title: Effect of temperature on short chain fatty acids (SCFAs) accumulation and microbiological transformation in sludge alkaline fermentation with Ca(OH)₂ adjustment.
abstract: The effects of temperatures (15-55 °C) on the alkaline fermentation of sewage sludge were investigated in semi-continuous stirred tank reactors (semi - CSTR) at the pH of 10. The highest soluble chemical oxygen demand (SCOD) yield was obtained at 55 °C (764.2 mg/(gVS L d)), while the highest short chain fatty acids (SCFAs) yield was observed at 35 °C (319.8 mg/(gVS L d)), 1.5 times higher than SCFAs yield at 55 °C (209.5 mg/(gVS L d)). The proportion of the intercellular organic substances being transferred to the slime layer of sludge flocs increased from 29% at 15 °C to 54% at 55 °C. But only a small part of soluble organic substances in the slime layers was converted to SCFAs at 55 °C. The dewaterability of sludge was better at 35 °C than that at 55 °C. Microbiological community analysis showed the acid-producing microorganisms at the medium temperatures (25 °C and 35 °C) were more diverse and abundant than those at the low (15 °C) and high temperatures (55 °C). Clodtridium and Bacillus in Firmicutes and Gamma proteobacterium in Proteobacteria were the dominant functional bacterial species for high SCFA accumulation.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, China.
authors.forename: XiaoLing
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, China; Key Laboratory of Beijing Water Quality Science and Water Environment Recovery Engineering, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, China. Electronic address: pyz@bjut.edu.cn.
authors.forename: YongZhen
authors.initials: Y
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, China.
authors.forename: NanQi
authors.initials: N
authors.lastname: Ren
authors.affiliation: Department of Civil and Environmental Engineering, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: BaiKun
authors.initials: B
authors.lastname: Li
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, China.
authors.forename: TongZhi
authors.initials: T
authors.lastname: Chai
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, Heilongjiang, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors; D002126:Calcium Hydroxide / Q000032:analysis*; D058645:Denaturing Gradient Gel Electrophoresis; D005232:Fatty Acids, Volatile / Q000378:metabolism*; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D016133:Polymerase Chain Reaction; D012722:Sewage / Q000032:analysis* / Q000382:microbiology*; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D005232:Fatty Acids, Volatile; D012722:Sewage; D014874:Water Pollutants, Chemical; D002126:Calcium Hydroxide
keywords: Alkaline fermentation of sewage sludge; Dewaterability; Microbial community; Short chain fatty acids (SCFAs); Temperature