College of Resources and Environmental Sciences, Henan Agricultural University, No. 63 Agricultural Road, Zhengzhou 450002, China.
College of Life Sciences, Henan Agricultural University, No. 63 Agricultural Road, Zhengzhou 450002, China.
Bioresour Technol. 2022 Feb;346:126600. doi: 10.1016/j.biortech.2021.126600. Epub 2021 Dec 29.
Volatile fatty acids (VFAs) accumulation caused by shock loading severely hampers the performance and stability of anaerobic digestion. An upflow anaerobic sludge blanket (UASB) was operated to examine its performance, sludge properties, and microbial community behavior during shock loading and recovery with exogenous N-hexanoyl-L-homoserine lactone (C-HSL). After shock loading, chemical oxygen demand (COD) removal was significantly reduced from 79.09% to 65.63%. The abundance of Methanosarcinales also significantly decreased, which resulted in acetate accumulation (1,163.55 mg/L). Sludge granules disintegrated along with the decrease in extracellular polymeric substances (EPS). After supplying 1 μg/L C-HSL, COD removal resumed to 75.10%. Furthermore, C-HSL enhanced the abundance and metabolic activity of aceticlastic methanogens, decreased acetate concentration to 146.87 mg/L, improved EPS secretion, and caused the re-assembly of disintegrated sludges to form large granules. These results advanced our understanding of microbial community behavior and provided an attractive strategy for restoration of UASB recovered from shock loading.
挥发性脂肪酸（VFAs）的积累会严重抑制厌氧消化的性能和稳定性。采用上流式厌氧污泥床（UASB）研究了在冲击负荷和外源性 N-己酰基-L-高丝氨酸内酯（C-HSL）恢复过程中冲击负荷对其性能、污泥特性和微生物群落行为的影响。冲击负荷后，化学需氧量（COD）去除率从 79.09%显著降低至 65.63%。甲烷八叠球菌的丰度也显著下降，导致乙酸积累（1163.55mg/L）。随着胞外聚合物（EPS）的减少，污泥颗粒解体。补充 1μg/L C-HSL 后，COD 去除率恢复至 75.10%。此外，C-HSL 增强了产乙酸甲烷菌的丰度和代谢活性，将乙酸浓度降低至 146.87mg/L，促进了 EPS 的分泌，并使解体的污泥重新组装成大颗粒。这些结果加深了我们对微生物群落行为的理解，并为从冲击负荷中恢复的 UASB 的恢复提供了一种有吸引力的策略。
