三种类型人工湿地对富营养化水体的净化效果比较

Research on Purification Efficiency of Removal From Three Different Type of Constructed Wetland

以富营养化水体为试材,采用室内化验的方法,研究了垂直流、水平流和沟渠型人工湿地对富营养化水质的净化效果,以期为人工湿地进行污水处理提供有益的参考。结果表明:不同类型人工湿地对富营养化水体中各种污染物去除率均呈倒"V"字形变化规律,不同时期的去除率排序基本表现为反弹期>稳定期>恢复期>启动期;综合比较可知,不同类型人工湿地均能有效促进水质的净化,其中垂直流人工湿地对污水中TP、BOD_5、COD_(Cr)的去除率较大,水平流人工湿地对污水中TN、NH_4^+-N的去除率较大;从出水口水质稳定性来看,垂直流人工湿地出水各项指标较稳定,水平流、沟渠型较差,说明不同类型人工湿地对污染物的去除效果和机制不同;不同类型人工湿地植被地上和地下氮、磷累积量均呈"V"字形变化规律,各时期积累量排序基本表现为反弹期>稳定期>恢复期>启动期;相关性分析表明,人工湿地植被氮、磷积累量分别与生物量、氮、磷含量呈显著(P<0.05)或极显著(P<0.01)的线性关系。综合分析表明,垂直流人工湿地对富营养化水体的净化效果更佳。

Domestic sewage was used as test material,comparison research on purification efficiency of plants removal from different type of constructed wetland including the vertical flow wetland （VFW） ,subsurface flow wetland （SFW） and trench type （TT） ,and the removal efficiencies of total nitrogen （TN） ,total phosphorus （TP） ,ammonia nitrogen （NH4^＋-N） ,biological oxygen consumption （BOD5） and chemical oxygen consumption （CODCr） were measured.The results showed that different type of constructed wetland plants could effectively promote the removal efficiency of sewage and different constructed wetland had a certain difference,of which the removal efficiency of sewage of these constructed wetland were in a‘V＇type with the seasons which showed rebound period〉stabilization period〉recovery period〉starting period.and the vertical flow wetland were the most effective on the removal of TP,BOD5 and CODCrand subsurface flow wetland were the most effective on the removal of TN and NH4^＋-N.In the same period,the outlet water concentration of NH4^＋-N,TN,TP,BOD5 and CODCrof the vertical flow wetland were more stable,that were different type of constructed wetland had their own pollutants removal efficiency and mechanism.Respectively,the N,P accumulation of different type of constructed wetland plants were in a ‘V＇type with the seasons which showed rebound period〉stabilization period〉recovery period〉starting period.Correlation analysis showed that the plant accumulations of nitrogen and phosphorus displayed significantly positive linear correlation with plant biomass and concentrations of nitrogen and phosphorus （P〈0.05） ,of which biomass,concentrations of nitrogen and phosphorus could be used as an indicators to screening appropriate constructed wetland plants.