Papers

20 results
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Article Tier 2

Effects of polystyrene nanoplastics on extracellular polymeric substance composition of activated sludge: The role of surface functional groups

Researchers investigated how three types of polystyrene nanoplastics with different surface functional groups affect activated sludge used in wastewater treatment. All three types significantly reduced total protein production in the sludge and caused cellular oxidative stress and membrane damage, with positively charged particles causing the most harm. The findings suggest that nanoplastic contamination in wastewater could impair the biological processes essential for effective sewage treatment.

2021 Environmental Pollution 79 citations
Article Tier 2

Metagenomic analysis reveals the responses of microbial communities and nitrogen metabolic pathways to polystyrene micro(nano)plastics in activated sludge systems

Scientists used genetic analysis to study how polystyrene micro- and nanoplastics disrupt the bacteria that process nitrogen in wastewater treatment systems. At high concentrations, the plastics reduced nitrogen removal efficiency by up to 30% by generating harmful reactive oxygen species that damaged key microbial processes. This is concerning because less effective wastewater treatment means more pollutants, including microplastics themselves, could end up in waterways.

2023 Water Research 135 citations
Article Tier 2

The effects of microplastics and nanoplastics on nitrogen removal, extracellular polymeric substances and microbial community in sequencing batch reactor

Researchers found that polystyrene nanoplastics and microplastics impaired nitrogen removal in sequencing batch reactors by reducing denitrification rates, altering extracellular polymeric substances, and shifting microbial community composition in activated sludge.

2023 Bioresource Technology 54 citations
Article Tier 2

The short and long-term effect of polystyrene nanoplastics on nitrifying sludge at high nitrite concentrations

Researchers examined polystyrene nanoplastic effects on nitrifying sludge and found that while short- and long-term exposure had little impact on nitrification performance, long-term exposure shifted the nitrite-oxidizing bacterial community from Nitrobacter to Nitrospira dominance and altered cell metabolism.

2023 Journal of Environmental Sciences 10 citations
Article Tier 2

Response of aerobic granular sludge under acute inhibition by polystyrene microplastics: Activity, aggregation performance, and microbial analysis

Researchers investigated how different concentrations of polystyrene microplastics affect the performance of aerobic granular sludge used in wastewater treatment. The study found that increasing microplastic concentrations inhibited nitrogen removal rates and disrupted the microbial community structure within the sludge. Evidence indicates that microplastic contamination in wastewater can compromise the effectiveness of biological treatment processes.

2024 Environmental Pollution 17 citations
Article Tier 2

Effect of polystyrene nanoplastics on the activated sludge process performance and biomass characteristics. A laboratory study with a sequencing batch reactor

Researchers evaluated the effect of 100 nm polystyrene nanoplastics at 2 micrograms per liter on activated sludge performance and microbial community composition in a sequencing batch reactor over an extended laboratory experiment. No significant changes in nitrification or organic matter removal efficiency (96% for both reactors) were observed, but a notable increase in Patescibacteria abundance and stagnation of Nitrotoga growth in the nanoplastic-exposed reactor suggested subtle community-level sensitivity.

2022 Journal of Environmental Management 17 citations
Article Tier 2

Polystyrene nanoparticles regulate microbial stress response and cold adaptation in mainstream anammox process at low temperature

Researchers found that polystyrene nanoplastics at concentrations above 0.5 mg/L significantly impair nitrogen removal by anammox bacteria (microbes that convert ammonia to nitrogen gas) in wastewater treatment, with nanoplastics inducing oxidative stress, damaging cell membranes, and binding to cold-shock proteins that are critical for low-temperature bacterial performance.

2024 Journal of Hazardous Materials 11 citations
Article Tier 2

Microplastics perturb nitrogen removal, microbial community and metabolism mechanism in biofilm system

Researchers found that polystyrene and PET microplastics reduced total nitrogen removal by 7-16% in biofilm wastewater treatment systems by causing cell damage, altering microbial community structure, and suppressing key genes involved in denitrification and nitrogen conversion.

2023 Journal of Hazardous Materials 57 citations
Article Tier 2

Mechanisms underlying the detrimental impact of micro(nano)plastics on the stability of aerobic granular sludge: Interactions between micro(nano)plastics and extracellular polymeric substances

Researchers found that both micro- and nanoplastics at realistic concentrations harmed the performance of aerobic granular sludge, a technology used for wastewater treatment, by reducing its ability to remove nitrogen. The plastic particles interacted with the sticky substances that hold the sludge granules together, weakening their structural integrity. The study reveals a specific mechanism by which plastic pollution can undermine wastewater treatment systems that communities rely on for clean water.

2024 Journal of Hazardous Materials 31 citations
Article Tier 2

Long-term exposure to nanoplastics reshapes the microbial interaction network of activated sludge

Researchers found that long-term nanoplastic exposure over 140 days progressively degraded activated sludge treatment performance, reducing nitrogen and phosphorus removal by reshaping microbial interaction networks into smaller, less complex structures.

