Quantifying Temporal Variations in Incinerability of Municipal Solid Waste

Abstract

Population explosion, economic growth, improved standards of living and uninhibited urban migration affects the quantity and characteristics of the municipal solid waste (MSW) generated. With the quantity of MSW on the rise, waste incineration may perhaps prove to be a crucial element of the integrated waste management system. The scenario is different in developed and developing economy largely due to the composition of the MSW generated. While the combustible fraction is higher in developed countries, the inert and biodegradable fraction is higher in developing countries. This consequently affects the thermal properties of the MSW. Being a technology with high installation, operational and maintenance costs, it becomes essential to ensure the feasibility of the process prior to its implementation. The incinerability index for MSW or the i-Index for MSW is a composite indicator developed to facilitate this decision-making. It incorporates the pollution potential, energy recovery potential as well as the economic sustainability of waste incineration. The present study helps assess the variation in the i-Index values and hence the incinerability of MSW across a developed country like the United Kingdom (UK) as well as a major metro in a developing economy like New Delhi. Further, an analysis of the variation in the incinerability over the years, during the period from 1981 to 2004 has also been carried out. While there was no significant variation in the incinerability of MSW generated in Delhi over the last couple of years, MSW generated in the UK had a nearly steady increase in the i-index. There was a substantial difference in the incinerability of MSW generated in Delhi and the UK, with the i-Index of the former recording a low value of 48.9, as opposed to the latter, amounting to 72.4 in 2005. High i-Index values for MSW generated in the UK indicate that incineration is a favourable treatment route; nearly, 32% of the MSW is incinerated for disposal with energy recovery in the UK. Such studies can help project the incinerability of MSW to the future years. The formulation of waste management strategies and design of incineration units may be done in accordance with results from such studies to prevent operational failures.