植物对水溶液中乐果的降解及影响因素分析

Evaluation of dimethoate degradation in water by phytoremediation

通过气相色谱分析,建立浓度换算标准曲线,研究了三种水生植物水葱、香蒲和石菖蒲对水溶液中乐果的降解效果,并进一步探讨了水葱对乐果降解的动力学过程和各因素对乐果去除的贡献。结果表明,三种植物对乐果去除能力由大到小依次为:水葱,香蒲,石菖蒲。水葱10天内对乐果的去除率为58%,香蒲和石菖蒲组对乐果的去除率分别为39%和33%。乐果的自然降解和挥发、植物吸收和微生物降解作用对乐果去除的贡献率约为:20%、40%、30%。水体的pH升高能够加速乐果的降解,营养盐质量浓度的下降不利于植物去除乐果。

The pudfieation efficiency to dimethoate by three aquatic plants, Scirppus validus、 Typha latifolia and Acorus tatarinowii Schott were studied. The results showed that Scirppus validus performed better in removing dimethoate than Typha latifolia and Acorus tatarinowii. The reduction percentage of dimethoate in Scirppus treatment was 58%. In Typha and Acorus tatarinowii treatments, the reduction percentages were 39% and 33% respectively. The kinetics process research demonstrated that plant uptake contributed about 40% to the total dimethoate removal, while microorganism did about 30%; evaporation and natural degradation did about 20% to the total reduction. The increase of pH of water accelerated degradation of dimethoate and the decrease of nutrients concentration imposed an obstructive effect on phytoremediation.