贵州典型土壤对重金属的蓄积特性
Accumulation Characteristics of Heavy Metals in Guizhou Province
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摘要: 以贵州省典型土壤黄壤和石灰土为研究对象,采用野外调查和室内分析相结合的方法,对贵州土壤重金属吸附解吸特性进行研究.结果表明:除了Cr和As,无论黄壤还是石灰土,土壤重金属的吸附固持的作用随碳酸钙含量的增加而增强,而随着黏粒含量的增加,黄壤和石灰土的吸附量都有所增加,但解吸量无明显促进或降低,即碳酸钙影响该地区土壤重金属蓄积的作用大于黏粒;黄壤和石灰土对重金属的吸附过程主要集中在前90 min内,其后的吸附则进行得十分缓慢,且对重金属的最大吸附量石灰土大于黄壤;三种动力学模型拟合中,伪二级动力学方程的拟合度最好,从动力学参数中可知,石灰土重金属平均吸附量大于黄壤重金属平均吸附量,黄壤重金属平均吸附速率大于石灰土重金属平均吸附速率.Abstract: Filed investigation and labratory analysis was used to research the effects of calcium carbonate and clay particle on accumulation capacity of heavy metals in contaminated soils.The results showed that the accumulation capacity of heavy metals in contaminated soils is increased with the increase of calcium carbonate content,that is calcium carbonate is one of the main effect of accumulation capacity of heavy metals in contaminated soils.Pseudo two order kinetic equation is the best one to fit the adsorption kinetics process and we will know that the average adsorption capacity of heavy metals is lime soil > yellow soil and the average adsorption rate is yellow soil > lime soil.
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