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13 pages, 664 KiB

Open AccessArticle

Advanced Treatment of the Municipal Wastewater by Lab-Scale Hybrid Ultrafiltration

by Tijana Marjanović, Minja Bogunović, Slaven Tenodi, Vesna Vasić, Djurdja Kerkez, Jelena Prodanović and Ivana Ivančev-Tumbas

Sustainability 2023, 15(12), 9519; https://doi.org/10.3390/su15129519 - 14 Jun 2023

Cited by 1 | Viewed by 1060

Abstract

In this study, hybrid ultrafiltration which involves adsorption onto activated carbon and/or coagulation was tested for the removal of ibuprofen, caffeine and diclofenac from the municipal wastewater treatment plant effluent (c₀ = 2–3 µg/L). Ultrafiltration was tested in combination with powdered activated [...] Read more.

In this study, hybrid ultrafiltration which involves adsorption onto activated carbon and/or coagulation was tested for the removal of ibuprofen, caffeine and diclofenac from the municipal wastewater treatment plant effluent (c₀ = 2–3 µg/L). Ultrafiltration was tested in combination with powdered activated carbon dose of 5 mg/L separately or with coagulants (FeCl₃, dose 4 mg Fe (III)/L and, natural coagulant isolated from bean seeds, dose 33 µL/L). In addition to the removal of organic micropollutants, the removal of As, Cr, Cu and Zn was also tested (c₀~100 µg/L). The research was conducted on a laboratory pilot plant (capacity 30 L/h, in-out dead-end filtration, flux of 80 L/m²h). The best results were obtained for caffeine when adsorption on PAC is combined with a FeCl₃ (removal efficiency 42–87%). The addition of a natural coagulant did not show benefits for the removal of organic micropollutants compared to the other tested processes, but both coagulants had similar effects on the content of metals and As Hybrid membrane processes proved to be the most efficient for Zn (44–87%) and Cr (33–87%) removal. The lowest efficiency was determined for As (˂19%). Ultrafiltration with PAC and coagulants removed 5–33% of effluent organic matter, depending on the type of coagulant; 57–87% of total nitrogen and PAC/FeCl₃/UF was also partially effective for removing total phosphorus (11–39%). Full article

(This article belongs to the Special Issue Water, Wastewater Treatment, and Sustainable Development)

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13 pages, 3619 KiB

Open AccessArticle

Effectively Recycling Swine Wastewater by Coagulation–Flocculation of Nonionic Polyacrylamide

by Wan-Chen Lee and Chih-Cheng Chang

Sustainability 2022, 14(3), 1742; https://doi.org/10.3390/su14031742 - 2 Feb 2022

Cited by 10 | Viewed by 2799

Abstract

Recycling swine wastewater is an environmental and economic issue for promoting the sustainable development of the pig industry worldwide. The application of a flocculant, non-ionic polyacrylamide (NPAM) for treating the contaminants in wastewater was trialed in this study. Firstly, the optimal pH value [...] Read more.

Recycling swine wastewater is an environmental and economic issue for promoting the sustainable development of the pig industry worldwide. The application of a flocculant, non-ionic polyacrylamide (NPAM) for treating the contaminants in wastewater was trialed in this study. Firstly, the optimal pH value for the coagulation–flocculation of NPAM was adjusted by hydrochloric acid and sodium hydroxide. The viscosity of the flocculant solution was examined by a rotational viscometer and the morphology of the flocculant on the glass surface was examined by an optical microscope and an atomic force microscope. The result showed that a pH value of 11 or more was best for NPAM coagulation–flocculation. Subsequently, the swine wastewater from the anoxic reactor of a three-stage manure treatment system was adjusted by a pH adjuster, calcium hydroxide, followed by the coagulation–flocculation of NPAM. The quality of the final, treated water was examined by a regular wastewater analysis. The results showed that the removal rates for copper ions, zinc ions, NH₄⁺–N, total phosphate (TP), and total nitrogen (TN) were 96.3%, 97.8%, 99.2%, 94.9%, and 99.1%, respectively. Our study concluded that this water recycling method combining the existing organic fertilizer production and power generation enhanced the recycling strategy for swine wastewater treatment and could further the sustainable development of the pig industry. Full article

(This article belongs to the Special Issue Water, Wastewater Treatment, and Sustainable Development)

