Abstract: The reverse osmosis concentration method and the crystal seed process are desulphurization wastewater subsequent depth treatment methods commonly used at present, but the treatment results of the methods are not so ideal. A composite method, which include pretreatment softening + mechanical steam recompression cycle evaporation + trieffects mixed flow forced circulation evaporation crystallization + centrifugal drying package technology, was adopted; and the disadvantages of the commonly used methods were improved. In this composite method, the wastewater will be treated by softening, evaporation, crystallization, drying and packaging, and will be emitted as steam or will be closed and buried as sewage sludge at last. This method with zero discharge of the liquid wastewater has favorable social and economical benefit.

Key words: industrial wastewater, desulphurization, reverse osmosis concentrating method, evaporation concentrating, materials recycle utilization, zero emission