Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China; School of Energy and Environment, Anhui University of Technology, Ma'anshan 243000, China.
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, 1 Xikang Road, Nanjing 210098, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, China.
Sci Total Environ. 2022 Sep 10;838(Pt 1):156054. doi: 10.1016/j.scitotenv.2022.156054. Epub 2022 May 18.
Percarbonate (PC), as a cheap and environmental-friendly chemical oxidant, has been applied extensively in various fields. However, the impacts of PC on the waste activated sludge (WAS) anaerobic fermentation process are unknown. This study mainly aimed to investigate its effects on the production of volatile fatty acids (VFAs) and disclose the underlying mechanisms. Results indicated that the maximal VFAs yield at 0.3 g PC/g TSS within 4 d was 1452.9 mg COD/L while it was only 296.4 mg COD/L in the control at the fermentation time of 6 d. The mechanistic analysis demonstrated that PC treatment substantially promoted the extracellular polymeric substances (EPS) disruption and cell lysis, and meanwhile improved the biodegradability of released organics, thereby providing more bio-availability substrates for further acidogenic metabolic processes. Moreover, the abundance of fermentative microorganisms (i.e., Proteiniclasticum) and the microbial activities correlated with substrates metabolism and VFAs biosynthesis (i.e. hydrolases and metabolic genetic expression levels) were also evidently improved by the PC. This work provides a feasible method for improving the resource recovery from WAS and discloses the responses of the microbial community to chemicals stimulus for the regulations of the biochemical fermentation process in anaerobic systems.
过碳酸盐（PC）作为一种廉价且环保的化学氧化剂，已广泛应用于各个领域。然而，其对剩余活性污泥（WAS）厌氧发酵过程的影响尚不清楚。本研究主要旨在探讨其对挥发性脂肪酸（VFAs）生成的影响，并揭示其潜在机制。结果表明，在 4 天内以 0.3 g PC/g TSS 的用量下，VFAs 的最大产量为 1452.9 mg COD/L，而在 6 天的发酵时间内，对照组仅为 296.4 mg COD/L。机理分析表明，PC 处理可显著促进细胞外聚合物（EPS）的解体和细胞裂解，同时提高释放有机物的生物降解性，从而为进一步的产酸代谢过程提供更多的生物可利用底物。此外，发酵微生物（如蛋白水解菌）的丰度及其与底物代谢和 VFAs 生物合成相关的微生物活性（如水解酶和代谢遗传表达水平）也明显得到了 PC 的改善。这项工作为提高 WAS 的资源回收提供了一种可行的方法，并揭示了微生物群落对化学刺激的反应，以调节厌氧系统中的生化发酵过程。
