Research On The Processing Technology Of Artificially Strengthen Ecological Filter Bed In Polluted Tributary

With the rapid social and economic development in China, the water resource is suffered serious damage. Now seven major river basins in our country have been subject to different degrees of pollution, among them Liaohe River is more seriously pollution. And the Tiaozi River is one of the most polluted tributaries of Liaohe River, it seriously affected the lives of people on both sides of Tiaozi River. So it is imperative to manage the Tiaozi River. And the non-point source pollution is more serious than the industrial pollution in that basin, non-point source becomes the key of Tiazi River’management.Artifical strengthen ecological filter bed is developed on basis of advection and subsurface flow constructed wetland, it is considered a practical and effective method to control the non-point source pollution. The effluent water of artificial strengthen ecological filter bed is of high quality and security and it enjoys low infrastructure and operating costs as well as a simple management. But on the other hand, there are usually too many affecting factors on the water quality including:load factors like hydraulic loading, pollutant load, water quality factors like water temperature, dissolved oxygen, pH etc. In this study, the first is the selection of filter material, after determining the filter material is the film formation experiment. The last is the studies of pollutant load, hydraulic load and aeration intensity impact on COD removal, ammonia nitrogen removal and total nitrogen removal, and to determine the optimum conditions.Experimental results show that:(1) When aeration intensity and hydraulic loading are in the same conditions, when the influent COD concentration is150mg/L, the maximum COD removal rate is87%. When the concentration is300mg/L, the COD removal rate is only40%, so when the influent COD concentration is higher than300mg/L, it is almost beyond the load of filter bed. When the influent ammonia concentration is20mg/L, the maximum ammonia nitrogen removal rate is71.2%. When the concentration is70mg/L, the removal rate is only27.1%, and it is beyond the load of filter bed.(2) When aeration intensity is in the same conditions, the hydraulic loading is20cm/d, the maximum removal rate is71.37%. When the hydraulic loading is10cm/d the ammonia nitrogen and total nitrogen removal rate are73.5%and55.3%, when the hydraulic loading is20cm/d, the removal rate is only decreased slightly, also to save energy, the best hydraulic loading selected as20cm/L.(3) When the hydraulic loading is10cm/d, the gas-water ratio is6, the removal rate of COD, ammonia nitrogen and total nitrogen has reached the maximum. So the best gas-water ratio is6.(4) Under the optimum conditions, the hydraulic loading is20cm/d and gas water radio is6. Effluent COD and ammonia nitrogen are meastued, they are26mg/L and1.6mg/L. And they can respectively achieveⅣ and Ⅴ class standard of "Surface Water Enviromental Quality Standard".