Constructed Wetland To Xiao River Water Quality Improvement Of Analysis And Evaluation

Currently,water pollution is one of the important environmental problem of our country.The constructed wetland as a new municipal sewage treatment technique has many merits such as stable effluent water quality,strongly resistance to impact load,the lower invest of infrastructure and operating cost,easily maintaining,and aesthetics value.As well as the effective removal of pollutants,it has the availability of denitrification and dephosphorization.And now constructed wetlands get people's more and more attention.Xiaohe wetland was selected for the study of constructed wetlands treatment effect on effluent of urban wastewater treatment plants.Xiao river wetland was built under the highway across Xiaohe,along north and south sides of the river in 2013.River water quality and the effects of the constructed wetland treatment were monitored and evaluated in this study.One-year field sampling of influent and effluent of wetland was carried out in 2015.The pH,CODCr,NH3-N,TN,and TP was tested and analyzed.The level characteristic value method was used.Results of water quality were divided into five grades in order to reflect the water quality conditions accurately.Membership degree of each measured parameter and each index weight was calculated by linear membership function.The comprehensive evaluation level of water quality was determined by fuzzy comprehensive evaluation.In order to find the treatment level of the river wetland,the analysis of comprehensive evaluation level and each index situation were carried out.The results of data analysis showed that the rates of various pollutants in water were above 50% by Xiao River wetland and the water quality meets the requirements of artificial wetland sewage treatment technical specification.NH3-N and TN removal efficiency was very high and it was 70.5% and 67.3%,respectively.The removal efficiency of CODCr and TP was relatively weak and it was 55.4% and 52.3%,respectively.CODCr removal rate of Xiao river wetland showed the best in flood season in summer.Lush plant growth enhanced water purification significantly.Although the concentration of influent pollutant changes greatly,the wetland effluent water quality was very stable.It can basically meet the national surface water environmental quality standards and reflects the high resistance to impact load.