Dioxins and Furans
In recent years, one group of chemical compounds, Polychlorinated dibenzofurans (PCDFs), commonly called dioxins and furans, has attracted special attention because of their toxicity, carcinogeecity and possible mutagenicity. These compounds are found in many foods - including fish, poultry and eggs - and occur in such common products as wood pulp and paper. About 75 different forms have been identified, of which five dioxins and seven furans are considered to be most toxic.
Fortunately, such compounds can be destroyed. It is claimed that by maintaining very high temperatures during the combustion process, waste-to-energy plants can eliminate virtually all of the dioxins that are produced. Also that a combination of scrubbers and fabric filtration systems can remove up to 99 percent of these large molecules. Activated carbon injection before the flue gas treatment has also proved to be effective. Activated carbon reactor and catalytic rectors can be used for advanced processing.
However, the dioxins and furans are the most controversial issues, and the mechanism of their production are not yet completely clarified and their removal methods are not yet completely established.
