The exhaust gases contain pollutants coming from chemical and electrochemical treatment. A wet scrubber is used to remove or neutralize unwanted particles. Water is sprayed with high pressure through nozzles into the air flow. Some of the water evaporates, especially if the process-air is hot, and disappear with the exhaust. Water droplets are separated from the exhaust and re-circulated back to the water reservoir. Aerosol and gaseous pollutants in the air stream are removed by either absorption or chemical reactions with the water solution.