Study On Technology Of Stabilizing Water Quantity And Quality Of Mengze Lake In Wuhan

With the development of society and the improvement of people's living standard, much more landscape water came out. In order to satisfy function requirement, it's especially important to keep the landscape water quantity balance.Mengze Lake in Wuhan will be bulit in Wangjiadun center business district. It is a 35 hektares artificial landscape lake. According to the water quantity balance equation, the rainfall and evaporation from the surface of the lake is analyzed, seepage quantity from vertical and horizontal sides of the lake is calculated with Darcy's Law, and the rain runoff discharging into Mengze Lake from the surrounding area is calculated also. The result indicates that if the seepage from the horizontal side of the lake is controlled with rammed wall together with the rain runoff from 55 hektares surrounding area of the lake feeding, the fluctuation of the lake can meet control requirement without any enforced water in normal years. If the water of Mengze Lake is used for road sprinkling and field plantation, it's necessary to be compensated with the same quantity from municipal water net. But in drought year, the fluctuation of water level may be a little beyond the storage capacity from Junly to Noverber. If the water of Mengze Lake is used for road sprinkling and field plantation, it's necessary to compensate it with the same quantity from municipal water net. Exploitating groundwater is sugested as the emergency complenment measure of the lake.Air fall-dust polluting contribution to the lake is studied by simulating with collecting dust barrels. We found that air fall-dust pollution is different every month in five different places. The pollution brought by rainoff and air fall-dust into the Mengze Lake is greater than its self-purification capability. So compulsory external cycle measurement must be taken to Mengze Lake to keep the water quality stabilite.The costructed greenland is one of the focus due to its ecological,scenical and economical performance. The result of the experimental research on the costructed greenland model to treat the water of East Lake of Wuhan indicate that the purifying efficiency of COD,TN and TP were good both in starting and stability period, and the water quality was improved with 1~2 grades. When the hydraulic loading rate of the system was 0.95m~3/m~2·d, the hydraulic retention time of the system was 6 hours and 10 minits. To get higher absorption efficiency of phosphorus, the medium of the IV district has been replaced with coal ash. The result indicted that coal ash has higher absorptive capability and the removeal of COD,TN and TP is increansed by 9,14 and 18 percent point. The coal ash is suitable for the medium of costructed greenland because it is easy to be get and it is the byproduct of industrial process.Compared with costructed greenland, the filtration of the choths-filter-jar and sands filter tank remove the contaminants depend on filtration. They have higher filtration capability and need less space, but the removal efficiency and ecological performance and economical performance are weaker .When we put some chemical enhance the removal of contaminants, we found the removal efficiency of the filters were increasedless. Through comprehensive considering, the costructed greenland is suggested as the best compulsory external cycle measure of Mengze Lake.