The Research On Treatment Of Eutrophication Of Raw Water By O₃-Biological Zeolite

China's water resource per capita is short, and eutrophication of the domestic lakes became more and more serious, so sometimes people have to take eutrophic water as the source of drinking water. The conventional treatment process can not effectively remove organic matter, ammonia nitrogen, and algae from such water. Therefore, in this paper, treatmeat of eutrophic water by ozone-biological zeolite process was studied.In this paper, the adsorption properties of natural zeolite were studied by static tests, the best ozone dosage and contact time in next dynamic experiments were determined by analyzing the ozone removal efficiency of pollutants in water. Also, under certain operating conditions, removal efficiency of COD_Mn, NH₄⁺-N and TP in water by ozone– biological zeolite process were investigated and the influence which was caused by the fill height, EBCT of biological zeolite filter, backwash were inspected, too.The results show that: the removal rate of COD_Mn by ozone in the water was not high, about 14%.Ozone could not remove ammonia, but increased its content in water by oxidize organic nitrogen.The ozone-biological zeolite process had a high removal efficiency of pollutants in eutrophication water, under the conditions of ozone dosage was 2.04mg/L, contact time was 10min, EBCT was 28.2min, the gas/water hydraulic modulus was 1.0, influent pH was under 6～7.5.When COD_Mn of influent was 8.03¹4.46mg/L, NH₄⁺-N was 12.8¹5.78mg/L, TP was 0.18⁰.32mg/L, its average concentration of effluent was 5.0mg/L, 0.68mg/L, 0.15mg/L, the average removal was 54.43%, 95.29%, 39.39%, respectively. The effluent quality achieved the classⅢof the surface water environment quality standard (GB3838-2002);The appropriate extension of EBCT can increase the removal efficiency of COD_Mn and TP. The removal rate of pollutants is different along the packing height, because the quantity and types of microorganisms are different. The proper backwash is conducive to the stable decontamination effect, after backwash, the biofilms get updated, activity is enhanced, the removal efficiency of COD_Mn and TP increased with time, and to be stable after 8h, the removal rate of NH₄⁺-N is not affected by the backwash.