in the chemical industry wet gas cleaning systems are frequently employed for the treatment of exhaust gases emerging from decentralized hazardous waste incinerators. With respect to the extremely high pollutant emissions, multistage gas cleaning processes are used that consist in most cases of a quench, one or more wet scrubbers and an optional aerosol separation stage. In order to select a suitable design of the gas cleaning process and equipment, beside the specific technical performance of each apparatus, particularly economic criteria have to be considered, like maintenance as well as investment costs. Additionally, the choice of the suitable material of construction plays a major role, especially at the transition section of dry to wetted gas in the quench. The present comparison of different process and equipment alternatives indicates that only the consideration of all relevant parameters yields to an optimal solution.