title: Two-stage biogas production by co-digesting molasses wastewater and sewage sludge.
abstract: We evaluated the feasibility of co-digesting molasses wastewater and sewage sludge in a two-stage hydrogen- and methane-producing system. The highest energy was recovered at the 21-h hydraulic retention time (HRT) of the first hydrogenic reactor and at 56-h HRT of the secondary methanogenic reactor. Hence, the two-stage system recovered 1,822 kJ from 1 L of the mixed wastes (19.7: hydrogenic reactor plus, 1,802 kJ L(-1): methanogenic reactor). Despite the overloaded VFA-run with a short HRT of 56 h, the GAC-CH4 reactor increased methane production rate and yields due to enhanced pH buffer capacity. An RNA-based community analysis showed that the Ethanoligenens and Methanosaeta dominated the hydrogen and methane bioreactor, respectively. The two-stage system of co-digesting molasses and sewage sludge is particularly cost-effective due to non-pretreatment of sewage sludge.
authors.affiliation: Global Top 5 Research Program, Ewha Womans University, 52, Ewhayeodae-gil, Seodaemun-gu, Seoul, South Korea.
authors.forename: Jung-Yeol
authors.initials: JY
authors.lastname: Lee
authors.forename: Jeonghee
authors.initials: J
authors.lastname: Yun
authors.forename: Tae Gwan
authors.initials: TG
authors.lastname: Kim
authors.forename: Daehyun
authors.initials: D
authors.lastname: Wee
authors.forename: Kyung-Suk
authors.initials: KS
authors.lastname: Cho
mesh_terms: D000085:Acetates / Q000737:chemistry; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D056804:Biofuels; D019149:Bioreactors; D006859:Hydrogen / Q000737:chemistry; D007220:Industrial Waste; D008697:Methane / Q000737:chemistry; D008965:Molasses; D012313:RNA / Q000737:chemistry; D017423:Sequence Analysis, RNA; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater; D014873:Water Pollutants / Q000737:chemistry*; D018508:Water Purification
chemical_list: D000085:Acetates; D056804:Biofuels; D006859:Hydrogen; D007220:Industrial Waste; D008697:Methane; D012313:RNA; D012722:Sewage; D062065:Wastewater; D014873:Water Pollutants