Papers

61,005 results
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Article Tier 2

Microplastic Pollution in Sewage Sludge from Wastewater Treatment Plants and Estimation of Microplastic Release

Researchers analyzed microplastic contamination in sewage sludge from wastewater treatment plants using infrared spectroscopy and estimated the quantities released into the environment when sludge is used for soil improvement. They found significant microplastic concentrations in the sludge samples, with the majority being fiber-shaped particles. The study highlights that the growing practice of applying sewage sludge to agricultural land is a meaningful pathway for microplastic transfer to soil environments.

2025 Water 5 citations
Article Tier 2

Nylon 6 and nylon 6,6 micro- and nanoplastics: A first example of their accurate quantification, along with polyester (PET), in wastewater treatment plant sludges

Researchers developed a novel quantification procedure for nylon 6 and nylon 6,6 polyamide microplastics along with PET in wastewater treatment plant sludges, representing the first accurate measurement of these dominant synthetic textile microfibre polymers in sludge matrices. The procedure uses acid hydrolysis depolymerisation followed by monomer derivatisation, providing a tool to assess risks from sludge applied as agricultural soil amendment.

2020 Journal of Hazardous Materials 67 citations
Article Tier 2

Sewage Sludge in Farmlands: A Gateway to Soil Microplastic Pollution?

Researchers analysed microplastic contamination in dewatered anaerobically digested sewage sludge and adjacent agricultural fields in the UK with varied sludge application histories, using fluorescence microscopy and FTIR/Raman spectroscopy to detect predominantly polyethylene, polyester, polypropylene, polystyrene, PVC, and polyamide particles.

2024
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
Article Tier 2

Microplastic in Danish wastewater: Sources, occurrences and fate

Researchers evaluated the role of Danish wastewater treatment plants in microplastic emissions by analyzing samples from 10 WWTPs, associated sludge, and farmland soils using FTIR imaging, identifying the amounts, polymer types, and potential sources of microplastics entering the environment.

2017 90 citations
Article Tier 2

Assessment of Microplastics Distribution in a Biological Wastewater Treatment

Researchers evaluated microfiber distribution in a lab-scale sequencing batch reactor fed synthetic wastewater over 93 days, using optical microscopy and FTIR spectroscopy to distinguish natural from synthetic fibers. They found that microfibers predominantly settled with the sludge at a concentration ratio of 1409:1 compared to effluent, and that larger surface area within the reactor was associated with higher microfiber retention.

2022 Microplastics 18 citations
Article Tier 2

Tracing the fate of microplastic in wastewater treatment plant: A multi-stage analysis of treatment units and sludge

Researchers tracked microplastics through every stage of a wastewater treatment plant and found that while treatment removes many particles from the water, most end up concentrated in the leftover sludge. Fibers and fragments were the most common shapes, made primarily of polyester and polyethylene. Since treated sludge is often spread on farmland, this creates a pathway for microplastics to enter soil and potentially the food chain.

2023 Environmental Pollution 60 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
Article Tier 2

Sewage sludge application as a vehicle for microplastics in eastern Spanish agricultural soils

Scientists measured microplastics in sewage sludge from Spanish wastewater treatment plants and in agricultural soils receiving sludge applications, finding that sludge application transferred hundreds to thousands of microplastic particles per kilogram into agricultural soil.

2020 Environmental Pollution 608 citations
Article Tier 2

Microplastics in sewage sludge from the wastewater treatment plants in China

Researchers analyzed microplastics in sewage sludge from wastewater treatment plants across China, finding high concentrations of microplastics — predominantly fibers and fragments — raising concerns about their spread when sludge is applied to agricultural land.

2018 Water Research 1001 citations
Article Tier 2

Hidden contaminants: Unveiling the content of microplastics in municipal sewage sludge that may affect soil ecosystems

Researchers analyzed sewage sludge from two municipal treatment plants and found up to 116,000 microplastic particles per kilogram of dry sludge, with fiber-shaped and film-shaped particles dominating each plant respectively — highlighting the risk of spreading microplastic contamination to farmland when sludge is used as fertilizer.

