Assessment of municipal solid waste compost characteristics

A pilot study was conducted to assess the feasibility of composting process of the source separated organic matter of municipal solid waste (MSW), generated in low, middle and high-income areas of Karachi city, (population over 12 million). The MSW collected from various socioeconomic localities have a high percentage of biodegradable organic matter ranging from (71-74%), moisture content (40-50%) and C/N ratio (38-40:1). The separated organic materials on windrow composting yields an economical natural product - the compost. All quality parameters of finished compost samples were found to be within the acceptable limits, set by international standards. The pH ranged between (6.8-8.1), soluble salts (3.90-5.10 m.mhos/cm), organic matter (45-60%) and have an acceptable amount of plant nutrients ( Nitrogen 0.91-1.35%, Phosphorus 0.42-0.85%, Potassium 1.00-1.80%). Comparison of compost results against those of organic fertilizer (cowdung) and chemical fertilizer, shows no significant differences. However the compost quality could further be improved by adding cow manure, poultry manure and yard waste etc. The results of compost analysis confirms its suitability for land reclamation application and would be an investment in the long-term for the health of soils and plants. It is concluded that the composting technique can be adapted country wide to recycle/reuse organic residuals as waste management option.