Study On AF+DWWSCW+EP Union Process Application In The Three Gorges Area

Eutrophication was more serious in the reservoir after construction of the Three Gorges Reservoir, it was urgent affairs to treat the sewage which discharge into Three Gorges Reservoir. However, there were lots of mountains and few lands, and the layout of towns are dispersed. so the traditional sewage treatment was difficult to be constructed, because it was difficult to confiscate the land and construct waste pipe. As an ecotypic technology for wastewater treatment, constructed wetland had more advantages than other technologies, such as simple in structure, low investment in building and operation, strong in anti-strike and stabilization in effluent quality. It showed broad development and application prospect to solve sewage treatment in small urban and prevention of eutrophication in rivers and reservoirs.But there were also many disadvantages in constructed wetland, such as their vast regions, lack of dissolved oxygen in conventional subsurface flow constructed wetland, and deficiency in extractive of nitrogen and phosphorus. So AF+DWWSCW+EP combined process was proposed, which combined of Anaerobic Filter, Drop water Wavy Subsurface Constructed Wetland and eco-pond. In order to study AF+DWWSCW+EP combined process, the research constructed a small constructed wetland in Lianglu town, Yubei district of Chongqing, the place is mountain land and had appropriate slope and much rain.The results of studying indicate: Anaerobic Filter should be put in the front of constructed wetland and it can hydrolysis and acidificate part of organic matter, reduce the SS, and reduce the pressure of process comes by, prevent to clog the constructed wetland efficiently. Eco-pond should be put in the back of Drop water Wavy Subsurface Constructed Wetland, which can intensification the treatment of nitrogen & phosphorus and improve removal rates of nitrogen & phosphorus. Constructed wetland using dropping aeration can save energy consumption and cost of construction and maintenance, for it isn't need aerated and dynamic equipments; Wave and subsurface-flow not only has features of plug flow insurface current- wetland but also has features of vertical current in vertical current-wetland, which created a better condition for removal nitrogen.