title: High-solids anaerobic co-digestion of sewage sludge and food waste in comparison with mono digestions: stability and performance.
abstract: System stability and performance of high-solids anaerobic co-digestion of dewatered sludge (DS) and food waste (FW) in comparison with mono digestions were investigated. System stability was improved in co-digestion systems with co-substrate acting as a diluting agent to toxic chemicals like ammonia or Na(+). For high-solids digestion of DS, the addition of FW not only improved system stability but also greatly enhanced volumetric biogas production. For high-solids digestion of FW, the addition of DS could reduce Na(+) concentration and help maintain satisfactory stability during the conversion of FW into biogas. System performances of co-digestion systems were mainly determined by the mixing ratios of DS and FW. Biogas production and volatile solids (VSs) reduction in digestion of the co-mixture of DS and FW increased linearly with higher ratios of FW. A kinetic model, which aimed to forecast the performance of co-digestion and to assist reactor design, was developed from long-term semi-continuous experiments. Maximum VS reduction for DS and FW was estimated to be 44.3% and 90.3%, respectively, and first order constant k was found to be 0.17d(-1) and 0.50 d(-1), respectively. Experimental data of co-digestion were in good conformity to the predictions of the model.
authors.affiliation: National Engineering Research Center for Urban Pollution Control, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
authors.forename: Xiaohu
authors.initials: X
authors.lastname: Dai
authors.forename: Nina
authors.initials: N
authors.lastname: Duan
authors.forename: Bin
authors.initials: B
authors.lastname: Dong
authors.forename: Lingling
authors.initials: L
authors.lastname: Dai
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors; D008962:Models, Theoretical; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000032:analysis*; D062611:Solid Waste / Q000032:analysis*; D018505:Waste Management / Q000379:methods*
chemical_list: D012722:Sewage; D062611:Solid Waste