The Research On The Treatment Of Polluted Municipal Surface Water By Subsurface Flow Constructed Wetland

Considering the characteristics of the surface water pollution in some city of China, as well as the climatic and geographical conditions, a special process called constructed wetland was applied for ecological recovery of the surface water. By analyzing the date of experiments in different season and different work situation, the removal efficiency of the suspended material , COD and N and the parameters was researched in subsurface flow constructed wetland . The disposing rules of the contaminants were simulated by the dynamical model.For the study of the parameters for different filling and different plant combination in subsurface flow constructed wetland, there are three systems with single plant - single filling , mix plant - single filling , single plant - mix filling . The research of surface water flowing into the subsurface flow constructed wetland indicates these results:(1) The systems have high elimination capacity to the suspended material , COD and N. The rules of the elimination to the suspended material were accordant by different HRT and different season. The system with mix plant - single filling was better than the others for the COD elimination. The system with mix filling was better than the systems with single filling for N elimination. (2) The removal efficiency of the suspended material , COD and N are better with the longer retention time, and the removal efficiency in summer and autumn were better than the spring and winter. The difference of removal efficiency of the suspended material was over 30% between the HRT=2d and the HRT=8d in winter. The removal efficiency of COD was remarkable only in spring, and the difference was about 10%. The removal efficiency of N in summer and autumn was better than the spring and winter. The difference of the removal efficiency of NH_~+-N was over 50% between in summer and in winter, and the TN was over 60%.By the study of the first-order kinetics and the ecological kinetics for the elimination, the first-order kinetic model could be used to simulate the disposing...