Papers

61,005 results
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Article Tier 2

Standardization: A Necessary Support to the Utilization of Sludge/Biosolids in Agriculture

This paper argues that standardized regulations are needed for applying wastewater treatment sludge to agricultural land, due to varying contaminant levels including microplastics. Without clear standards, land application of sludge risks introducing plastic particles and other pollutants into farmland soils and the food supply.

2023 Preprints.org
Article Tier 2

Sampling, pre-treatment, and identification methods of microplastics in sewage sludge and their effects in agricultural soils: a review

This review examines methods for sampling, pre-treating, and identifying microplastics in sewage sludge, which accumulates microplastics removed during wastewater treatment. Researchers found that standardized protocols for sludge analysis are still lacking, making it difficult to compare results across studies. The study also highlights that when microplastic-laden sludge is applied to agricultural soils, it may introduce persistent plastic contamination into terrestrial ecosystems.

2021 Environmental Monitoring and Assessment 65 citations
Article Tier 2

Land Application of Biosolids in Europe: Possibilities, Con-Straints and Future Perspectives

This review examines how sewage sludge, or biosolids, is used as agricultural fertilizer across European countries and the regulations governing this practice. While biosolids provide valuable nutrients like phosphorus, the study highlights concerns about contaminants including microplastics, pharmaceuticals, and heavy metals that could enter soil and food chains through land application.

2021 Water 119 citations
Systematic Review Tier 1

Assessing metal contamination and speciation in sewage sludge: implications for soil application and environmental risk

This systematic review estimated that global sewage sludge production could triple to 160 million tons if all wastewater were treated to EU standards, and found that metals in sludge applied to farmland are predominantly in less bioavailable forms. The research is relevant to microplastics because sewage sludge is a major pathway for microplastic contamination of agricultural soils, carrying both metal and plastic pollutants to farmland.

2023 Reviews in Environmental Science and Bio/Technology 110 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

Risk Assessment and Regulatory Overview of Sewage Sludge

This review examines the risks associated with using sewage sludge biosolids as agricultural soil amendments, including contamination by heavy metals, pharmaceuticals, pathogens, and microplastics. Researchers summarized the concentrations of harmful substances found in biosolids and their potential effects on human health and the environment. The study provides reference standards for improving national regulations around biosolid application in agriculture.

2025 Applied and Computational Engineering 1 citations
Article Tier 2

Sewage Sludge in Agricultural Lands. The Legislative Framework in EU-28

This review examines the legislative framework across EU member states for using sewage sludge as agricultural fertilizer. While sludge provides valuable nutrients and organic matter, researchers found it can also contain contaminants including microplastics, heavy metals, and pathogens. The study highlights the need for updated regulations that account for emerging pollutants like microplastics to better protect soil health and food safety.

2024 Preprints.org 5 citations
Article Tier 2

Biosolids-derived fertilisers: A review of challenges and opportunities

This review examines the use of treated sewage sludge (biosolids) as farm fertilizer and the concern that it introduces microplastics and persistent organic contaminants into agricultural soil. While biosolids provide valuable nutrients for crops, the microplastics they contain can accumulate in soil over time and potentially enter the food chain. The authors discuss thermal processing and nutrient recovery technologies that could help remove contaminants while preserving the fertilizer value of biosolids.

2023 The Science of The Total Environment 104 citations
Review Tier 2

Microplastics in biosolids: A review of ecological implications and methods for identification, enumeration, and characterization

This review examines the presence of microplastics in biosolids from wastewater treatment plants and their ecological effects when applied to agricultural soils. Researchers found conflicting evidence about the extent of negative ecosystem impacts, with some studies showing harmful effects and others reporting minimal consequences. The study highlights the lack of standardized methods for measuring microplastics in biosolids and calls for consistent analytical approaches to better assess the risks.