2025 Desalination and Water Treatment 5 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

Microplastics in the effluent of a German wastewater treatment plant ‒ analysis with μ-FTIR spectroscopy

A German wastewater treatment plant was found to release microplastics in its treated effluent, with fibers as the dominant type. The study used detailed chemical characterization and identified wastewater plants as ongoing point sources of microplastic pollution entering aquatic environments.

2020 Helmholtz-Zentrum für Polar-und Meeresforschung (Alfred-Wegener-Institut)
Article Tier 2

Fate of microplastics in wastewater treatment plants and their environmental dispersion with effluent and sludge

Researchers tracked microplastics through a wastewater treatment plant and found 12 different polymer types in effluents and sludge, with smaller particles (25–104 μm) most abundant and fibres displaying lower sizes than fragments. The study demonstrates that WWTPs do not fully remove microplastics and that processed sludge marketed as soil amendment carries plastic contamination.

2019 Environmental Pollution 589 citations
Article Tier 2

A comparative study on the distribution behavior of microplastics through FT-IR analysis on different land uses in agricultural soils

Researchers compared microplastic distribution in agricultural soils under different land uses, including soil mulching, plastic housing, and sewage sludge composting. Using FT-IR analysis, the study found that plastic particles smaller than 100 micrometers were present across all conditions, highlighting the widespread and persistent nature of microplastic contamination in agricultural environments.

2022 Environmental Research 50 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

Investigation and fate of microplastics in wastewater and sludge filter cake from a wastewater treatment plant in China

A wastewater treatment plant in Harbin, China, removed about 76% of incoming microplastics, but the remainder accumulated in dewatered sludge used as agricultural fertilizer, representing billions of plastic particles returned to soils annually. Polyester and polyamide from laundry and personal care products were identified as the dominant polymer types.

2020 The Science of The Total Environment 206 citations
Article Tier 2

Stabilized Sewage Sludge as Fertilizer: Risks Related to the Presence of Microplastics

Researchers analyzed microplastic content in sewage sludge-derived fertilizer collected in June and July, finding an average of ~460 mg of microplastics per 100 g of fertilizer with fragments and fibers predominating — raising concerns about agricultural land contamination from sewage sludge application.

2025 Applied Sciences 2 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

Effect of Thermal Drying and Chemical Treatments with Wastes on Microbiological Contamination Indicators in Sewage Sludge

This study evaluated thermal drying and chemical treatments for reducing bacterial contamination in sewage sludge from Portuguese wastewater treatment plants. Sewage sludge is a major pathway by which microplastics from wastewater reach agricultural soils when used as fertilizer.

2020 Microorganisms 25 citations
Article Tier 2

Risk of re-release of microplastics from sewage fertilisers into the environment

This paper reviews the risk that microplastics in sewage sludge (biosolids used as agricultural fertilizer) will be re-released into soils and water when the sludge is land-applied. Microplastics from cosmetics and clothing fibers concentrate in sludge during wastewater treatment and persist because they resist biodegradation. Applying microplastic-contaminated biosolids to farmland is one of the major pathways through which microplastics enter agricultural soils.

2023 1 citations
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

Detection of microplastic traces in four different types of municipal wastewater treatment plants through FT-IR and TED-GC-MS

Researchers detected microplastic traces in four different types of municipal wastewater treatment plants using FT-IR and TED-GC-MS, finding that while treatment processes removed most microplastics, some were still released into receiving water bodies.

2023 Environmental Pollution 51 citations
Article Tier 2

Optimising sample preparation for FTIR-based microplastic analysis in wastewater and sludge samples: multiple digestions

Researchers optimized sample digestion protocols for FTIR-based microplastic analysis in wastewater and sludge, finding that multiple sequential digestion steps improve removal of organic matter while minimizing polymer degradation.

2021 Analytical and Bioanalytical Chemistry 97 citations