1. INTRODUCTION
In the last few decades of the 20th century it became obvious that the large quantities of waste produced by the modern consumer society cause serious environmental damage when they are disposed of without any treatment. Modern landfills for municipal solid waste (MSW) have a complex design and should be able to carry out several processes such as leachate and gas management and monitoring. This makes the disposal space for a volume unit of waste rath expensive. In order to minimise disposal space, it has become common practice to sort, reuse and incinerate waste materials. Incineration and landfilling are integral components of waste management in many countries across the world. The relative importance of incineration as opposed to direct landfilling varies substantially from country to country. Incineration is often the preferred option in countries with limited availability or accessibility of space for landfilling. Switzerland, Japan, France, Germany, Sweden and Denmark are examples of countries in which 50% or more of the un-recycled waste is being or will be incinerated; some of these countries have even passed legislation which will prohibit future landfilling of combustible waste.