Biological and Intensive Coagulating Treatment for Waste Water from Coating White Paperboard Mill

A general three stages process to treat the integrated waste water in a laboratory scale, including anaerobic, aerobic and intensive coagulating treatment, was discussed in this paper. After being filtrated and coagulation simply, the effluent was treated with two steps of biological process combined with one step of intensive coagulation process. The result shows that the chemical impurities, including COD, BOD, colored substances and turbidity were removed efficiently,and after anaerobic biological treatment, effluent become easy to be biologically treated, and after aerobic aeration treatment, the BOD of the effluent from the clarifier was lower than 25 mg/l，and the BOD total removal ratio was as high as 90%. The result shows also that when poly aluminum silicate chloride (PASC) combing with APAM was effective to remove the colored substances more than 95%. Being treated for the three stages, the water quality of the treated effluent was higher than that discharge requirements by National Effluent Discharge Standards in China.