Papers

61,005 results
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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

Microplastic Retention in Secondary Sewage Sludge: Characterization and Influence of Solid Concentration

Researchers examined microplastic retention in secondary sewage sludge from a municipal wastewater treatment plant and found that fibers made up 61% of the trapped particles. Testing different solid concentrations in settling experiments, they achieved a maximum microplastic capture rate of 63% without adding any chemicals. The study provides practical insights into how wastewater treatment plants can optimize sludge settling to better capture microplastics before they are released into the environment.

2025 Applied Sciences 15 citations
Article Tier 2

Microplastics in the continuous biofilm reactor: Occurrence, fate, and removal

A laboratory-scale continuous biofilm reactor was monitored for microplastic occurrence, fate, and removal over 53 days. Microplastics were detected at all stages of the reactor and were partially retained within the biofilm. The study shows that biofilm reactors can reduce microplastic concentrations in treated water but do not eliminate them entirely.

2022 IOP Conference Series Earth and Environmental Science 4 citations
Article Tier 2

Effects and Fate of Microfibres on Wastewater Treatment: Insights into Treatment Performance, Microbiome Selection and Synergetic Impacts on Functional Organisms in Granular Sludge Reactors

Researchers examined the effects of polyester and denim microfibres on aerobic granular sludge reactors used in wastewater treatment, finding that fibre presence influences treatment performance, microbiome community composition, and the function of key organisms in the granular sludge. The findings reveal that textile microfibres reaching wastewater plants can have synergistic negative impacts on biological treatment processes.

2025
Article Tier 2

Microplastics and microfibers in the sludge of a municipal wastewater treatment plant

Researchers monitored microplastics and synthetic microfibers in the sludge of a Spanish municipal wastewater treatment plant throughout 2015, identifying polypropylene, nylon, and polyamide among others using FTIR and differential scanning calorimetry, and noting that sludge applied as agricultural fertilizer could transfer these contaminants to crop soils.

2016 International Journal of Sustainable Development and Planning 100 citations
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

Transport and fate of microplastic particles in wastewater treatment plants

Researchers tracked microplastic particles through multiple stages of a wastewater treatment plant, finding that particles were concentrated in sludge but that a fraction passed through each treatment stage and remained in the final effluent.

2016 Water Research 1704 citations
Article Tier 2

Mechanistic understanding of microplastic fiber fate and sampling strategies: Synthesis and utility of metal doped polyester fibers

Researchers synthesized polyester microplastic fibers embedded with an indium metal tracer to simplify tracking fiber fate and transport, demonstrating that the label does not alter fiber behavior, leaches minimally, and that over 99.9% of fibers associate with activated sludge in wastewater treatment batch experiments.

2019 Water Research 61 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

Wastewater treatment alters microbial colonization of microplastics

Analysis of microplastics and their biofilms across raw sewage, effluent, and sludge at two wastewater treatment plants found that >99% of influent MPs were retained in sludge, and that wastewater treatment substantially altered biofilm microbial composition, enriching bioflocculation-associated taxa.

2021 PLoS ONE 133 citations
Article Tier 2

Effects and fate of microfibres on wastewater treatment: Insights into treatment performance, microbiome selection and synergetic impacts on functional organisms in granular sludge reactors

Researchers investigated the effects of denim and polyester microfibres on aerobic granular sludge reactor performance, examining how these commonly encountered anthropogenic fibres influence wastewater treatment efficiency, microbiome selection, and interactions with functional organisms.

2025
Article Tier 2

Microplastic Monitoring at Different Stages in a Wastewater Treatment Plant Using Reflectance Micro-FTIR Imaging

Researchers used reflectance micro-FTIR imaging to monitor microplastic presence at multiple treatment stages within a wastewater treatment plant, addressing the challenge of analyzing MPs in biogenic organic matter-rich matrices. The study mapped how microplastic identity, abundance, and size distribution changed through primary and secondary treatment, providing insight into WWTP contributions to aquatic microplastic pollution.

