Papers

61,005 results
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Article Tier 2

Microplastics in Wastewater Sludges : Extraction, Occurrence and Implications for the Circular Economy

This thesis examines microplastic extraction methods, occurrence levels, and circular economy implications for wastewater treatment sludges, including both municipal sewage sludge and industrial sludges from pulp and paper processing.

2025 Trepo - Institutional Repository of Tampere University
Article Tier 2

The fate of microplastic in sludge management systems

This review assessed the fate of microplastics in sewage sludge management systems, finding that standard stabilization processes including anaerobic digestion and composting do not substantially reduce MP concentrations. Land application of MP-rich sludge was identified as a major pathway for plastic particles entering agricultural soils, with the review calling for alternative sludge disposal strategies aligned with circular economy principles.

2022 The Science of The Total Environment 62 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 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
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

Microplastics removal from a primary settler tank in a wastewater treatment plant and estimations of contamination onto European agricultural land via sewage sludge recycling

Researchers found that primary settling in wastewater treatment removes significant microplastics from sewage, but these particles concentrate in sludge that is often recycled onto agricultural land, creating a pathway back into the environment.

2022 Environmental Pollution 99 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 pollution from wastewater treatment plants: A critical review on challenges, detection, sustainable removal techniques and circular economy

This review critically examines the challenges of detecting and removing microplastics from wastewater treatment plants, evaluating sustainable removal technologies and circular economy approaches to address this persistent source of aquatic microplastic pollution.

2022 Environmental Technology & Innovation 134 citations
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

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

A method for the characterisation of microplastics in sludge

Researchers developed a method for detecting and characterizing microplastics in sewage sludge, which concentrates the majority of microplastics removed during wastewater treatment. This method is important because sludge is widely spread on agricultural land, making it a key pathway for microplastics entering soils.

2019 MethodsX 23 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

[Microplastics in wastewater treatment: current status and future trends].

This review summarizes current research on microplastic occurrence, removal, and fate in wastewater treatment plants, noting that while plants capture most microplastics in activated sludge, significant numbers still escape into effluent. The sludge itself then becomes a major pathway for microplastics to enter agricultural soils when applied as fertilizer. Future treatment improvements and sludge management policies are needed to reduce these release pathways.

2022 PubMed 4 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

Assessment and accumulation of microplastics in sewage sludge at wastewater treatment plants located in Cádiz, Spain

Researchers sampled microplastics from primary, secondary, and digested sludge at seven wastewater treatment plants in southern Spain, finding sludge acts as a significant sink for microplastics. Fragments and fibers under 2 mm were dominant, and concentrations varied significantly between urban and industrial plant types.

2022 Environmental Pollution 57 citations
Review Tier 2

A global review of microplastics in wastewater treatment plants: Understanding their occurrence, fate and impact

A global review of 121 wastewater treatment plants found that microplastics are consistently present in both influent and effluent, with WWTPs acting as major conduits delivering plastics into aquatic and terrestrial ecosystems. While removal efficiencies varied widely, the sludge produced by these plants represents a concentrated secondary pathway for microplastic release to land.

2022 Environmental Research 76 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

Microplastic contamination in sewage sludge: Abundance, characteristics, and impacts on the environment and human health

This review focuses on microplastics found in sewage sludge, which is often spread on agricultural land as fertilizer. The practice introduces microplastics directly into farm soil, where they can be taken up by crops or leach into groundwater. This creates a pathway for microplastics to reach human food and drinking water, raising concerns about the safety of using sewage sludge in agriculture.

2023 Environmental Technology & Innovation 98 citations
Article Tier 2

Microplastics in sewage sludge: Captured but released?

This book chapter reviews how wastewater treatment plants capture microplastics from sewage but then release them back into the environment through the application of sewage sludge to agricultural land. Treating sewage sludge as a microplastic disposal route transfers the pollution problem from water to soil.

2019 IWA Publishing eBooks 9 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

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

Circulation of microplastics in a municipal wastewater treatment plant with multiphase activated sludge

Researchers tracked the circulation of microplastics through a municipal wastewater treatment plant, from raw wastewater through sludge processing. They found that most microplastics accumulated in sewage sludge at high concentrations, and that leachate from sludge treatment recycled microplastics back into the treatment process. The study highlights how wastewater treatment plants can inadvertently redistribute microplastics rather than fully removing them from the waste stream.

2024 Desalination and Water Treatment 10 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

Identification and quantification of microplastics in wastewater treatment plant effluent: Investigation of the fate and biological effects

This study identified and quantified microplastics in wastewater treatment plant effluents and sludge, finding particles in all samples with fibers being the dominant type. The research contributes to understanding how much microplastic reaches surface waters via wastewater discharge and how much is captured in sludge that is subsequently applied to agricultural land.

2018 Griffith Research Online (Griffith University, Queensland, Australia) 4 citations