含磷材料对土壤溶液稀土元素含量的影响

Effects of phosphorated materials on the concentrations of rare earth elements in soil solution

稀土矿产开采导致土壤稀土污染严重。本研究报道几种含磷材料(过磷酸钙、磷矿粉、骨炭、磷酸二氢钙)对土壤溶液稀土元素含量的影响。结果表明,4种含磷材料添加到2种不同的稀土污染土壤(寻乌、龙南)中,可导致土壤溶液15个稀土元素的浓度均显著降低,降低比例在20.8%~99.2%;不同稀土类型降幅比率顺序:轻稀土元素(镧、铈、镨、钕、钐)>中稀土元素(铕、钆、铽、镝)>重稀土元素(钇、钬、铒、铥、镱、镥)。不同含磷材料中,添加2.5%~5.0%磷酸二氢钙、骨炭、磷矿粉和过磷酸钙处理导致土壤溶液稀土元素浓度比对照处理分别降低55.3%~99.2%、86.8%~99.1%、80.7%~99.3%和9.8%~96.2%。说明这几种含磷材料可以用来修复稀土污染土壤,降低稀土元素对环境的污染。

Mining of rare earth minerals can cause serious rare earth pollution to the soils. In this study,four types of phosphorated materials（ superphosphate,phosphate rock,bone charcoal and monocalcium phosphate） were added into two types of soil polluted by rare earth in Xunwu and Longnan counties of Jiangxi Province,respectively,to examine their influences on the concentrations of rare earth elements（ REE） in soil solution. Results showed that the addition of phosphorated materials significantly decreased the concentrations of 15 types of REE in soil solution,with the amplitude of reduction between 20.8% and 99.2%. The order of the reduction percentage of different types of REE was as follows： light REE of La,Ce,Pr,Nd and Sm 〉 middle REE of Eu,Gd,Tb,Dy 〉 heavy REE of Y,Ho,Er,Tm,Yb and Lu. Adding 2.5%-5% of superphosphate,phosphate rock,bone charcoal and monocalcium phosphate decreased REE concentration by 55.3%-99. 2%,86. 8%-99. 1%,80. 7%-99. 3% and 9. 8%-96. 2% respectively. These results suggested that application of phosphorated materials could remediate the rare earth polluted soils and reduce the pollution of REE.