Enhancement of volatile fatty acid production by co-fermentation of food waste and excess sludge without pH control: The mechanism and microbial community analyses.
The study provided a cost-effective and high-efficiency volatile fatty acid (VFA) production strategy by co-fermentation of food waste (FW) and excess sludge (ES) without artificial pH control. VFA production of 867.42mg COD/g-VS was obtained under the optimized condition: FW/ES 5, solid retention time 7d, organic loading rate 9g VS/L-d and temperature 40°C. Mechanism exploration revealed that the holistic biodegradability of substrate was greatly enhanced, and proper pH range (5.2-6.4) was formed by the high buffering capacity of the co-fermentation system itself, which effectively enhanced hydrolysis yield (63.04%) and acidification yield (83.46%) and inhibited methanogenesis. Moreover, microbial community analysis manifested that co-fermentation raised the relative abundances of hydrolytic and acidogenic bacteria including Clostridium, Sporanaerobacter, Tissierella and Bacillus, but suppressed the methanogen Anaerolineae, which also facilitated high VFA production. These results were of great guiding significance aiming for VFA recovery from FW and ES in large-scale.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Qing-Lian
QL
Wu
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China. Electronic address: guowanqian@126.com.
Wan-Qian
WQ
Guo
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
He-Shan
HS
Zheng
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Hai-Chao
HC
Luo
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Xiao-Chi
XC
Feng
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Ren-Li
RL
Yin
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Nan-Qi
NQ
Ren
D000641:Ammonia / Q000378:metabolism; D001421:Bacteria, Anaerobic / Q000378:metabolism; D003013:Clostridium / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000378:metabolism*; D005285:Fermentation; D005502:Food; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008697:Methane / Q000096:biosynthesis; D059013:Microbial Consortia; D012722:Sewage / Q000382:microbiology*; D013696:Temperature; D018505:Waste Management / Q000379:methods*
D005232:Fatty Acids, Volatile; D012722:Sewage; D000641:Ammonia; D008697:Methane
Co-fermentation; DOM; Excess sludge; Food waste; Microbial community; Volatile fatty acid