Editorial

3 pages, 173 KiB

Open AccessEditorial

Special Issue: Valorization of Material Waste for Environmental, Energetic, and Biomedical Applications

by Antonio Gil

Eng 2022, 3(1), 24-26; https://doi.org/10.3390/eng3010003 - 29 Dec 2021

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Waste management and its recovery to provide it with added value are increasingly important lines of research that fall within the concept of a Circular Economy [...] Full article

(This article belongs to the Special Issue Valorization of Material Wastes for Environmental, Energetic and Biomedical Applications)

Research

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19 pages, 3692 KiB

Open AccessArticle

Selective Recovery of Copper from a Synthetic Metalliferous Waste Stream Using the Thiourea-Functionalized Ion Exchange Resin Puromet MTS9140

by Alex L. Riley, Christopher P. Porter and Mark D. Ogden

Eng 2021, 2(4), 512-530; https://doi.org/10.3390/eng2040033 - 05 Nov 2021

Cited by 7 | Viewed by 2972

Abstract

The extraction of Cu from mixed-metal acidic solutions by the thiourea-functionalized resin Puromet MTS9140 was studied. Despite being originally manufactured for precious metal recovery, a high selectivity towards Cu was observed over other first-row transition metals (>90% removal), highlighting a potential for this [...] Read more.

The extraction of Cu from mixed-metal acidic solutions by the thiourea-functionalized resin Puromet MTS9140 was studied. Despite being originally manufactured for precious metal recovery, a high selectivity towards Cu was observed over other first-row transition metals (>90% removal), highlighting a potential for this resin in base metal recovery circuits. Resin behaviour was characterised in batch-mode under a range of pH and sulphate concentrations and as a function of flow rate in a fixed-bed setup. In each instance, a high selectivity and capacity (max. 32.04 mg/g) towards Cu was observed and was unaffected by changes in solution chemistry. The mechanism of extraction was determined by XPS to be through reduction of Cu(II) to Cu(I) rather than chelation. Elution of Cu was achieved by the use of 0.5 M–1 M NaClO₃. Despite effective Cu elution (82%), degradation of resin functionality was observed, and further detailed through the application of IC analysis to identify degradation by-products. This work is the first detailed study of a thiourea-functionalized resin being used to selectively target Cu from a complex multi-metal solution. Full article

(This article belongs to the Special Issue Valorization of Material Wastes for Environmental, Energetic and Biomedical Applications)

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13 pages, 1806 KiB

Open AccessArticle

Adsorption of Estradiol by Natural Clays and Daphnia magna as Biological Filter in an Aqueous Mixture with Emerging Contaminants

by Andrés Pérez-González, Verónica Pinos-Vélez, Isabel Cipriani-Avila, Mariana Capparelli, Eliza Jara-Negrete, Andrés Alvarado, Juan Fernando Cisneros and Piercosimo Tripaldi

Eng 2021, 2(3), 312-324; https://doi.org/10.3390/eng2030020 - 26 Jul 2021

Cited by 9 | Viewed by 3179

Abstract

Among emerging pollutants, endocrine disruptors such as estradiol are of most concern. Conventional water treatment technologies are not capable of removing this compound from water. This study aims to assess a method that combines physicochemical and biological strategies to eliminate estradiol even when [...] Read more.

Among emerging pollutants, endocrine disruptors such as estradiol are of most concern. Conventional water treatment technologies are not capable of removing this compound from water. This study aims to assess a method that combines physicochemical and biological strategies to eliminate estradiol even when there are other compounds present in the water matrix. Na-montmorillonite, Ca-montmorillonite and zeolite were used to remove estradiol in a medium with sulfamethoxazole, triclosan, and nicotine using a Plackett–Burman experimental design; each treatment was followed by biological filtration with Daphnia magna. Results showed between 40 to 92% estradiol adsorption in clays; no other compounds present in the mixture were adsorbed. The most significant factors for estradiol adsorption were the presence of nicotine and triclosan which favored the adsorption, the use of Ca-montmorillonite, Zeolite, and time did not favor the adsorption of estradiol. After the physicochemical treatment, Daphnia magna was able to remove between 0–93% of the remaining estradiol. The combination of adsorption and biological filtration in optimal conditions allowed the removal of 98% of the initial estradiol concentration. Full article

(This article belongs to the Special Issue Valorization of Material Wastes for Environmental, Energetic and Biomedical Applications)

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11 pages, 3227 KiB

Open AccessArticle

Accounting Greenhouse Gas Emissions from Municipal Solid Waste Treatment by Composting: A Case of Study Bolivia

by Magaly Beltran-Siñani and Antonio Gil

Eng 2021, 2(3), 267-277; https://doi.org/10.3390/eng2030017 - 30 Jun 2021

Cited by 3 | Viewed by 2671

Abstract

Waste generation is one of the multiple factors affecting the environment and human health that increases directly with growing population and social and economic development. Nowadays, municipal solid waste disposal sites and their management create climate challenges worldwide, with one of the main [...] Read more.

