柳树对亚铁氰化物的吸收、代谢及其毒性研究

为探明亚铁氰化物在植物体内的迁移、转化及对植物的毒性作用,以长出新根须和嫩叶的垂柳(SalixbabylonicaL.)枝条为材料,在自行设计的250ml生物反应器中生长192h,培养温度为24.0±1℃,亚铁氰化物水溶液的浓度分别为52.99,105.98,211.95和317.93mgCNL-1。结果表明:(1)低浓度实验组(52.99mgCNL-1)水溶液中10.85%的亚铁氰化物被植物吸收,随着浓度的升高吸收到植物体内的亚铁氰化物的比例(%)依次递减,但是统计学分析显示各实验组单位体重(湿重)的植物吸收亚铁氰化物的量无显著性差异;(2)在植物的各个部位都能检测到微量的亚铁氰化物,表明亚铁氰化物通过植物的蒸腾作用在植物体内的迁移。由于没有检测到在气态下的总氰化物,表明植物的蒸腾作用没有将亚铁氰化物释放到大气中;(3)尽管植物吸收到体内的亚铁氰化物是有限的,但物质平衡实验证明其在植物体内迁移的过程中超过96%的都能被植物有效转化;(4)所用的4种亚铁氰化物浓度在192h内没有对柳树产生毒性作用。因此认为:依据亚铁氰化物在水溶液→植物→空气系统内的迁移和转化,亚铁氰化物的植物修复是可能的。

Uptake, Metabolism, and Toxicity of Iron Cyanide Complex in Weeping Willows

Uptake, metabolism and toxicity of iron cyanide complex in trees were investigated. Pre-rooted weeping willows (Salix babylonica L.) were exposed to hydroponic solution spiked with ferrocyanide at 24.0±1 ℃C for 192 h.Four different treatment concentrations of ferrocyanide were used (52.99, 105.98, 211.95 and 317.93 mg CN L-1).Cyanide in water, in tissues of aerial part of plants and in air was analyzed spectrophotometrically. Results from this study indicated less than 10.85% reduction of the applied iron cyanide complex was detected in hydroponic solution in the presence of plants. Little amounts of cyanide were found in all parts of plant tissues, indicating the passage of ferrocyanide through the plants. Mass balance studies showed that iron cyanide complex moving into plants from hydroponic solution can be metabolized during transport. Phytotoxic effects were not found in all treatment groups, even at high doses of ferrocyanide within a 192-h exposure period. In conclusion, transport and metabolism of ferrocyanide in plants is most likely to happen and phytoremediation of this iron cyanide complex in field application may be possible.