title: Feasibility study on the operation of UASB reactor treating acidified food waste. Upflow anaerobic sludge blanket.
abstract: A mesophilic upflow anaerobic sludge blanket (UASB) reactor seeded with granules adapted to VFA wastewater was operated as the methanogenic phase of a two-phase anaerobic batch process for food waste digestion. A semi-liquid recycle reactor filled with food waste was used as the acidification reactor and first recirculated for 8 days in the pre-acidification stage, resulting in 14,500 mg/L of total VFA and 15,800 mg/L of COD in the leachate. During the subsequent 8 days of two-phase operation, the leachate was circulated to the UASB reactor. In methanogenic phase, biogas with methane content of 68% on average was generated, and COD and total VFA removals were 74-93% and 77-99%, respectively. At the end of two-phase process, 65% of volatile solids removal and 0.30 L/gVS of methane yield were obtained. The results of this laboratory-scale study show that an UASB system can be used as the methanogenic phase in a two-phase anaerobic batch process, and is effective for conversion of the acidified food waste.
authors.affiliation: Environmental Engineering Research Centre, School of Civil and Environmental Engineering, Nanyang Technological University, Singapore. hlxu@sp.edu.sg
authors.forename: Hai-Lou
authors.initials: HL
authors.lastname: Xu
authors.forename: Jing-Yuan
authors.initials: JY
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Joo-Hwa
authors.initials: JH
authors.lastname: Tay
mesh_terms: D000143:Acids / Q000737:chemistry; D000693:Anaerobiosis; D019149:Bioreactors; D005240:Feasibility Studies; D019649:Food Industry; D007220:Industrial Waste; D008697:Methane / Q000032:analysis; D012722:Sewage / Q000382:microbiology; D012846:Singapore; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000143:Acids; D007220:Industrial Waste; D012722:Sewage; D014874:Water Pollutants, Chemical; D008697:Methane