Waste generation is one of the multiple factors affecting the environment and human health that increases directly with growing population and social and economic development. Nowadays, municipal solid waste disposal sites and their management create climate challenges worldwide, with one of the main problems being high biowaste content that has direct repercussions on greenhouse gases (GHG) emissions. In Bolivia, as in the most developing countries, dumps are the main disposal sites for solid waste. These places usually are non-engineered and poorly implemented due to social, technical, institutional and financial limitations. Composting plants for treatment of biowaste appear as an alternative solution to the problem. Some Bolivian municipalities have implemented pilot projects with successful social results; however, access to the economic and financial resources for this alternative are limited. In order to encourage the composting practice in the other Bolivian municipalities it is necessary to account for the GHG emissions. The aim of the present study compiles and summarizes the Intergovernmental Panel on Climate Change (IPCC) guidelines methodology and some experimental procedures for accounting of the greenhouse gases emissions during the biowaste composting process as an alternative to its deposition in a dump or landfill. The GHG emissions estimation results by open windrow composting process determined in the present study show two scenarios: 38% of reduction when 50% of the biowaste collected in 2019 was composted; and 12% of reduction when 20% of the biowaste was composted. Full article

(This article belongs to the Special Issue Valorization of Material Wastes for Environmental, Energetic and Biomedical Applications)

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18 pages, 6015 KiB

Open AccessArticle

Elevated LNG Vapour Dispersion—Effects of Topography, Obstruction and Phase Change

by Felicia Tan, Vincent H. Y. Tam and Chris Savvides

Eng 2021, 2(2), 249-266; https://doi.org/10.3390/eng2020016 - 15 Jun 2021

Cited by 1 | Viewed by 2613

Abstract

The dispersion of vapour of liquefied natural gas (LNG) is generally assumed to be from a liquid spill on the ground in hazard and risk analysis. However, this cold vapour could be discharged at height through cold venting. While there is similarity to [...] Read more.

The dispersion of vapour of liquefied natural gas (LNG) is generally assumed to be from a liquid spill on the ground in hazard and risk analysis. However, this cold vapour could be discharged at height through cold venting. While there is similarity to the situation where a heavier-than-air gas, e.g., CO₂, is discharged through tall vent stacks, LNG vapour is cold and induces phase change of ambient moisture leading to changes in the thermodynamics as the vapour disperses. A recent unplanned cold venting of LNG vapour event due to failure of a pilot, provided valuable data for further analysis. This event was studied using CFD under steady-state conditions and incorporating the effect of thermodynamics due to phase change of atmospheric moisture. As the vast majority of processing plants do not reside on flat planes, the effect of surrounding topography was also investigated. This case study highlighted that integral dispersion model was not applicable as key assumptions used to derive the models were violated and suggested guidance and methodologies appropriate for modelling cold vent and flame out situations for elevated vents. Full article

(This article belongs to the Special Issue Valorization of Material Wastes for Environmental, Energetic and Biomedical Applications)

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16 pages, 4812 KiB

Open AccessArticle

Influence of the Precoat Layer on the Filtration Properties and Regeneration Quality of Backwashing Filters

by Volker Bächle, Patrick Morsch, Marco Gleiß and Hermann Nirschl

Eng 2021, 2(2), 181-196; https://doi.org/10.3390/eng2020012 - 21 May 2021

Cited by 4 | Viewed by 3665

Abstract

For solid–liquid separation, filter meshes are still used across large areas today, as they offer a cost-effective alternative, for example, compared to membranes. However, particle interaction leads to a continuous blocking of the pores, which lowers the flow rate of the mesh and [...] Read more.

For solid–liquid separation, filter meshes are still used across large areas today, as they offer a cost-effective alternative, for example, compared to membranes. However, particle interaction leads to a continuous blocking of the pores, which lowers the flow rate of the mesh and reduces its lifetime. This can be remedied by filter aids. In precoat filtration, these provide an already fully formed filter cake on the fabric, which acts as a surface and depth filter. This prevents interaction of the particles to be separated with the mesh and thus increases the service life of the mesh. In this work, the influence of a precoat layer with different fibre lengths of cellulose on the filtration behavior is investigated. A satin with a pore size of 11 µm is used as the filter medium. The effects of the precoat layer on the filter media resistance, the filter cake resistance, the turbidity impact, and the regenerability of the fabrics are investigated. This study shows an overview of the suitability of various cellulose fibres based on different aspects as filter aids for particles in ultrafine filtration. Full article

(This article belongs to the Special Issue Valorization of Material Wastes for Environmental, Energetic and Biomedical Applications)

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25 pages, 3805 KiB

Open AccessArticle

A Critical Review of the Equivalent Stoichiometric Cloud Model Q9 in Gas Explosion Modelling

by Vincent H. Y. Tam, Felicia Tan and Chris Savvides

Eng 2021, 2(2), 156-180; https://doi.org/10.3390/eng2020011 - 16 Apr 2021

Cited by 4 | Viewed by 5363

Abstract

Q9 is widely used in industries handling flammable fluids and is central to explosion risk assessment (ERA). Q9 transforms complex flammable clouds from pressurised releases to simple cuboids with uniform stoichiometric concentration, drastically reducing the time and resources needed by ERAs. Q9 is [...] Read more.

