Papers

61,005 results
|
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

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

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

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

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

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

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

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

Nanoplastics Disturb Nitrogen Removal in Constructed Wetlands: Responses of Microbes and Macrophytes

The impact of nanosized plastics on nitrogen removal in constructed wetlands was investigated by examining microbial community responses and denitrification processes. Nanoplastics disturbed biological nitrogen removal in the wetland system, with microorganisms showing altered community structure and reduced denitrification efficiency.

2020 Environmental Science & Technology 270 citations
Article Tier 2

Microplastics provide new niches for nitrifiers to maintain nitrification performance in nitrifying bioreactors

Researchers found that microplastics provide novel niches for nitrifying bacteria in wastewater treatment systems, with MP surfaces maintaining nitrification performance even under stress conditions that suppress conventional nitrifiers, suggesting unexpected ecosystem services from plastic contamination in treatment settings.

2025 Environmental Research
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

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

Nitrogen removal performance of bioretention cells under polyethylene (PE) microplastic stress

Researchers investigated how polyethylene microplastics affect the nitrogen removal performance of bioretention cells used to filter stormwater runoff. The study found that microplastic accumulation reduced overall nitrogen removal efficiency by up to 28% while altering the microbial community structure responsible for denitrification.

2023 Environmental Pollution 13 citations
Article Tier 2

The Effects of Microplastics on Floc Formation, Nutrient Removal and Settleability in Wastewater Treatment

Researchers examined the interactions of microplastics with activated sludge in wastewater treatment plants, investigating effects on floc formation, nutrient removal efficiency, and settleability to understand how microplastic contamination may compromise treatment performance.

2024
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

Impact and mechanism of microplastics on the denitrification of a bioretention system

Researchers studied how microplastics from disposable face masks affect the ability of bioretention systems to remove nitrogen from stormwater runoff. They found that accumulating microplastics reduced nitrogen removal efficiency and suppressed key denitrifying bacteria and enzyme activity. The study suggests that microplastic pollution may compromise the performance of green infrastructure designed to filter and clean urban stormwater.

2025 Journal of Hazardous Materials 4 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

Microplastics inhibit biofloc formation and alter microbial community composition and nitrogen transformation function in aquaculture

Microplastics were found to inhibit biofloc formation in aquaculture systems and alter microbial community composition and nitrogen transfer processes. The findings raise concerns about the growing use of intensive biofloc-based aquaculture in areas where microplastic contamination is prevalent.

2023 The Science of The Total Environment 25 citations
Article Tier 2

Do Microplastics Affect Biological Wastewater Treatment Performance? Implications from Bacterial Activity Experiments

Researchers tested the effects of polyester, polyethylene, and polyvinylchloride microplastics at concentrations of 50-10,000 particles/L on the activities of key wastewater treatment bacteria, finding no statistically significant differences in the activity of ammonium-oxidising bacteria, nitrite-oxidising bacteria, denitrifiers, or polyphosphate-accumulating organisms. The study concludes that microplastics at tested concentrations do not meaningfully impair biological wastewater treatment performance.

2019 ACS Sustainable Chemistry & Engineering 80 citations
Article Tier 2

A review of microplastics stress on nitrogen conversion and nitrous oxide emissions from biological wastewater treatment: Efficiency, mechanism and prospects

This review analyzes how microplastics affect nitrogen conversion processes and nitrous oxide emissions during biological wastewater treatment. Researchers found that microplastics can disrupt key nitrogen-cycling steps including nitrification and denitrification, potentially increasing emissions of the potent greenhouse gas nitrous oxide. The study highlights the dual environmental concern of microplastics interfering with both water treatment efficiency and climate-relevant gas emissions.

2026 The Science of The Total Environment
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

Effect of Polypropylene Microplastics Concentration on Wastewater Denitrification

Researchers investigated the effect of polypropylene microplastic concentration on wastewater denitrification, finding that PP microplastics impaired the NO2-N reduction step and increased greenhouse gas N2O production in a concentration-dependent manner, with significant NO2-N accumulation observed at 60 mg/L, while NO3-N removal remained largely unaffected.

2022 Science Journal of Chemistry 8 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

A review of microplastics on anammox: Influences and mechanisms

This review summarizes how microplastics affect anammox, a key biological process used in wastewater treatment to remove nitrogen. Microplastics disrupt the microbial communities that perform this process, reducing treatment efficiency depending on plastic concentration, size, and type. Since wastewater treatment is a critical barrier preventing pollutants from reaching drinking water sources, any reduction in treatment performance could increase human exposure to contaminants.

2024 Journal of Environmental Management 14 citations