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14 pages, 3295 KiB

Open AccessArticle

Optimization of Chitosan Surface Response Methodology (Natural and Commercial) Used for Chromium Ion Removal from Wastewater across Different Parameters

by Mai Sheta, Basant Yousry, Ahmed Zattot and Nahla A. Taha

Sustainability 2021, 13(23), 13494; https://doi.org/10.3390/su132313494 - 6 Dec 2021

Cited by 2 | Viewed by 1619

Abstract

Chromium is one of the most significant metals used in the industry. There are many techniques for treating different types of industrial waste water that include chromium ion. In this study, the authors successfully adsorbed the chromium ion from alkaline aqueous solutions using [...] Read more.

Chromium is one of the most significant metals used in the industry. There are many techniques for treating different types of industrial waste water that include chromium ion. In this study, the authors successfully adsorbed the chromium ion from alkaline aqueous solutions using different prepared types of chitosan as adsorbent materials. For the simultaneous sorption behaviour, the adsorption potential of the produced adsorbent was investigated for Cr⁺⁶ in a batch system. Natural chitosan was extracted from shrimp shell as it contains about 8–10% chitin which is used in the production of chitosan. The removal percentage of Cr⁺⁶ reached 99% after grafting natural and commercial chitosan at specific conditions. Several isotherm models have been used for mechanistic studies. The results indicated that the adsorption data for commercial chitosan is well-fitted by the Freundlich isotherm, Langmuir for commercial grafted, natural and natural grafted chitosan. Kinetic and equilibrium studies showed that the experimental data of Cr⁺⁶ were better described by the pseudo-first-order model for commercial chitosan and fitted the pseudo-second-order model for different types of chitosan used. Significantly, in order to scale this effective strategy on an industrial scale, response surface methodology (RSM) was used as a modelling tool to optimise process parameters such as ion concentrations, utilising Statistica Software. Full article

(This article belongs to the Special Issue Water, Wastewater Treatment, and Sustainable Development)

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21 pages, 4058 KiB

Open AccessEditor’s ChoiceArticle

Urban Wastewater Treatment in African Countries: Evidence from the Hydroaid Initiative

by Marco Ravina, Sergio Galletta, Augustin Dagbetin, Omama Ahmed Hussein Kamaleldin, Madalitso Mng’ombe, Lameck Mnyenyembe, Alemayehu Shanko and MariaChiara Zanetti

Sustainability 2021, 13(22), 12828; https://doi.org/10.3390/su132212828 - 19 Nov 2021

Cited by 8 | Viewed by 5277

Abstract

This study is based on the evidence collected during the “Technical e-Learning Course on Wastewater Treatment”, an international training project developed in 2020 in Italy by the Hydroaid Association, in collaboration with Turin Polytechnic. This work intended to address the sustainability of urban [...] Read more.

This study is based on the evidence collected during the “Technical e-Learning Course on Wastewater Treatment”, an international training project developed in 2020 in Italy by the Hydroaid Association, in collaboration with Turin Polytechnic. This work intended to address the sustainability of urban sanitation in various African countries, which the world of international cooperation has been looking at in recent years with growing interest. A comparative analysis of the current strategies and technological solutions was conducted. Data and information reported by the project participants were elaborated and verified. Four African countries—Benin, Egypt, Ethiopia, and Malawi—were considered and two relevant case studies among those proposed by the participants were presented. Starting from this analysis, significant elements about the status and coverage of wastewater management were extracted and reported. The analysis of existing wastewater treatment plants (WWTPs) allowed evaluating their design features and current status of operation. Considerations about the environmental, economic, social, and technical sustainability of wastewater treatment and management were finally reported. Conducting such an analysis provided support in identifying the best practices and the most recurrent problems linked to the various African contexts, which need to be considered for a complete definition of the planning strategy for accessible, efficient, and sustainable sanitation infrastructures. Full article

(This article belongs to the Special Issue Water, Wastewater Treatment, and Sustainable Development)

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11 pages, 1541 KiB

Open AccessArticle

Enhancement of Methanogenic Activity in Volumetrically Undersized Reactor by Mesophilic Co-Digestion of Sewage Sludge and Aqueous Residue

by Vincenzo Torretta, Athanasia K. Tolkou, Ioannis A. Katsoyiannis, Francesca Maria Caccamo, Marco Carnevale Miino, Marco Baldi and Maria Cristina Collivignarelli

Sustainability 2021, 13(14), 7728; https://doi.org/10.3390/su13147728 - 10 Jul 2021

Cited by 4 | Viewed by 2014

Abstract

To date, energy recovery from biological sewage sludge (BSS) by anaerobic digestion has been very popular. However, it can often happen that anaerobic reactors are volumetrically undersized, thus reducing performance in terms of biogas production. A continuous-flow pilot-scale plant was used to investigate, [...] Read more.

