Effects of free nitrous acid combined with alkyl polyglucoside on short-chain fatty acids production from waste activated sludge anaerobic fermentation and fermentation liquor for polyhydroxyalkanoates synthesis
Effects of free nitrous acid combined with alkyl polyglucoside on short-chain fatty acids production from waste activated sludge anaerobic fermentation and fermentation liquor for polyhydroxyalkanoates synthesis
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游离亚硝酸与烷基多糖苷联用对废活性污泥厌氧发酵产短链脂肪酸及聚羟基脂肪酸酯合成发酵液的影响
DOI：
10.1016/j.jwpe.2023.103515
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发表时间：
2023
影响因子：
7
通讯作者：
Zhou Yiwen
中科院分区：
文献类型：
--
作者：
Wu Yuqi;Song Xiulan;Zhang Yuhong;Liu Yaohui;Su Bingqin;Zhou Yiwen
游离亚硝酸（FNA）预处理和烷基糖苷（APG）添加是提高废弃活性污泥（WAS）厌氧发酵（AF）性能的环保方法。所产生的短链脂肪酸（SCFAs）是用于聚羟基脂肪酸酯（PHAs）合成以降低C源成本的可用底物。本研究旨在探讨FNA + APG处理的最佳发酵条件以及AF系统中SCFAs合成PHA的性能。通过考察FNA + APG组合处理效果、关键酶活性和微生物群落变化，确定了最佳发酵条件下的AFL作为PHA合成的碳源。结果表明，0.653 mg/L FNA + 0.075 g/g VSS APG处理在AF第5 d时可获得最大的SCFAs产量，为324.94 mg COD/g VSS，远高于单独FNA或APG处理。机理分析表明，FNA + APG处理可促进WAS的溶解、水解和产酸，但严重抑制甲烷生成。微生物群落分析结果表明，SCFA生产菌，包括肠球菌和梭菌，成为FNA + APG反应器中的优势菌属。最后，将氨去除后的AF液用于分批模式PHA合成，并且PHA产率在五个操作周期后增加到最大为生物量的44.44%（w/w）。
Free nitrous acid (FNA) pretreatment and alkyl polyglucoside (APG) addition are environmentally-friendly methods for enhancing waste activated sludge (WAS) anaerobic fermentation (AF) performances. The short-chain fatty acids (SCFAs) produced are available substrates for polyhydroxyalkanoates (PHAs) synthesis to reduce the C-source cost. This study aims to investigate the optimal fermentation conditions of FNA + APG treatment and the performance of PHAs synthesis by the SCFAs from AF system. Through investigating the FNA + APG combined treatment effects, key enzyme activities, and microbial community variation, the AFL from optimal fermentation condition was utilized as a C-source for PHAs synthesis. Experimental results indicated that 0.653 mg/L FNA + 0.075 g/g VSS APG treatment could synergistically achieve the maximum total SCFAs yield of 324.94 mg COD/g VSS at day 5 of AF, which was much more than those of sole FNA or APG treatment. Mechanism analysis indicated that FNA + APG treatment could promote WAS solubilization, hydrolysis and acidogenesis, while severely inhibiting methanogenesis. Microbial community analysis results demonstrated that SCFA producers, including Enterococcus and Clostridium, became the dominant genera in the FNA + APG reactor. Finally, AF liquor after ammonia removal was applied for batch-mode PHAs synthesis, and PHA yields increased to a maximum of 44.44 % of biomass (w/w) after five operation periods.