Comparison of Methane Production from Household Waste Using Pond Soil and Horse Dung as Microbial Inocula

摘要

The results obtained from the current study can be summarized as follows: For both sets of reactors in experiments A and B, the reactor seeded with pond bottom soil obtained from Pond1 started gas formation earlier, had the highest methane generation rate, as well as the largest cumulative volume of methane, followed by Pond 2 and finally the reactor seeded with Horse Dung. The cumulative average methane generation in 95 days for the reactor seeded with Pond 1 was 19.4 % higher than reactor seeded with Pond 2 and 72% higher than reactor seeded with Horse Dung. Similarly, reactor Pond 2 generated 44% more methane than the reactor with Horse Dung. Pond soils obtained from Pond 1 and Pond 2 gave better performance than Horse Dung as an inoculum for treating household wastes. In experiment C, for all reactors (food, paper, and yard) inoculated with digested waste of Pondl (B),the reactor with more food started gas formation sooner and had the largest cumulative volume of methane, compared to the paper and yard reactors. Cumulative methane generation of the reactor containing the most food was 1.13 times more than paper and 2 times more than the yard reactor through 68 days of reactor operation. It is likely that food waste decomposes faster than paper and yard waste because food waste has the highest amount of cellulose, as well as more surface area per unit volume of waste for the microbes to access.