title: Continuous volatile fatty acid production from waste activated sludge hydrolyzed at pH 12.
abstract: This study adopted rapid alkaline treatment at pH 12 to hydrolyze 66% of total chemical oxygen demands. Then the hydrolyzed liquor was fermented in a continuous-flow stirred reactor to produce volatile fatty acids (VFAs) at 8-h hydraulic retention time and at 35 °C. The maximum VFA productivity reached 365 mg VFAs g(-1) volatile suspended solids in a 45-d operation, with most produced VFAs being acetate and propionate, principally produced by protein degradation. The Bacteroidia, ε-proteobacteria and the Clostridia were identified to be the classes correlating with the fermentation processes. The fermented liquor was applied to denitrifying phosphorus removal process as alternative carbon source after excess phosphorus and nitrogen being recycled via struvite precipitation. Fermented liquors from alkaline hydrolysis-acid fermentation on waste activated sludge are a potential renewable resource for applications that need organic carbons.
authors.affiliation: Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang 830011, China; School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Environmental Science and Engineering, Fudan University, Shanghai 20043, China.
authors.forename: Chunli
authors.initials: C
authors.lastname: Wan
authors.affiliation: Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang 830011, China; Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan. Electronic address: djleetw@yahoo.com.tw.
authors.forename: Duu-Jong
authors.initials: DJ
authors.lastname: Lee
authors.affiliation: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Maoan
authors.initials: M
authors.lastname: Du
authors.affiliation: Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang 830011, China.
authors.forename: Xiangliang
authors.initials: X
authors.lastname: Pan
authors.affiliation: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wan
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D019149:Bioreactors / Q000382:microbiology; D011232:Chemical Precipitation; D005232:Fatty Acids, Volatile / Q000096:biosynthesis*; D005285:Fermentation; D059014:High-Throughput Nucleotide Sequencing; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D017616:Magnesium Compounds / Q000737:chemistry; D009584:Nitrogen / Q000302:isolation & purification; D010710:Phosphates / Q000737:chemistry; D010758:Phosphorus / Q000302:isolation & purification; D011134:Polysaccharides / Q000032:analysis; D012722:Sewage / Q000737:chemistry*; D000069877:Struvite; D014866:Waste Products
chemical_list: D001426:Bacterial Proteins; D005232:Fatty Acids, Volatile; D017616:Magnesium Compounds; D010710:Phosphates; D011134:Polysaccharides; D012722:Sewage; D014866:Waste Products; D010758:Phosphorus; D000069877:Struvite; D009584:Nitrogen
keywords: Continuous; Denitrifying phosphorus removal; Fermentation; Volatile fatty acids; Waste activated sludge