To date, energy recovery from biological sewage sludge (BSS) by anaerobic digestion has been very popular. However, it can often happen that anaerobic reactors are volumetrically undersized, thus reducing performance in terms of biogas production. A continuous-flow pilot-scale plant was used to investigate, for the first time, the effects of mesophilic anaerobic co-digestion (MACoD) of sewage sludge and aqueous residue (AR) from a biosolids treatment plant (BTP) on methanogenic activity under low hydraulic retention time (HRT) conditions (to simulate the undersizing of the reactor). The results showed that the digestate is always more rapidly biodegradable than the matrices fed, while particulate COD hydrolyzed (12 ± 1.3%) is independent of the quantity of AR dosed. Feeding over 35% of soluble OLR, the total VFAs in the system strongly decreased, despite the low HRT. In correspondence with higher dosages of AR, the percentage of CH₄ increased up to 77–78% and the CO₂ CH₄⁻¹ ratio decreased to 0.25 ± 0.2. Specific methane production increased from 0.09 ± 0.01 m³_CH4 kgCOD_removed⁻¹ with BSS alone to 0.28 ± 0.01 m³_CH4CH4 kgCOD_removed⁻¹ in the case of BSS co-digested with AR. Moreover, co-digestion with AR from a BTP allowed continuous specific methanogenic activity to be enhanced from 1.76 ± 0.02 m³_CH4 t_VSS⁻¹ d⁻¹ to 6.48 ± 0.88 m³_CH4 t_VSS⁻¹ d⁻¹. Therefore, the MACoD of BSS and AR from a BTP could be a good solution to enhance methanogenic activity in a volumetrically undersized anaerobic digester with reduced HRT. Full article

(This article belongs to the Special Issue Water, Wastewater Treatment, and Sustainable Development)

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Review

Jump to: Research

17 pages, 1588 KiB

Open AccessReview

Removal of Per- and Polyfluoroalkyl Substances by Adsorption on Innovative Adsorbent Materials

by Maria Cristina Collivignarelli, Stefano Bellazzi, Francesca Maria Caccamo, Silvia Calatroni, Chiara Milanese, Marco Baldi, Alessandro Abbà, Sabrina Sorlini and Giorgio Bertanza

Sustainability 2023, 15(17), 13056; https://doi.org/10.3390/su151713056 - 30 Aug 2023

Cited by 1 | Viewed by 1508

Abstract

Per- and polyfluoroalkyl substances (PFAS) constitute a group of organofluorine chemical synthetic compounds widely used in industries and manufacturing due to their hydrophobic properties. However, PFAS have been found to cause negative human health outcomes. Therefore, a strong interest in the possible removal [...] Read more.

Per- and polyfluoroalkyl substances (PFAS) constitute a group of organofluorine chemical synthetic compounds widely used in industries and manufacturing due to their hydrophobic properties. However, PFAS have been found to cause negative human health outcomes. Therefore, a strong interest in the possible removal of these compounds from wastewater (WW) has been shown. This work aims to present a systematic analysis of the scientific literature related to the innovative and alternative adsorbent materials that can be used for treating PFAS-contaminated WW. Moreover, the adsorption processes are considered, focusing the attention on virgin adsorbent materials and biochar as adsorbents. Virgin adsorbent materials comprise conventional adsorbent materials, functional clays, metal–organic frameworks, and functionalized organic polymers. Biochar includes materials obtained from agricultural or food residues and from sewage sludge. The review shows that conventional treatment units using virgin adsorbent materials are characterized by high adsorption capacity, but also high costs. In addition, the refunctionalization of adsorbent materials is difficult to obtain. On the contrary, biochar, which is a residual product of other production processes, appears to be a cost-effective solution. Full article

(This article belongs to the Special Issue Water, Wastewater Treatment, and Sustainable Development)

