Papers

61,005 results
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Article Tier 2

Changes in physicochemical and leachate characteristics of microplastics during hydrothermal treatment of sewage sludge

Researchers examined hydrothermal treatment of sewage sludge containing microplastics and found that while the process degraded polyethylene, polystyrene, and PET to varying degrees, it also generated potentially harmful leachates, highlighting trade-offs in this treatment approach.

2022 Water Research 86 citations
Article Tier 2

How does alkaline-thermal pretreatment followed by anaerobic digestion affect the content of polyethylene terephthalate and polyamide 66 microplastics?

Researchers investigated how alkaline-thermal pretreatment of sludge followed by anaerobic digestion affects PET and polyamide-66 microplastics in wastewater treatment. Different NaOH concentrations, temperatures, and retention times altered the physical and chemical characteristics of both MP types, informing strategies for reducing MP persistence in sludge destined for agricultural reuse.

2025 The Science of The Total Environment 3 citations
Article Tier 2

Microplastics in sewage sludge destined to anaerobic digestion: The potential role of thermal pretreatment

Researchers found that thermal pretreatment of sewage sludge at 120°C did not degrade conventional PET microplastics but did alter biodegradable microplastics, which also boosted methane production during anaerobic digestion, raising concerns about how different microplastic types behave in sludge treatment.

2022 Chemosphere 27 citations
Article Tier 2

Biodegradation of Poly(Ethylene Terephthalate) Microplastics by Baceterial Communities From Activated Sludge

Scientists isolated bacteria from wastewater treatment sludge that can biodegrade PET plastic, used in plastic bottles and food packaging. The bacteria broke down PET microplastics over a 60-day period, pointing toward a potential biological tool for removing plastic contamination from water treatment systems.

2021
Article Tier 2

Biodegradation of Poly(Ethylene Terephthalate) Microplastics by Baceterial Communities From Activated Sludge

Scientists isolated bacteria from wastewater treatment sludge that can biodegrade PET plastic, used in plastic bottles and food packaging. The bacteria broke down PET microplastics over a 60-day period, pointing toward a potential biological tool for removing plastic contamination from water treatment systems.

2021 1 citations
Article Tier 2

Microplastic Degradation in Sewage Sludge by Hydrothermal Carbonization: Efficiency and Mechanisms

Researchers evaluated hydrothermal carbonization as a method for degrading microplastics in sewage sludge. The study found that treatment at 260 degrees Celsius achieved a 79% reduction in microplastic concentrations, and investigated the decomposition mechanisms for different polymer types. The findings suggest that hydrothermal carbonization could be an effective approach for removing microplastics from sewage sludge before environmental disposal.

2022 Chemosphere 74 citations
Article Tier 2

The interaction between sludge and microplastics during thermal hydrolysis of sludge

Researchers studied how polyethylene and PET microplastics behave during thermal hydrolysis of municipal sludge at temperatures between 120 and 180 degrees Celsius. They found a mutual promotion relationship where sludge degradation accelerated microplastic aging, while the microplastics enhanced the breakdown of organic compounds in the sludge. The study suggests that thermal hydrolysis of sludge shows promise for simultaneously treating both sludge and microplastic contamination.

2024 Journal of Hazardous Materials 10 citations
Article Tier 2

Fate and effects of polyethylene terephthalate (PET) microplastics during anaerobic digestion of alkaline-thermal pretreated sludge

This study investigated the fate and effects of polyethylene terephthalate microplastics during alkaline-thermal pretreatment and anaerobic digestion of wastewater sludge. PET microplastics were partially degraded under alkaline-thermal conditions, and their presence at elevated concentrations inhibited biogas production and reduced methane yield in anaerobic digesters.

2022 Waste Management 59 citations
Article Tier 2

Fate of microplastics during conventional and hydrothermal treatments of sewage sludge: a short review

This review examines the fate of microplastics during conventional and hydrothermal treatment of sewage sludge, noting that approximately 90% of microplastics entering wastewater treatment plants are retained in sludge. Researchers found that while conventional disposal routes concentrate microplastics in sludge destined for land application, hydrothermal treatments offer potential pathways to degrade or transform microplastics, though the efficiency and byproducts of these processes require further investigation.

2025 IOP Conference Series Earth and Environmental Science
Article Tier 2

Simultaneous degradation of microplastics and sludge during wet air oxidation

This study showed that wet air oxidation (WAO) — a high-temperature, high-pressure sludge treatment — can simultaneously break down polyethylene, polystyrene, and PET microplastics along with the sewage sludge they contaminate. All three plastic types were degraded without leaving detectable solid plastic residues, with acetic acid as the primary breakdown product. This is significant because conventional wastewater treatment cannot destroy microplastics, so WAO represents a promising upgrade for eliminating a major environmental release pathway.

2023 Environmental Pollution 12 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

Microplastic Degradation through Thermal Hydrolysis in Sewage Sludge and Its Impact on the Anaerobic Process

Researchers found that thermal hydrolysis pretreatment of sewage sludge reduced microplastic concentrations from 206 particles/g to lower levels, with approximately 54% of microplastics initially in solid phase, and examined the implications for sludge management and microplastic fate.

2025 ACS ES&T Water
Article Tier 2

Microplastics degradation through hydrothermal liquefaction of wastewater treatment sludge

Researchers tested whether hydrothermal liquefaction (HTL) — a high-temperature, high-pressure process that converts sewage sludge into bio-crude oil — could also destroy microplastics in the sludge, finding it reduced microplastic numbers by 76% and mass by 97%, with no microplastics detected in the bio-crude product. This suggests HTL could serve a dual purpose: producing renewable fuel while significantly reducing microplastic pollution from the sludge that would otherwise be spread on farmland.

