Journal of Pure and Applied MicrobiologyVol. 8 No. May 2014 Special Edition

Evolution of Multiple Kitchen Waste Components and Each Components Anaerobic Digestion

Lei Feng1,2*, Xueyi You1, Rundong Li2 and Xudong Zhang2

1School of Environmental Science and Engineering, Tianjin University, Tianjin - 300072, PR China. 2Department of Energy and Environment, Shenyang Aerospace University, Shenyang - 110136, PR China.

Received on 12 April 2014 and accepted on 09 May 2014

 

ABSTRACT

A laboratory procedure is described for measuring the methane potentials of kitchen waste and each of its components. Triplicate reactors with about 20 grams of fresh material were incubated at 37! with 300ml inoculum for 50-days for each feed. The total volatile fatty acids (VFAs) concentration showed an initial increase from day 0 to day 3 to a maximum value of 3426 mg/L. The last 9 days ranged from 2907 to 2359 mg/L and then later decreased to 1329 mg/L on day 12. Finally, the total VFAs stabilized at 650 mg/L. On day 6, the kitchen waste achieved its maximum methane production rate of 32.32 mL/g. The cumulative methane production for all the kitchen waste at the end of day 50 was 218.15 L/kgVSfeed, whereas the protein and animal fats achieved their maximum methane production rates of 23.27 and 15.91 mL/g on day 15 and day 19, respectively. The final methane potentiality of the kitchen waste was 194.2 and 257.82 L/kgVSfeed, respectively. The average methane concentration of all the feeds is about 55-58%. The kitchen waste removal efficiency of the total solids (TS) and the volatile solids (VS) in anaerobic digestion was 28.64% and 56.88%. Compared to other components, starch, protein, paper, and animal fats achieved the following removal efficiencies: 9.79%, 14.67%, 21.00%, and 17.64% for TS and 31.23%, 37.33%, 34.59%, and 46.38% for VS, respectively.

Keywords : Kitchen waste; Anaerobic digestion; Total VFAs; Removal efficiency.