Introduction Municipal solid waste (MSW) is something of an “orphan child” (Melosi 2000) in urban service studies. It is nevertheless acquiring major importance today because of its obvious environmental impact, particularly in emerging countries, where waste quantities are starting to soar and waste content is becoming more diverse. At the same time, industrial growth in emerging countries is playing a key role in the rise in worldwide demand for raw materials, contributing to a diminution in easily exploitable sources and to the rising prices of these materials. In these circumstances, urban waste is increasingly perceived as a potential (secondary) source of materials.