不同螯合剂处理下杨树对土壤中Cd的吸收和富集效应

通过盆栽试验,研究了分别投加1,3,9mmol/kg的EDTA、EGTA和柠檬酸(CA),新疆杨对干旱区污染土壤中Cd的吸收和富集特征.实验结果表明,投加螯合剂的处理土壤中水提态Cd的含量是对照的4.27~249.12倍,但杨树地上部的生物量和对照相比并未显著降低.投加螯合剂的处理显著提高了杨树叶部Cd的含量和积累量,其值分别是对照的1.05~2.90和1.42~2.77倍.综合来看,螯合剂的投加有效活化了土壤中的Cd和促进了Cd从杨树根部向其地上部的转移,3种螯合剂的作用效果表现为EGTA>EDTA>CA的顺序.

Chelate-induced uptake and accumulation of Cd in soil by poplar (Populus bolleana Lauche)

In order to investigate the uptake and accumulating characteristics of Cd by poplar (Populus bolleana Lauche) in response to the addition of ethylenediamine tetraacetic acid (EDTA), ethylene glycol-bis(2-aminoethylether)- N,N,N′,N′-tetraacetic acid (EGTA) and citric acid (CA) at levels of 1, 3 and 9 mmol/kg, respectively, a pot experiment was designed and performed. Results showed that water-extractable Cd concentration in soils added with chelating agents was 4.27~249.12 times higher than the control, while no significant reduction in aboveground biomass was observed in response to the addition of chelating agents compared with the control. The addition of chelating agents significantly increased the concentration and amount of Cd in poplar leaves, the values which were 1.05~2.90 and 1.42~2.77 times higher than the control, respectively. In general, chelating agents effectively mobilized Cd in the soil and promoted the translocation of Cd from roots to shoots as EGTA>EDTA>CA.