Measuring stack emissions of micro-pollutants

It has been found that incinerator emissions from refuse combustion, produce large quantities of artifacts in the collection media (XAD2 resin) used to sample the vapor phase component. Consequently, a form of sampling for vapor phase components has been adopted which is considered to be more consistent with obtaining samples more representative of the emission as a whole. A number of other methods exist but probably the other most important method is the German dilution method. Here a sample of flue gas is withdrawn from the stack and immediately mixed with clean and dry dilution air. The stack gas particulates, together with any condensation products are then removed on a filter. As with the WSL system the dilution rate is such that acid condensation is prevented. Collection efficiencies are reported to be comparable with the EPA variants described.