We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
An in-depth analysis of microbial response to exposure to high concentrations of microplastics in anaerobic wastewater fermentation
AI summary Read the abstract
This study investigated how high concentrations of three common microplastic types affect the microbes used in anaerobic wastewater treatment, finding that microplastics reduced methane production by up to 56%. PVC had the most damaging effect on the microbial communities that break down waste, while polyethylene was somewhat less disruptive. The findings matter because impaired wastewater treatment means more pollutants, including microplastics themselves, could escape into waterways that feed human water supplies.
The impact of microplastics (MPs) in anaerobic wastewater treatment on microbial metabolism is significant. Anaerobic granular sludge (AS) and biofilm (BF) are two common ways, and their responses to microplastics will have a direct impact on their application potential. This study investigated the microbial reactions of AS and BF to three types of MPs: polyethylene (PE), polyvinyl chloride (PVC), and a mixture of both (MIX). Results exhibited that MPs reduced methane output by 44.65 %, 55.89 %, and 53.18 %, elevated short-chain fatty acid (SCFA) levels by 95.93 %, 124.49 %, and 110.78 %, and lowered chemical oxygen demand (COD) removal by 28.77 %, 36.78 %, and 33.99 % for PE-MP, PVC-MP, and MIX-MP, respectively, with PVC-MP showing the greatest inhibition. Meanwhile, microplastics also facilitated the relative production of reactive oxygen species (ROS, 40.29 %-96.99 %), lactate dehydrogenase (LDH, 20.01 %-75.02 %), and adenosine triphosphate (ATP, 26.64 %-43.80 %), while reducing cytochrome c (cyt c, 23.60 %-49.02 %) and extracellular polymeric substances (EPS, 17.44 %-26.58 %). AS and BF displayed distinct enzymatic activities under MPs exposure. Correspondingly, 16S-rRNA sequencing indicated that AS was mainly involved in acetate generation by Firmicutes, while BF performed polysaccharide degradation by Bacteroidota. Metatranscriptomic analysis showed AS to be rich in acetogens (Bacillus, Syntrophobacter) and methanogens (Methanothrix, Methanobacterium), while BF contained more fermentation bacteria (Mesotoga, Lentimicrobium) and electroactive microorganisms (Clostridium, Desulfuromonas) under MIX-MP. Moreover, BF exhibited higher glycolysis gene expression, whereas AS was more active in methane metabolism, primarily through the acetoclastic methanogenic pathway's direct acetate conversion. This study provides new insights into understanding the microbial response produced by microplastics during anaerobic wastewater digestion.
More Papers Like This
Effects of Microplastics Type, Particle Size, and Concentration on the Anaerobic Digestion of Food Waste and Residual Sludge: Methane Yield, Organic Matter Degradation
AI summary Read the abstract
Researchers co-digested food waste and residual sludge in the presence of polyethylene, polypropylene, and PVC microplastics of varying sizes and concentrations, finding that smaller particles and higher doses increasingly inhibited methane production — with 3 µm PVC at 100 particles/g-TS cutting cumulative methane by 54.6% and halting output entirely by day 17.
Unraveling the effects and mechanisms of microplastics on anaerobic fermentation: Exploring microbial communities and metabolic pathways
AI summary Read the abstract
Researchers investigated how five types of microplastics affect the anaerobic fermentation process used to treat sewage sludge. They found that polyethylene microplastics caused the greatest reduction in volatile fatty acid production, while polyvinyl chloride had the least impact, and all types disrupted microbial communities in distinct ways. The study suggests that microplastic contamination in wastewater could meaningfully interfere with sludge treatment efficiency.
Long-Term Effects of Polyvinyl Chloride Microplastics on Anaerobic Granular Sludge for Recovering Methane from Wastewater
AI summary Read the abstract
Researchers studied the long-term effects of PVC microplastics on anaerobic granular sludge used in wastewater treatment over 264 days. They found that microplastic exposure significantly reduced organic matter removal efficiency by up to 35.5% and decreased methane production by up to 32.3%, while disrupting the protective biofilm around sludge granules. The study demonstrates that microplastic contamination in wastewater can impair the biological treatment processes that cities rely on for waste management and energy recovery.
Ecological Impact of PVC Microplastics on Microbial Communities in Wet Waste Treatment Systems
AI summary Read the abstract
Researchers reviewed how PVC microplastics disrupt microbial communities in wet waste treatment systems through a combination of surface aging, preferential colonization, and time-dependent leaching of chlorinated additives and plasticizers, with chronic stress — rather than acute toxicity — emerging as the dominant mechanism impairing methane production.
Revealing How Polyvinyl Chloride Microplastic Physicochemically Affect the Anaerobic Digestion of Waste Activated Sludge
AI summary Read the abstract
PVC microplastics in sewage sludge change the surface chemistry of sludge flocs, raising the energy barrier between sludge and the microbes that break it down and causing microbial communities to reorganise. At low concentrations PVC initially increases contact efficiency, but at higher concentrations it coats sludge surfaces and blocks microbial access, ultimately reducing methane production in anaerobic digesters — a finding relevant to the performance and safety of wastewater treatment plants receiving plastic-contaminated sludge.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.