi Arabia

by Yasir Ali Soomro, Irfan Hameed, Muhammad Yaseen Bhutto, Idrees Waris, Yasser Baeshen and Bader Al Batati

Sustainability 2022, 14(2), 998; https://doi.org/10.3390/su14020998 - 17 Jan 2022

Cited by 23 | Viewed by 5098

Abstract

This extant study attempts to present a comprehensive predictive model for solid waste recycling behavior. Solid waste is a major environmental concern globally. Particularly, the kingdom of Saudi Arabia (KSA), being the larger gulf country in the Middle East is a major contributor [...] Read more.

This extant study attempts to present a comprehensive predictive model for solid waste recycling behavior. Solid waste is a major environmental concern globally. Particularly, the kingdom of Saudi Arabia (KSA), being the larger gulf country in the Middle East is a major contributor to solid waste. Consequently, this study was carried out to identify the motivational factors that consumers consider important for recycling their household waste. We extended the theory of planned behavior (TBP) and utilized actual behavioral variables such as resell, reuse, and donation. A structured questionnaire was carried out with 365 purposively selected respondents in the KSA. Among several other noteworthy findings consistent with previous studies, we found that reselling was the most significant factor of recycling behavior followed by donation. Further, the multi-group analysis (MGA) results reveal significant group differences in gender and age variables; the significance test indicates that the male group has much better pro-environmental behavior than the female group. In terms of age, our results showed that recycling intention and reselling behavior passed a significant test in the elderly group when compared to a younger group. This study has unique contributions and findings leading to practical implications for government authorities, businesses, and non-governmental organizations. The findings will particularly aid in increasing the recycling intention and behavior among household consumers. This research will guide in making laws and policies that can help to embrace the green challenges and boost recycling activities for a sustainable environment. Full article

(This article belongs to the Topic Solid Waste Management)

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14 pages, 1762 KiB

Open AccessArticle

Chemical and Microbiological Air Quality in a Municipal Solid Waste Landfill and Its Surroundings, in South-Eastern Romania

by Mirel Pop, Iulia Bucur, Dan Zoldan, Kálmán Imre, Ileana Nichita, Gașpar Cristina, Andreea Tîrziu and Emil Tîrziu

Sustainability 2022, 14(1), 156; https://doi.org/10.3390/su14010156 - 24 Dec 2021

Cited by 5 | Viewed by 2937

Abstract

The aim of this study was to assess the microbiological and chemical air quality in a municipal solid waste landfill and its inhabited surroundings, in a particular context in which Romania struggles with the incapacity to comply with its environmental commitments. The research [...] Read more.

The aim of this study was to assess the microbiological and chemical air quality in a municipal solid waste landfill and its inhabited surroundings, in a particular context in which Romania struggles with the incapacity to comply with its environmental commitments. The research was conducted on a landfill near the capital Bucharest between November 2018 and September 2019. To evaluate the chemical (oxygen, carbon dioxide, methane, hydrogen sulfide, ammonia and carbon monoxide–MX6 iBrid™ Détector multigas) and microbiological (airborne bacteria and fungi–aspiration method) parameters, eight sampling points were established, located both on the perimeter of the landfill and within its surroundings. CO and CH₄ were not detected in any of the sampling points, during the study period; O₂ was in normal values 20.09–21.05%; CO₂ had a maximum average concentration of 620 ± 215; H₂S had values between 0.1 and 5.0 ppm only in the sampling points inside the landfill; NH₃ was present only once in a single sampling point with values between 1.0 and 3.0 ppm. The microbiological results provide an overview of the total plate count and total fungal count, with no significant differences between the level of contamination inside the landfill and within its surroundings (p > 0.05). Ten bacterial species and fungi from six genera have been identified. It was also found that the number of microorganisms in the air was significantly lower during the winter, spring and early summer months compared with the late summer and autumn months (p < 0.05). Full article

(This article belongs to the Topic Solid Waste Management)

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12 pages, 9299 KiB

Open AccessArticle

Investigating Food Waste Recycling in Local Food Service Businesses: A Case Study from a Local Government Area in Australia

by Ellen Fogarty, Beverley Clarke and Kirstin E. Ross

Sustainability 2021, 13(24), 13846; https://doi.org/10.3390/su132413846 - 15 Dec 2021

Cited by 6 | Viewed by 6328

Abstract

Worldwide, over 1.3 billion tonnes of food goes to waste each year, and much of this is disposed of in landfill, which is costly to the economy and the environment. This study targeted food waste management in local food service businesses as the [...] Read more.

