Papers

61,005 results
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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

Exposure to nanoplastic induces cell damage and nitrogen inhibition of activated sludge: Evidence from bacterial individuals and groups

Researchers exposed activated sludge in a wastewater treatment reactor to polystyrene nanoplastics at concentrations up to 10 mg/L over 30 days. They found that nanoplastic exposure caused cell membrane damage, increased oxidative stress, and significantly inhibited nitrogen removal processes. The study suggests that nanoplastic accumulation in wastewater treatment plants could compromise their ability to effectively process nitrogen-containing pollutants.

2022 Environmental Pollution 52 citations
Article Tier 2

Microplastics shaped performance, microbial ecology and community assembly in simultaneous nitrification, denitrification and phosphorus removal process

This study found that polystyrene and PVC microplastics disrupted the performance of wastewater treatment systems designed to remove nitrogen and phosphorus, reducing nitrogen removal by up to 10%. The microplastics altered microbial communities, decreased cooperation between beneficial bacteria, and blocked important biological pathways. Since wastewater treatment is a key barrier against pollution reaching drinking water, microplastic interference with these systems could indirectly increase human exposure to harmful contaminants.

2024 The Science of The Total Environment 12 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

Metagenomic insight into the enrichment of antibiotic resistance genes in activated sludge upon exposure to nanoplastics

Researchers used metagenomic analysis to show that polystyrene nanoplastics at environmentally relevant concentrations increased antibiotic resistance genes in activated sludge by up to 59%, primarily by promoting horizontal gene transfer and enriching Proteobacteria host populations — raising concerns about nanoplastic-driven spread of antibiotic resistance in wastewater treatment.

2024 Environmental Pollution 7 citations
Article Tier 2

Polystyrene nanoplastics shape microbiome and functional metabolism in anaerobic digestion

Researchers studied how polystyrene nanoplastics and microplastics affect the microbial communities and biochemical processes in anaerobic digestion systems used for waste treatment. They found that nanoplastics had a more disruptive effect than microplastics, significantly altering the composition and metabolic functions of the microbial community. The study suggests that plastic contamination in waste streams could reduce the efficiency of anaerobic digestion, a widely used waste processing technology.

2022 Water Research 88 citations
Article Tier 2

Insight into effect of polyethylene microplastic on nitrogen removal in moving bed biofilm reactor: Focusing on microbial community and species interactions

Researchers studied how polyethylene microplastics affect nitrogen removal in wastewater treatment bioreactors and found that low concentrations slightly improved the process, while higher concentrations disrupted it. The microplastics changed the microbial communities responsible for breaking down nitrogen in wastewater. This matters because less effective wastewater treatment means more nitrogen pollution in waterways, and microplastics entering treatment plants could reduce their ability to clean water effectively.

2024 The Science of The Total Environment 17 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

Deciphering the role of polystyrene microplastics in waste activated sludge anaerobic digestion: Changes of organics transformation, microbial community and metabolic pathway

Researchers found that polystyrene microplastics in sewage sludge affected the anaerobic digestion process used to treat waste, with low concentrations slightly boosting methane production but high concentrations reducing it by up to 11%. The microplastics disrupted key bacterial communities and enzyme activities needed for proper waste breakdown. This matters because wastewater treatment plants handle enormous volumes of microplastic-laden sludge, and impaired digestion could reduce treatment effectiveness and release more pollutants into the environment.

2023 The Science of The Total Environment 43 citations
Article Tier 2

Mechanistic insights into the impact of multi-dimensional microplastic stress on nitrogen removal by heterotrophic nitrifying-aerobic denitrifying bacteria: A meta-transcriptomic analysis

Researchers studied how different types of microplastics affect bacteria that are used to remove nitrogen from wastewater. They found that PVC microplastics were particularly disruptive, interfering with enzyme function and gene expression needed for denitrification. The study provides molecular-level insights into how microplastic pollution could undermine biological wastewater treatment systems.

2025 Journal of Environmental Management 2 citations
Article Tier 2

Comprehensive metagenomic and enzyme activity analysis reveals the negatively influential and potentially toxic mechanism of polystyrene nanoparticles on nitrogen transformation in constructed wetlands

Researchers exposed constructed wetlands to polystyrene nanoparticles and found that even 1–10 mg/L concentrations suppressed denitrification and nitrification enzyme activities, reduced the abundance of nitrogen-cycling microbial genes, and generated oxidative stress in both macrophytes and microorganisms — disrupting the nitrogen transformation essential to wetland water-purification function.

