镉-砷污染苜蓿的联合效应及机理的研究

JOINT EFFECTS AND MECHANISMS OF Cd AND As SIMULTANEOUSLY POLLUTING ALFALFA

采用盆栽模拟方法,试验共存条件下的有毒元素镉(阳离子)和砷(阴离子)对首蓿污染的生态效应及其机制。结果发现:(1)当土壤环境同时存在Cd和As时,As有促进苜蓿吸收Cd的功能,而Cd则抑制苜蓿吸收As;(2)当苜蓿受到Cd和As的联合污染时,植株体偏向于吸收更多的有毒元素Pb和过多的Cu,从而加剧Cd和As对苜蓿的污染,反映了Cd—As—Pb—Cu四元素间复杂的交互作用机制,这是多因子污染与理想的单元素污染的明显差异。

Joint ecological effects and mechanisms of Cd(a prsitive ion)and As(a negative ion)si-multaneously polluting alfalfa were studied using the pot-culture simulant method. The following phenmena were first found out. (1)the capacity of alfalfa absorbing As was inhibited because of the action of Cd; (2)Contents of Cd in alfalfa were increased because of the coexistence of as in soil; (3)The intake of Pb and Cu in alfalfa was more than that under single-factor (adding Cd or As)conditions. It is thus clear that multi-factor contamination of soil-plant systems is markedly kifferent from ideal single-factor pollution due to complex mechanisms of the interaction between Cd and As. accurately speaking, mechanisms of the effects resulted from not only Cd and As,but also Pb and Cu.