Worldwide, over 1.3 billion tonnes of food goes to waste each year, and much of this is disposed of in landfill, which is costly to the economy and the environment. This study targeted food waste management in local food service businesses as the third largest producer of food waste and a sector that has received less academic attention than other food waste producers (such as household food waste). Questionnaires and interviews were used to investigate current food waste management practices within food service businesses in a Local Government Area in Adelaide, South Australia. Twenty-two respondents completed the online questionnaire and three of these businesses also participated in an interview—two in-person at their business premises and one via an online teleconferencing system. It was found that 54% (n = 12) of these businesses have practices in place to recycle their food waste, while 46% (n = 10) do not. Insufficient kitchen space and the difficulty of separating food waste from non-compostable rubbish were reasons given for not recycling food waste, and the single most important factor that would encourage food waste recycling cited by businesses was the provision of a free, green organics bin. Motivations for recycling food waste included compassion for the environment and the desire to divert waste from landfill. These insights may help local government implement solutions to reduce food waste from entering landfill. Full article

(This article belongs to the Topic Solid Waste Management)

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15 pages, 1272 KiB

Open AccessArticle

Sustainable Solid Waste Management Strategies for Higher Education Institutions: Diponegoro University, Indonesia Case Study

by Mochamad Arief Budihardjo, Natasya Ghinna Humaira, Soraya Annisa Putri, Bimastyaji Surya Ramadan, Syafrudin Syafrudin and Eflita Yohana

Sustainability 2021, 13(23), 13242; https://doi.org/10.3390/su132313242 - 30 Nov 2021

Cited by 9 | Viewed by 6263

Abstract

Effective solid waste management strategies are recognized as efforts to achieve campus sustainability. The university campus is currently considered the center of various activities involving students, lecturers, staff, and other parties contributing to the consumption pattern of energy, water, and other resources. This [...] Read more.

Effective solid waste management strategies are recognized as efforts to achieve campus sustainability. The university campus is currently considered the center of various activities involving students, lecturers, staff, and other parties contributing to the consumption pattern of energy, water, and other resources. This study aims to estimate the quantity and compositions of waste generated on the Universitas Diponegoro (UNDIP) campus, identify the causes of waste generation, evaluate the relationships between variables through statistical analysis, and recommend possible strategies to reduce solid waste generation. The results show that the simultaneous contribution of the student-gender ratio, student awareness level, administrative staff background, and green space amounted to 67.7% of the waste generation at UNDIP. Therefore, these four factors need to be a concern for campus authorities in their efforts to handle campus waste. Student awareness in particular was determined to be the only factor that significantly affects solid waste generation. UNDIP may implement proper environmental education through sustainability courses in each faculty to reduce solid waste in higher education institutions since it has the most significant impact. Outcomes of this study could be used as a reference to develop sustainable campus strategies, recycling plans, and comprehensive waste management in higher education. Full article

(This article belongs to the Topic Solid Waste Management)

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25 pages, 2875 KiB

Open AccessArticle

Experimental Quantification of the Lateral Mixing of Binary Solids in Bubbling Fluidized Beds

by Huanan Li, Jikai Huang, Zhigang Liu, Mingming Lv and Can Ji

Energies 2021, 14(22), 7796; https://doi.org/10.3390/en14227796 - 22 Nov 2021

Cited by 2 | Viewed by 1406

Abstract

A novel experimental method for the lateral mixing of binary solids in bubbling fluidized beds was developed based on the capacitance probe technique. The evolutions of local mixing ratios in a fluidized bed which can be assumed as one mixing cell were analyzed [...] Read more.

