The effect of PBS on methane production in combined MEC-AD system fed with alkaline pretreated sewage sludge
Journal
Renewable Energy
Journal Volume
152
Pages
229-236
Date Issued
2020
Author(s)
Xu, X.-J. et al.
Abstract
Batch experiments were conducted to study bioelectrochemical enhancement of the anaerobic digestion (AD) of alkaline-pretreated sewage sludge in microbial electrolysis cell (MEC) in the presence or absence of phosphate buffer solution (PBS). Experimental results showed that the maximum methane production rate was increased from 0.18 mL-CH4/(mLreactor·d) (control) to 0.2 mL-CH4/(mLreactor·d) in the presence of PBS and cumulative methane production was 1.4-fold higher than that of control. The initial concentrations of SCOD, protein, polysaccharide and VFAs in the presence of PBS were slightly higher than those of control, suggesting that PBS might facilitate the release of organics into mixed liquor. The microbial community analysis results showed that the microbial community with PBS had higher diversity and Bacteroidetes and Firmicutes were the two most abundant phyla in the communities. Moreover, the PBS addition could enhance the growth of aceticlastic methanogens (Methanosaeta) and inhibit a portion of hydrogenotrophic methanogens (Methanobacterium), possibly due to the different cell wall composition.
Type
journal article