Prof. Hamidi Abdul Aziz
Universiti Sains Malaysia, Malaysia
Title: The science and engineering of landfill leachate pollution control
Abstarct: Most of the present solid waste landfill sites in developing countries are practising either unsanitary landfilling or open dumping. One of the main concerns of landfilling is leachate production. Leachate is created when water passes through the waste body. The water mainly occurs from rain and through waste degradation process. Leachate contains significant amounts of organic compounds, heavy metals, ammonia, and many other hazardous chemicals. COD, NH3-N, and colour are among the difficult parameters which are hard to be completely removed. Proper treatment facilities are needed before leachate can be released to the environment. The treatment depends on the leachate qualities, operation and capital costs, and regulations. Up to now, researchers worldwide are still looking for a total solution to the leachate problem. Multiple-stage treatments are normally necessary through blend of biological, physical, chemical and their combinations. The science and engineering aspects in treating landfill leachate treatment will be shared in this paper. Special consideration will also be made on the application of leachate treatment for semi-aerobic landfill in developing countries. Its biodegradability is low and riched in COD, NH3-N, and colour.The paper also highlights some of the challenges in the overall leachate treatment processes.