土壤改良剂对Cd污染土壤的修复效果研究

Study on Effects of Soil Amendment on the Remediation of Cd Contaminated Soil

[目的]探究试配的土壤改良剂对Cd污染土壤的修复效果及最佳施用比例。[方法]利用盆栽试验向Cd污染土壤中添加不同比例的土壤改良剂,通过指示植物小麦的发芽率、株高及小麦植株SOD活性、MDA含量、Cd富集量等统计学指标,分析不同土壤改良剂对Cd污染土壤种植小麦的影响;通过土壤中不同形态Cd含量的变化,分析不同土壤改良剂对土壤重金属Cd的钝化效果的影响。[结果]随土壤改良剂添加比例的增加,小麦发芽率呈先增后减的趋势;随土壤改良剂添加比例的增加,小麦株高呈先升高后下降的趋势,添加比例为5%时最高;小麦植株内SOD活性、MDA含量和Cd富集量呈先下降后升高的趋势,在添加比例为5%时最低;添加5%土壤改良剂1(泥炭∶膨润土∶生物炭∶微生物=14∶7∶10∶1)的处理组中小麦植株Cd富集量较对照组降低了30.24%;土壤改良剂的添加显著降低了Cd污染土壤中酸溶态Cd的含量,使Cd的迁移性减弱,其中添加5%土壤改良剂1的处理组效果最佳,90 d土壤中酸溶态Cd含量由31.40%降低至9.72%,相较于空白对照组降低了65.43%。[结论]5%土壤改良剂1的施加可有效修复重金属Cd污染土壤。

[Objective]To explore the remediation effect and the best application ratio of the trial soil amendment on Cd contaminated soil.[Method]Pot experiments were conducted to add different proportions of soil amendments to Cd contaminated soil,the germination rate,plant height,SOD activity,MDA content,Cd enrichment and other statistical indicators of wheat were used as indicators,the effects of different soil amendments on planting wheat in Cd polluted soil were analyzed.Through the changes of different forms of Cd in soil,the effects of different soil amendments on the passivation effect of heavy metal Cd in soil were analyzed.[Result]As the proportion of soil amendments increased,the germination rate of wheat showed a trend of first increasing and then decreasing.With the increase of the proportion of soil amendment,the wheat plant height showed a trend of first increasing and then decreasing,and the addition proportion of 5%was the highest.The SOD activity,MDA content and Cd enrichment in wheat plants showed a trend of decreasing first and then increasing,and it was the lowest when the addition proportion was 5%.The Cd enrichment of wheat plants in the treatment group added with 5%soil amendment 1(peat∶bentonite∶biochar∶microorganisms=14∶7∶10∶1)was 30.24%lower than that in the control group.The addition of soil amendment significantly reduced the content of acid soluble Cd in Cd contaminated soil,and weakened the mobility of Cd.The treatment group added 5%soil amendment 1 had the best effect.The content of acid soluble Cd in 90 day soil decreased from 31.40%to 9.72%,which was 65.43%lower than that of the blank control group.[Conclusion]The application of 5%soil amendment 1 can effectively repair the soil polluted by heavy metal Cd.