Research On Micro-polluted Water With Biological Contact Oxidation-Ozone Biological Activated Carbon

At present the source as raw water for water treatment factories has been increasingly polluted. It is difficult for the conventional water purification system (CWPS) to remove the pollutants including the dissolved organic matter, NH4+-N and NO2--N in the raw water, especially the disinfection by-products. Therefore the biological water purification process developed rapidly in removing the pollutants in the raw water. The biological contact oxidation process, which has a series of advantages including the low cost of running, high efficiency, stable running and convenient management, has been extensively taken and followed with interest all over the world. The pilot research has been conducted in micro-polluted water by the optimal combination system of the biological contact oxidation process using elastic stereo packing with the follow-up ozone-biological activated carbon method in order that the pollutants in the raw water can be removed efficiently.The biological contact oxidation treating micro-polluted water is studied, and the effects of various environment factors and operation condition are also researched in this paper. The experiment results represent high removal efficiency of organic material, ammonia, nitrite and algae at different HRTs and the DOs of effluent. Parameters such as HRT, the ratio of air to water and water temperature show strong effect on removal efficiency. Higher removal efficiency is obtained when HRT is prolonged. Although high resolved oxygen is maintained by high ratio of air to water so as to keep the biological activity, too large ratio can lead to not only bio-membrane break off and effluent SS higher, but energy waste. Removal efficiency is improved in the reactor along with the water temperature increased.The biological contact oxidation combined with ozone-biological activated carbon test is discussed in the paper. The biological contact oxidation combined with ozone-biological activated carbon process has a good removal rate of TOC and CODMn.Through the removal rates of TOC, CODMn and NH4+-N during the biological contact oxidation combined with ozone-biological activated carbon process, the optimal oxidation time of ozone is 30min. The process of biological contact oxidation combined with ozone-biological activated carbon gets high removal of TOC and CODMn. The total removal rates of TOC, CODMn are 76.6% and 66.5% respectively. The removal of NH4+-N doesn't rely on the ozone-biological activated carbon but the biological contact oxidation.The economic analysis of the biological contact oxidation process is conducted in the test. The cost for one cubic meter raw water is 0.044 RMB under the influent flow rate was 7 thousand 5 hundred cubic meter per day. The biological contact oxidation process is an economical, high-efficient and feasible process in treating the micro-polluted water. The process has a good application prospect in the pollutant removal of micro-polluted water in China.