Q9 is widely used in industries handling flammable fluids and is central to explosion risk assessment (ERA). Q9 transforms complex flammable clouds from pressurised releases to simple cuboids with uniform stoichiometric concentration, drastically reducing the time and resources needed by ERAs. Q9 is commonly believed in the industry to be conservative but two studies on Q9 gave conflicting conclusions. This efficacy issue is important as impacts of Q9 have real life consequences, such as inadequate engineering design and risk management, risk underestimation, etc. This paper reviews published data and described additional assessment on Q9 using the large-scale experimental dataset from Blast and Fire for Topside Structure joint industry (BFTSS) Phase 3B project which was designed to address this type of scenario. The results in this paper showed that Q9 systematically underpredicts this dataset. Following recognised model evaluation protocol would have avoided confusion and misinterpretation in previous studies. It is recommended that the modelling concept of Equivalent Stoichiometric Cloud behind Q9 should be put on a sound scientific footing. Meanwhile, Q9 should be used with caution; users should take full account of its bias and variance. Full article

(This article belongs to the Special Issue Valorization of Material Wastes for Environmental, Energetic and Biomedical Applications)

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15 pages, 1868 KiB

Open AccessArticle

Kinetic Modelling of Biodegradability Data of Commercial Polymers Obtained under Aerobic Composting Conditions

by Ilenia Rossetti, Francesco Conte and Gianguido Ramis

Eng 2021, 2(1), 54-68; https://doi.org/10.3390/eng2010005 - 20 Feb 2021

Cited by 16 | Viewed by 3092

Abstract

Methods to treat kinetic data for the biodegradation of different plastic materials are comparatively discussed. Different samples of commercial formulates were tested for aerobic biodegradation in compost, following the standard ISO14855. Starting from the raw data, the conversion vs. time entries were elaborated [...] Read more.

Methods to treat kinetic data for the biodegradation of different plastic materials are comparatively discussed. Different samples of commercial formulates were tested for aerobic biodegradation in compost, following the standard ISO14855. Starting from the raw data, the conversion vs. time entries were elaborated using relatively simple kinetic models, such as integrated kinetic equations of zero, first and second order, through the Wilkinson model, or using a Michaelis Menten approach, which was previously reported in the literature. The results were validated against the experimental data and allowed for computation of the time for half degradation of the substrate and, by extrapolation, estimation of the final biodegradation time for all the materials tested. In particular, the Michaelis Menten approach fails in describing all the reported kinetics as well the zeroth- and second-order kinetics. The biodegradation pattern of one sample was described in detail through a simple first-order kinetics. By contrast, other substrates followed a more complex pathway, with rapid partial degradation, subsequently slowing. Therefore, a more conservative kinetic interpolation was needed. The different possible patterns are discussed, with a guide to the application of the most suitable kinetic model. Full article

(This article belongs to the Special Issue Valorization of Material Wastes for Environmental, Energetic and Biomedical Applications)

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29 pages, 3362 KiB

Open AccessArticle

Integrating LCA with Process Modeling for the Energetic and Environmental Assessment of a CHP Biomass Gasification Plant: A Case Study in Thessaly, Greece

by Ioannis Voultsos, Dimitrios Katsourinis, Dimitrios Giannopoulos and Maria Founti

Eng 2020, 1(1), 2-30; https://doi.org/10.3390/eng1010002 - 21 Sep 2020

Cited by 7 | Viewed by 3119

Abstract

The energetic and environmental performance of a cogeneration biomass gasification plant, situated in Thessaly, Greece is evaluated via a methodology combining process simulation and Life Cycle Assessment (LCA). Initially, the gasification process of the most common agricultural residues found in the Thessaly region [...] Read more.

The energetic and environmental performance of a cogeneration biomass gasification plant, situated in Thessaly, Greece is evaluated via a methodology combining process simulation and Life Cycle Assessment (LCA). Initially, the gasification process of the most common agricultural residues found in the Thessaly region is simulated to establish the effect of technical parameters such as gasification temperature, equivalence ratio and raw biomass moisture content. It is shown that a maximum gasification efficiency of approximately 70% can be reached for all feedstock types. Lower efficiency values are associated with increased raw biomass moisture content. Next, the gasifier model is up-scaled, achieving the operation of a 1 MW_el and 2.25 MW_th cogeneration plant. The Life Cycle Assessment of the operation of the cogeneration unit is conducted using as input the performance data from the process simulation. Global Warming Potential and the Cumulative Demand of Non-Renewable Fossil Energy results suggest that the component which had the major share in both impact categories is the self-consumption of electricity of the plant. Finally, the key conclusion of the present study is the quantification of carbon dioxide mitigation and non-renewable energy savings by comparing the biomass cogeneration unit operation with conventional reference cases. Full article

(This article belongs to the Special Issue Valorization of Material Wastes for Environmental, Energetic and Biomedical Applications)

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