2022 The Science of The Total Environment 42 citations
Article Tier 2

Sewage Sludge in Agricultural Lands: The Legislative Framework in EU-28

This study examines how European Union member states regulate the use of sewage sludge in agriculture, finding significant inconsistencies in permissible heavy metal limits and a near-total absence of regulations for emerging contaminants like microplastics and pharmaceuticals. The core EU directive governing sewage sludge application has not been substantially updated since 1986. The findings highlight a critical need for harmonized, modernized regulations to protect soil health and food safety across Europe.

2024 Sustainability 5 citations
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 as an underestimated emerging contaminant in solid organic waste and their biological products: Occurrence, fate and ecological risks

This review identified solid organic waste streams including compost, sewage sludge, and food waste as important but underappreciated repositories of microplastics that can reintroduce particles into agricultural soils and water systems. The authors call for standardized monitoring of microplastics in organic waste before environmental application.

2022 Journal of Hazardous Materials 71 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 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
Meta Analysis Tier 1

Occurrence, spatiotemporal trends, fate, and treatment technologies for microplastics and organic contaminants in biosolids: A review

This meta-analysis examines how microplastics and organic pollutants end up in biosolids (treated sewage) and what happens when those biosolids are applied to farmland. The data show that microplastics are among the most common contaminants found in biosolids, raising concerns about long-term buildup in the soils where our food is grown.

2024 Journal of Hazardous Materials 25 citations
Article Tier 2

Microplastics in soils: a review of possible sources, analytical methods and ecological impacts

This review of over 60 studies examines the sources, global distribution, and analytical methods for microplastics in soil, finding that agricultural soils are particularly contaminated via sewage sludge application, plastic mulch, and atmospheric deposition. The authors call for standardized extraction and identification protocols to enable cross-study comparisons.

2020 Journal of Chemical Technology & Biotechnology 242 citations
Article Tier 2

Agricultural Use of Sewage Sludge as a Threat of Microplastic (MP) Spread in the Environment and the Role of Governance

This study examines how agricultural use of sewage sludge introduces large amounts of microplastics into soil ecosystems. The researchers propose a multi-stakeholder governance strategy for the European Union that balances the benefits of sludge as fertilizer against microplastic contamination, recommending stricter regulations on sludge quality including limits on microplastic content.

2021 Energies 53 citations
Article Tier 2

A review on the fate and effects of contaminants in biosolids applied on land: Hazards and government regulatory policies

This review examines the contaminants, including microplastics and persistent organic pollutants, that remain in treated sewage sludge (biosolids) when it is applied to farmland as fertilizer. These pollutants can accumulate in soil and potentially enter crops and groundwater, creating exposure pathways to humans. The authors argue that current government regulations on biosolid use, particularly in the US, are outdated and need updating to address emerging contaminants like microplastics.

2023 Heliyon 40 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

Investigation and analysis of microplastics in sewage sludge and biosolids: A case study from one wastewater treatment works in the UK

Researchers investigated microplastic contamination in sewage sludge and biosolids at a UK wastewater treatment plant and found significant quantities of microplastics persisting through the treatment process. Since millions of tonnes of biosolids are applied to farmland annually in the UK, this represents a major pathway for microplastic pollution entering agricultural soils. The study highlights the need for better monitoring and treatment methods to reduce microplastic transfer from wastewater to the terrestrial environment.

2022 The Science of The Total Environment 175 citations
Article Tier 2

An overview of the potential risks, sources, and analytical methods for microplastics in soil

This review systematically covers the potential risks, sources, analytical methods, and characteristics of microplastics in soil, identifying agricultural plastic films, sewage sludge application, and atmospheric deposition as major sources and calling for standardized detection protocols.

2022 AIMS environmental science 11 citations
Article Tier 2

Extent and effects of microplastic pollution in soil with focus on recycling of sewage sludge and composted household waste and experiences from the long-term field experiment CRUCIAL

Researchers reviewed microplastic contamination in agricultural soils amended with sewage sludge and compost, finding that current microplastic levels in farm fields remain below those shown to harm soil organisms in lab studies, though they caution that more long-term research is needed to confirm safety.

2023 TrAC Trends in Analytical Chemistry 19 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
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