State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Lake and Watershed Science for Water Security, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Lake and Watershed Science for Water Security, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China; Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei, 430070, China.
J Environ Manage. 2024 Oct;369:122412. doi: 10.1016/j.jenvman.2024.122412. Epub 2024 Sep 4.
Perfluorooctanoic acid (PFOA) as emerging pollutants was largely produced and stable in nature environment. Its fate and effect to the wasted sludge digestion process and corresponding microbial mechanism was rarely reported. This study investigated the different dose of PFOA to the wasted sludge digestion process, where the methane yield and microbial mechanism was illustrated. The PFOA added before digestion were 0-10000 μg/L, no significant variation in daily and accumulated methane production between each group. The 9th day methane yield was significantly higher than other days (p < 0.05). The soluble protein was significantly decreased after 76 days digestion (p < 0.001). The total PFOA in sludge (R = 0.8817) and liquid (R = 0.9083) phase after digestion was exponentially correlated with PFOA dosed. The PFOA in liquid phase was occupied 54.10 ± 18.38% of the total PFOA in all reactors. The dewatering rate was keep decreasing with the increase of PFOA added (R = 0.7748, p < 0.001). The mcrA abundance was significantly correlated with the pH value and organic matter concentration in the reactors. Chloroflexi was the predominant phyla, Aminicenantales, Bellilinea and Candidatus_Cloacimonas were predominant genera in all reactors. Candidatus_Methanofastidiosum and Methanolinea were predominant archaea in all reactors. The function prediction by FAPROTAX and Tax4fun implied that various PFOA dosage resulted in significant function variation. The fermentation and anaerobic chemoheterotrophy function were improved with the PFOA dose. Co-occurrence network implied the potent cooperation among the organic matter degradation and methanogenic microbe in the digestion system. PFOA has little impact to the methane generation while affect the microbe function significantly, its remaining in the digested sludge should be concerned to reduce its potential environmental risks.
全氟辛酸（PFOA）作为新兴污染物，在自然环境中大量产生且稳定存在。其对废弃污泥消化过程的命运和影响及其相应的微生物机制鲜有报道。本研究考察了不同剂量的 PFOA 对废弃污泥消化过程的影响，阐述了甲烷生成和微生物机制。在消化前添加的 PFOA 浓度为 0-10000μg/L，各实验组的每日和累积甲烷产量没有明显变化。第 9 天的甲烷产量明显高于其他天数（p<0.05）。76 天后消化液中的可溶性蛋白显著降低（p<0.001）。消化后污泥（R=0.8817）和液相（R=0.9083）中总 PFOA 与投加的 PFOA 呈指数相关。液相中的 PFOA 占所有反应器中总 PFOA 的 54.10±18.38%。随着添加的 PFOA 增加，脱水率呈下降趋势（R=0.7748，p<0.001）。mcrA 丰度与反应器中 pH 值和有机物浓度呈显著相关。优势菌门为绿弯菌门，优势属为 Aminicenantales、Bellilinea 和 Candidatus_Cloacimonas。所有反应器中优势古菌为 Methanofastidiosum 和 Methanolinea。FAPROTAX 和 Tax4fun 的功能预测表明，不同剂量的 PFOA 导致功能发生显著变化。随着 PFOA 剂量的增加，发酵和厌氧化能异养功能得到改善。共现网络暗示在消化系统中，有机物降解和产甲烷微生物之间存在潜在的协同作用。PFOA 对甲烷生成的影响较小，但对微生物功能有显著影响，应关注其在消化污泥中的残留，以降低其潜在的环境风险。
