Papers

61,005 results
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Article Tier 2

Microplastics in Sewage Sludge: Worldwide Presence in Biosolids, Environmental Impact, Identification Methods and Possible Routes of Degradation, Including the Hydrothermal Carbonization Process

This review examines the worldwide presence of microplastics in sewage sludge and biosolids, along with their environmental impact when applied to agricultural land. Researchers found that wastewater treatment plants capture roughly 90% of incoming microplastics in sludge, but land application of biosolids then redistributes these particles into soils, highlighting the need for better degradation methods.

2024 Energies 15 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 Effect of Hydrothermal Carbonization Temperature on Microplastic Content in Digested Sewage Sludge and Its Relation to the Fuel Properties of Hydrochars

Hydrothermal carbonization temperature was found to influence how microplastics are transformed into hydrochar, affecting the properties of the resulting material. Optimizing this process could convert plastic waste into useful biochar-like materials while reducing the persistence of microplastics in the environment.

2025 Energies 1 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

Sewage Sludge Valorization via Hydrothermal Carbonization: Optimizing Dewaterability and Phosphorus Release

This study optimized conditions for hydrothermal carbonization of sewage sludge, finding that the process improves sludge dewaterability and can release phosphorus for potential nutrient recovery. While not directly about microplastics, sewage sludge is a major reservoir of microplastics that accumulates during wastewater treatment, and managing sludge safely is important for preventing plastic particles from reaching agricultural soils.

2020 Energies 32 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

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

Sludge-derived biochar: Physicochemical characteristics for environmental remediation

This review examines how sewage sludge can be converted into biochar, a carbon-rich material useful for cleaning up environmental contaminants including microplastics and heavy metals from water and soil. The process turns a waste product into an effective pollution filter while reducing the volume of sludge that needs disposal. This approach is relevant to microplastics research because biochar could help remove plastic particles from contaminated water and agricultural land.

2023 Applied Physics Reviews 38 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

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

Insights into hydro thermal gasification process of microplastic polyethylene via reactive molecular dynamics simulations

Researchers used molecular dynamics simulations to study the hydrothermal gasification process of polyethylene microplastics. The study found that temperature and water content significantly affect carbon conversion efficiency and product distribution, providing insights that could help optimize this technology for converting microplastic waste into useful syngas.

2024 Scientific Reports 19 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

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

Effects of chemical pretreatments on microplastic extraction in sewage sludge and their physicochemical characteristics

This study evaluated different chemical pretreatment methods for extracting microplastics from sewage sludge, finding that some treatments can alter the physical and chemical properties of plastic particles in ways that affect identification. Choosing the right extraction method is important for accurately characterizing microplastic contamination in biosolids.

2019 Water Research 166 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

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

A review of methods for mitigating microplastic contamination in biosolids from wastewater treatment plants before agricultural soil application

This review examines methods for reducing microplastic contamination in biosolids from wastewater treatment plants before they are applied to agricultural soils. Researchers assessed physical, physicochemical, and biological approaches and found that each has inherent limitations, from inconsistent microbial degradation efficiency to filter design constraints. The study suggests that combining multiple methods at different intervention points within the treatment process offers the most promising path toward effective microplastic mitigation.

2024 The Science of The Total Environment 13 citations
Article Tier 2

Microplastics and antibiotic resistance genes nexus in sewage sludge: impact of thermal hydrolysis process- anaerobic digestion

Researchers reviewed the interactions between microplastics, antibiotic resistance genes, and biofilm-embedded microbial communities in sewage sludge treatment processes. The study found that these contaminants persist through wastewater treatment including thermal hydrolysis and anaerobic digestion, posing environmental and public health risks when treated biosolids are applied to agricultural land.

2026 Bioresource Technology
Article Tier 2

Analytical Approaches for Analyzing Microplastics Using Pyrolysis Gas Chromatography Mass Spectrometry and Accelerated Solvent Extraction

Using a combination of solvent extraction and pyrolysis-based mass analysis, researchers quantified five plastic polymers in biosolids from two municipal wastewater treatment plants, finding that polyethylene dominated by mass. This mass-based approach complements particle-counting methods and provides a clearer picture of the true polymer burden in sludge that is often spread on agricultural soil, creating a potential pathway for microplastics to enter the food chain.

2026 CUNY Academic Works (City University of New York)
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

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
Review Tier 2

Microplastics contamination associated with low-value domestic source organic solid waste: A review

This review examines how microplastics contaminate domestic organic solid wastes — particularly sewage sludge and food waste — and traces their migration pathways through biological and thermal treatment processes, landfills, and soil application.

2022 The Science of The Total Environment 24 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

Hydrothermal carbonization of plastic waste: A review of its potential in alternative energy applications

Researchers reviewed how hydrothermal carbonization — a process that converts materials into a coal-like substance using heat and water under pressure — can transform plastic waste into useful products like solid fuels, catalysts, and materials for energy storage devices. While the technology is promising, challenges like variable plastic feedstock quality and scaling up production must be addressed before widespread commercial use.

2023 Fuel Communications 36 citations