植被过滤带对地表径流中泥沙和杀虫剂的净化效果

Clarification efficiency of vegetative filter strips on sediment and pesticide in surface runoff

通过含沙水流试验,测定了植被过滤带对泥沙、高效氯氟氰菊酯的净化效果。结果表明:入流流量、植被条件是影响植被过滤带拦沙效果的重要因素;高效氯氟氰菊酯的入流浓度越高,植被过滤带断面测定浓度沿程降低越快,当入流浓度分别为0.3、0.6、0.9 mg·L^(-1)时,草地过滤带对高效氯氟氰菊酯的拦截率平均达到61%、71%、75%,灌草地过滤带对高效氯氟氰菊酯的拦截率平均达到52%、69%、74%;入流流量越大,植被过滤带监测断面上的高效氯氟氰菊酯浓度沿程降低越慢,当流量分别为0.87、3.98、7.8 L·s^(-1)时,草地过滤带对高效氯氟氰菊酯的拦截率平均达到61%、50%、33%,灌草地过滤带对高效氯氟氰菊酯的拦截率平均达到52%、44%、40%。研究证实,植被过滤带能有效拦截泥沙、高效氯氟氰菊酯,对农业面源污染具有较好的防治效果。

 In this study, via the field flow experiment, the interception efficiency of Vegetative filter strips（VFS）on sediment and Lambda-cyhalothrin was measured. The results showed that the inflow discharge and vegetation conditions are important influencing factors for sedi-ment retention. The higher the inflow concentration of Lambda-cyhalothrin is, the more quickly the VFS＇s sectional concentrations decrease with the length. When the inflow concentrations are 0.3, 0.6, 0.9 mg·L^-1, the interception rate of the herb VFS on Lambda-cyhalothrin are 61%, 71%, 75%, respectively, and the interception rate of the shrub-herb VFS on Lambda-cyhalothrin are 52%, 69%, 74%, respectively. The greater the inflow discharge is, the lower the VFS＇s sectional concentrations decrease lengthwise. When the inflow discharges are 0.87, 3.98, 7.8 L·s-1, the interception rate of the herb VFS on Lambda-cyhalothrin are 61%, 50%, 33%, respectively, and the interception rate of the shrub-herb VFS on Lambda-cyhalothrin are 52%, 44%, 40%, respectively. The study evidenced that VFS can effectively intercept sedi-ment and Lambda-cyhalothrin, which has better prevention effects on agricultural non-point source pollution.