BIOCHEMICAL METHANE POTENTIAL OF MUNICIPAL SOLID WASTE COMPONENTS

Abstract

Solid waste comprises all the wastes arising from human & animal activities that are normally solid and are discarded as useless or unwanted and has been generating from the day one of the resource utilisation and the rapid development has stressed the recipient environment beyond its assimilative capacity. The Municipal Solid Waste has been reported to be containing vegetable/ putrescible matter to a range of 20-85% suggesting the composting to be an ideal disposal option. In the present work the biochemical methane potential of the Municipal Solid Waste components viz. vegetable, fruit & blended (vegetable & fruit blended in the ratio of 1:1 of their VS) was conducted. The sets were operated in two different environments one containing the defined media & the other with out the defined media at 35°C for 35 days. The BM? in both the cases was found to be increasing with the increase in time & also with the increase in loading rate. In case of the defined media the blended component had the best CH4 yield of 0.026m3/ kg of VS, followed by vegetable and fruit component with a yield of 0.0204m3/ kg of VS and 0.0164 m3/ kg of VS respectively. In case of the decomposition without the defined media the fruit component had the best yield of CH4 with 0.236m3/ kg of VS followed by blended & the vegetable component with the CH4 yield of 0.158m3/ kg of VS & 0.088m3/ kg of VS respectively showing the fruit to be more decomposable as compared to the vegetable waste. The vegetable waste was found rich in Nitrogen (Organic & Ammonical) with N content of 3.54% & the fruit with 2.17% of N. The organic loading was varied as 0.5, 1.5, 2.0 & 2.5 gm of VS/ litre in case of the set with the defined media & as 1.5, 2.0 & 2.5 gm of VS/ litre in case of the set with out the defined media. The C/N ratio in case of the set with the defined media ranged from 2.34 - 7.20, 2 - 7.46 and 2.57 - 8.14 for vegetable, fruit and the blended waste components respectively as compared to 13.73, 23.22 & 17.35 for these components with the set operated without the defined media. The lower CH4 yield for the sets operating with the defined media as compared to the one operating with out the defined media is attributed due to the lower C/N ratio in the first case