title: Anaerobic digestion of sludge differing in inorganic solids content: performance comparison and the effect of inorganic suspended solids content on degradation.
abstract: High inorganic suspended solids (ISS) content of sludge in many areas (especially with combined sewage systems) results in low VS/TS (volatile solids, VS; total solids, TS) levels and raises concerns about its effect on anaerobic digestion. The performances of sludge anaerobic digestion with different feeding VS/TS levels as well as the effect of ISS content on the anaerobic degradation process were investigated in completely stirred tank reactors by semi-continuous and batch experiments. In semi-continuous experiment with sludge at VS/TS of 61.4%, 45.0, 30.0% and 15.0%, biogas yield, VS reduction and methane content decreased logarithmically with the feeding VS/TS decreasing; slightly higher volatile fatty acid concentration was observed at VS/TS 15%. Results of the batch experiments suggested that acetogenesis and methanogenesis are obviously affected by high ISS addition, while hydrolysis is less affected. The retardment of substrate conversion rate is probably attributed to decreased mass transfer efficiency at high ISS content.
authors.affiliation: Post-Doctoral Research Center for Civil Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Nina
authors.initials: N
authors.lastname: Duan
authors.affiliation: National Engineering Research Center for Urban Pollution Control, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China E-mail: daixh_ss@163.com.
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Dai
authors.affiliation: National Engineering Research Center for Urban Pollution Control, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China E-mail: daixh_ss@163.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Dong
authors.affiliation: National Engineering Research Center for Urban Pollution Control, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China E-mail: daixh_ss@163.com.
authors.forename: Lingling
authors.initials: L
authors.lastname: Dai
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels / Q000032:analysis; D019149:Bioreactors; D008697:Methane / Q000737:chemistry / Q000378:metabolism; D012722:Sewage / Q000737:chemistry*
chemical_list: D056804:Biofuels; D012722:Sewage; D008697:Methane