title: Effect of influent COD/SO4(2-) ratios on biodegradation behaviors of starch wastewater in an upflow anaerobic sludge blanket (UASB) reactor.
abstract: A lab-scale upflow anaerobic sludge blanket (UASB) has been run for 250days to investigate the influence of influent COD/SO4(2-) ratios on the biodegradation behavior of starch wastewater and process performance. Stepwise decreasing COD/SO4(2-) ratio enhanced sulfidogenesis, complicating starch degradation routes and improving process stability. The reactor exhibited satisfactory performance at a wide COD/SO4(2-) range ⩾2, attaining stable biogas production of 1.15-1.17LL(-1)d(-1) with efficient simultaneous removal of total COD (73.5-80.3%) and sulfate (82.6±6.4%). Adding sulfate favored sulfidogenesis process and diversified microbial community, invoking hydrolysis-acidification of starch and propionate degradation and subsequent acetoclastic methanogenesis; whereas excessively enhanced sulfidogenesis (COD/SO4(2-) ratios <2) would suppress methanogenesis through electrons competition and sulfide inhibition, deteriorating methane conversion. This research in-depth elucidated the role of sulfidogenesis in bioenergy recovery and sulfate removal, advancing the applications of UASB technology in water industry from basic science.
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
authors.forename: Xueqin
authors.initials: X
authors.lastname: Lu
authors.affiliation: National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, Ibaraki 305-0053, Japan.
authors.forename: Guangyin
authors.initials: G
authors.lastname: Zhen
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
authors.forename: Jialing
authors.initials: J
authors.lastname: Ni
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Hojo
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Kubota
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan; Graduate School of Environmental Studies, Tohoku University, Sendai, Miyagi 980-8579, Japan. Electronic address: gyokuyu.ri.a5@tohoku.ac.jp.
authors.forename: Yu-You
authors.initials: YY
authors.lastname: Li
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D056804:Biofuels; D019149:Bioreactors; D008697:Methane / Q000378:metabolism; D012722:Sewage / Q000737:chemistry*; D013213:Starch / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D056804:Biofuels; D008697:Methane; D012722:Sewage; D013213:Starch; D062065:Wastewater
keywords: Energy conversion; Methane; Starch; Sulfate reduction; Upflow anaerobic sludge blanket (UASB)