南方离子型稀土矿区芒萁的稀土提取能力

Rare Earth Element Extraction Ability of Dicranopreris Dichotoma in Ionic Type Rare Earth Mining Area,Southern China

为探讨南方稀土矿区芒萁对土壤稀土元素的提取能力,三洲桐坝(SZ,5a治理地)、下坑(XK,8a治理地)、牛屎塘(NS,10a治理地)、龙颈(LJ,对照地)为实验样地,研究芒萁的生长特征(株高、密度、生物量)、稀土元素富集能力及稀土元素提取能力。研究发现,各样地间株高、密度、地上生物量和总生物量均显著差异(P<0.05),而地下生物量则差异不显著。地上部分对稀土元素的积累量以LJ最高,分别是SZ、XK及NS的5.45、3.51、2.33倍;而地下部分积累量以NS最高,分别是SZ、XK及LJ的5.24、6.36、3.96倍。芒萁地上部分轻稀土元素含量和稀土元素总量在各样地间差异显著(P<0.05),LJ≈NS>XK≈SZ,且芒萁地上部分主要是累积轻稀土元素。通过芒萁净化矿区稀土元素,通过计算分别需要58年、36年、20年芒萁提取,才能将中度污染的NS、轻度污染的SZ、XK的稀土矿区表层土壤(0~10 cm)中稀土元素含量降低到全国土壤稀土元素含量的平均水平(186.76 mg·kg^-1)。

In order to explore the rare earth element extraction ability of dicranopreris dichotoma in southern rare earth mining area to extract rare earth elements in the soil,this paper takes the southern ionic type rare earth mining area as experimental plots,including Sanzhoutongba(SZ,5 a governance land),Xiakeng(XK,8 a governance land),Niushitang(NS,10 a governance land).and Longjing(LJ,reference),to study the growth characteristics(plant height,density,biomass),rare earth element enrichment ability and rare earth element extraction ability.The study found that among those experimental plots,plant height,density,aboveground biomass and total biomass were significantly different(P<0.05),while underground biomass was not significantly different.The highest accumulation of rare earth elements in aboveground part is LJ,which is 5.45,3.51 and 2.33 times of SZ,XK and NS respectively.The highest accumulation of underground part is NS,which is 5.24,6.36 and 3.96 times of SZ,XK and LJ respectively.ΣLREE andΣREE were significantly different in the aboveground part of dicranopreris dichotoma(P<0.05),LJ≈NS>XK≈SZ,and the aboveground part of dicranopreris dichotoma was mainly composed of LREE.In order to purify the rare earth elements in the mining area by dicranopreris dichotoma,it will take 58,36 and 20-years to reduce the rare earth element content in the topsoil(0~10 cm)of NS,SZ,and XK,respectively,to the average level of soil rare earth elements in China(186.76 mg·kg^-1).