A novel experimental method for the lateral mixing of binary solids in bubbling fluidized beds was developed based on the capacitance probe technique. The evolutions of local mixing ratios in a fluidized bed which can be assumed as one mixing cell were analyzed in detail. The solids mixing within one mixing cell was resolved and the effect of convection and diffusion mechanism on lateral mixing was evaluated individually. The results show that at lower part of the fluidized bed, convection plays a more important role in the mixing process near the wall; meanwhile, diffusion is very important for the mixing around the center line. This is opposite with that at the higher part. A lateral micro dispersion coefficient was proposed to characterize the lateral mixing within the mixing cell and the value is generally between 0.005 and 0.025 m/s. A new mixing index was proposed to evaluate the lateral mixing quality of binary solids. It was found that at the lower part of the fluidized bed, the best mixing is acquired at the half radius, whereas mixing at the center line is the worst. At the higher part, solid mixing is better when increasing the distance from the wall. The influences of gas velocity and static bed on the lateral mixing were also discussed from a microscopic perspective. Full article

(This article belongs to the Topic Solid Waste Management)

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13 pages, 303 KiB

Open AccessArticle

Negotiations and Conflict in the Implementation of a Waste Pickers’ Cooperative: A Sociology of Translation Approach

by Priscila Soraia da Conceição Ribeiro, Emília Wanda Rutkowski and Sonaly Rezende

Sustainability 2021, 13(22), 12889; https://doi.org/10.3390/su132212889 - 21 Nov 2021

Cited by 2 | Viewed by 1969

Abstract

The complexity of converting political options into socially, economically, and environmentally acceptable strategies places collectors of recyclable material and the challenges they experience on the agendas of research in science, technology, and society. This article aims to investigate the negotiations and conflicts that [...] Read more.

The complexity of converting political options into socially, economically, and environmentally acceptable strategies places collectors of recyclable material and the challenges they experience on the agendas of research in science, technology, and society. This article aims to investigate the negotiations and conflicts that permeated the implementation of a waste pickers’ cooperative and its integration into the municipal solid waste management system. Considering the complexity of the theme, the methodological approach adopted was grounded theory. This method encourages the expansion of knowledge in an area through the connection of theoretical concepts and significant aspects of the actors’ experiences. The techniques applied for data collection included semi-structured interviews, participant observation, document analysis, and informal interviews. The results are based on narratives analyzed from concepts derived from the Sociology of Translation. It was possible to observe the efforts undertaken by multiple actors, sometimes in the construction and other times in the destabilization of a support network for the establishment of a cooperative. The network suffered dissidents and was destabilized by the habits of the original network and by unexpected events, which made the results achieved opposite to desired ones. In the end, the network was not stabilized, and municipal solid waste management was unchanged. Full article

(This article belongs to the Topic Solid Waste Management)

15 pages, 4848 KiB

Open AccessArticle

Effects of Air Temperature and Humidity on the Kinetics of Sludge Drying at Low Temperatures

by Zhenyu Wang, Lin Xu, Dong Liu, Qing Zhang, Anjie Hu, Ruheng Wang and Yongcan Chen

Energies 2021, 14(22), 7722; https://doi.org/10.3390/en14227722 - 18 Nov 2021

Cited by 8 | Viewed by 2621

Abstract

In this study, a low-air temperature sludge drying system was constructed and the effects of temperature and relative humidity on the characteristics of the system were investigated. The results showed that the drying rate of sludge increased with an increase in air temperature [...] Read more.

