Modern flue gas cleaning systems guarantee a targeted degradation of pollutants by means of different system chains. Which system chain is used again depends on the particular conditions of the site location and the composition of the waste.
 
None of these system components purifies one exclusive flue gas component. It can for instance contribute to separation of solids as well as to cleaning from organic trace impurities and heavy metals.

Various manufacturer-specific flue gas cleaning methods exist at present, which are composed of variable system components. Irrespective of the procedure, solids, contaminated gases and organic trace impurities are separated, and heavy metal components are removed by filtration.
 
The waste incineration process produces dioxins and furans (from combustion) as well as gaseous forms of heavy metals such as mercury and cadmium. These substances are already contained in the waste and are liberated by the combustion process.
 
In old landfill sites, these pollutants were allowed to enter the environmental cycle untreated. Even the redevelopment of old and the construction of new waste dumps did not prevent the continued existence of these pollutants in spite of environmental barriers.
 
Flue gas cleaning however removes these pollutants from the environment permanently.