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25 pages, 3160 KiB

Open AccessReview

Sources of Antibiotic Contamination in Wastewater and Approaches to Their Removal—An Overview

by Antony V. Samrot, Samraj Wilson, Ram Singh Sanjay Preeth, Pandurangan Prakash, Mahendran Sathiyasree, Subramanian Saigeetha, Nagarajan Shobana, Senthilkumar Pachiyappan and Vinod Vincent Rajesh

Sustainability 2023, 15(16), 12639; https://doi.org/10.3390/su151612639 - 21 Aug 2023

Cited by 8 | Viewed by 5379

Abstract

In the practice of medicine, antibiotics are extremely important and are employed in the treatment of infections. A lot of antibiotics are consumed by humans and excreted via urine and feces into sewage systems and treatment plants. These are considered to be non-biodegradable, [...] Read more.

In the practice of medicine, antibiotics are extremely important and are employed in the treatment of infections. A lot of antibiotics are consumed by humans and excreted via urine and feces into sewage systems and treatment plants. These are considered to be non-biodegradable, and over the years they accumulate in the aquatic environment. The presence of antibiotics in water resources causes the emergence of antibiotic-resistant bacteria, posing a serious threat to the health of human beings. Water bodies must be adequately treated before being discharged to prevent the spread of antibiotic resistance. In the present article, the sources of antibiotics and strategies used for their effective removal, such as ultrafiltration, microfiltration, nanofiltration, membranous biological reactor treatment, Advanced Oxidation Process (AOP), Reverse Osmosis (RO) and Nano sorbents, are discussed. Conventional wastewater treatment plants are not able to eliminate antibiotics deposition/resistance genes effectively and efficiently. In this regard, the adsorption method is the most effective way of removing antibiotics from wastewater from various sources. Full article

(This article belongs to the Special Issue Water, Wastewater Treatment, and Sustainable Development)

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19 pages, 896 KiB

Open AccessReview

Fate and Removal of Microplastics from Industrial Wastewaters

by Despina A. Gkika, Athanasia K. Tolkou, Eleni Evgenidou, Dimitrios N. Bikiaris, Dimitra A. Lambropoulou, Athanasios C. Mitropoulos, Ioannis K. Kalavrouziotis and George Z. Kyzas

Sustainability 2023, 15(8), 6969; https://doi.org/10.3390/su15086969 - 21 Apr 2023

Cited by 5 | Viewed by 2486

Abstract

Industrial sites are typically located in close proximity to bodies of water, making industrial wastewater a prevalent source of pollution. Microplastics, which are plastic fragments generated from everyday activities or industrial operations and are smaller than 5 mm in size, can readily find [...] Read more.

Industrial sites are typically located in close proximity to bodies of water, making industrial wastewater a prevalent source of pollution. Microplastics, which are plastic fragments generated from everyday activities or industrial operations and are smaller than 5 mm in size, can readily find their way into wastewater treatment plants (WWTPs). The objective of this research was to offer extensive insight into the fate of microplastics in industrial WWTPs worldwide, as well as to explore the effectiveness of diverse advanced treatment technologies in eliminating microplastics. The prevalence of microplastics and their negative impact on aquatic environments has been acknowledged in recent years. The progressive discharge of plastic waste, insufficient detection processes with specialized elimination methods and a sluggish disposal rate have led to the continuous presence of microplastics in various ecosystems worldwide, such as domestic wastewater and industrial wastewater. Research outcomes have revealed that they can adsorb a variety of pathogens, heavy metals and chemical substances that are commonly used in production processes. Microplastics can be consumed by aquatic life, which might lead them up the food chain to human bodies, resulting in potential digestion tract blockage, digestion disturbance and diminished reproductive growth. Microplastics have thus become a growing threat and cause for concern, demanding the containment of their dispersion. This work offers a critical evaluation of current and developing techniques for microplastic detection and separation from industrial wastewater, which are the most challenging endeavors when treating systems containing microplastics. A review of the effect of microplastics on aquatic environments and human health is also conducted. This analysis offers a comprehensive view of the full microplastic detection and removal strategies and their related concerns in order to establish a waste disposal standard that minimizes the potential hazardous effects of microplastics in aquatic systems. Full article

(This article belongs to the Special Issue Water, Wastewater Treatment, and Sustainable Development)

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