RESEARCH AND ADVANCE IN WASTEWATER TREATMENT BY FLOTATION
WEI Zai shan, XU Xiao jun, NING Ping & XU Jin qiu (College of Environmental and Engineering, Kunming University of Science and Technology, Kunming 650093, China)
In the present paper, research, theory, equipment, application and prospect of flotation technique in wastewater treatment are summarized. Flotation method is a high speed and efficient technique in separation of solid and liquid. Flotation technique is paid close attention to by domestic and abroad scholars in the field of wastewater treatment. The techniques have been developed quickly since 1970, being used comprehensively in treating house sewage of urban, all kinds of industrial wastewater, as well as water supply, especially in purifying water of low temperature, low turbidity and rich algae. Flotation technigue not only substitute for sedimentation, but also serve as treatment of wastewater in advance, as well as contraction sludge. Compared with sedimentation, flotation technique has many advantages such as: (1) small occupying equipment, economical investment of capital construction; (2) good treatment efficiency, it treats plankton of low turbidity, rich algae water and original water that removed difficultly by sedimentation; (3) more economical in coagulant quantity than that of sedimentation; (4) reclaiming useful materials. There are many kinds of flotation, such as eletroflotation, disperse air flotation, dissolve air flotation according to ways of producing tiny air bubble. Industrial equipment of high efficient flotation includes flotation column, flotation pool and flotation machine. After treatment of wastewater containing oil and emulsion by flotation technique, total removal efficiency of COD cr and oil are 80%~99.5% and 70%~99.9% respectively, and every index is up to effluent standard. Also flotation can treats wastewater from a paper mill, reclaiming useful materials such as pulp fiber and packing materials, and the removal efficiency of BOD 5, COD cr , SS, TP are all 80%~90%. It is well known that it not only treats electrolytic cobalt wastewater and wastewater containing heavy metal ions, ions dyeing liquid and wool scouring effluent, but also treats tannery wastewater and house sewage of urban better, removes trihalomethane precursors from eutrophic water.
【Fund】： 云南省亚太工程公司合作项目 (编号 :2 0 0 34)
【CateGory Index】： X703.1
【CateGory Index】： X703.1