2022 Journal of Cleaner Production 90 citations
Article Tier 2

Microplastics in sewage sludge: Distribution, toxicity, identification methods, and engineered technologies

This review examines how microplastics accumulate in sewage sludge from wastewater treatment plants, which then becomes a major pathway for spreading these particles into the environment. Researchers found that sludge can contain extremely high concentrations of microplastics, ranging from thousands to hundreds of thousands of particles per kilogram. The study evaluates current detection methods and emerging technologies for removing microplastics from sludge before it is applied to agricultural land or disposed of.

2022 Chemosphere 106 citations
Article Tier 2

Thermal hydrolysis alleviates polyethylene microplastic-induced stress in anaerobic digestion of waste activated sludge

Scientists found that pretreating waste sludge with heat before anaerobic digestion reduced the negative effects that polyethylene microplastics have on the process. The thermal treatment improved methane production and helped maintain healthy microbial communities even in the presence of microplastics. The study suggests that thermal hydrolysis could be a practical strategy for wastewater treatment plants dealing with microplastic-contaminated sludge.

2024 Journal of Hazardous Materials 28 citations
Article Tier 2

Biodegradation of polyethylene terephthalate microplastics by bacterial communities from activated sludge

Bacterial communities from activated sludge were shown to grow on PET microplastics as a sole carbon source and achieved measurable biodegradation of heat-pretreated PET fragments in a standardized CO₂ evolution test, identifying activated sludge as a source of PET-degrading microbes.

2020 The Canadian Journal of Chemical Engineering 61 citations
Article Tier 2

Current understanding on the fate of contaminants during hydrothermal treatment of sewage sludge

This review examines how hydrothermal treatment of sewage sludge handles various contaminants including microplastics, heavy metals, and pharmaceuticals. While the high-temperature water treatment can break down many pollutants, its effectiveness against microplastics specifically is still being studied. Since sewage sludge is often spread on farmland, understanding how well treatment destroys microplastics is important for preventing them from entering the food supply.

2024 Current Opinion in Green and Sustainable Chemistry 10 citations
Article Tier 2

Impact of alkaline thermal hydrolysis on anaerobic digestion of mixed sludge contaminated with microplastics

Researchers tested alkaline thermal hydrolysis pretreatment on sludge containing polyethylene and PVC microplastics before anaerobic digestion, finding that the pretreatment altered how microplastics affected subsequent methane production, with effects varying by polymer type and concentration.

2025 Journal of Water Process Engineering
Article Tier 2

Fate of microplastic during pyrolysis of sewage sludge

Researchers investigated what happens to microplastics embedded in sewage sludge when sludge is treated by pyrolysis, a high-temperature thermochemical process. Pyrolysis effectively destroyed most microplastic particles, but some residual polymer-derived compounds partitioned into the pyrolysis products.

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

Unraveling Co-Pyrolysis Mechanisms for Municipal Sludge and Microplastics: Thermodynamic, Kinetic, and Product Insights

Wastewater treatment plants produce large quantities of sewage sludge, which is often contaminated with microplastics from household and industrial sources. This study tested whether co-pyrolyzing sludge with polyethylene (HDPE) or PET plastic waste at high temperatures could improve energy recovery while processing microplastics. Adding 30% HDPE maximized the overall pyrolysis efficiency and changed the chemical reaction pathways, while PET had stronger facilitating effects at mid-range temperatures. The research suggests that co-pyrolysis could serve the dual purpose of sludge disposal and microplastic destruction, though the altered reaction kinetics and product mixtures require careful management.

2026 Processes
Article Tier 2

Enzymatic remediation of polyester microfibers in sewage sludge and green compost samples

Researchers tested a heat-tolerant enzyme (LCC ICCG cutinase) on PET plastic microfibers in sewage sludge and compost, successfully breaking down up to 16.6 mg of PET per cubic centimeter within 24 hours — demonstrating that enzyme-based bioremediation could help remove microplastics from agricultural biofertilizers before they contaminate soil.

2025 Microplastics and Nanoplastics 2 citations
Article Tier 2

Exploring the Potential of Hydrothermal Treatment for Microplastics Removal in Digestate

Researchers explored hydrothermal treatment as a method to remove microplastics from digestate -- the organic residue from anaerobic digestion that is widely applied to agricultural land. Hydrothermal treatment effectively degraded microplastics present in the digestate, offering a processing step that could reduce microplastic loading in biosolids before land application.

2024 ACS Sustainable Chemistry & Engineering 8 citations
Article Tier 2

Inhibitory effect of microplastics derived organic matters on humification reaction of organics in sewage sludge under alkali-hydrothermal treatment

This study investigated how microplastics in sewage sludge affect the formation of humic acids during alkali-hydrothermal treatment, a common method for recovering valuable organic matter. Researchers found that organic compounds leached from microplastics inhibited the humification process, suggesting that microplastic contamination can reduce the quality of recovered materials from wastewater sludge.

2024 Water Research 10 citations
Article Tier 2

Tackling microplastic contamination in sewage sludge: Optimizing organic matter degradation, quantifying microplastic presence, and evaluating ecological risks for sustainable agriculture

Researchers optimized a Fenton reagent-based method to remove 86.6% of organic matter from sewage sludge, enabling more accurate quantification of microplastics in the samples. Analysis of sludge from 14 treatment plants in Ahmedabad, India revealed microplastic concentrations ranging from 2,430 to 227,200 particles per kilogram, with small fibers and fragments being the most abundant. Ecological risk assessments indicated extreme hazard levels, raising concerns about using contaminated sewage sludge as agricultural fertilizer.

2025 The Science of The Total Environment 8 citations