Papers

61,005 results
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Article Tier 2

Microplastics in anaerobic digestion: occurrence, impact, and mitigation strategies

This review examines the presence and impact of microplastics within anaerobic digestion systems used to process sewage sludge and organic waste. Researchers found that microplastics enter these systems through diverse waste inputs and may affect biogas production, microbial community composition, and overall process performance. The study highlights the need for further research into how microplastics interact with anaerobic digestion and what mitigation strategies could minimize their interference.

2024 Journal of Environmental Health Science and Engineering 17 citations
Article Tier 2

Systematic study of microplastics on methane production in anaerobic digestion: Performance and microbial response

Microplastics are increasingly found in wastewater treatment systems, and this study systematically examined how different types, concentrations, and sizes of microplastics affect the anaerobic digestion process used to break down sewage sludge and generate biogas. Polyethylene microplastics were found to inhibit methane production, with finer particles and higher concentrations causing greater disruption to the microbial communities driving digestion. The findings matter because microplastics in sewage sludge can impair the treatment process and also end up spread on agricultural land when sludge is used as fertilizer.

2025 Journal of environmental chemical engineering 1 citations
Article Tier 2

Impact of micro-nanoplastics on biochemical phases of anaerobic digestion in sewage sludge treatment: mechanistic insights and future prospects

Micro- and nanoplastics were found to disrupt the biochemical phases of anaerobic digestion, affecting the efficiency of the biological process used to treat organic waste. Understanding these impacts is important because anaerobic digestion is a common wastewater and sludge treatment method that may both receive and process microplastic-contaminated materials.

2025 International Journal of Theoretical and Applied Research 1 citations
Article Tier 2

Effects of microplastics on substance transformation, sludge characteristics, toxicological effect, and microbial communities in different biochemical sludge systems: A review

This review synthesizes evidence that microplastics impair the biological and physical processes in wastewater treatment sludge systems, inhibiting nutrient removal, disrupting microbial communities, and degrading sludge structure—with smaller particles and higher concentrations causing greater damage. Because sludge is widely applied to agricultural land, any microplastic-driven impairment of treatment efficiency also increases the risk of plastic particles and associated pollutants reaching soils and food crops.

2023 Critical Reviews in Environmental Science and Technology 10 citations
Article Tier 2

The removal of microplastics in the wastewater treatment process and their potential impact on anaerobic digestion due to pollutants association

A review of microplastics in wastewater treatment found that while treatment processes transfer most microplastics from water into sludge, this concentrated plastic material then carries adsorbed pollutants like antibiotics and heavy metals into anaerobic digestion systems. The desorption behavior of these toxic compounds from microplastics under digestion conditions is identified as a key determinant of whether sludge treatment remains effective and safe.

2020 Chemosphere 232 citations
Review Tier 2

Microplastics in Sewage Sludge: A review

This review examines the presence and fate of microplastics in sewage sludge from municipal wastewater treatment plants, a topic that has received less attention than microplastics in the water treatment line. The study highlights that agricultural application of sewage sludge is a primary source of microplastic contamination in soils, and provides a comprehensive overview of detection methods, concentrations, and the environmental implications of sludge-borne microplastics.

2023 Environmental Science and Pollution Research 64 citations
Article Tier 2

Effects of microplastics on the properties of different types of sewage sludge and strategies to overcome the inhibition: A review

This review examined how microplastics trapped in sewage sludge during wastewater treatment affect sludge properties, microbial communities, and treatment efficiency, while discussing strategies to overcome microplastic-induced inhibition of sludge processing.

2023 The Science of The Total Environment 44 citations
Article Tier 2

Revealing the Mechanisms of Polyethylene Microplastics Affecting Anaerobic Digestion of Waste Activated Sludge

Researchers studied how polyethylene microplastics affect the anaerobic digestion of sewage sludge, a common wastewater treatment process. They found that higher concentrations of microplastics significantly reduced methane production by disrupting microbial communities and enzyme activities essential for digestion. The study reveals that microplastic contamination in wastewater systems can undermine the efficiency of sludge treatment and biogas generation.

