Papers

20 results
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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

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

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

Effect mechanism of polyethylene nanoplastics on biological phosphorus removal and microbial extracellular polymers

Researchers found that polyethylene nanoplastics (PE-NPs) at 0-20 mg/L concentrations reduced biological phosphorus removal efficiency from 96.16% to 83.97% in wastewater treatment systems. Mechanistic analysis revealed that PE-NPs induced oxidative stress, altered extracellular polymeric substance composition, and caused a microbial community shift from phosphorus-accumulating organisms to glycogen-accumulating organisms, decoupling carbon-phosphorus metabolism.

2025 Journal of Environmental Science and Health Part A
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
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

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

Effect of long-term exposure to non-biodegradable and biodegradable microplastics in continuous anoxic/aerobic bioreactors: Nitrogen removal performance, microbial communities and functional gene responses

Researchers compared the effects of biodegradable and non-biodegradable microplastics on nitrogen removal in wastewater treatment bioreactors over an extended period. They found that biodegradable polylactic acid particles were actually more harmful than conventional PET microplastics, significantly reducing the efficiency of ammonia removal by damaging beneficial bacteria. The study challenges the assumption that biodegradable plastics are always safer for wastewater treatment systems.

2024 Journal of Environmental Management 8 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

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

Response mechanism of non-biodegradable polyethylene terephthalate microplastics and biodegradable polylactic acid microplastics to nitrogen removal in activated sludge system

Researchers compared how non-biodegradable PET and biodegradable PLA microplastics affect nitrogen removal in wastewater treatment systems. Surprisingly, the biodegradable PLA caused a much larger reduction in ammonia removal efficiency than the conventional PET plastic. The study suggests that even biodegradable plastics can significantly disrupt the microbial processes that wastewater treatment plants rely on to clean water.

2024 The Science of The Total Environment 24 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
Article Tier 2

Long-term exposure of polytetrafluoroethylene-nanoplastics on the nitrogen removal and extracellular polymeric substances in sequencing batch reactor

Researchers investigated the long-term effects of polytetrafluoroethylene nanoplastics on nitrogen removal and extracellular polymeric substances in a sequencing batch reactor system. The study found that PTFE nanoplastics reduced the efficiency of chemical oxygen demand and ammonia nitrogen removal, and altered microbial activity and the composition of extracellular polymers in the biological wastewater treatment process.

2023 Enzyme and Microbial Technology 19 citations
Article Tier 2

Pseudomonas Stutzeri may alter the environmental fate of polystyrene nanoplastics by trapping them with increasing extracellular polymers

Researchers found that the denitrifying bacterium Pseudomonas stutzeri physically traps polystyrene nanoplastics within secreted extracellular polymers, which impairs bacterial growth and nitrogen removal gene expression while altering the particles' environmental fate and dispersal.

2024 The Science of The Total Environment 5 citations
Article Tier 2

Responses of nitrogen removal, microbial community and antibiotic resistance genes to biodegradable microplastics during biological wastewater treatment

Researchers compared the effects of three biodegradable microplastics on nitrogen removal and microbial communities in activated sludge wastewater treatment. They found that PHA and PLA at higher concentrations enhanced denitrification but also promoted antibiotic resistance genes, while PBS had minimal effects. The study suggests that the breakdown of biodegradable plastics into microplastics in wastewater systems may have complex and sometimes counterintuitive effects on treatment performance.

2025 Biochemical Engineering Journal 7 citations
Article Tier 2

Impaired denitrification of aerobic granules in response to micro/nanoplastic stress: Insights from interspecies interactions and electron transfer processes

This study found that micro- and nanoplastics in wastewater disrupt the ability of beneficial bacteria to remove nitrogen through a process called denitrification. After 90 days of plastic exposure, the communication system bacteria use to coordinate their activity broke down, leading to an imbalance where some bacteria stopped contributing while still consuming shared resources. This reduced the overall efficiency of biological wastewater treatment, a system many communities rely on to clean their water.

2025 Water Research 23 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

Microplastics in granular sequencing batch reactors: Effects on pollutant removal dynamics and the microbial community

Researchers investigated how polyethylene and polyethylene terephthalate microplastics affect pollutant removal in granular sludge wastewater treatment reactors. They found that microplastic type and concentration influenced nitrogen, phosphorus, and organic compound removal rates, with PET particles showing a stronger tendency to accumulate within the biomass. The study indicates that microplastic contamination in wastewater treatment systems may compromise treatment efficiency and alter microbial community dynamics.

2024 Journal of Hazardous Materials 12 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 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