title: Enhancement of hydrogen production during waste activated sludge anaerobic fermentation by carbohydrate substrate addition and pH control.
abstract: The effects of carbohydrate/protein ratio (CH/Pr) and pH on hydrogen production from waste activated sludge (WAS) were investigated. Firstly, the optimal pH value for hydrogen production was influenced by the CH/Pr ratio, which was pH 10, 9, 8, 8, 8 and 6 at the CH/Pr ratio (COD based) of 0.2 (sole sludge), 1, 2.4, 3.8, 5 and 6.6, respectively. The maximal hydrogen production (100.6 mL/g-COD) was achieved at CH/Pr of 5 and pH 8, which was due to the synergistic effect of carbohydrate addition on hydrogen production, the enhancement of sludge protein degradation and protease and amylase activities, and the suitable fermentation pathway for hydrogen production. As hydrogen consumption was observed at pH 8, in order to further increase hydrogen production a two-step pH control strategy (pH 8+pH 10) was developed and the hydrogen production was further improved by 17.6%.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China. yg2chen@yahoo.com
authors.forename: Yinguang
authors.initials: Y
authors.lastname: Chen
authors.forename: Naidong
authors.initials: N
authors.lastname: Xiao
authors.forename: Yuxiao
authors.initials: Y
authors.lastname: Zhao
authors.forename: Hui
authors.initials: H
authors.lastname: Mu
mesh_terms: D001421:Bacteria, Anaerobic / Q000737:chemistry* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D050260:Carbohydrate Metabolism / Q000502:physiology*; D005285:Fermentation; D006859:Hydrogen / Q000302:isolation & purification* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000517:prevention & control*; D012722:Sewage / Q000382:microbiology*
chemical_list: D007220:Industrial Waste; D012722:Sewage; D006859:Hydrogen