Disposal strategies for municipal solid waste incineration residues

An overview is presented of the various types of municipal solid waste incinerator (MSWI) residues produced, their characteristics and their leaching properties, It is established that short- and long-term leaching and release of contaminants constitute the most important potential environmental problems related to disposal of MSWI residues. A set of basic principles of waste disposal or leachate management strategy which takes the specific properties of the various types of residues into account and which may lead to sustainable waste disposal solutions is presented and discussed. Application of these principles to MSWI residues indicates that an environmentally sustainable disposal solution for MSWI bottom ash and air pollution control (APC) residues in the long term should be based on a controlled contaminant release strategy, i.e. a strategy which allows the leachate to leak into the surroundings at a controlled and environmentally acceptable rate. Leachate collection and treatment is therefore only required when such a disposal strategy is not feasible or during an initial stage of disposal. Landfilling of bottom ash is less problematic than landfilling of APC residues in terms of practical implementation of the disposal strategy and management of the leachate. Monofilling and separate management and disposal of MSWI bottom ash and APC residues are generally recommended.