FEASIBILITY STUDY ON THE OPERATION OF UASB REACTOR TREATING ACIDIFIED FOOD WASTE

• Published in: Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering Vol. 37; no. 9; pp. 1757 - 1764
• Main Authors: Xu, Hai-Lou, Wang, Jing-Yuan, Zhang, Hua, Tay, Joo-Hwa
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.10.2002
• Subjects: Acidification; Anaerobic digestion; Anaerobic processes; Crack opening displacement; Food waste; Foods; Methane; Methanogenesis; Pre-acidification; Reactors; Two-phase process; UASB; UASB reactors; Waste water; Wastes
• ISSN: 1093-4529; 1532-4117
• DOI: 10.1081/ESE-120015434

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.