Strategic Water Infrastructure Lab, School of Civil, Mining and Environmental Engineering, University of Wollongong, NSW 2522, Australia.
Sydney Water, Parramatta, NSW 2124, Australia.
Bioresour Technol. 2017 Jun;234:439-447. doi: 10.1016/j.biortech.2017.03.051. Epub 2017 Mar 12.
Recuperative thickening can intensify anaerobic digestion to produce more biogas and potentially reduce biosolids odour. This study elucidates the effects of sludge shearing during the thickening process on the microbial community structure and its effect on biogas production. Medium shearing resulted in approximately 15% increase in biogas production. By contrast, excessive or high shearing led to a marked decrease in biogas production, possibly due to sludge disintegration and cell lysis. Microbial analysis using 16S rRNA gene amplicon sequencing showed that medium shearing increased the evenness and diversity of the microbial community in the anaerobic digester, which is consistent with the observed improved biogas production. By contrast, microbial diversity decreased under either excessive shearing or high shearing condition. In good agreement with the observed decrease in biogas production, the abundance of Bacteroidales and Syntrophobaterales (which are responsible for hydrolysis and acetogenesis) decreased due to high shearing during recuperative thickening.
恢复性增稠可以强化厌氧消化，从而产生更多沼气，并有可能减少生物固体的臭味。本研究阐明了增稠过程中污泥剪切对微生物群落结构的影响及其对沼气生产的影响。中等程度的剪切可使沼气产量增加约 15%。相比之下，过度或高剪切会导致沼气产量明显下降，这可能是由于污泥解体和细胞裂解所致。使用 16S rRNA 基因扩增子测序进行微生物分析表明，中等程度的剪切增加了厌氧消化器中微生物群落的均匀度和多样性，这与观察到的沼气产量提高是一致的。相比之下，在过度剪切或高剪切条件下，微生物多样性会降低。与观察到的沼气产量下降情况非常吻合的是，在恢复性增稠过程中由于高剪切，负责水解和产乙酸作用的拟杆菌门和互营杆菌门的丰度下降。
