title: Effect of mixing ratio of food waste and rice husk co-digestion and substrate to inoculum ratio on biogas production.
abstract: Aim of this study was to find out suitable mixing ratio of food waste and rice husk for their co-digestion in order to overcome VFA accumulation in digestion of food waste alone. Four mixing ratios of food waste and rice husk with C/N ratios of 20, 25, 30 and 35 were subjected to a lab scale anaerobic batch experiment under mesophilic conditions. Highest specific biogas yield of 584L/kgVS was obtained from feedstock with C/N ratio of 20. Biogas yield decreased with decrease in food waste proportion. Further, fresh cow dung was used as inoculum to investigate optimum S/I ratio with the selected feedstock. In experiment 2, feedstock with C/N ratio 20 was subjected to anaerobic digestion at five S/I ratios of 0.25, 0.5, 1.0, 1.5 and 2.0. Specific biogas yield of 557L/kgVS was obtained at S/I ratio of 0.25. However, VFA accumulation occurred at higher S/I ratios due to higher organic loadings.
authors.affiliation: Department of Environmental Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: environmentalist43@gmail.com.
authors.forename: Muhammad Rizwan
authors.initials: MR
authors.lastname: Haider
authors.affiliation: Department of Environmental Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: zeshan90@gmail.com.
authors.lastname: Zeshan
authors.affiliation: Department of Environmental Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: rasy1023@hotmail.com.
authors.forename: Sohail
authors.initials: S
authors.lastname: Yousaf
authors.affiliation: Department of Environmental Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: r_n_malik2000@yahoo.co.uk.
authors.forename: Riffat Naseem
authors.initials: RN
authors.lastname: Malik
authors.affiliation: Environmental Engineering and Management, School of Environment, Resources and Development, Asian Institute of Technology, Bangkok, Thailand. Electronic address: visu@ait.ac.th.
authors.forename: Chettiyappan
authors.initials: C
authors.lastname: Visvanathan
mesh_terms: D000818:Animals; D056804:Biofuels / Q000382:microbiology*; D002417:Cattle; D005243:Feces / Q000382:microbiology*; D019649:Food Industry; D005516:Food Microbiology; D007220:Industrial Waste / Q000517:prevention & control; D012275:Oryza / Q000382:microbiology*; D010936:Plant Extracts / Q000378:metabolism*; D012037:Refuse Disposal / Q000379:methods*
chemical_list: D056804:Biofuels; D007220:Industrial Waste; D010936:Plant Extracts
keywords: Cellulosic biomass; Co-digestion; Food waste; Rice husk; Substrate to inoculum ratio