3种水生植物对水溶液中乐果的降解作用研究

Effects of Three Aquatic Plants on the Degradation of Dimethoate in Water

通过在人工配制的含有机磷农药乐果的营养液中培养水生植物,研究了水葱、香蒲和石菖蒲对水溶液中有机磷农药乐果的去除效果,并探讨了水葱对乐果降解的动力学过程。结果表明,在抑菌条件下,3种植物都能够显著促进乐果的降解,去除能力为:水葱>香蒲>石菖蒲。水葱10d内对5mg·L-1乐果的去除率为59.8%,香蒲和石菖蒲组对乐果的去除率分别为42.5%和36.9%。在不抑菌条件下,水葱对乐果的去除符合一级动力学方程,去除速率常数为0.099d-1,水溶液中未检测到乐果降解的中间产物。

Using plants to treat polluted sites and groundwater, termed phytoremediation, is a low-cost, promising method for pollution control. Phytoremediation of dimethoate in water solutions by three species of aquatic plants were evaluated in this paper. The efficiency of three plants, Scirppus Validus、Typha latifolia and Acorus tatarinowii Schott to eliminate dimethoate in water solutions, and the kinetics process as well as the degradation mechanism of dimethoate in Scirppus treatment were studied. The plants were grown in synthesized Hoagland solution as nutrient solution with clean sand as substrate. The results showed that, under sterilized condition, all three plants promoted dimethoate degradation significantly compared with the control. Scirppus Validus performed best among them in reducing dimethoate, removing 59.8% of 5 mg·L^-1 dimethoate in 10 days. Typha latifolia and Acorus tatarinowii removed 42.5% and 36.9% of all the dimethoate, respectively. In the unsterilized kinetics experiment, dimethoate concentration was measured at 2, 5, 9, 16 day, with initial concentration of 5mg·L^-1, the kinetics process of dimethoate degradation by Scirppus was conformed with first-order kinetics equation, with the k constant being 0.099 dI1. No intermediate product of dimethoate degradation was detected by analyzing water samples using GC-MS.