2021 Water Research 196 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

Deciphering the inhibitory mechanisms of polystyrene microplastics on thermophilic methanogens from the insights of microbial metabolite profiling and metagenomic analyses

Researchers studied how polystyrene microplastics affect methane production during the thermophilic anaerobic digestion of food waste. They found that increasing microplastic concentrations reduced methane yield by up to 47.8%, driven by the accumulation of reactive oxygen species that inhibited key enzymes in the digestion process. Metagenomic analysis revealed that microplastics downregulated genes involved in methane metabolism, providing new insights into how plastic contamination can disrupt waste treatment systems.

2025 Journal of Hazardous Materials 5 citations
Article Tier 2

Polystyrene microplastics induce microbial dysbiosis and dysfunction in surrounding seawater

Researchers used gene sequencing to study how polystyrene microplastics disrupt the microbial community and function in surrounding aquaculture water. The study found that microplastic exposure shifted the balance of beneficial and potentially harmful bacteria, altered nitrogen cycling pathways, and enriched antibiotic resistance genes, suggesting that microplastics in aquaculture settings could compromise water quality and ecosystem health.

2021 Environment International 88 citations
Article Tier 2

Unveiling microplastic's role in nitrogen cycling: Metagenomic insights from estuarine sediment microcosms

Researchers used metagenomic analysis to examine how polyethylene and polystyrene microplastics affect nitrogen cycling in estuarine sediments. They found that microplastics altered the abundance of genes involved in key nitrogen transformation processes like nitrification and denitrification. The study reveals that microplastic pollution in estuaries may disrupt important biogeochemical cycles that support aquatic ecosystem health.

2024 Environmental Pollution 12 citations
Article Tier 2

Responses of syntrophic microbial communities and their interactions with polystyrene nanoplastics in a microbial electrolysis cell

Researchers investigated how polystyrene nanoplastics affect microbial communities in a microbial electrolysis cell, a technology used for energy recovery during wastewater treatment. They found that nanoplastics disrupted the biofilm structure and altered the composition of the microbial communities responsible for breaking down waste. The study suggests that nanoplastic contamination in wastewater could reduce the efficiency of these promising electrochemical treatment systems.

2023 The Science of The Total Environment 24 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

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

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

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

Adaptation responses of microalgal-bacterial granular sludge to polystyrene microplastic particles in municipal wastewater

Researchers found that polystyrene microplastics of varying sizes did not significantly impair organic, ammonia, or phosphorus removal in microalgal-bacterial granular sludge systems treating municipal wastewater, though the microplastics did alter microbial community composition.

2022 Environmental Science and Pollution Research 28 citations
Article Tier 2

Polystyrene microplastics accumulation in lab-scale vertical flow constructed wetlands: impacts and fate

Researchers tested how polystyrene microplastics affect constructed wetlands, a nature-based system used to treat wastewater. They found that while the wetlands still removed most pollutants effectively, nitrogen removal decreased by up to 5% in the presence of microplastics, and the particles accumulated mainly in the upper layers of the wetland substrate. The study suggests that microplastics can alter the microbial communities responsible for breaking down nitrogen in these treatment systems.

2023 Journal of Hazardous Materials 24 citations
Article Tier 2

Revealing the influencing mechanisms of polystyrene microplastics (MPs) on the performance and stability of the algal-bacterial granular sludge

Researchers investigated how polystyrene microplastics affect algal-bacterial granular sludge used in wastewater treatment, finding that the sludge removed over 96% of incoming microplastics but that microplastics inhibited COD removal by 2.6 to 4.1% and total phosphorus removal by 2.9 to 5.8%. Structural stability was compromised through oxidative stress, altered protein composition, and reduced abundance of key functional bacteria.

2022 Bioresource Technology 73 citations
Article Tier 2

Impact of polyethylene microplastics on the nitrogen removal and bacterial community in sequencing batch reactor at different hydraulic retention times

Researchers examined how polyethylene microplastics affect nitrogen removal performance in biological wastewater treatment at different hydraulic retention times. The study found that the presence of microplastics amplified the negative effects of shortened treatment times on nitrogen removal efficiency and altered bacterial communities and enzyme levels involved in nitrification and denitrification, offering new insights into how microplastics interfere with wastewater treatment processes.

2025 Journal of Environmental Management 7 citations