Study on Anaerobic Digestion of Kitchen Waste for Biogas Production

Abstract

The effect of initial total solid (TS) concentrations on the volume percent of methane and TAN contents from the anaerobic digestion of kitchen waste was studied in this paper by setting the initial TS as 4 wt%, 5 wt%, 6 wt%, 7 wt%. The inflection points of the cumulative biogas productions curve of different initial TS concentration took place at day 8,19 day, 17 day, 15 day, 9,20 day, respectively. The concentrations of methane generally rose firstly and then declined except that two different peaks (71.54% and 64.31%) of the methane volume percent were observed in day 15 and day 25 respectively under the condition of initial TS mass fraction of 4 wt%. The maximum methane volume percent under the condition of initial TS mass fraction of 5 wt%, 6 wt%, and 7 wt% was 76.7%, 73.93%, and 74.32% respectively in day 20. The TAN contents increased with the reaction time under the influence of varied initial TS contents. When the initial TS content was 4 wt%, 5 wt%, 6 wt%, and 7 wt%, the accumulated total ammonia nitrogen (TAN) content in day 30 was 1830, 2659, 2647, and 3040 mg/L respectively.