Enhanced food waste degradation in integrated two-phase anaerobic digestion: Effect of leachate recirculation ratio

• Published in: Bioresource technology 2019-11, Vol.291, p.121813-121813, Article 121813
• Main Authors: Luo, Liwen, Wong, Jonathan W.C.
• Format: Article
• Language: English
• Subjects: Food waste; Hydrogen; Hydrolysis; Leachate recirculation; Two-phase anaerobic digestion
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121813

•More water replacement accelerated solid waste solubilization.•Highest H2 and CH4 yield was achieved under 50% leachate recirculation.•Valerate production was promoted when leachate recirculation ratio over than 50%.•Bacteria community structure well correlated with degradation performance. The aim of this study is to evaluate the effect of leachate recirculation at a ratio of 0%, 25%, 50% or 75% of collected leachate from the Leach Bed Reactor (LBR) on food waste digestion efficiency and its subsequent methane production in the second phase of a two-phase anaerobic system. Higher hydrolysis-acidogenesis efficiency and lower energy loss were achieved in LBR with higher leachate recirculation ratio. Better biochemical balance between metabolic products and microorganisms in leachate was revealed under 50% leachate recirculation ratio, which leads to the highest hydrogen production yield in LBR resulting the highest methane production yield in the corresponding methanogenic phase which was at least 15% higher than that in other conditions. This provides an easy approach to enhance the hydrolysis efficiency and in the same time a biochemical balanced leachate to enhance methanogenic reaction of a two-phase anaerobic digestion.