Thermal treatment of sewage sludge: One of possible disposal methods

Waste water treatment is a standard process in developed countries. It is intended to minimize the influence of waste water on the environment. The treatment process produces various remains that are generally called sewage sludge. In general, the remaining material is treated physically to dewater the sludge to reduce the volume and mass before disposal. This treated sewage sludge has around 25% of dry solids. The chemical and physical properties of the sewage sludge have to be monitored to determine the correct method of disposal. If the sewage sludge contains higher concentrations of heavy metals the only method for the disposal is thermal treatment. This article will present possible technologies for sewage sludge thermal treatment and the experience of Slovene waste thermal treatment plant that incinerates sewage sludge.