2019 Environmental Science & Technology 351 citations
Article Tier 2

Effects of mesophilic and thermophilic anaerobic digestion of sewage sludge on different polymers: Perspectives on the potential of the treatment to degrade microplastics

Researchers tested whether mesophilic and thermophilic anaerobic digestion of sewage sludge could degrade common microplastic polymers. While they observed some surface changes and degradation signs in certain plastics, the process could not comprehensively break down any of the eight polymer types tested. The study concludes that anaerobic digestion of sewage sludge, under the conditions tested, is not an effective method for eliminating microplastics before sludge is applied to soil.

2023 The Science of The Total Environment 31 citations
Article Tier 2

Deciphering the inhibition mechanisms of microplastics on the full-stage sludge anaerobic digestion via enrichment to anaerobic microbes and toxicity of released compounds

This study found that microplastics in sewage sludge significantly interfere with the waste treatment process by reducing the activity of key microorganisms needed to break down waste. More than half of the negative effect came from toxic chemicals released when microplastic particles rub against sludge, and the disrupted treatment also increased the risk of spreading antibiotic-resistant bacteria.

2024 Journal of Hazardous Materials 21 citations
Article Tier 2

Contemporary Drift in Emerging Micro(nano)plastics Removal and Upcycling Technologies from Municipal Wastewater Sludge: Strategic Innovations and Prospects

This review evaluates both conventional and advanced methods for removing microplastics from sewage sludge before it is applied to farmland as fertilizer. Current treatment processes like anaerobic digestion and composting reduce but do not eliminate microplastics, and some methods can actually fragment larger plastics into more numerous smaller pieces. The authors identify emerging technologies and upcycling strategies that could better address this pathway of microplastic contamination in agricultural soils.

2023 Current Pollution Reports 36 citations
Article Tier 2

Fate and Impacts of Microplastics in Sludge Anaerobic Digestion: Effects on Methanogenic and Acidogenic Pathways

This review examined how microplastics in sewage sludge influence anaerobic digestion performance, covering effects on methane production, volatile fatty acid accumulation, and microbial community function. MPs inhibited methanogenesis at higher concentrations by altering microbial community structure and disrupting electron transfer pathways in the anaerobic digestion process.

2025 ChemistrySelect
Article Tier 2

The occurrence and fate of microplastics in a mesophilic anaerobic digester receiving sewage sludge, grease, and fatty slurries

Researchers analyzed microplastic loads entering and leaving a mesophilic anaerobic digester at a wastewater treatment plant serving nearly 800,000 people. They found that the digester received approximately 7,326 kg of microplastics per year, with digested sludge containing about 30% less, though this reduction was within the variability of the measurements. The study provides important data on the fate of microplastics during sewage sludge treatment processes.

2021 The Science of The Total Environment 52 citations
Article Tier 2

Microplastic Behavior in Sludge Pretreatment and Anaerobic Digestion: Impacts, Mechanistic Insights, and Mitigation Strategies

This review examines how microplastics behave during sludge pretreatment and anaerobic digestion, finding that microplastics frequently persist through these processes and can affect methane production and microbial communities when present at elevated concentrations, calling for mitigation strategies in wastewater treatment.

2025 Sustainability 2 citations
Article Tier 2

Occurrence, effect, and fate of residual microplastics in anaerobic digestion of waste activated sludge: A state-of-the-art review

This review assessed the occurrence, behavior, and fate of microplastics in anaerobic digestion of waste activated sludge, finding that MPs survive digestion largely intact but can affect methane production and microbial community composition, and that digestate land application remains a major pathway for releasing sludge-retained MPs to soil.

2021 Bioresource Technology 100 citations
Article Tier 2

Fate of microplastics in a centralized biogas plant treating mainly sewage sludge

Researchers tracked the fate of microplastics through a centralized biogas plant treating sewage sludge, examining how anaerobic digestion and subsequent dewatering partition microplastics between solid and liquid digestate fractions. The study informs efforts to develop safer digestate-based recycled fertilizers that minimize microplastic introduction to agricultural soils, where 20-55% of microplastics entering wastewater treatment plants are estimated to end up in sludge.

