草地过滤带对地表径流中不同吸附性农药的截留

Interception Effects of Grass Filter Strips on Pesticides with Different Absorbability in Surface Runoff

构建模拟降雨产流小区,以裸露土壤径流区为对照系统,考察以百慕大、高羊茅、白三叶植被组成的草地过滤带对降雨水力侵蚀形成的地表径流中弱吸附性除草剂阿特拉津和强吸附性杀菌剂百菌清的截留效果,并对两种不同吸附性污染物的迁移特征进行探讨。结果表明:对照系统和草地过滤带出水中阿特拉津溶解态质量浓度和吸附态质量比均明显高于百菌清的;相比于对照系统,草地过滤带径流出水中溶解态阿特拉津质量浓度减小60%以上,溶解态百菌清质量浓度减小6%以上,悬浮固体减少94.70%以上,吸附态阿特拉津和百菌清污染负荷减小80%以上。研究证实,草地过滤带可有效拦截地表径流中的溶解态和吸附态有机农药污染物,相比于百菌清,植被的存在更有利于对阿特拉津的截留。

A series of simulated rainfall experiments were conducted to determine the interception effects of grass filter strip(GFS)estab⁃lished by bermuda,tall fescue and white clover on atrazine with weaker absorbability and chlorothalonil with stronger absorbability in surface runoff by comparison with control system(CS),while the migration characteristics of the two kinds of pesticides with different absorbability were discussed.The results show that the outflow concentrations of dissolved and adsorbed atrazine are higher than that of chlorothalonil both from CS and GFS;compared with CS,the concentrations of dissolved atrazine and dissolved chlorothalonil from GFS are decreased by more than 60%and 6%respectively.The reduction of suspended particles amount from GFS is more than 94.70%,and the load reductions of ad⁃sorbed atrazine and chlorothalonil from GFS are more than 80%by comparison with CS.The study evidences that GFS can effectively inter⁃cept the pesticide carried both in solid and liquid phases,and vegetation is more important to atrazine interception.