Removing sulphur di:oxide from waste gas - by contacting with salt water in absorption tower, to form bi:sulphite which is then oxidised to bi:sulphate which is used to adjust pH of salt water feed

摘要

is removed from waste gas by allowing it to impinge on salt water in an absorption tower. The salt water contains sufficient bicarbonate for the stoichiometric conversion of the SO2 into bisulphite. The sump of the absorption tower is aerated so that bisulphite is converted into bisulphate. This bisulphate is then passed into secondary reaction vessels to form sulphate and to adjust the pH of fresh salt water.