title: Management of various organic fractions of municipal solid waste via recourse to VFA and biogas generation.
abstract: A hybrid anaerobic solid-liquid system was used for anaerobic digestion of organic fraction of municipal solid waste (OFMSW) consisting of mixed food + fruit waste and vegetable waste. Hydrolysis and acidogenesis potential of the above wastes were evaluated with the aim of producing value-added products in the form of volatile fatty acids (VFAs) and biogas recovery. Efficient hydrolysis and acidogenesis of mixed food + fruit waste was observed at a hydraulic retention time (HRT) of 1-3 d with a five-fold increase in soluble chemical oxygen demand (SCOD) followed by VFA production consisting of 50-75% acetic acid. Longer time was required for hydrolysis of vegetable waste with optimum hydrolysis and SCOD generation at 9 d HRT followed by VFA synthesis consisting of 45% acetic acid. Higher inoculum:substrate ratios resulted in improved hydrolysis and acidogenesis rates for vegetable waste in shorter time of 6 d with higher VFA production and increase in acetic acid content to 70%. When acidogenic leachate was fed into methanogenic reactors, detectable biogas production was observed after 25 d with 37-53% SCOD removal from leachate from mixed food + fruit waste and methane production of 0.066-0.1 L g(-1) SCOD removed and methane content of 38%. Though biogas yield from acidogenic leachate from vegetable waste was lower, nearly 94% volatile solids (VS) removal was observed in the reactors thereby providing methane yield of 0.13-0.21 L g(-1) VS consumed. Thus, the study provided a method for generation of value-added products from an otherwise misplaced resource in the form of OFMSW.
authors.affiliation: Environmental Genomics Division, CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur 440020, India. aa_khardenavis@neeri.res.in
authors.forename: Anshuman Arun
authors.initials: AA
authors.lastname: Khardenavis
authors.affiliation: Nanyang Environment & Water Research Institute, Nanyang Technological University, #06-08 Clean Tech One, 1 Cleantech Loop, Singapore 637141, Singapore.
authors.forename: Jing Yuan
authors.initials: JY
authors.lastname: Wang
authors.affiliation: Nanyang Environment & Water Research Institute, Nanyang Technological University, #06-08 Clean Tech One, 1 Cleantech Loop, Singapore 637141, Singapore.
authors.forename: Wun Jern
authors.initials: WJ
authors.lastname: Ng
authors.affiliation: Environmental Genomics Division, CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur 440020, India.
authors.forename: Hemant J
authors.initials: HJ
authors.lastname: Purohit
mesh_terms: D056804:Biofuels; D019149:Bioreactors; D005502:Food; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008697:Methane / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D062611:Solid Waste
chemical_list: D056804:Biofuels; D062611:Solid Waste; D008697:Methane