2022 Environmental Pollution 39 citations
Article Tier 2

Effects of unmodified and amine-functionalized polystyrene nanoplastics on nitrogen removal by Pseudomonas stutzeri: strain characteristics, extracellular polymers, and transcriptomics

Researchers investigated how two types of polystyrene nanoplastics — plain and amine-modified — affect the ability of bacteria to remove nitrogen from water, a process important for wastewater treatment. The amine-coated nanoplastics were found to be more disruptive than unmodified ones, altering the bacteria's cell surface, extracellular proteins, and gene expression. This matters because nanoplastics entering wastewater systems could undermine the biological processes that keep treated water safe to release into the environment.

2025 Environmental Science Nano 1 citations
Article Tier 2

Responses of nitrogen removal under microplastics versus nanoplastics stress in SBR: Toxicity, microbial community and functional genes

Researchers compared the effects of microplastics versus nanoplastics on nitrogen removal in sequencing batch reactors used in wastewater treatment. The study found that microplastics had no significant effect on nitrogen removal, while high concentrations of nanoplastics impaired the process by disrupting microbial communities and functional gene expression. The results suggest that nanoplastics may pose a greater threat to biological wastewater treatment performance than microplastics.

2022 Journal of Hazardous Materials 73 citations
Article Tier 2

Uncovering the toxic effects and adaptive mechanisms of aminated polystyrene nanoplastics on microbes in sludge anaerobic digestion system: Insight from extracellular to intracellular

Researchers investigated how nanoplastics with amino functional groups affect the anaerobic digestion process used to treat sewage sludge. They found that these surface-modified nanoplastics reduced methane production and disrupted the microbial communities responsible for breaking down waste. The study reveals that chemically modified nanoplastics may be more disruptive to wastewater treatment processes than unmodified particles.

2024 Journal of Hazardous Materials 23 citations
Article Tier 2

Influence of nanoplastic type on the short-cut nitrification-denitrification in a sequencing batch reactor: Elucidating the metabolic relationship of nitrogen, extracellular polymeric substances, and oxidative stress

Researchers compared the effects of biodegradable (PBAT) and non-biodegradable (polyethylene) nanoplastics on nitrogen-removing bacteria in a wastewater reactor, finding that both types disrupted nitrogen metabolism, extracellular polymer production, and oxidative stress pathways, with non-biodegradable polyethylene causing more severe inhibition of the treatment process.

2026 Journal of Hazardous Materials
Article Tier 2

Impact and microbial mechanism of continuous nanoplastics exposure on the urban wastewater treatment process

Researchers investigated the effects of continuous nanoplastic exposure on wastewater treatment over 200 days, finding that while total nitrogen removal was not significantly inhibited, nanoplastics altered microbial community composition and affected nitrification and denitrification processes.

2022 Water Research 37 citations
Article Tier 2

Polystyrene nanoplastics reshape the anaerobic granular sludge for recovering methane from wastewater

Researchers investigated the long-term effects of polystyrene nanoplastics on anaerobic granular sludge used for methane recovery from wastewater over a 120-day continuous test. The study found that while low nanoplastic concentrations had minimal impact, higher concentrations reshaped the microbial community structure and altered sludge performance, raising concerns about nanoplastic effects on wastewater treatment processes.

2020 Water Research 170 citations
Article Tier 2

Effect evaluation of microplastics on activated sludge nitrification and denitrification

Researchers found that microplastics entering wastewater treatment plants interfere with the nitrification and denitrification processes carried out by activated sludge microbes, potentially reducing the effectiveness of nutrient removal in sewage treatment. This effect could undermine water quality if microplastic loads in wastewater continue to increase.

2019 The Science of The Total Environment 172 citations
Article Tier 2

Response of aerobic granular sludge under polyethylene microplastics stress: Physicochemical properties, decontamination performance, and microbial community

Researchers investigated the impact of polyethylene microplastics on aerobic granular sludge used in wastewater treatment. The study found that microplastics significantly disrupted sludge structure, settling properties, and enzyme activities related to denitrification and phosphorus removal, with increased reactive oxygen species and cell membrane damage at higher concentrations.

2022 Journal of Environmental Management 79 citations
Article Tier 2

Role of extracellular polymeric substances in the acute inhibition of activated sludge by polystyrene nanoparticles

Researchers investigated how extracellular polymeric substances — the sticky biofilm matrix produced by bacteria — affected the acute inhibition of activated sludge by microplastics, finding that these substances played a protective role by reducing microplastic toxicity in wastewater treatment systems.

2018 Environmental Pollution 157 citations
Article Tier 2

Nanoplastics impacts on Thiobacillus denitrificans: Effects of size and dissolved organic matter

Researchers found that 100 nm polystyrene nanoplastics inhibited growth and denitrification ability of Thiobacillus denitrificans more than 350 nm particles, and that dissolved organic matter modulated nanoplastic bioavailability and toxicity in sewage systems.

2023 Environmental Pollution 6 citations