海泡石及其复配材料钝化修复镉污染土壤

选取湖北大冶Cd污染土壤,采用室外盆栽实验,研究了海泡石、酸改性海泡石以及二者与石灰、磷酸盐配合使用对油菜生物量、体内Cd含量以及土壤pH和有效态Cd含量的影响。结果表明,不同钝化剂处理均能有效提高油菜地上部和根部生物量,最大分别提高1.03和1.43倍,复合处理以及改性海泡石单一处理的增产效果优于海泡石单一处理。不同钝化剂处理均能显著降低油菜地上部和根部Cd含量,最大分别降低66.40%和22.68%。钝化剂复合处理比单一处理对降低油菜Cd吸收的效果显著,6%的钝化剂添加量较为合适。钝化剂复合处理以及海泡石单一处理均能显著提高土壤pH。不同钝化剂处理均能显著降低土壤有效态Cd含量,钝化剂复合处理对土壤Cd有效性的影响要比单一处理显著。综合实验结果,海泡石与磷酸盐复合处理对土壤Cd污染的钝化修复效果最佳。

Immobilization of cadmium contaminated soils using sepiolite and its compound materials

An outdoor pot-culture experiment was carried out to study the effects of different sepiolite treatments on immobilization of cadmium (Cd) contaminated soils collected from Daye County, Hubei Province. The effects of sepiolite, acid-modified sepiolite and their compound treatments with lime and phosphate on plant growth and Cd accumulation in Brassica chinensis and pH value and available Cd concentration of polluted soils were determined. Different sepiolite treatments could effectively increase dry biomass of shoots and roots, with maximal increases of 1.03 and 1.43 folds, respectively. And the yield increasing effect of compound treatments and single treatment of modified sepiolite was better than that of single treatment of sepiolite. Different sepiolite treatments could significantly reduce Cd concentration in shoots and roots, with maximal reductions of 66.40% and 22.68%, respectively. The compound amendment treatments appeared more efficient than the single amendment treatments in reducing Cd uptake of Brassica chinensis, and the optimum dosage of amendments was 6%. The compound amendment treatments and single treatment of sepiolite could markedly increase pH values of soils. Different sepiolite treatments could significantly decrease available Cd concentration of soils, and the compound amendment treatments appeared more efficient than the single amendment treatments in reducing Cd availability of soils. In summary, the compound treatment of sepiolite and phosphate is the most effective treatment for immobilization of Cd contaminated soils.