title: Optimization of separate hydrogen and methane production from cassava wastewater using two-stage upflow anaerobic sludge blanket reactor (UASB) system under thermophilic operation.
abstract: The objective of this study was to investigate the separate hydrogen and methane productions from cassava wastewater by using a two-stage upflow anaerobic sludge blanket (UASB) system under thermophilic operation. Recycle ratio of the effluent from methane bioreactor-to-feed flow rate was fixed at 1:1 and pH of hydrogen UASB unit was maintained at 5.5. At optimum COD loading rate of 90 kg/m3 d based on the feed COD load and hydrogen UASB volume, the produced gas from the hydrogen UASB unit mainly contained H2 and CO2 which provided the maximum hydrogen yield (54.22 ml H2/g COD applied) and specific hydrogen production rate (197.17 ml/g MLVSSd). At the same optimum COD loading rate, the produced gas from the methane UASB unit mainly contained CH4 and CO2 without H2 which were also consistent with the maximum methane yield (164.87 ml CH4/g COD applied) and specific methane production rate (356.31 ml CH4/g MLVSSd). The recycling operation minimized the use of NaOH for pH control in hydrogen UASB unit.
authors.affiliation: The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Patcharee
authors.initials: P
authors.lastname: Intanoo
authors.affiliation: The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok, Thailand; Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Pramoch
authors.initials: P
authors.lastname: Rangsanvigit
authors.affiliation: The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok, Thailand; Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Pomthong
authors.initials: P
authors.lastname: Malakul
authors.affiliation: The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok, Thailand; Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: sumaeth.c@chula.ac.th.
authors.forename: Sumaeth
authors.initials: S
authors.lastname: Chavadej
mesh_terms: D000693:Anaerobiosis; D006859:Hydrogen / Q000378:metabolism*; D002365:Manihot; D008697:Methane / Q000378:metabolism*; D012722:Sewage; D062065:Wastewater
chemical_list: D006859:Hydrogen; D008697:Methane; D012722:Sewage; D062065:Wastewater
keywords: Cassava wastewater; Hydrogen and methane production; Thermophilic operation; Upflow anaerobic sludge blanket reactor (UASB)