【摘要】 试验采用室内培养的方法,研究了不同剂量天然沸石、改性沸石（氯化铵和氯化钙改性）对土壤中重金属Cd赋存形态的影响。结果表明,同一剂量天然沸石与氯化钙改性沸石处理中随时间推移土壤p H先升高后降低,最后趋于稳定,氯化铵改性沸石处理则呈现持续下降的趋势。在整个培养时期,氯化铵改性沸石处理组中土壤交换态Cd含量呈先降低后升高的趋势,在30 d时达到最低值;氯化钙改性沸石与天然沸石处理土壤交换态Cd呈现持续降低的趋势,三者土壤交换态Cd分别降低了18.74～30.82 mg kg^-1、18.5～30.12 mg kg-1、13.71～28.28 mg kg^-1。三种处理对土壤中残渣态镉的转化率为氯化铵改性沸石>氯化钙改性沸石>天然沸石,50 d时三者残渣态镉含量分别增加了21.48%、18.23%、14.08%。根据土壤pH与土壤交换态Cd含量相关性分析表明,二者呈显著负相关,土壤p H值与改良剂修复土壤重金属污染的修复效率密切相关。更多还原

【Abstract】 The effects of different amounts of natural or modified zeolites with ammonium chloride（NH4 Cl） and calcium chloride（CaCl₂） on cadmium（Cd） speciation were investigated by the incubation experiment. After the application of natural zeolite and modified zeolites with NH4 Cl at the same level, the soil pH values were firstly increased and then declined, and finally tended to be stable. The CaCl₂-modified zeolite showed a continuously decreased trend. During the whole incubation period, the contents of soil exchangeable Cd after the addition of zeolite treated with NH4 Cl decreased to be the lowest value at 30 d and then increased with incubation time. The contents of soil exchangeable Cd after the addition of natural or modified zeolites with CaCl₂ showed a persistently descend trend. The contents of soil exchangeable Cd were decreased by 18.74-30.82 mg kg^-1, 18.5-30.12 mg kg^-1, and 13.71-28.28 mg kg^-1,respectively. Conversion percentages of soil residual Cd were in the order: NH4 Cl-modified zeolite > CaCl₂-modified zeolite > natural zeolite. At 50 d, the contents of residual Cd increased by 21.48%, 18.23% and 14.08%, respectively.There was a significant negative correlation between soil p H value and the content of soil exchangeable Cd. Soil pH was closely related with the remediation efficiency with the amendments for soil heavy metal pollution.更多还原