Papers

61,005 results
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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

Microplastic removal and management strategies for wastewater treatment plants

This review examines how well different wastewater treatment technologies remove microplastics and what management strategies can improve performance. While conventional treatment plants can remove a large percentage of microplastics from water, the particles often end up concentrated in sewage sludge that gets applied to farmland. The study highlights the need for advanced treatment options and better management of biosolids to prevent microplastics from simply being transferred from water to soil.

2023 Chemosphere 133 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

Removal of Microplastic Pollution through Waste Water Treatment: A Review

This review examines how wastewater treatment plants reduce microplastic contamination, comparing biological and advanced treatment methods and highlighting that residual microplastics in sewage sludge applied to agricultural land remain a significant pathway for environmental release.

2022 Journal for Research in Applied Sciences and Biotechnology 7 citations
Article Tier 2

Variation in microplastic concentration, characteristics and distribution in sewage sludge & biosolids around the world

This review synthesizes global data on microplastic concentrations, characteristics, and distribution in sewage sludge and biosolids, drawing on studies showing wastewater treatment works remove 57-99% of incoming microplastics, concentrating them in sludge byproducts. The review highlights the significance of this concentration pathway and what happens to these microplastics when sludge is applied to land or otherwise managed.

2025 Figshare
Article Tier 2

Fate of Microplastic Pollution Along the Water and Sludge Lines in Municipal Wastewater Treatment Plants

Researchers evaluated microplastic abundance and distribution across three municipal wastewater treatment plants using different treatment technologies. The study found that all three plants achieved greater than 97% microplastic removal along the water treatment line, with microplastics concentrating in the sludge fraction, underscoring the important role of sludge treatment in sequestering microplastics from wastewater.

2025 Microplastics 6 citations
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

Variation in microplastic concentration, characteristics and distribution in sewage sludge & biosolids around the world

Researchers systematically reviewed 65 studies on microplastics in sewage sludge and biosolids from wastewater treatment plants around the world. They found that while treatment processes remove 57% to 99% of microplastics from wastewater, the removed particles concentrate in sludge that is often applied to agricultural land. The review highlights that land application of biosolids may be a significant, underappreciated pathway for microplastic pollution in soils.

2023 The Science of The Total Environment 95 citations
Article Tier 2

A review of the removal of microplastics in global wastewater treatment plants: Characteristics and mechanisms

This review analyzed data from 38 wastewater treatment plants across 11 countries to understand how effectively they remove microplastics. While treatment plants can remove the majority of microplastics from wastewater, significant quantities still pass through into waterways, and the microplastics captured in sewage sludge may re-enter the environment when that sludge is applied to farmland.

2020 Environment International 589 citations
Article Tier 2

Characterization and removal of microplastics in a sewage treatment plant from urban Nagpur, India

Researchers detected microplastics in all stages of a sewage treatment plant in Nagpur, India, finding that the treatment process reduced but did not eliminate microplastics from effluent. Sludge accumulated high concentrations of microplastics, raising concerns about land application of treated sludge.

2022 Environmental Monitoring and Assessment 41 citations
Review Tier 2

The Effect of Wastewater Treatment Plants on Retainment of Plastic Microparticles to Enhance Water Quality—A Review

This review examined how well wastewater treatment plants remove microplastics, finding that most conventional systems achieve high removal rates but still discharge significant plastic quantities in treated effluent and sludge. Improving treatment efficiency and preventing sludge application to farmland are key strategies for reducing microplastic release.

2021 Journal of Environmental Protection 12 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

Microplastics removal through water treatment plants: Its feasibility, efficiency, future prospects and enhancement by proper waste management

Researchers reviewed over 80 studies on water treatment plant performance and found microplastic removal ranges widely — from 16% in basic primary treatment up to near 100% with advanced membrane systems — but a major flaw is that removed microplastics concentrate in sludge, which can re-enter the environment. The review recommends optimizing coagulants and sludge treatment to prevent microplastics from simply being relocated rather than eliminated.

2021 Environmental Challenges 181 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
Article Tier 2

Fate of microplastics during conventional and hydrothermal treatments of sewage sludge: a short review

This review examines the fate of microplastics during conventional and hydrothermal treatment of sewage sludge, noting that approximately 90% of microplastics entering wastewater treatment plants are retained in sludge. Researchers found that while conventional disposal routes concentrate microplastics in sludge destined for land application, hydrothermal treatments offer potential pathways to degrade or transform microplastics, though the efficiency and byproducts of these processes require further investigation.

2025 IOP Conference Series Earth and Environmental Science
Review Tier 2

Microplastics removal in wastewater treatment plants: A review of the different approaches to limit their release in the environment

This review examines how wastewater treatment plants handle microplastics, finding that while some plants remove up to 99% of microplastics from water, they concentrate the removed plastics in sewage sludge. When that sludge is spread on farmland as fertilizer, over 65% of the captured microplastics can re-enter the environment and potentially contaminate crops and groundwater. The authors argue that treatment plants should be reimagined as key barriers against microplastic pollution, with targeted technologies added at strategic points in the treatment process.

2024 The Science of The Total Environment 58 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
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

Combined application of analytical techniques for microplastic determination to achieve comprehensive results for sewage sludge samples

Researchers combined multiple analytical techniques for comprehensive microplastic determination in sewage sludge samples, addressing the challenge that more than 90% of microplastics entering wastewater treatment plants are retained in sludge and require robust multi-method characterization.

2024 Zenodo (CERN European Organization for Nuclear Research)
Article Tier 2

Approaching the environmental problem of microplastics: Importance of WWTP treatments

This review examines the role of wastewater treatment plants as sources and sinks of microplastics, noting that while treatment removes significant quantities, remaining particles concentrate in sewage sludge which is then applied to agricultural land as fertilizer. The authors survey available technologies for improving microplastic removal and call for better policy to address this gap.

2020 The Science of The Total Environment 262 citations
Article Tier 2

Seasonal Variation, Distribution and Characteristics of Microplastic in Sewage Sludge

Researchers investigated seasonal variation in microplastic concentration, distribution, and characteristics within sewage sludge at wastewater treatment plants, examining how precipitation patterns and sludge treatment processes influence microplastic retention and the pathways by which sludge-borne microplastics enter agricultural soils upon land application.

2022 Zenodo (CERN European Organization for Nuclear Research)
Article Tier 2

Abundance of Microplastics in Wastewater Treatment Sludge

This review found that wastewater treatment plants trap a substantial proportion of incoming microplastics into sludge, with abundance varying widely by region based on population density, urbanization, and treatment technology, raising concerns about the land application of microplastic-laden biosolids.

2022 Journal of Human Earth and Future 39 citations
Article Tier 2

Sewage sludge as a source of microplastics in the environment: A review of occurrence and fate during sludge treatment

This review assessed how wastewater treatment plants concentrate microplastics from influent into sludge, estimating that sewage sludge applied to agricultural land represents a major secondary pathway for MPs entering terrestrial ecosystems, with estimated releases of millions to billions of particles per hectare.

2021 Journal of Environmental Management 139 citations
Article Tier 2

Microplastics and Wastewater Treatment Plants—A Review

This review examines the role of wastewater treatment plants in retaining microplastics before they enter the environment. Studies show that no wastewater treatment method achieves complete microplastic removal, making treatment plants themselves point sources of microplastic discharge into aquatic environments. The review also discusses concerns about microplastic-laden sewage sludge being applied to agricultural land.

2020 Journal of Water Resource and Protection 161 citations