Effects of combination treatments of mercapto palygorskite and hematite on remediation of Cd-As contaminated soil
A pot experiment was performed to investigate the remediation effects of single and combination treatments of mercapto palygorskite(MPAL)and hematite(Fe2O3)on Cd-As contaminated soil.The soil pH value,availability and speciation distribution of Cd and As in the soil,biomass of different parts of rice,and contents of Cd,As,and Fe in the rice parts were determined.The results showed that all treatments significantly increased the biomass of rice grains by 2.37-2.45 times in comparison to the control.The DTPA-Cd content in the soil was reduced by 16.94%-22.57%(P<0.05).The combination treatment of MPAL and Fe2O3 increased the proportion of amorphous iron oxide-bound Cd/As in the soil,as demonstrated by sequential extraction results.The combination treatment significantly reduced Cd and As concentrations in roots by 7.14%and 25.13%,respectively.All treatments reduced the Cd concentration in grain by 40.00%-60.00%,but they had no significant effect on the As concentration in grain.These results showed that combination treatment of MPAL and Fe2O3 can effectively reduce the available Cd and As contents in soil and the Cd and As concentrations in rice,indicating that the combination treatment has potential application value for remediation and safe utilization of Cd-As contaminated farmland.
万方数据
维普
