镉污染对蔬菜镉吸收和积累的影响

The Effect on Cadmium Uptake and Accumulation of Vegetable under Cadmium Pollution

通过水培和土培试验研究了外源镉添加对3种蔬菜镉吸收和积累的影响。结果表明,随着外源镉添加质量浓度的提高,蔬菜可食用部位镉含量随着增加,蔬菜可食用部位镉含量与环境介质中外源镉添加质量浓度呈现出显著的线性相关。3种蔬菜中,芹菜对镉的吸收能力最强,其次为小白菜,而辣椒果实对镉的吸收能力最弱,仅为小白菜的25%。(以小白菜、芹菜、辣椒)中镉元素的最大允许量为限值,根据相关回归方程计算得到了溶液中镉的临界质量浓度值分别为0.06,0.086,0.11 mg/L,而土壤中镉的临界质量分数分别为0.68、0.57、0.60 mg/kg。

The hydroponic and pot culture experiment was carried out to study the effect on cadmium uptake and accumulation of vegetable under exogenous cadmium addition. The results showed that the cadmium content of vegetables increased with the increasing of exogenous cadmium. There are a marked relativity between cadmium content in vegetable and cadmium concentration in ambient medium. Among the three vegetables, the cadmium content of pakchoi is the highest, then is celery, the pepper is the lowest, which is less than 25 % of the pakchoi. Based on the threshold of human dietary toxicity for Cd, the critical levels of Cd for pakchoi, celery, and pepper were 0.06, 0. 086, and 0. 11 mg/L under hydroponic conditions, and the corresponding value for total cadmium in soil were 0. 68, 0. 57, 0. 60 mg/kg respectively.