Papers

61,005 results
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Article Tier 2

Digestate from Biowaste and Sewage Sludge as Carriers of Microplastic into the Environment: Case Study of a Thermophilic Biogas Plant in Ostrobothnia, Finland

This Finnish study found microplastics in every waste fraction sampled from a thermophilic biogas plant — including reject water and digestate from both biowaste and sewage sludge digestion. Because digestate is commonly spread on agricultural land as a fertilizer, biogas plants represent an underappreciated pathway for microplastics to enter soil ecosystems at scale. The findings highlight a critical gap in microplastic regulation: current wastewater treatment frameworks do not adequately address plastic contamination in biogas waste streams.

2023 Water Air & Soil Pollution 11 citations
Article Tier 2

Fate of microplastics in a centralized biogas plant treating mainly sewage sludge

Researchers tracked the fate of microplastics through a centralized biogas plant treating sewage sludge, examining how anaerobic digestion and subsequent dewatering partition microplastics between solid and liquid digestate fractions. The study informs efforts to develop safer digestate-based recycled fertilizers that minimize microplastic introduction to agricultural soils, where 20-55% of microplastics entering wastewater treatment plants are estimated to end up in sludge.

2025 Journal of Environmental Management
Article Tier 2

Baseline levels of microplastics in agricultural soils obscure the effects of additional microplastics from recycled fertilizers

Researchers investigated whether liquid or solid digestate fertilizer from a Swiss biogas plant adds detectable microplastic loads to agricultural soils above natural background levels. Despite finding microplastics in digestate, treated soil concentrations were not significantly different from the unfertilized control, suggesting high baseline soil microplastic levels obscure the signal from digestate inputs.

2025 Microplastics and Nanoplastics 4 citations
Article Tier 2

Unmasking microplastics in anaerobic digestion: Hidden threats, synergistic pollutants, and biodegradation Frontiers — A comprehensive hotspot review

Researchers reviewed how microplastics disrupt anaerobic digestion — the process used to convert organic waste into biogas — finding that microplastics suppress methane production, harm microbial communities, and carry along other pollutants like antibiotics and heavy metals into the system.

2025 Environmental Chemistry and Ecotoxicology 10 citations
Article Tier 2

Characteristics, limitations and global regulations in the use of biogas digestate as fertilizer: A comprehensive overview

This review examines the use of biogas digestate, the leftover material from biogas production, as agricultural fertilizer, highlighting both its benefits and risks. While digestate is rich in nutrients, it can contain contaminants including heavy metals, pathogens, and microplastics that may enter the food chain through treated crops. The authors review global regulations and call for stricter quality controls to prevent microplastic and other contaminant transfer to agricultural soils.

2024 The Science of The Total Environment 19 citations
Article Tier 2

Combining industrial ecology tools to assess potential greenhouse gas reductions of a circular economy: Method development and application to Switzerland

Researchers developed a framework combining multiple environmental analysis methods to assess how circular economy strategies — like plastic recycling, food waste reduction, and carbon capture — could cut Switzerland's greenhouse gas emissions by up to 14% by 2050.

2022 Journal of Industrial Ecology 33 citations
Review Tier 2

A review on mechanistic understanding of microplastic pollution on the performance of anaerobic digestion

This review examines how microplastic contamination affects anaerobic digestion, a process used to convert organic waste into biogas. Researchers found that microplastics can harm the microbial communities essential to this process through direct contact, leaching of toxic chemicals, and generating harmful reactive oxygen species. The findings raise concerns that microplastic pollution could reduce the efficiency of waste treatment systems and contribute to the spread of antibiotic resistance genes.

2023 Environmental Pollution 41 citations
Article Tier 2

Estimation of microplastics entering agricultural soil through the use of biofertilizers

Scientists found that organic fertilizers made from food waste contain tiny plastic particles called microplastics, which end up in farm soil when the fertilizers are applied. These microscopic plastic bits can potentially enter our food chain through crops grown in that soil. This research helps us understand another way that plastic pollution might affect the food we eat, though more studies are needed to determine the actual health risks.

2026
Article Tier 2

Plastic impurities in biowaste treatment: environmental and economic life cycle assessment of a composting plant

Researchers assessed an Italian composting facility and found that conventional plastic contaminants in food waste account for nearly half the residual waste produced and roughly 7% of annual operating costs, highlighting how plastic pollution undermines the economics and environmental benefits of composting.

2023 Environmental Science and Pollution Research 7 citations
Meta Analysis Tier 1

Microplastics divert carbon flow in anaerobic digestion: a meta-analysis reveals product-specific effects

Researchers conducted a meta-analysis of 55 studies and found that microplastics do not simply inhibit anaerobic digestion but redirect carbon flow within it — suppressing methane production while boosting volatile fatty acid accumulation — with the direction and magnitude of effects determined by polymer type, concentration, size, and temperature.

2026 Bioresource Technology
Article Tier 2

Plastics in biogenic matrices intended for reuse in agriculture and the potential contribution to soil accumulation

Researchers measured plastic contamination across agricultural input materials including manures, digestate, compost, and sewage sludge, finding plastics in all samples ranging from 0.06 plastics/g in animal manure to 986 plastics/g in compost. Fibres were the dominant shape and polyester, polypropylene, and polyethylene were the most common polymers, highlighting the risk these reused matrices pose for soil plastic accumulation.

2024 Environmental Pollution 9 citations
Article Tier 2

Occurrence of macroplastics and microplastics in biogenic waste digestate: Effects of depackaging at source and dewatering process

Researchers investigated plastic debris in digestate from anaerobic digestion of biogenic waste, finding that both preprocessing and dewatering steps significantly influence the quantity of macroplastics and microplastics in the resulting material used as a soil conditioner.

