title: Optimization of food waste hydrolysis in leach bed coupled with methanogenic reactor: effect of pH and bulking agent.
abstract: The effects of pH and bulking agents on hydrolysis/acidogenesis of food waste were studied using leach bed reactor (LBR) coupled with methanogenic up-flow anaerobic sludge blanket (UASB) reactor. The hydrolysis rate under regulated pH (6.0) was studied and compared with unregulated one during initial experiment. Then, the efficacies of five different bulking agents, i.e. plastic full particles, plastic hollow sphere, bottom ash, wood chip and saw dust were experimented under the regulated pH condition. Leachate recirculation with 50% water replacement was practiced throughout the experiment. Results proved that the daily leachate recirculation with pH control (6.0) accelerated the hydrolysis rate (59% higher volatile fatty acids) and methane production (up to 88%) compared to that of control without pH control. Furthermore, bottom ash improved the reactor alkalinity, which internally buffered the system that improved the methane production rate (0.182 l CH(4)/g VS(added)) than other bulking agents.
authors.affiliation: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong SAR, Hong Kong.
authors.forename: Su Yun
authors.initials: SY
authors.lastname: Xu
authors.forename: Hoi Pui
authors.initials: HP
authors.lastname: Lam
authors.forename: O Parthiba
authors.initials: OP
authors.lastname: Karthikeyan
authors.forename: Jonathan W C
authors.initials: JW
authors.lastname: Wong
mesh_terms: D000143:Acids / Q000737:chemistry; D000693:Anaerobiosis; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods; D004867:Equipment Design; D005232:Fatty Acids, Volatile / Q000737:chemistry; D019649:Food Industry / Q000379:methods*; D005740:Gases; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007220:Industrial Waste; D008697:Methane / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000143:Acids; D005232:Fatty Acids, Volatile; D005740:Gases; D007220:Industrial Waste; D012722:Sewage; D014874:Water Pollutants, Chemical; D008697:Methane