改性膨润土钝化修复镉污染土壤及对生物有效性的影响

选用产自辽宁省的改性膨润土,对浙江湖州某重金属Cd元素污染修复试验田开展试验研究,分析改性膨润土对重金属有效态及其对水稻农作物有效性的影响,分析水稻植株中重金属富集系数的分布特征。研究表明,膨润土能够有效降低土壤中Cd的迁移能力,能有效降低土壤中离子交换态Cd元素、水溶态Cd元素、碳酸盐态Cd元素的含量,施加后能够减少农作物对Cd的吸收量,减轻Cd对作物的毒害,且具有环境友好的特征。对比水稻根系和与试验田块表层土壤Cd元素的含量发现,大部分水稻根系Cd元素含量超过甚至远远超过土壤中Cd元素的含量,表明水稻根系对Cd元素具有较强的富集作用。

A study was initiated in an experimental field for the remediation of heavy metal cadmium(Cd)contamination in Huzhou,Zhejiang Province,employing modified bentonite sourced from Liaoning Province.This investigation analyzed the effects of modified bentonite on the bioavailability of heavy metals and its influence on the productivity of rice crops.The study also focused on the distribution features of heavy metal enrichment coefficients in rice plants.The findings revealed that bentonite has the capability to significantly mitigate the migration potential of cadmium in the soil.The substance efficiently reduces the concentration of ion-exchangeable Cd,water-soluble Cd,and carbonate Cd in the soil.Post-application,the uptake of cadmium by crops was reduced,thereby mitigating the toxicity of cadmium to crops and highlighting the environmentally friendly features of this approach.Upon comparing the concentration of cadmium elements in the rice root system with the topsoil of the experimental field,it was found that the Cd element content in the majority of the rice root systems surpassed,and in some cases,greatly exceeded that in the soil.This indicated that the rice root system has a strong enrichment effect on Cd elements.