Effects of shearing on biogas production and microbial community structure during anaerobic digestion with recuperative thickening

Authors

Shufan Yang, University of WollongongFollow
Hop Phan, University of WollongongFollow
Heriberto A. Bustamante, University of Technology, SydneyFollow
Wenshan Guo, University of Technology SydneyFollow
Hao H. Ngo, University of Technology SydneyFollow
Long D. Nghiem, University of WollongongFollow

RIS ID

113364

Publication Details

Yang, S., Phan, H. V., Bustamante, H., Guo, W., Ngo, H. & Nghiem, L. D. (2017). Effects of shearing on biogas production and microbial community structure during anaerobic digestion with recuperative thickening. Bioresource Technology, 234 439-447.

Abstract

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.