Resistance of anaerobic activated sludge acclimated by different feeding patterns: response to different stress shocks

Abstract. Anaerobic activated sludge plays a key role in the anaerobic digestion (AD) treatment of wastewater. The ability of anaerobic activated sludge to endure stress shock determines the performance of AD. In this study, the resistance of anaerobic activated sludge acclimated by three feeding patterns (continuous, semi-continuous, and pulse) to four stress shocks, including low pH influent, high OLR (organic loading rate), high ammonium and high sulfate, was investigated respectively. The results showed that the anaerobic activated sludge acclimated by semi-continuous feeding had the best resistance to high OLR shock, followed by pulse feeding, and then continuous feeding. There was no significant difference in the resistance of the three activated sludge to the other stress shocks. Under stress shock, the microbial community structure and abundance of specific functional microorganisms in the activated sludge acclimated by different feeding patterns varied, while the relative abundance of Methanosarcinaceae in the anaerobic activated sludge increased. The variation in the relative abundance of specific functional microorganisms was in charge of the differences in the resistance of anaerobic activated sludge. Overall, the results presented herein provide reference for improving the stability and effectiveness of activated sludge under adverse conditions.

摘要。厌氧活性污泥在废水的厌氧消化（AD）处理中起着关键作用。厌氧活性污泥承受应激冲击的能力决定了厌氧消化的性能。在本研究中，分别研究了通过三种进料模式（连续、半连续和脉冲）驯化的厌氧活性污泥对四种应激冲击的抗性，包括低pH进水、高有机负荷率（OLR）、高铵和高硫酸盐。结果表明，半连续进料驯化的厌氧活性污泥对高OLR冲击的抗性最佳，其次是脉冲进料，然后是连续进料。三种活性污泥对其他应激冲击的抗性没有显著差异。在应激冲击下，不同进料模式驯化的活性污泥中微生物群落结构和特定功能微生物的丰度发生变化，而厌氧活性污泥中甲烷八叠球菌科的相对丰度增加。特定功能微生物相对丰度的变化是导致厌氧活性污泥抗性差异的原因。总体而言，本文所呈现的结果为提高活性污泥在不利条件下的稳定性和有效性提供了参考。