Study On The Process Of Emulsive Wastewater Treatment

Emulsion wastewater was mainly from machining operation and metal surface treatment. Its discharge was small, but it would cause serious pollution. It was because of high concentration oil, nitrites and COD in waste emulsion. The experiment was to use miniature equipment to treat waste emulsion in laboratory, using group technology of co-coagulation flotation, suspended active carbon, bio-contact oxidation process, and sedimentation-filtration-adsorption.In the process of co-coagulation flotation, appropriate amount of PAC was 6 g/L, PAM was 0.03 g/L, pH was about 8.5, the flow amount of dissolved-air water was 50L/h , and dissolved-air pressure was at 0.2 MPa. When raw water COD was 2.2×10~4 mg/L and SS was 1716 mg/L, putted them into coagulation floatation reaction instrument. COD removal rate reached about 84.00%. SS removal rate reached about 88.98%. In final, COD was 3520 mg/L, SS was 189 mg/L.In the process of suspended activated carbon, the activated carbon did not only have the adsorbability, but also become a carrier of microorganism. It could treat the outflow of co-coagulation floatation. The active carbon in the instrument was small and roundish shape, whose diameter was 3 mm. After 6 hours process, the removal rate of COD was 68.01%. The removal rate of SS was 51.32%. COD was 1126 mg/L. SS was 92 mg/L.In the process of bio-contact oxidation, Put them into Bio-contact oxidation instrument, they became liquid state after aeration. The material which used in was macroporous PU. After 9 hours, COD was 112 mg/L with a 90% removal rate. The removal rate of SS was low, because organism membrane fell off.In the process of sedimentation-filtration-adsorption, Diameter of active carbon was 1 mm, and fine sand diameter was 1~3 mm. Flow rate was controlled at 20 ml/min. COD and SS was 48 mg/L and 11 mg/L respectively. The removal rate of COD and SS was 57.14% and 92.76% respectively.After the four processes, COD of effluent has been reduced from 2.2×10~4 mg/L to 48 mg/L, with a removal rate of 99.78%. SS has been reduced from 1.8×10~3 mg/L to 11 mg/L, with a removal rate of 99.36%. The quality of final water reached the standard of integrated waste water emission in Liaoning province (DB 21/1627-2008).