Abstract: Based on the results of the experimental research on flocculation and biochemical treatment of paper making midcourse wastewater, the technical roads to the treatment of paper making midcourse wastewater were discussed. It has been concluded that the combination of flocculation and aerobic biooxidation treatment is an appropriate way for treatment of this kind of wastewater. On the basis of the pollution characteristics of two kinds of wastewater from beating and washing processes of broke recovering, five design principles have been proposed. 

Key words: paper making, midcourse wastewater, broke recovering wastewater, wastewater treatment, process design