| 长江中游故道区高碘地下水分布与形成机理 |
| |
| 引用本文： | 罗义鹏,邓娅敏,杜尧,薛江凯,孙晓梁.长江中游故道区高碘地下水分布与形成机理[J].地球科学,2022,47(2):662-673. |
| |
| 作者姓名： | 罗义鹏 邓娅敏 杜尧 薛江凯 孙晓梁 |
| |
| 作者单位： | 1.中国地质大学地质调查研究院, 湖北武汉 430074 |
| |
| 基金项目： | 国家自然科学基金面上项目（No.41977174）； |
| |
| 摘 要： | 高碘地下水（碘浓度大于100 μg/L）广泛分布于我国沿海地区和干旱内陆盆地，威胁近千万人口的饮水安全，但目前对湿润区河湖平原地下水中碘的分布与成因机制的认识还十分薄弱.通过采集长江中游故道区75组浅层地下水样品和7组地表水样品进行了水化学分析，查明了地下水中碘的空间分布特征，并运用主成分分析识别了碘富集的水环境要素和水文地球化学过程，并结合4个不同位置的钻孔岩性特征探讨了沉积环境演化对地下水中碘富集的控制作用.研究发现地下水中碘的浓度范围为0.78~1 590 μg/L，其中25%样品超过我国水源性高碘地区水碘含量判定值（100 μg/L）.高碘地下水主要赋存于长江河曲凹岸和粘土充填的牛轭湖区的浅层承压含水层.长江中游故道埋藏的丰富有机质形成的强还原环境有利于碘从沉积物释放至地下水中，微生物介导下沉积物有机质降解和铁的氢氧化物还原性溶解是区内高碘地下水形成的主要水文地球化学过程.牛轭湖区后期填充的低渗透率粘粒填塞体和河曲凹岸沉积的厚层粘土层创造了利于碘富集的封闭且水流滞缓的地下水环境.
|
| 关 键 词： | 高碘地下水 空间分布 水文地球化学 主成分分析 沉积演化 长江中游故道区 水文地质 |
| 收稿时间： | 2021-03-29 |
Occurrence and Formation of High Iodine Groundwater Inoxbows of the Middle Reach of the Yangtze River |
| |
| Luo Yipeng,Deng Yamin,Du Yao,Xue Jiangkai,Sun Xiaoliang.Occurrence and Formation of High Iodine Groundwater Inoxbows of the Middle Reach of the Yangtze River[J].Earth Science-Journal of China University of Geosciences,2022,47(2):662-673. |
| |
| Authors: | Luo Yipeng Deng Yamin Du Yao Xue Jiangkai Sun Xiaoliang |
| |
| Abstract: | High iodine groundwater (iodine concentration greater than 100 μg/L) is widely distributed in coastal areas and arid inland basins in China, threatening the drinking water safety of nearly ten million people, but the understanding of the distribution andformationof iodine in groundwater in humid areas is still very weak. In this study, 75 shallow groundwater samples and 7 surface water samples were collected fromoxbowsof the middle reach of the Yangtze River for hydrogeochemical analysis, the spatial distribution characteristics of iodine in groundwater were identified, the water environmental factors and hydrogeochemical process of iodine enrichment were identified by principal component analysis, and the control effect of sedimentary environment evolution on iodine enrichment was discussed through the lithological analysis of four boreholes at different locations. The concentration of iodine in groundwater ranged from 0.78 μg/L to 1 590 μg/L, and 25% of the samples exceed the determination value of water iodine content in water source areas with high iodine content in China (100 μg/L). The high iodine groundwater mainly occurs in the shallow confined aquifer, distributed in the concave bank of the Yangtze River and the clayfilled oxbow lake. The strong reducing environment rich in organic matter buried under the deposition in oxbows of the middle reach of Yangtze River is conducive to the release of iodine from the sediments to groundwater. Microbially degradation of organic matter and reductive dissolution of iron hydroxide in aquifer sediments are the main hydrogeochemical processes controlling the formation of high iodine groundwater in the study area. The low-permeability clay packing in the later period of the oxbow lake and the thick clay layer deposited on the concave bank of the river meander created a closed and stagnant groundwater environment for iodine enrichment. |
| |
| Keywords: | |
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《地球科学》浏览原始摘要信息 |
|
点击此处可从《地球科学》下载全文 |
|
