A comparative study of the decomposition processes and products of rich and poor refuse in South Africa

Abstract

The Minimum Requirements for Waste Disposal by Landfill, published by the Department of Water Affairs and Forestry in 1994, was the first document of its kind advocating graded standards for the safe disposal of solid waste. The document introduced the concepts of affordability and technological compatibility into the everincreasing spiral of landfilling standards. A further way to increase the affordability of waste disposal is to exploit the inherent variation of waste composition across socioeconomic levels. In this study waste from rich and poor areas was classified and samples of the wastes allowed to degrade in large scale field cells, intermediate test cells and laboratory scale lysimeters while the decomposition processes and products were monitored. The principal findings to date indicate that there is a large difference in the waste steams arising from rich and poor areas in South Africa. This difference does have an effect on the decomposition processes and products that occur in the landfill body, which in turn has an effect on the impact the waste has on the environment. Pollutant loads, particularly inorganic pollution, are less from poor waste. This is due to its low organic content combined with its alkali nature, which accelerates the onset of methanogenisis. These factors can be used to further increase the affordability of landfilling standard for poor communities.