College of Environmental Science and Engineering, Taiyuan University of Technology, 209 Daxue Road, Jinzhong, 030600, PR China.
College of Environmental Science and Engineering, Taiyuan University of Technology, 209 Daxue Road, Jinzhong, 030600, PR China; National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing, 100124, PR China.
J Environ Manage. 2024 May;359:121078. doi: 10.1016/j.jenvman.2024.121078. Epub 2024 May 9.
Peracetic acid (PAA) combined with free ammonia (FA) pretreatment can be utilized to promote anaerobic fermentation (AF) of waste activated sludge (WAS) to produce short-chain fatty acids (SCFAs), and the resulting SCFAs are desirable carbon sources (C-sources) for polyhydroxyalkanoate (PHA) biosynthesis. This work aimed to determine the optimum conditions for PAA + FA pretreatment of sludge AF and the feasibility of using anaerobic fermentation liquor (AFL) for PHA production. To reveal the mechanisms of integrated pretreatment, the impacts of PAA + FA pretreatment on different stages of sludge AF and changes in the microbial community structure were explored. The experimental results showed that the maximum SCFA yield reached 491.35 ± 6.02 mg COD/g VSS on day 5 after pretreatment with 0.1 g PAA/g VSS +70 mg FA/L, which was significantly greater than that resulting from PAA or FA pretreatment alone. The mechanism analysis showed that PAA + FA pretreatment promoted sludge solubilization but strongly inhibited methanogenesis. According to the analysis of the microbial community, PAA + FA pretreatment changed the microbial community structure and promoted the enrichment of bacteria related to hydrolysis and acidification, and Proteiniclasticum, Macellibacteroides and Petrimonas became the dominant hydrolytic and acidifying bacteria. Finally, after alkali treatment, the AFL was utilized for batch-mode PHA production, and a maximum PHA yield of 55.05 wt% was achieved after five operation periods.
过氧乙酸（PAA）与游离氨（FA）联合预处理可用于促进废活性污泥（WAS）的厌氧发酵（AF）以生产短链脂肪酸（SCFAs），所得到的 SCFAs 是合成聚羟基烷酸（PHA）的理想碳源（C 源）。本研究旨在确定污泥 AF 中 PAA+FA 预处理的最佳条件，以及利用厌氧发酵液（AFL）进行 PHA 生产的可行性。为了揭示集成预处理的机制，研究了 PAA+FA 预处理对污泥 AF 不同阶段的影响以及微生物群落结构的变化。实验结果表明，在 0.1 g PAA/g VSS +70 mg FA/L 预处理 5 天后，SCFA 最大产量达到 491.35 ± 6.02 mg COD/g VSS，显著高于 PAA 或 FA 单独预处理的产量。机制分析表明，PAA+FA 预处理促进了污泥的溶解，但强烈抑制了甲烷生成。根据微生物群落分析，PAA+FA 预处理改变了微生物群落结构，促进了与水解和酸化相关的细菌的富集，而 Proteiniclasticum、Macellibacteroides 和 Petrimonas 成为主要的水解酸化细菌。最后，经过碱处理，利用 AFL 进行批式 PHA 生产，经过五个运行周期，PHA 的最大产量达到 55.05wt%。
