Research On Mechanism Of Ecological Restoration For The High Turbid Matter Of Qianwei Village

Based on the Science and Technology Commission of Shanghai Municipality program "Research on high efficient removal of contaminants from high turbid matter and key technologies of ecological restoration for the rural river system of Chongming"(Grant No.06DZ12307), the phenomenon of eutrophic water was studied by the integrated constructed wetland ecological system at Qianwei village of Shanghai. The effect of water purification and the mechanism of nitrogen and phosphorus removal by the ICW were also studied.A constructed wetland system was built, and its purification efficiency was simulated under different operating conditions. The role of Stuff, Oxidation pond and algae and the mechanism of Nitrogen and phosphorus removal by the ICW were studied.The oxygen pond was cultivated directly in domestic sewage under appropriate weather conditions. After about 5-day cultivation, it was concluded that there was a time sequence of the growth of aerobi heterotrophic bacteria, nitrosomonas, nitrobacer in the cultivation process. The cultivation took about 25～30d. The algae cultivation in the system was simple and the startup was quick. Both were good for the application of the ICW system in rural areas.The study between the nitrogen, phosphorus and SS show that most of the phosphorus in Chongming surface water is insoluble, Density of TP linear with the turbidity and little insoluble nitrogen exists.The Contribution of each part of ICW in nitrogen & phosphorus removal was analyzed. The stuff of wetland can adjust the pH and plays an important role in phosphorus removal. Ceramic pellet have many holes and relative surface product, so it's a good habitat for microorganisms; Oxygen pond can reduce the suspension density (SS) and the load of the wastewater.The effect of multiplexed system under the different water load conditions on the pollutants removal rate was studied. The result indicated that turbidity removal rate decreases with the rise of water load, and it remained constant when the water load reduces to 0.015m~3 /m~2·h below,Through the massive experimental data and related researches at home and abroad, the Chongming water mathematical model was formed and it can be used to forecast the system processing water quality.The central lake water quality was greatly improved by use of the ICW system project. It changed to be II, III from poor V, and the ICW had passed expert group's approval of the Science and Technology Commission of Shanghai Municipality.