Study On The Pool-chain System In Situ Water Purification Of Fu Niu Creek

With the development of society and economy, people gradually pay attention to environmental problems of the secondary river, and the treatment of the secondary river has been imperative. The paper is focused on a typical mountain type secondary river Fu Niu creek in Dudukou district, Chongqing, constructing an alternate waterfall-pool water purification system called as Pool-chain system in the Fu Niu creek, which imitates the step-pool form naturally forming in Mountain-type river and is combined with kinds of river water purification technologies, studying the performance of water purification to gain an economical and effective river water purification technology which is suitable for mountain-type urban secondary river. The main research contents and conclusions are as follows:The effects of initial phosphorus concentration, temperature, p H and adsorption time on the phosphorus adsorption of zeolite, ceramsite, blast furnace slag, silica sand and gravel are studied, the results showing that blast furnace slag has the best phosphorus adsorption performance under all kinds of conditions. The isothermal adsorption performances of the five kinds of materials are studied and both Freundlich and Langmuir isotherm are used to fit the results of the isothermal adsorption, resulting that blast furnace slag has the maximum adsorption capacity followed by ceramsite, zeolite, gravel and silica sand. The experiments show that the blast furnace slag is suitable to be used as the substrate in Pool-chain system.Taking full advantage of terrain, a six-stage alternate waterfall-pool water purification system called as Pool-chain system which combined with biological-film, ecological embankment and constructed wetlands technology is designed and constructed. 2-5stage pools contain partitions making the water flowing through the bottom of the partition, thereby increasing the contacting time and area between water and substrate.Combined with water-falling reoxygenation, aerobic micro-degradation of contaminant is enhanced, thereby improving the performance of water purification of Pool-chain system.Water quality of Pool-chain system has been monitored for 3 months after the project completed. The results shows that the removal rate of CODmn, ammonia, TN and TP are 14.8%, 39%, 10% and 28%, respectively, and the effluent concentration of CODmn, ammonia and TP are 11.70mg/L, 0.88mg/L and 0.17mg/L, reaching the National Standard of Environmental Quality Grade V. Pool-chain system is beneficial to reoxygenation of Fu Niu creek. The influent and effluent concentration of DO are 6.24mg/L and 9.734mg/L, increasing 55.94%.