In this study, a low-air temperature sludge drying system was constructed and the effects of temperature and relative humidity on the characteristics of the system were investigated. The results showed that the drying rate of sludge increased with an increase in air temperature and a decrease in the air’s relative humidity. The influence of temperature on the average drying rate exhibited an approximate quadratic distribution, while the influence of relative humidity on the average drying rate exhibited an almost linear distribution. The relationship equations of the average drying rate, temperature, and humidity were summarized and compared with the experimental results, and the maximum relative error was 7.6375%. By comparing the experimental results with the commonly used thin-layer drying models, it was found that the sludge drying characteristics were more consistent with the Midilli model. Based on the relevant parameters of the Midilli model, the relationship between the segmented drying moisture content and the average drying rate was proposed, and the empirical formula of the drying rate and MR under different conditions was fitted. Full article

(This article belongs to the Topic Solid Waste Management)

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16 pages, 1867 KiB

Open AccessArticle

Applicability of Membranes in Protective Face Masks and Comparison of Reusable and Disposable Face Masks with Life Cycle Assessment

by Huyen Trang Do Thi, Peter Mizsey and Andras Jozsef Toth

Sustainability 2021, 13(22), 12574; https://doi.org/10.3390/su132212574 - 14 Nov 2021

Cited by 16 | Viewed by 4724

Abstract

In the COVID-19 pandemic period, the role of face masks is critical as a protective physical barrier to prevent droplets and filtrate exhalations coming from infected subjects or against various environmental threats, including the SARS-Cov-2 virus. However, the plastic and microplastic waste from [...] Read more.

In the COVID-19 pandemic period, the role of face masks is critical as a protective physical barrier to prevent droplets and filtrate exhalations coming from infected subjects or against various environmental threats, including the SARS-Cov-2 virus. However, the plastic and microplastic waste from the used face masks pollute the environment, cause a negative impact on human health and the natural ecosystem, as well as increase landfill and medical waste. The presented paper focuses on providing an overview of the application of membrane technology in face mask products as well as the development of protection mechanisms in the future. The authors performed an environmental analysis of reusable (cloth) masks and disposable masks (surgical masks and filtering facepiece respirators) using the Life Cycle Assessment methodology to assess the impacts on the environment, human health, and ecosystem. IMPACT 2002+ V2.14, ReCiPe 2016 Endpoint (H) V1.02, IPCC 2013 GWP 100a V1.03 methods were applied using specialized software (SimaPro V9.1). The disposable masks consistently provide higher protection, though they also carry several multiple environmental burdens. Conversely, reusable masks improve environmental performance, reduce 85% of waste, have a 3.39 times lower impact on climate change, and are 3.7 times cheaper than disposable masks. Full article

(This article belongs to the Topic Solid Waste Management)

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12 pages, 3316 KiB

Open AccessArticle

Numerical Simulation of Combustion and Characteristics of Fly Ash and Slag in a “V-type” Waste Incinerator

by Zixue Luo, Wei Chen, Yue Wang, Qiang Cheng, Xiaohua Yuan, Zhigang Li and Junjie Yang

Energies 2021, 14(22), 7518; https://doi.org/10.3390/en14227518 - 11 Nov 2021

Cited by 10 | Viewed by 2327

Abstract

This study is focused on a “V-type” waste incinerator for municipal solid waste (MSW) combustion. Computational fluid dynamics (CFD) methods are used to study the MSW combustion process. The characteristics of fly ash and slag are analyzed by using a laser particle analyzer, [...] Read more.

This study is focused on a “V-type” waste incinerator for municipal solid waste (MSW) combustion. Computational fluid dynamics (CFD) methods are used to study the MSW combustion process. The characteristics of fly ash and slag are analyzed by using a laser particle analyzer, scanning electron microscope, X-ray fluorescence, and X-ray diffraction. The results show that the error between the CFD simulation data and measured data is less than 10%, and the changing trend of the combustion process is well-modeled. The fly ash mainly has an irregular spherical or ellipsoid structure, whereas the slag mainly has an irregular porous structure. The main constituents of the ash and slag are CaO and SiO₂, along with heavy metal elements such as Cu, Pb, and Cr. Full article

(This article belongs to the Topic Solid Waste Management)

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