Batch biodegradability study of fresh and aged food waste: performance and kinetic

Peninsular Malaysia generates 17000 tonnes of municipal solid waste (MSW) per day in 2002 and it is estimated to increase to 31,000 tonnes per day on 2020, unfortunately food waste (FW) is the largest component of MSW. The high amount of FW generated related to landfill's main issues such as foul odour, toxic leachate, emission of greenhouse gases and vermin infestation. FW is highly potential in producing methane because it is rich in volatile solid. Therefore, the research trend on anaerobic digestion of FW has shifted for methane production because methane can be transformed to electrical energy production. The objective of this research is to evaluate the methane potential and kinetics of methane production from the anaerobic digestion of fresh and aged food waste taken from fast food restaurant. The methane production under mesophilic condition was monitored by using Automatic Methane Potential Test System II (AMPTS II). Triplicate sample reactors were prepared for each substrate (fresh and aged FW) at IS ratio of 2.0 on VS basis. Besides that, duplicate blank reactors were prepared concurrently, contained only inoculum. The fresh FW resulted in higher ultimate methane yield (M_o) and methane production rate (R_m). Comparing to results from fresh FW, the M_o and R_m observed from digestion of aged FW were decreased by 17% and 27% respectively. Kinetic analysis using Modified Gompertz modelling showed that Mo for fresh and aged FW were increased, as well as for lag phase (λ). Meanwhile the decreased R_m was observed for fresh and aged FW. (paper)