Study on Solidification and Remediation of Uranium Contaminated Soil by Different Phosphorus Compounds
SU Fengbing;LUO Xuegang;TANG Yongjin;JIN Xing;Life Science and Engineering College,Southwest University of Science and Technology;State Defense Key Laboratory of the Nuclear Waste and Environmental Security,Southwest University of Science and Technology;
In order to investigate the passivation effect of phosphorous compounds on uranium( U) contaminated soil( including original uranium contaminated soil and simulated uranium contaminated soil),a pot experiment under greenhouse was conducted to examine the influence of applying calcium superphosphate( SSP),potassium dihydrogen phosphate( KH_2PO_4),and Nano-hydroxyapatite( NHAP) to uranium contaminated soil of different concentrations( original uranium contaminated soil,25 mg·kg~(-1),50 mg·kg~(-1)) on uranium speciation in uranium contaminated soil and absorption/transfer of uranium by Alfalfa plants. The results show that,the addition of phosphorous compounds significantly promotes the growth of plants,among which calcium superphosphate works best. In comparison with control groups,when adding SSP,KH_2PO_4 and NHAP to the original uranium contaminated soil decreases the uranium content of Alfalfa plants by 21. 16% ,40. 59% and 36. 61% ,respectively. When adding SSP,KH_2PO_4,NHAP to the simulated soil containing 25 mg·kg~(-1) uranium pollution,the uranium content of Alfalfa plants was reduced by 76. 68% ,89. 67% and 74. 95% ,respectively. While adding SSP,KH_2PO_4,NHAP to the simulated soil containing 50 mg·kg~(-1) uranium pollution,the uranium content of Alfalfa plants was reduced by 66. 33% ,81. 07% ,86. 78% ,respectively. Aiming at three kinds of uranium contaminated soil,KH_2PO_4 is the best in reducing plants uranium enrichment. Those three kinds of phosphorus compounds have notably reduced available content of uranium in the soil and increased the levels of low toxicity and content of the lowest toxic level of residual uranium,which indicates that the phosphorous compounds reduce uranium transfer to plants mainly by reducing the available uranium content in the soil. To sum up,it can be seen that phosphorous compounds have a better passivation repair effect on uranium( U) contaminated soil,provided a relatively favorable soil environment for the safety of primary agricultural products. In this study,the effect of different phosphorus compounds on the remediation of uranium contaminated soil provides some references for treatment of radioactive nuclide contaminated soil and environmental restoration.
【Fund】： 国家国防基础科研计划(JCKY2016404C002);; 研究生创新基金(17ycx89)
【CateGory Index】： X53
【CateGory Index】： X53