植被过滤带对地表径流中污染物的净化效果

植被过滤带是控制非点源污染的“最佳管理措施”之一。为了探讨植被过滤带在中国西北地区的实际应用，该文作者在陕西小华山水库岸坡地建设了3条不同配置方式的植被过滤带，通过试验测定了植被过滤带对地表径流中几种污染物的净化效果，并分析其影响因素。结果表明，植被过滤带对地表径流中的颗粒态氮、颗粒态磷、总氮、总磷和化学需氧量浓度削减率分别达到82.02%、77.13%、46.05%、73.28%和60.48%以上，负荷削减率分别达到89.98%、87.25%、69.93%、85.11%和77.97%以上，并能有效地削减溶解态氮和溶解态磷的负荷量；自然草地过滤带和沙棘-草本过滤带对地表径流中这几种污染物的削减主要发生在前10 m。过滤带内的植被条件、入流流量和入流污染物浓度是影响过滤带净化效果的重要因素。

Clarification efficiency of vegetative filter strips to several pollutants in surface runoff

Vegetative filter strip (VFS) is a main kind of Best Management Practices for the control of non-point pollution. For investigating the practical use of VFS in Chinese northwest, three VFSs with different vegetation planting patterns have been constructed in the bank slop of Xiaohuashan Reservoir, Huaxian County, Shanxi Province. Clarification effects of VFSs to pollutants in surface runoff and influencing factors have been analyzed based on the measured data of plot experiments. Results show that the concentration reduction rate of particulate N, particulate P, total N, total P and COD in surface runoff by VFS reached 82.0%, 77.13%, 46.05%, 73.28% and 60.48%, respectively, under the test conditions; and load reduction rate for these pollutants achieved 89.98%, 87.25%, 69.93%, 85.11% and 77.97%, respectively; In addition, the load of dissolved N and dissolved P could be decreased effectively. The experiment also shows that the most pollutants were entrapped in the first 10 m of the grassed strip and the Hippophae rhamnoides sub.sinensis/grass strips. The main factors influencing clarification efficiency of VFS include vegetation conditions, inflow rate and inflow pollutant concentration.