江汉平原浅层含砷地下水稀土元素特征及其指示意义

发布时间：2018-06-02 06:52

本文选题：砷 + 地下水　；参考：《地球科学》2017年05期

【摘要】：江汉平原被确认为我国南方新的饮水型砷中毒病区,目前对于江汉平原高砷地下水的成因机理研究还有待完善.综合运用水文地球化学分析与PHREEQC地球化学模拟计算,分析了地下水和沉积物中REE分异特征及其沿地下水流向形态变化规律.江汉平原地下水REE含量为0.0320.843μg/L,富集LREE,具显著Eu正异常,且地下水中Eu异常与As含量呈正相关关系.地下水中REE形态主要以LnCO_3~+及Ln(CO_3)_2~-为主,沿地下水流向LnCO_3~+降低、Ln(CO_3)_2~(2-)升高.地下水REE浓度分布受到HCO_3~-的络合作用及Fe氧化物矿物的还原性解吸附过程控制,径流途径中继承沉积物矿物的REE配分模式及Fe氧化物矿物对LREE的优先解吸附可能是地下水富集LREE的原因,并且沿流向上REE形态分布受到pH控制.研究区中Eu含量及Eu正异常对地下水As富集程度具有一定的指示意义.
[Abstract]:Jianghan Plain has been identified as a new drinking water arsenism area in the south of China. At present, the study on the formation mechanism of high arsenic groundwater in Jianghan Plain needs to be improved. Based on hydrogeochemical analysis and PHREEQC geochemical simulation, the characteristics of REE differentiation in groundwater and sediment and its variation law along groundwater flow direction are analyzed. The REE content of groundwater in Jianghan Plain is 0.0320.843 渭 g / L, which is rich in LREE and has significant positive EU anomaly, and there is a positive correlation between EU anomaly and as content in groundwater. The main forms of REE in groundwater are LnCOS _ 3 ~ and Ln _ NCO _ I _ 3s _ 2S _ 2, and the increase of LnCO _ 3 / T _ 3s _ (2) is reduced by the flow of LnCO _ 3 ~. The concentration distribution of REE in groundwater is controlled by the complexation of HCO _ 3- and the reductive desorption process of Fe oxide minerals. The REE partitioning model of sediment minerals inherited from runoff pathway and the preferential desorption of LREE by Fe oxide minerals may be the reasons for the enrichment of LREE in groundwater, and the distribution of REE forms along the upper flow direction is controlled by pH. The EU content and positive EU anomalies in the study area are of certain significance for the enrichment of as in groundwater.
【作者单位】：中国地质大学地质调查研究院;中国地质大学环境学院;
【基金】：国家自然科学基金面上项目(No.41572226) 中央高校基本科研业务费专项基金“摇篮计划”项目(No.CUGL140412) 中国地质调查局项目(No.12120114069301)
【分类号】：P641.3

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