Evaluating the Recovery Potential of Solid Wastes

Abstract

The purpose of this research was to evaluate the recovery potential of solid waste in Mashhad. The solid waste generated in the regions 4, 5 and 6 has been quantified and characterized using direct weighing, physical testing and truckload sampling methods. To determine the quantity and quality of waste generated and its seasonal variations, chemical and physical analysis were carried out for one year. The current situation concerning resource recovery and disposal of solid waste in Mashhad is also described. Results show that the average solid waste generation rate is around 0.58 kg/capita per day in these regions. Statistical studies reveal that the quantity of waste generated differ significantly in various seasons. The composition (on a weight basis) of the solid wastes sampled was as follows: food wastes 46%, yard waste 8%, plastics 12%, paper and cardboard 6%, textiles 15%, metals 2%, glass 6% and rubber 4% indicating a high amount of organic matter. Vegetable and food wastes from the kitchen and yard wastes accounted for more than 50% of the waste stream. The moisture content was around 45% and the heating value of the mixed wastes around 4228 KJ/Kg (as-discarded basis). The nature of the wastes indicate that amongst the recovery options, composting at household level would be most appropriate as it would divert more than 50% of the wastes from the traditional waste stream and provide households with compost which could be used to enrich soils in the gardens.