2022 Waste Management 27 citations
Article Tier 2

Organics Recycling Tradeoffs: Biogas Potential and Microplastic Content of Mechanically Depackaged Food Waste

Researchers examined the tradeoffs between biogas energy recovery potential and microplastic contamination in mechanically depackaged food waste intended for anaerobic digestion, finding that imperfect separation of packaging materials introduces microplastics into the resulting digestate.

2023 ACS Sustainable Chemistry & Engineering 19 citations
Article Tier 2

Waste-Derived Fertilizers: Conversion Technologies, Circular Bioeconomy Perspectives and Agronomic Value

A review assessed conversion technologies that transform waste materials into fertilizers, examining how the resulting products may introduce microplastics and other contaminants into agricultural soils. The study raises concerns about the circularity of nutrient recovery if it inadvertently spreads plastic pollution.

2025 Agronomy 1 citations
Article Tier 2

Systematic study of microplastics on methane production in anaerobic digestion: Performance and microbial response

Microplastics are increasingly found in wastewater treatment systems, and this study systematically examined how different types, concentrations, and sizes of microplastics affect the anaerobic digestion process used to break down sewage sludge and generate biogas. Polyethylene microplastics were found to inhibit methane production, with finer particles and higher concentrations causing greater disruption to the microbial communities driving digestion. The findings matter because microplastics in sewage sludge can impair the treatment process and also end up spread on agricultural land when sludge is used as fertilizer.

2025 Journal of environmental chemical engineering 1 citations
Review Tier 2

Anaerobic Digestate as a Soil Amendment: Impacts on Crop Production, Soil Ecology, and Environmental Quality. A Review

This review examines the environmental impacts of applying anaerobic digestate to agricultural soils, including the introduction of microplastic contaminants from digested feedstocks, assessing how MP-laden digestate affects soil ecology, crop production, and long-term soil health.

2025 Preprints.org
Commentary Tier 3

Editorial: Anaerobic digestion of waste organics: toxicity and management

This editorial introduces a special journal issue on anaerobic digestion — a biological process that breaks down organic waste to produce biogas — discussing how toxic substances including microplastics can disrupt this process. The papers explore strategies to manage toxicity and improve waste treatment efficiency.

2023 Frontiers in Microbiology
Article Tier 2

Microplastics in anaerobic digestion: occurrence, impact, and mitigation strategies

This review examines the presence and impact of microplastics within anaerobic digestion systems used to process sewage sludge and organic waste. Researchers found that microplastics enter these systems through diverse waste inputs and may affect biogas production, microbial community composition, and overall process performance. The study highlights the need for further research into how microplastics interact with anaerobic digestion and what mitigation strategies could minimize their interference.

2024 Journal of Environmental Health Science and Engineering 17 citations
Review Tier 2

Anaerobic Digestate as a Soil Amendment: Impacts on Crop Production, Soil Ecology, and Environmental Quality. A Review

This review examines the agronomic and environmental variability of anaerobic digestate as a biofertilizer, noting that digestate inputs introduce microplastic contamination into agricultural soils and that careful characterization of digestate quality is needed before large-scale application.

2025 Preprints.org
Article Tier 2

Microplastics, antibiotics, and heavy metals in anaerobic digestion systems : a critical review of sources, impacts, and mitigation strategies

This critical review examined how microplastics, antibiotics, and heavy metals—as co-occurring contaminants—affect the performance of anaerobic digestion systems, finding that all three impair microbial processes, reduce biogas yields, and accumulate in digestates that are then applied to agricultural soils.

2025 OPUS Publication Server of the University of Stuttgart (University of Stuttgart)
Article Tier 2

Sustainable Management of Organic Waste and Recycling for Bioplastics: A LCA Approach for the Italian Case Study

Researchers used life cycle assessment to evaluate the environmental trade-offs of collecting organic waste for biodegradable plastic production in Italy, finding that the system could reduce fossil resource use but that impacts depended heavily on collection efficiency and the end-of-life pathway chosen.

2021 Sustainability 36 citations
Article Tier 2

The occurrence and fate of microplastics in a mesophilic anaerobic digester receiving sewage sludge, grease, and fatty slurries

Researchers analyzed microplastic loads entering and leaving a mesophilic anaerobic digester at a wastewater treatment plant serving nearly 800,000 people. They found that the digester received approximately 7,326 kg of microplastics per year, with digested sludge containing about 30% less, though this reduction was within the variability of the measurements. The study provides important data on the fate of microplastics during sewage sludge treatment processes.

2021 The Science of The Total Environment 52 citations
Article Tier 2

Do contaminants compromise the use of recycled nutrients in organic agriculture? A review and synthesis of current knowledge on contaminant concentrations, fate in the environment and risk assessment

This review examines whether recycled nutrients from waste streams, such as sewage sludge and compost, introduce harmful contaminants including microplastics into organic farmland. While levels of heavy metals and many pollutants have decreased in European waste streams, microplastic contamination in agricultural soil remains widespread and poorly understood. The review highlights that spreading waste-derived fertilizers on farmland is a significant pathway for microplastics to enter the food production system.

2023 The Science of The Total Environment 51 citations
Article Tier 2

Harnessing Biogas in India: A Sustainable Pathway for Sustainable Energy Development

This review examines the role of the biogas sector in India in addressing sanitation challenges and providing sustainable energy, analyzing the potential of biogas to reduce plastic and organic waste while generating clean fuel for rural communities.

2024 Green and Low-Carbon Economy 5 citations