Municipal solid waste composting and its assessment for reuse in plant production

A pilot study was conducted to assess the feasibility of composting of source separated organic matter of municipal solid waste (MSW) generated in low, middle and high income areas of Karachi city with a population over 14 million. Results of MSW analysis indicate the presence of high percentage of biodegradable organic matter (71-74%), acceptable moisture content (40-50%) and C/N ratio (38-40:1). On windrow composting, not only the volume of waste was reduced but also produced a crumbly earthy smelling soil-like, compost material. All quality parameters in the compost samples were found to be within the acceptable limits set by international standard. The pH ranged between 6.8-8.1, soluble salts 3.90-5.10 mS/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%). The compost quality could further be improved by adding cow manure, poultry manure or yard waste etc. Its use in plant production or land reclamation may be helpful to maintain soil fertility and improve moisture holding capacity. MSW composting could be adapted country wide to recycle/reuse the organic residues as solid waste management option.