2020 Frontiers in Environmental Science 82 citations
Article Tier 2

Occurrence and Characteristics of Microplastics in a Wastewater Treatment Plant

Researchers sampled the inflow, outflow, and sludge of a Chinese wastewater treatment plant, finding up to 44 microplastic particles per liter in incoming water — mostly polyester fibers. The plant removed about 96% of microplastics, but the remaining fraction was still discharged into receiving waterways.

2021 Bulletin of Environmental Contamination and Toxicology 24 citations
Article Tier 2

Circulation of fibrous microplastic (microfiber) in sewage and sewage sludge treatment processes

The circulation of microfibers through sewage and sludge treatment processes was tracked in a Japanese facility, finding that while most microfibers were removed from wastewater into sludge during primary and secondary treatment, some were re-released during sludge digestion and dewatering, creating a secondary recirculation pathway back into treated effluent.

2021 The Science of The Total Environment 55 citations
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

Microplastic distributions in a domestic wastewater treatment plant: Removal efficiency, seasonal variation and influence of sampling technique

A year-long study of a municipal wastewater treatment plant found 97% removal efficiency for microplastics overall, but fibers made up a larger proportion of remaining particles in treated water than in raw sewage, and winter samples had notably higher microplastic concentrations. The study highlights seasonal variation as an important factor in assessing wastewater microplastic loads.

2020 The Science of The Total Environment 220 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

Understanding the retention of microplastics in wastewater treatment plants: Insights from tracer tests and numerical modeling

This study used tracer experiments and numerical modeling in a full-scale wastewater treatment plant to show that about 70% of microplastic fibers introduced into a disinfection tank were retained within 20 minutes after the minimum hydraulic retention time, revealing flow pattern as a key driver of microplastic removal efficiency.

2025 Environmental Research 2 citations
Article Tier 2

The fate of microplastics in an Italian Wastewater Treatment Plant

Microplastics were tracked through influent, settler, and effluent stages of a major northern Italian WWTP (serving 1.2 million population equivalents), finding high removal efficiency but continued discharge of fibers and fragments to receiving water and concentration of retained plastics in sludge. The study provides detailed mass flow data for an Italian WWTP and highlights sludge as the dominant plastic-retention compartment.

2018 The Science of The Total Environment 616 citations
Article Tier 2

Microplastics in real wastewater treatment schemes: comparative assessment and relevant inhibition effects on anaerobic processes

Researchers investigated microplastic occurrence and removal in an Italian wastewater treatment plant, finding 3.6 MPs/L in influent dominated by polyester fibers, with conventional activated sludge achieving 86% removal, and demonstrating that concentrated sludge-associated microplastics can inhibit downstream anaerobic digestion.

2021 Zenodo (CERN European Organization for Nuclear Research) 5 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
Article Tier 2

Microfibres from Textile Industry Effluents

Researchers reviewed the fate of microfibres released from textile industry effluents, finding that conventional wastewater treatment is insufficient to fully remove fibres, which then enter receiving waterways and contribute to environmental microplastic loads.

2024
Article Tier 2

Effects and fate of microfibres on wastewater treatment: Insights into treatment performance, microbiome selection and synergetic impacts on functional organisms in granular sludge reactors

Researchers investigated the effects of denim and polyester microfibres on the performance of aerobic granular sludge wastewater treatment reactors, examining impacts on treatment efficiency, microbiome composition, and synergistic effects on functional microbial organisms.

2025
Article Tier 2

Microplastics in Influents and Effluents of Estonian Wastewater Treatment Plants

This Estonian study is the first systematic investigation of microplastic concentrations in both the influent and effluent of Estonian wastewater treatment plants, using continuous filtration sampling and FTIR spectroscopy. The research establishes baseline data for microplastic removal efficiency in Baltic state wastewater infrastructure, documenting how treatment reduces but does not eliminate microplastic discharge.

2023