Papers

61,005 results
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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

Recycling – The future urban sink for wastewater and organic waste

Researchers analyzed how recycling urban wastewater and organic waste as agricultural fertilizer could become a sustainable solution for feeding a growing global population, finding that keeping nutrient-rich sewage separate from chemically contaminated greywater is essential to making this work. The analysis suggests that cities could replace environmentally damaging phosphorus and potassium mining with urban waste recycling if infrastructure is redesigned accordingly.

2023 City and Environment Interactions 11 citations
Article Tier 2

Are Agricultural Soils Dumps for Microplastics of Urban Origin?

Researchers investigated whether agricultural soils serve as dumping grounds for urban-origin microplastics, finding evidence that sewage sludge application and atmospheric deposition deliver city-sourced plastics to farmland.

2016 Environmental Science & Technology 1621 citations
Article Tier 2

Soil fertility effects of repeated application of sewage sludge in two 30-year-old field experiments

Two long-term Swedish field experiments found that repeated application of sewage sludge over 30 years maintained or improved soil fertility metrics including nitrogen, phosphorus, and organic matter content, though concerns about contaminants including microplastics were noted. The study is relevant to microplastic research because sewage sludge is one of the main pathways through which microplastics enter agricultural soils.

2018 Nutrient Cycling in Agroecosystems 43 citations
Article Tier 2

Assessing emerging and priority micropollutants in sewage sludge: environmental insights and analytical approaches

Researchers reviewed the presence of emerging pollutants, including microplastics, pharmaceuticals, and industrial chemicals, in sewage sludge that is commonly applied to agricultural land. They found that current analytical methods are improving but still face challenges in detecting these contaminants at low concentrations in complex sludge samples. The study highlights the environmental risks of spreading pollutant-laden sludge on farmland and calls for better monitoring standards.

2023 Environmental Science and Pollution Research 19 citations
Article Tier 2

Impact of sewage sludge application on soil microplastic accumulation and nutrient levels: Analysis of 22 years of data from central UK farmland

Researchers analyzed a 22-year dataset from 5,323 fields in central UK to examine the relationship between repeated sewage sludge application and microplastic accumulation in agricultural soils, alongside changes in nutrient levels such as nitrogen and phosphorus. They found that microplastic concentrations increased with cumulative sludge applications while nutrients were taken up by crops, raising concerns about long-term plastic accumulation in farmland receiving sludge-derived fertilizers.

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

Effects of long-term fertilization with contemporary Danish human urine, composted household waste and sewage sludge on soil nematode abundance and community structure.

Researchers conducted long-term fertilization trials with human urine, composted household waste, and sewage sludge on Danish agricultural fields, finding that repeated application of these waste-derived fertilizers altered soil nematode community structure, with effects linked to accumulated heavy metals, organic pollutants, and microplastic contamination.

2023 The Science of the total environment
Article Tier 2

Agricultural application of microplastic-rich sewage sludge leads to further uncontrolled contamination

Researchers found that 44% of microplastics from sewage sludge applied to agricultural land migrated to nearby untreated areas, demonstrating that this common fertilizer practice leads to further uncontrolled contamination of surrounding soils.

2021 The Science of The Total Environment 103 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

Long-term agricultural reuse of treated wastewater and sewage sludge: developing a Time to Critical Content Index for metal species

Researchers reviewed long-term effects of treated wastewater and sewage sludge reuse in agriculture, developing a framework to assess microplastic and contaminant accumulation in soils and crops over repeated application cycles.

2024 Environmental Monitoring and Assessment 4 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

Sewage sludge as a sustainable fertilizer: Promise, pitfalls, and future directions

This review examines both the promise and pitfalls of using sewage sludge as a fertilizer, finding that while it reduces agrochemical costs and provides nutrients for crops, it also introduces microplastics, pathogens, and heavy metals into agricultural soils with implications for food safety and public health.

2025 Cleaner Water
Article Tier 2

Fertilization of poplar plantations with dried sludge : a demonstration trial in Hillebola - central Sweden

Researchers demonstrated that dried pelletized sewage sludge — which contains microplastics and heavy metals alongside plant nutrients — can serve as a viable fertilizer for short-rotation poplar plantations in Sweden, supporting a circular nutrient-recycling model while acknowledging ongoing environmental risk questions.

2023 Report from the Department of Crop Production Ecology (VPE)
Article Tier 2

Contemporary Drift in Emerging Micro(nano)plastics Removal and Upcycling Technologies from Municipal Wastewater Sludge: Strategic Innovations and Prospects

This review evaluates both conventional and advanced methods for removing microplastics from sewage sludge before it is applied to farmland as fertilizer. Current treatment processes like anaerobic digestion and composting reduce but do not eliminate microplastics, and some methods can actually fragment larger plastics into more numerous smaller pieces. The authors identify emerging technologies and upcycling strategies that could better address this pathway of microplastic contamination in agricultural soils.

2023 Current Pollution Reports 36 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

Trace metal fate in soil after application of digestate originating from the anaerobic digestion of non-source-separated organic fraction of municipal solid waste

Researchers tracked the fate of trace metals in agricultural soil after applying digestate from anaerobic digestion of municipal solid waste, assessing whether this organic amendment safely recycles nutrients or risks accumulating harmful heavy metals in farmland.

2023 Frontiers in Environmental Science 12 citations
Systematic Review Tier 1

The overlooked pathway: A systematic review on sewage sludge treatment as a critical secondary source of terrestrial micro(nano)plastics

This systematic review examines sewage sludge as an overlooked pathway for microplastics to contaminate land, with concentrations reaching over 1,300 particles per kilogram. When this sludge is applied to farmland as fertilizer, aged and chemically modified microplastics enter agricultural soil, where they may be more toxic than fresh particles and can potentially be taken up by crops.

2025 The Science of The Total Environment
Article Tier 2

Recent Research on Municipal Sludge as Soil Fertilizer in China: a Review

Researchers reviewed the use of municipal sewage sludge as agricultural fertilizer in China, concluding that its nutrient content makes it potentially valuable for soil amendment, but that repeated application risks accumulating heavy metals, organic pollutants, and pathogens in soils and food chains — requiring long-term field studies before widespread adoption.

2023 Water Air & Soil Pollution 39 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

Impact of sewage sludge application on soil microplastic accumulation and nutrient levels: Analysis of 22 years of data from central UK farmland

Researchers analyzed 22 years of data from central UK farmland to assess how repeated sewage sludge application accumulates microplastics in agricultural soil while nutrients are absorbed by crops, finding that microplastic buildup disrupts geochemical cycling of carbon, nitrogen, and phosphorus.

2024 Zenodo (CERN European Organization for Nuclear Research)
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

Investigating the dispersal of macro- and microplastics on agricultural fields 30 years after sewage sludge application

Researchers investigated plastic dispersal on agricultural fields 30 years after sewage sludge application, finding that macro- and microplastics persisted and migrated both horizontally and vertically in soil, demonstrating the long-term contamination legacy of sludge-based fertilization.

2022 Scientific Reports 119 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

Extent and impact of microplastics on soil nutrients and biota: a trade-off assessment

This review examines the extent of microplastic inputs from sewage sludge applied to agricultural soils, synthesizing evidence on how sludge-derived microplastics affect soil nutrient availability, soil biota, plant performance, and crop productivity, concluding that the benefits of sludge as a soil amendment must be weighed against its role as a vector for microplastic contamination.

2022 Zenodo (CERN European Organization for Nuclear Research)