title: Responses of microbial community and acidogenic intermediates to different water regimes in a hybrid solid anaerobic digestion system treating food waste.
abstract: This study investigated the effects of different water regimes in an acidogenic leach bed reactor (LBR) during 16-day batch mode food waste digestion. LBRs were operated under five water replacement ratios (WRRs) (100%, 75%, 50%, 25% and 5% in LBRs R1, R2, R3, R4 and R5, respectively) and methanogenic effluent (ME) addition with two leachate recirculation frequencies (once in 24 h and 12 h in LBRs R6 and R7, respectively). Results showed that 50-100% WRRs accelerated the hydrolysis and acidogenesis with butyrate as the dominant product (∼35% of COD); whereas 5-25% WRRs promoted propionate production. The ME recirculation enhanced protein decomposition and reduced ethanol production. Lactobacillus dominated in LBRs with water addition (R1-R5), while Clostridium and hetero-fermenting lactic acid bacteria dominated in LBR with ME addition (R7). The highest volatile solid degradation (82.9%) and methane yield (0.29 L-CH4/g VS) were obtained with ME addition at 0.7 d hydraulic retention time.
authors.affiliation: Department of Environmental & Low-Carbon Science, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, PR China; Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region, PR China.
authors.forename: Suyun
authors.initials: S
authors.lastname: Xu
authors.affiliation: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region, PR China.
authors.forename: Ammaiyappan
authors.initials: A
authors.lastname: Selvam
authors.affiliation: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region, PR China.
authors.forename: Obuli P
authors.initials: OP
authors.lastname: Karthikeyan
authors.affiliation: Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region, PR China. Electronic address: jwcwong@hkbu.edu.hk.
authors.forename: Jonathan W C
authors.initials: JW
authors.lastname: Wong
mesh_terms: D000143:Acids / Q000378:metabolism*; D000693:Anaerobiosis; D001105:Archaea / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D056804:Biofuels; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology; D004275:DNA, Ribosomal / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D005232:Fatty Acids, Volatile / Q000032:analysis; D005502:Food; D006863:Hydrogen-Ion Concentration; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D025341:Principal Component Analysis; D012037:Refuse Disposal / Q000295:instrumentation* / Q000379:methods*; D062611:Solid Waste; D014867:Water / Q000737:chemistry*
chemical_list: D000143:Acids; D056804:Biofuels; D004275:DNA, Ribosomal; D005232:Fatty Acids, Volatile; D062611:Solid Waste; D014867:Water
keywords: Enzymatic activity; Methanogenic effluent recirculation; Microbial community; Volatile fatty acids; Water replacement