Journal of Shanghai University(Natural Science Edition) ›› 2017, Vol. 23 ›› Issue (1): 81-90.doi: 10.3969/j.issn.1007-2861.2015.04.010

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Combined system for biogas production using kitchen wastes and recycled water

MA Zhen1, WAN Hao2, ZHANG Meng2   

  1. 1. School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China;
    2. Energy Management Office, Shanghai University, Shanghai 200444, China
  • Received:2014-12-17 Online:2017-02-28 Published:2017-02-28

Abstract:

Regarding the current situation of treatment of kitchen wastes and sewage in colleges, constructing a combined energy-saving system to produce biogas using kitchen wastes and recycled water is proposed. The two recycling systems have a complementary relation. It can provide a new mode of energy-saving work in general, and for colleges in particular. Different mixing ratios of kitchen wastes and sludge are considered in the experiment of biogas production. With the ratio of 1:1, the cumulative yield of biogas reaches a maximum value. The cumulative biogas yield for 40 days is 621 mL/(g·VS), the removal rate of volatile solid (VS) is up to 67.5% and efficiency of methane production is 78.6%. The removal efficiencies of solluted chemical oxygen demand (SCOD), soluble carbohydrate and protein after the reaction by mixed substrate of 1:1 are 55.7%, 68.7%, and 22.7%, respectively. The pH values of the substrate is between 6.8 and 7.2. According to an estimation of energy saving in the South Campus of Shanghai University, the program can save energy costing 260 000 RMB every year after reconstruction, making a good economic benefit.

Key words: biogas, energy conservation, kitchen waste, sewage, college