Physicochemical characteristics and Biodegradability of organic fraction of solid wastes generated in Eldoret Municipality, Kenya

Abstract

This study was designed to characterise and assess the biodegradability of the organic portion of the waste from a fast growing agricultural urban centre, Eldoret, in North Rift of Kenya. This is because new strategies for waste management are aimed at integrating mechanical, thermal and biological processing for energy and reduction of the volume of waste to be disposed. Therefore bbiological methods are designed degrade organic carbon of MSW under controlled conditions to produce desired quality for final disposal should take into account, the proportions and characteristics of the components as a factor that would influence the biodegradability of the wastes. The study was carried out in Eldoret municipality, a fast expanding urban setting in Western Kenya that serves as an administrative centre of Uasin Gishu County. Waste samples were collected on delivery at dumpsite and categorised by source of waste based on the economic status of the households. Waste composition, proximate analysis for crude nutrients, volatile solids and biochemical gas potential of the waste were carried out to estimate the physicochemical and biodegradability characteristics of the waste. Results showed that putrescible/organic material constituted the largest component of the waste irrespective of the source. Its moisture content was expectedly high (> 50%). The organic fraction contains high levels of crude nutrients that can support microbial activities thus biodegradability. This was supported by the volatile solids profiles and the biochemical gas potential. Statistically, biodegradability of wastes from central business district was significantly (p<0.05) more degradable than from residential areas. This was attributable to the high organic carbon content.