植被过滤带对地表径流中泥沙和杀虫剂的净化效果

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。

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

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 sediment 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 sediment and Lambda-cyhalothrin, which has better prevention effects on agricultural non-point source pollution.