Abstract
The volatile fatty acids (VFAs) accumulation pattern and microbial community succession were studied during excess sludge (ES) alkaline fermentation at pH of 10.0 with expanded granular sludge blanket reactor over 5 cyclers. Microbial community shifted conspicuously as ES suffered alkaline fermentation. Both VFAs and acid-producing bacteria increased rapidly during the first 8 days fermentation time, and they showed a quite positive correlation relationship. In addition, soluble chemical oxygen demand (SCOD) also dramatically increased during the first 8 days, which implied 8 day was the optimum sludge retention time (SRT) for ES alkaline fermentation and VFAs accumulation time. Illumina Miseq Sequencing analysis indicated that Clostridium, Bacillus, Amphibacillus and Peptostreptococcaceae were the dominant bacteria genus to produce VFAs. Acetic acid took about 84% in total VFAs because among the total acid-producing bacteria most bacteria could produce acetic acid.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
