STUDY ON REFUSE INCINERATION PLANT LEACHATE PRETREATMENT TECHNOLGY

A combined process of coagulation-filtration-air stripping was applied to remove pollutants from leachate in a fullscale municipal refuse incineration plant in attempt to assess the feasibility of joint-treatment of leachate and municipal sewage． The results showed that the removal rate of COD，TN，ammonium，and TP content in raw leachate reached 6. 0%，33. 3%， 32. 0%，and 71. 3%，respectively，when the dosage of FeCl3 and CaO were kept at 1‰ and 20 g /L in coagulation process． Then，the removal rates of TN and ammonium in landfill-leachate were increased to 83. 9% and 91. 4% after air stripping for 6 hours at 50 ℃． The pre-treated leachate was mixed with municipal sewage at a ratio of 1 /250，and C/N and C/P value of the mixed sewage increased from 2. 4 and 27. 7，to 3. 7 and 45. 5． Therefore，it can be inferred that the pre-treated leachate could be regarded as a potential carbon source for denitrification in the biological nitrogen removal process of municipal discharges． In view of the above，this combined process exhibits a promising application prospect in the treatment of sewage with low C/N value．