No abstract

The generation of contaminated leachate remains an inevitable consequence of the practice of solid waste disposal in landfills. The collection and treatment of leachate have become common practice in order to prevent environmental pollution. Leachate treatment is highly dependent on the quality of leachate, which in turn is influenced by various factors including waste composition and operational procedures. This paper investigates the treatability of high-strength leachate from pre-sorted and baled municipal solid waste characterized by high organic and moisture content. For this purpose, waste disposal and leachate generation rates were monitored. Leachate samples were collected and analysed for selected indicators including BOD, COD, pH, and NH 4 -N and a pilot scale treatment plant with coagulation, precipitation and sequential batch biological reactors was constructed to evaluate the feasibility of leachate treatment. Concentration levels were related to biological activity within the landfill and the results indicated that (1) pre-sorting and baling of the waste did not hinder waste stabilization; and (2) the high organic and moisture contents resulted in an extremely strong leachate, particularly at the onset of biodegradation processes, which can affect the leachate treatment facility. The effectiveness of the pilot plant in treating the leachate exceeded 90% using COD and NH 4 -N as indicators.

Problems associated with the disposal of municipal solid waste have become a source of public concern worldwide as awareness of potential adverse environmental impacts and health threats from solid waste has increased. Communities are concerned about the generation and management of solid waste to the extent of refusing to allow new disposal facilities near their homes, often after witnessing the legacy of existing facilities. Under these conditions, the development of national policies for the management of solid waste becomes highly political, all while requiring appropriate technical solutions that ensure environmental protection and proper management plans that support an acceptable solution for the disposal of municipal solid waste. In some locations, the conversion of old quarries into well-engineered and controlled landfills appears as a promising solution to a continuously increasing problem, at least for many decades to come. This paper describes the environmental impacts associated with solid waste disposal in a converted quarry site and the mitigation measures that can be adopted to alleviate potential adverse impacts. Environmental management and monitoring plans are also discussed in the context of ensuring adequate environmental protection during and after the conversion process.