潜流湿地控制暴雨径流中氮磷冲击负荷中试研究

进行了3种人工潜流湿地（无植物空白床、芦苇床、茭草床）控制暴雨径流中氮、磷浓度的冲击负荷试验，考察了潜流湿地对氮、磷的去除效果及其耐冲击负荷能力。结果表明，潜流湿地能够有效控制暴雨径流中的氮、磷浓度，且具有较强的耐冲击负荷能力，其中以芦苇床潜流湿地对暴雨径流中氮、磷的去除效果为最好。处理滇池流域重现期为5a的单场降雨，试验床体面积占汇水面积的比例〉3．7％时，芦苇床湿地对总磷的去除率高达92％，对总氮的去除率为63％；当冲击负荷流量增大后，处理系统面积占汇水面积的比例减小到2％时，芦苇床对总氮和总磷的去除率分别为38．6％和52．6％。在相同水力停留时间下，潜流湿地的冲击试验与前期的连续流试验结果相比，冲击负荷会降低系统的脱氮除磷率，降低的脱氮率〈10％，降低的除磷率在15％左右。

Study on Nitrogen and Phosphorus Treatment in Storm Runoff by Subsurface Constructed Wetland

A simulation of storm runoff treatment with three types of subsurface flow wetlands(SFS) of the pilot-scale bed of blank plant,Phramites communis and Zizania caduciflora was studied.The three types of wetlands' removals of nitrogen and phosphorus and their abilities to withstand shock loadings were investigated.The results show that the subsurface flow wetlands can control the nitrogen and phosphorus concentrations in storm runoff effectively and can strongly withstand shock loading,and that the Phragmites communis of the three SFS techniques preformes the best of all.Using the Phragmites communis,the removal rates of TP,TN reach 92% and 63% respectively when the storm recurrence interval is 5 years and the treatment system area occupies above 3.7% of the catchment area.When the runoff load increases,the treatment system area occupies below 2% of the catchment area and the TN and TP removal rates of using the Phragmites communis bed are 38.6% and 52.6% respectively and that of using the blank plant are 36.3% and 42.7%.At the same HRT averages and compared to previous similar studies,the shock loading can now decrease systematic nitrogen and phosphorus removal.TN and TP removal rates can decrease by about 10% and 15%.