The Application of Constructed Wetland in Sewage Treatment in Small Towns

The sewage treatment in small towns becomes an environmental problem exactly solved at present. This paper introduced the concept, classification, principle of constructed wetland. Connected with the sewage treatment in Yongchuan City.it comes out that the constructed wetlands have the advantages of low investment, simple performance , cheap operation cost and so on. The technology of constructed wetlands have widely application prospect. Removal rates of CODcr, BOD3, SS, NH3-N and TP by this treatment were studied. Removal rates of CODcr,BOD5,SS were about 90%. Removal rates of NH3-N,TP were 83% and 72% , respectively. Removal rates of N and P is better than other treatments. Discharge water quality is better than the discharge standard for urban sewage farm.