We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Impact and microbial mechanism of continuous nanoplastics exposure on the urban wastewater treatment process
Summary
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.
Contamination by nanoplastics in urban water has aroused increasing concern. The impact of nanoplastic exposure on the wastewater treatment process in the long term is still unclear. This study investigated the effect of continuous nanoplastic exposure (R1:0, R2:10, R3:100, and R4:1000 μg/L) on the nitrification and denitrification processes for over 200 days in a sequencing batch reactor (SBR). The results revealed that nanoplastic exposure does not demonstrate significant inhibition of total nitrogen removal. The ammonia oxidation rate (19.24 ± 0.01 mgN/gMLVSS/h, p < 0.05) and denitrification rate (11.78 ± 0.11 mgN/ gMLVSS/h, p < 0.05) in R4 was significantly lower than the control (R1: 0 μg/L). The maximal reaction velocities of NO reduction (Vmax) were improved after long-term exposure to nanoplastics in high concentrations. The R3 demonstrated the highest Vmax value-six times higher than R4 and approximately 20 times higher than R1 and R2. The microbial structure largely varied with the exposure to nanoplastics, where the exposure to a high concentration largely suppressed the nitrifier and selectively enriched the denitrifier. The percentage of the top 20 genera of denitrifiers increased from 31.76% to 63.42%, and the nitrifiers decreased from an initial 12.40% to 2.83% for R4. The predominant genera were found to be Thauera, Azoarcus, and Defluviicoccus in R4 and R3 which indicated their tolerance to nanoplastics. The function prediction results indicated that the membrane transport function was significantly enhanced and the lipid metabolism function was significantly reduced in R4 as compared with the control (R1, p<0.05). This may be attributed to the adsorption of nanoplastics on bacteria. Observation under a scan electronic microscope demonstrated that the nanoplastics were firmly attached to the microbe surface and aggregated in activated sludge at high nanoplastics dosed reactor. These results deepen the understanding of the effect of nanoplastics on the urban wastewater treatment process and provide valuable information for the management of nanoplastic contamination in urban wastewater.
Sign in to start a discussion.
More Papers Like This
Unveiling the plastisphere in anammox process: Physicochemical evolution of microplastics and microbial succession dynamics
Researchers tracked how polyethylene terephthalate microplastics change physically and chemically over 30 days in an anaerobic wastewater treatment system. They found that while the microplastics had minimal impact on nitrogen removal efficiency, they developed distinct microbial communities on their surfaces that evolved over time. The study provides new insights into how microplastics interact with beneficial microbes in wastewater treatment processes.
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.
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.
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.
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.