Hydrogen and methane production by co-digestion of waste activated sludge and food waste in the two-stage fermentation process: substrate conversion and energy yield.
Batch experiments were conducted to produce hydrogen and methane from waste activated sludge and food waste by two-stage mesophilic fermentation. Hydrogen and methane production, energy yield, soluble organic matters, volatile solid removal efficiency and carbon footprint were investigated during two-stage digestion at various food waste proportions. The highest energy yield reached 14.0 kJ/g-VS at the food waste proportion of 85%, with hydrogen and methane yields of 106.4 ml-H2/g-VS and 353.5 ml-CH4/g-VS respectively. The dominant VFA composition was butyrate for co-digestion and sole food waste fermentation, whereas acetate was dominate in VFA for sole waste activated sludge fermentation. The VS removal efficiencies of co-digestion were 10-77% higher than that of waste activated sludge fermentation. Only 0.1-3.2% of the COD in feedstock was converted into hydrogen, and 14.1-40.9% to methane, with the highest value of 40.9% in methane achieved at food waste proportion of 85%.
School of Environmental Science and Engineering, Tianjin University, Weijin Road 92, Tianjin 300072, China. Electronic address: liuxinyuan11@163.com.
Xinyuan
X
Liu
School of Environmental Science and Engineering, Tianjin University, Weijin Road 92, Tianjin 300072, China. Electronic address: liruying@tju.edu.cn.
Ruying
R
Li
School of Environmental Science and Engineering, Tianjin University, Weijin Road 92, Tianjin 300072, China. Electronic address: jimin@tju.edu.cn.
Min
M
Ji
School of Environmental Science and Engineering, Tianjin University, Weijin Road 92, Tianjin 300072, China. Electronic address: hanlitju@163.com.
Li
L
Han
D064751:Ammonium Compounds / Q000737:chemistry; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D002241:Carbohydrates / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D005285:Fermentation; D005502:Food; D006859:Hydrogen / Q000737:chemistry*; D008697:Methane / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D013997:Time Factors
D064751:Ammonium Compounds; D002241:Carbohydrates; D005227:Fatty Acids; D011506:Proteins; D012722:Sewage; D006859:Hydrogen; D008697:Methane
Food waste; Hydrogen production; Methane production; Two-stage fermentation; Waste activated sludge