Influence of coastal groundwater salinization on the distribution and risks of heavy metals
Influence of coastal groundwater salinization on the distribution and risks of heavy metals
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沿海地下水盐化对重金属分布及风险的影响
DOI：
10.1016/j.scitotenv.2018.10.250
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发表时间：
2019-02-20
影响因子：
9.8
通讯作者：
Luo, Yongming
中科院分区：
文献类型：
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作者：
Wen, Xiaohu;Lu, Jian;Luo, Yongming
由于沿海地区水资源短缺，沿海地区地下水水质严重影响区域可持续发展。目前对滨海地下水的研究主要集中在咸水入侵和超采方面。有盐碱化趋势的沿海地下水重金属污染信息有限。本研究调查了人类活动强烈、咸水入侵的典型沿海地区地下水中的重金属。研究区西南沿海平原表现出明显的地下水盐渍化趋势。主成分分析表明，滨海地下水中的重金属主要来源于人类活动和地下水盐渍化。砷、钴、铬、铜、铁、锰、镍等重金属在研究区西南部沿海TDS水平较高的区域出现，表明研究区浅层含水层中这些重金属的浓度可能受到地下水盐渍化的影响。研究区地下水重金属平均含量在0.03mU/L~686.92 mU/L之间，以铁为主，最高含量为2333.76 mU/L，超标率达98.23%。以重金属污染指数计算，约有13.27%的采样点地下水重金属污染为中度以上。地下水中重金属具有较低的生态风险。元素Fe、Ni、As是生态风险的主要贡献者。在所有采样点，成人和儿童患重金属的致癌风险都很高。成人和儿童的非癌症风险分别在4.42%和17.70%的采样点是不可接受的。沿海地下水的盐碱化还可能导致沿海地下水中重金属的生态和健康风险增加。这些发现为咸水入侵的沿海含水层重金属污染提供了初步和重要的信息。(C)2018爱思唯尔B.V.保留所有权利。
Coastal groundwater quality significantly affects the regional sustainable development, due to the water resource shortage in coastal zone. Current studies on coastal groundwater have mainly focused on saline water intrusion and over-extraction. Information on the heavy metal pollution of coastal groundwater with salinization trend is limited. This study investigated heavy metals in groundwater from a typical coastal region with intensive anthropogenic activities and saline water intrusion. The southwestern coastal plains of the study area showed significant groundwater salinization trend. Heavy metals in the coastal groundwater mainly originated from anthropogenic activities and groundwater salinization according to principal component analysis. Relative high concentrations of As, Co, Cr, Cu, Fe, Mn, and Ni occurred in the southwestern coast of the study area with high TDS level, indicating that the concentrations of these heavy metals in shallow aquifer of the study area might be influenced by the groundwater salinization. Average concentrations of heavy metals in groundwater of the study area ranged from 0.03 (Cd) to 686.92 (Fe) mu g/L. Fe was the dominant heavy metal in groundwater with the maximal concentration of 2333.76 mu g/L and exceeding-standard rate reaching 98.23%. Approximately 13.27% of sampling sites showed moderate or higher heavy metal pollution of groundwater based on heavy metal pollution index. Heavy metals in groundwater exerted low ecological risks. Elements Fe, Ni, and As were the main contributors for ecological risks. Cancer risks of heavy metals for both adults and children were high at all sampling sites. Non-cancer risks for adults and children were unacceptable at 4.42% and 17.70% of sampling sites, respectively. The salinization of the coastal groundwater could also lead to the increase in the ecological and health risks of heavy metals in coastal groundwater. These findings provide initial and important information on heavy metals pollution in coastal aquifer with saline water intrusion. (C) 2018 Elsevier B.V. All rights reserved.