1. Electrochemical pretreatment enhancing co-fermentation of waste activated sludge and food waste into volatile fatty acids: Performance, microbial community dynamics and metabolism.
- Author
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Lin, Qingshan, Dong, Xinlei, Luo, Jinming, Zeng, Qian, Ma, Jie, Wang, Zongping, Chen, Guanghao, and Guo, Gang
- Subjects
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FOOD waste , *MICROBIAL communities , *FATTY acids , *DISSOLVED organic matter , *METABOLISM , *LYSIS , *BIOELECTROCHEMISTRY - Abstract
[Display omitted] • WAS-FW Co-AF with EPT for VFAs production was investigated. • The mechanism of WAS-FW Co-AF with EPT for VFAs production was revealed. • EPT produced RCS to promote disintegration of WAS-FW and biodegradability of DOM. • Residual RCS causes a dramatic shift of microbial community structure. • EPT and the addition of FW synergistically promoted VFAs production. Waste activated sludge (WAS) has low biodegradability that restricts acidogenic fermentation (AF), thereby limiting the high-value volatile fatty acids (VFAs) production. This study investigated an alternative electrochemical pretreatment (EPT) approach that can facilitate AF of WAS and food waste (FW) and therefore enhance VFAs production. The results showed through introducing 50 % volatile solid basis of FW (containing massive chloride) into WAS, a 60-min EPT produced reactive chlorine species (RCS), which diffused into WAS-FW inner layers resulting in cell lysis, therefore significantly promoted and accelerated WAS-FW disintegration, contributing to more soluble and biodegradable dissolved organic matter (DOM). Then during the subsequent 15-day acidogenic co-fermentation (Co-AF), the residual RCS (approximate 5 mg Cl 2 /L) also caused acidogenic bacteria (including Prevotella_7 , Lactobacillus and Veillonella) gradually outcompeted methanogens due to their different tolerance to residual RCS. Consequently, the maximum VFAs yield of the WAS-FW Co-AF with EPT was 40.8 % higher than WAS-AF without EPT. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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