2025 Journal of Environmental Management
Article Tier 2

Mesophilic anaerobic digestion of mixed sludge in CSTR and AnMBR systems: A perspective on microplastics fate

Researchers compared how two types of anaerobic digesters used in wastewater treatment affect the fate of microplastics in sewage sludge. They found that while digestion reduced some types of microplastics, it also fragmented larger particles into smaller ones, and a membrane bioreactor retained more microplastics than a conventional stirred tank. The study suggests that current wastewater treatment processes may not fully eliminate microplastics and could even create smaller, harder-to-remove particles.

2025 Journal of Environmental Management 11 citations
Article Tier 2

Aging and mitigation of microplastics during sewage sludge treatments: An overview

Researchers reviewed how microplastics change and break down during sewage sludge treatment processes such as composting, anaerobic digestion, and thermal treatment. They found that while some treatment methods can reduce microplastic levels, others may actually fragment particles into smaller, potentially more harmful sizes. The study highlights the importance of optimizing sludge treatment to prevent microplastics from reaching agricultural soils when sludge is applied as fertilizer.

2024 The Science of The Total Environment 24 citations
Review Tier 2

A review on mechanistic understanding of microplastic pollution on the performance of anaerobic digestion

This review examines how microplastic contamination affects anaerobic digestion, a process used to convert organic waste into biogas. Researchers found that microplastics can harm the microbial communities essential to this process through direct contact, leaching of toxic chemicals, and generating harmful reactive oxygen species. The findings raise concerns that microplastic pollution could reduce the efficiency of waste treatment systems and contribute to the spread of antibiotic resistance genes.

2023 Environmental Pollution 41 citations
Article Tier 2

Microplastics in Sewage Sludge: A Known but Underrated Pathway in Wastewater Treatment Plants

This review finds that wastewater treatment plants effectively transfer microplastics from effluent into sewage sludge, creating a significant but underrated pathway for MP contamination when sludge is applied to agricultural soils.

2021 Sustainability 46 citations
Article Tier 2

Overcoming micro/nanoplastics-induced inhibition in anaerobic digestion: Advances in remediation techniques

This review examines how micro- and nanoplastics inhibit anaerobic digestion performance — reducing biogas yield and organic removal — and surveys remediation strategies including physical, chemical, and biological approaches to overcome their disruptive effects in waste treatment systems.

2025 Renewable and Sustainable Energy Reviews
Article Tier 2

Microplastics in sewage sludge: Distribution, toxicity, identification methods, and engineered technologies

This review examines how microplastics accumulate in sewage sludge from wastewater treatment plants, which then becomes a major pathway for spreading these particles into the environment. Researchers found that sludge can contain extremely high concentrations of microplastics, ranging from thousands to hundreds of thousands of particles per kilogram. The study evaluates current detection methods and emerging technologies for removing microplastics from sludge before it is applied to agricultural land or disposed of.

2022 Chemosphere 106 citations
Article Tier 2

Methods to alleviate the inhibition of sludge anaerobic digestion by emerging contaminants: a review

This review examines emerging contaminants in sewage sludge, including pharmaceuticals and microplastics, that inhibit the anaerobic digestion process used in wastewater treatment. Researchers found that pharmaceuticals were detected in about 50% of sludge samples, and that remediation methods such as ozonation, electrooxidation, and bioaugmentation can help alleviate inhibition, though liquid digestates still contain concerning pollutant levels.

2022 Environmental Chemistry Letters 53 citations
Article Tier 2

Fate of microplastics in sewage sludge and in agricultural soils

Researchers reviewed how microplastics accumulate in sewage sludge at wastewater treatment plants and then spread into agricultural soils when that sludge is applied as fertilizer, finding that sludge treatment processes can alter microplastic size and shape but do not eliminate them. The review calls for standardized methods to study how different sludge treatments affect microplastic properties and their downstream risks to soil health.

2023 TrAC Trends in Analytical Chemistry 52 citations