Papers

61,005 results
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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

MicroplasticDegradation through Thermal Hydrolysisin Sewage Sludge and Its Impact on the Anaerobic Process

Researchers investigated the fate of microplastics in sewage sludge during thermal hydrolysis pretreatment and found that temperatures of 140-180°C significantly degraded microplastics while also affecting subsequent anaerobic biogas production from the treated sludge.

2025 Figshare
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

Pyrolysis behavior of sewage sludge coexisted with microplastics: Kinetics, mechanism, and product characteristics

Researchers investigated the co-pyrolysis behavior of sewage sludge mixed with polyethylene and polylactic acid microplastics. They found that the presence of microplastics improved the overall pyrolysis performance and altered the composition of the resulting bio-oil and gas products. The study suggests that understanding how microplastics in sewage sludge affect thermal treatment could help optimize waste processing at wastewater treatment plants.

2024 Journal of Environmental Management 11 citations
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

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

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

Efficient Depolymerization and Low-Toxicity Leaching of Polyester Microplastics through Alkali-Hydrothermal Treatment of Sewage Sludge

Researchers developed an alkali-hydrothermal treatment method that degraded 82% of PET microplastics trapped in sewage sludge, converting them into low-toxicity dissolved organic matter. The approach works by leveraging alkalinity, metal ions, and organic matter naturally present in sludge to break down plastic through hydrolysis and radical oxidation, offering a practical strategy for reducing microplastic contamination before sludge is applied to agricultural land.

2026 Environmental Science & Technology
Article Tier 2

Characteristics and aging of microplastics in waste activated sludge under persulfate and hydrothermal co-treatment: Impact of solid content and temperature

Researchers investigated how persulfate-assisted hydrothermal treatment of waste activated sludge affects microplastic behavior, finding that at higher temperatures the treatment causes sludge floc disruption and melting deformation of plastic particles. Solid content and temperature significantly influenced microplastic migration and aging outcomes.

2024 Environmental Pollution 6 citations
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

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

How microplastics affect sludge pyrolysis behavior: Thermogravimetry-mass spectrum analysis and biochar characteristics

Microplastics in sewage sludge alter how the sludge burns during pyrolysis: PVC microplastics sped up decomposition while polyethylene and polypropylene slowed it down. This matters because sewage sludge from wastewater plants contains thousands of microplastic particles per kilogram, and understanding how they change the energy recovery and byproduct quality of sludge treatment helps improve the management of this widespread microplastic sink.

2023 Waste Management 9 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

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

Microplastics Mitigation in Sewage Sludge through Pyrolysis: The Role of Pyrolysis Temperature

The effect of pyrolysis on reducing microplastic content in sewage sludge was investigated in a lab-scale study evaluating multiple pyrolysis temperature conditions. Pyrolysis effectively degraded microplastic particles in sludge, with higher temperatures achieving greater microplastic reduction, positioning pyrolysis as a viable treatment for managing microplastic-laden organic waste.

2020 Environmental Science & Technology Letters 151 citations
Article Tier 2

Fate of microplastic during pyrolysis of sewage sludge

Researchers examined how pyrolysis as a sewage sludge treatment method affects the fate of embedded microplastics, finding that thermal treatment largely destroys plastic particles. However, some polymer-derived volatile compounds transferred to pyrolysis gases and oils, suggesting that microplastic destruction does not eliminate all associated chemical risks.

2024 Zenodo (CERN European Organization for Nuclear Research)
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

Migration and transformation modes of microplastics in reclaimed wastewater treatment plant and sludge treatment center with thermal hydrolysis and anaerobic digestion

Researchers tracked how microplastics move and change throughout a wastewater treatment plant and a sludge treatment center that uses thermal hydrolysis and anaerobic digestion. They found that while the treatment plant removed about 98% of microplastics from the water, most particles ended up concentrated in the sludge. The study suggests that sludge disposal and reuse practices need to account for the microplastics that accumulate during wastewater treatment.

2024 Bioresource Technology 28 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

Evaluating effects of tetrabromobisphenol A and microplastics on anaerobic granular sludge: Physicochemical properties, microbial metabolism, and underlying mechanisms

Researchers investigated the combined effects of the flame retardant tetrabromobisphenol A and two types of microplastics on anaerobic granular sludge used in wastewater treatment. They found that co-exposure altered the physicochemical properties, microbial communities, and metabolic activity of the sludge. The study suggests that the interaction between microplastics and other emerging contaminants may compound their effects on wastewater treatment processes.

2024 Journal of Environmental Management 3 citations
Article Tier 2

Impact and mechanism of polyethylene terephthalate microplastics with different particle sizes on sludge anaerobic digestion

Researchers examined how polyethylene terephthalate (PET) microplastics of different particle sizes and physical aging states affect anaerobic digestion of municipal wastewater treatment sludge, conducting comparative experiments to elucidate the impact mechanisms. They found that PET microplastics accumulated in sludge alter the digestion process, with particle size influencing the degree of disruption to microbial activity and biogas production.

2024 Environmental Pollution 1 citations
Article Tier 2

Effects of mesophilic and thermophilic anaerobic digestion of sewage sludge on different polymers: Perspectives on the potential of the treatment to degrade microplastics

Researchers tested whether mesophilic and thermophilic anaerobic digestion of sewage sludge could degrade common microplastic polymers. While they observed some surface changes and degradation signs in certain plastics, the process could not comprehensively break down any of the eight polymer types tested. The study concludes that anaerobic digestion of sewage sludge, under the conditions tested, is not an effective method for eliminating microplastics before sludge is applied to soil.

2023 The Science of The Total Environment 31 citations
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

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