College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
J Hazard Mater. 2022 Feb 15;424(Pt B):127418. doi: 10.1016/j.jhazmat.2021.127418. Epub 2021 Oct 3.
Perfluorooctanoic acid (PFOA), as a recalcitrant organic pollutant, inevitably enters wastewater treatment facilities and is enriched in settled sludge. However, the potential impact of PFOA on sludge treatment has never been documented. In this study, the effect of PFOA on anaerobic digestion of sewage sludge and its underlying mechanism were investigated through batch and long-term experiments. The presence of PFOA was found to be deleterious for methane production from sewage sludge. 170 mg/kg total solids PFOA reduced the cumulative methane production from 197.1 ± 1.92-159.9 ± 3.10 mL/g volatile solids. PFOA induces the production of reactive oxygen species, which directly leads to cell inactivation and interferes with methane production. PFOA stimulates microorganisms to secrete more extracellular polymeric substances (mainly proteins), which not only hinders the solubilization of organic matter but also down-regulate enzyme activities to inhibit acidification and methanogenesis. In addition, PFOA reduces the diversity of microorganisms, especially the abundance of acid-producing bacteria and methanogens, making the microbial community unfavorable for methane production.
全氟辛酸（PFOA）作为一种难降解的有机污染物，不可避免地会进入废水处理设施，并在沉淀污泥中富集。然而，PFOA 对污泥处理的潜在影响从未被记录过。在这项研究中，通过批处理和长期实验研究了 PFOA 对污水污泥厌氧消化的影响及其潜在机制。研究发现，PFOA 的存在不利于污水污泥产甲烷。170 mg/kg 总固体 PFOA 使累积甲烷产量从 197.1±1.92-159.9±3.10 mL/g 挥发性固体降低。PFOA 诱导活性氧的产生，这直接导致细胞失活，并干扰甲烷的产生。PFOA 刺激微生物分泌更多的胞外聚合物物质（主要是蛋白质），这不仅阻碍了有机物的溶解，而且还下调了酶活性，抑制了酸化和产甲烷作用。此外，PFOA 降低了微生物的多样性，特别是产酸细菌和产甲烷菌的丰度，使微生物群落不利于甲烷的产生。
