空心菜对水中3种除草剂的去除作用

Effects of Water Spinach on the Removal of Three Herbicides in Water

为探讨空心菜对水溶液中典型除草剂的去除作用,采用静态水培实验方法,研究了空心菜水培溶液中丙草胺、丁草胺和恶草酮3种除草剂去除的动力学过程、空心菜生长状况及空心菜对除草剂的富集情况。结果表明,在50~1000μg·L^(-1)浓度下,空心菜在丙草胺和丁草胺水溶液中生长状况良好,但在较高浓度(≥250μg·L^(-1))恶草酮水溶液中无法生长;在抑菌处理下,空心菜培养水溶液中丁草胺、丙草胺和恶草酮3种除草剂的平均去除率比无植物组分别提高了65.19%、70.49%和10.50%;丙草胺和丁草胺的去除过程基本符合一级动力学反应方程,且去除反应速率常数受除草剂浓度影响较为明显。植物组织中丙草胺和丁草胺在根中的残留浓度显著高于茎叶中。研究表明,空心菜能够促进水溶液中丙草胺和丁草胺的去除,植物代谢、吸收与根系吸附占主导作用。

In order to investigate the removal efficiency of the herbicides by water spinach(Ipomoea aquatica),the hydroponic culture was conducted to study the removal kinetics of three herbicides(pretilachlor,butachlor and oxadiazon).The growth status of plant and the herbicides enrichment by water spinach were also studied during this hydroponic culture process.The results showed that the water spinach grew well when the concentrations of pretilachlor and butachlor were between 50~1000μg·L^(-1),but it could not survive in the oxadiazon aqueous solution if oxadiazon concentration was greater than 250μg·L^(-1).Compared with the control group(non-plant group),the removal efficiencies of pretilachlor,butachlor and oxadiazon in water spinach group were increased by 65.19%,70.49%,and 10.50%,respectively.The removal processes of pretilachlor and butachlor accorded with the first-order kinetic reaction equation,and the removal reaction rate constant was significantly affected by the herbicide concentration.The pretilachlor and butachlor concentrations in roots were both significantly higher than that in stems and leaves.This study indicated that the water spinach could effectively remove the pretilachlor and butachlor in aqueous solution through growth metabolism and roots absorption.