TREATMENT OF WASTE-WATER FROM FLUE-GAS CLEANING

Wet scrubber systems for flue gas treatment, giving rise to a producti on of wastewater contaminated with heavy metals, are used at many coal -fired power stations in Europe, the USA and Japan. In order to remove the heavy metals from the wastewater, chemical precipitation with hyd roxide and sulphide is applied. Results from two full-scale plants are given. Due to strict regulations for landfilling of waste contaminate d with heavy metals, the amount of sludge must be minimised. Different techniques to meet this requirement are described. Biological post-tr eatment to reduce the nitrogen content of the wastewater will apparent ly be a need in the future, and pilot-scale testing is presently being carried out to determine the basic operation rules for a full-scale p lant.