赣南小流域水体中溶解态稀土含量及pH和Eh值变化特征  

pH and Eh Variations and the DREEs Contents of a Small Watershed in South Jiangxi Province

作　　者：何晗晗[1] 于扬[2] 刘新星[3] 黄凡[2] 赵芝[2] 李超[4] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]国土资源部成矿作用与资源评价重点实验室,中国地质科学院矿产资源研究所,北京100037 [3]中国地质大学(北京)地球科学与资源学院,北京100083 [4]国家地质实验测试中心,北京100037

出　　处：《岩矿测试》2015年第4期487-493,共7页Rock and Mineral Analysis

基　　金：国家自然科学基金青年基金项目“稀土矿开发排放尾砂中可吸入颗粒物的地球化学特征及环境效应研究”(41202254);中国地质调查局地质矿产调查项目“我国离子吸附型稀土战略调查及研究”(1212011220804);中央公益性科研院所基本科研业务费专项资金资助项目“赣南离子吸附型稀土矿开采的环境效应研究”(K1209)

摘　　要：测试流经稀土矿区河水的p H和Eh值,可以反映矿区的酸碱性、氧化还原环境。本文以赣南地区濂水、桃江、东江流域为研究对象,利用ICP-MS和三通道多参数测试仪分别测试水样中溶解态稀土含量(DREEs)和p H、Eh值,分析p H、Eh值的变化特征以及DREEs含量与p H值的相关性。结果表明:1研究区水体中DREEs含量变化较大,介于几μg/L至几十mg/L之间;DREEs经球粒陨石标准化后表现为弱的轻稀土富集模式,Eu、Ce显示负异常;2溶解态稀土及La含量分别与p H值呈弱的负相关性,说明地表水体中DREEs浓度及分布模式在一定程度上受外部环境酸碱性的影响;3对于流经地层、地层内离子吸附型稀土矿区的水样,其p H均值分别为7.40、6.94,Eh均值分别为-0.023 V、6.55 mV;对于流经岩体、风化壳离子吸附型稀土矿区的水样,其p H均值分别为6.61、4.37,Eh均值分别为0.024 V、0.15 V,表明赣南地区离子吸附型稀土矿区处于中酸性的氧化环境。Knowing the pH and Eh values of stream water flowing through the rare earth element deposits can lead to an understanding of the acidity and alkalinity and oxidation-reduction environment of deposits. For this purpose, the Lianshui,Taojiang and Dongjiang rivers in South Jiangxi were selected for study. The dissolved rare earth elements （ DREEs ） and pH-Eh values of water samples were analyzed by Inductively Coupled Plasma-Mass Spectrometry（ ICP-MS）and Three-channel Multi-parameter,respectively. Conclusions are listed as follows：（1）DREEs contents range widely from several μg/L to tens of mg/L,and chondrite-normalized DREEs patterns show a slightly right-inclined trend with Eu and Ce negative anomalies. （ 2 ）The weakly negative correlations of DREEs and La contents with pH values indicate that the DREEs contents in water and distribution patterns are affected by the pH values of external environment. （ 3 ）Stream water samples flowing through stratums and ion-adsorbed type REE deposits in stratums have pH values of 7. 40 and 6. 94,respectively,and Eh values of -0. 023 V and 6. 55 mV,respectively,whereas stream water flowing through granite plutons or weathering crust ion-adsorbed type REE deposits have respective pH values of 6 . 61 and 4 . 37 ,and respective Eh values of 0 . 024 V and 0. 15 V. It indicates that ion-adsorbed type REE deposits formed in a neutral-acid oxidized environment.

关 键 词：赣南小流域 溶解性稀土 电感耦合等离子体质谱法 PH值 Eh值 

分 类 号：O614.33[理学—无机化学] O657.63[理学—化学]