海水对含水层沉积物中镭解吸的模拟实验
发布时间：2018-12-28 20:43
【摘要】：本研究采用莱州湾沿岸含水层中的沉积物,通过渗滤实验模拟镭的解吸过程。结果表明,在典型的地下水流速范围内(0.02~0.30 cm/min),镭同位素(~(223)Ra、~(224)Ra、~(226)Ra)的解吸没有显著变化。在海水与淡水的混合过程中,解吸的镭比活度与水的盐度呈显著的线性正相关关系。当盐度超过海水盐度时(如S=80的卤水中),解吸的镭比活度则趋于最值平台。对比模拟估算的地下水中镭的比活度与莱州湾沿岸实测间隙水中镭的比活度,~(223)Ra和~(224)Ra的结果基本一致,而~(226)Ra的实测结果较模拟估算结果偏小。可能由于含水层中~(226)Ra经反复解吸后得不到母体核素及时补充所致。本研究将为更好地理解镭同位素在含水层中的地球化学行为提供科学依据,为合理地选择量化海底地下水排放(submarine groundwater discharge,SGD)模型的镭端元值提供新的参考视角。
[Abstract]:In this study, the desorption process of radium was simulated by leachate experiments using sediments from the littoral aquifer of Laizhou Bay. The results show that the desorption of radium isotope (~ (223) Ra,~ _ (224) Ra,~ (226) Ra) has no significant change in the typical range of groundwater velocity (0.02 ~ 0.30 cm/min). In the process of mixing seawater with fresh water, the specific activity of radium desorbed has a significant linear positive correlation with the salinity of water. When the salinity exceeds the salinity of seawater (such as in the brine of Sch 80), the desorption specific activity of radium tends to the maximum platform. The specific activity of radium in groundwater estimated by comparison and simulation is basically consistent with the measured specific activity of radium in interstitial water along the coast of Laizhou Bay. The results of ~ (223) Ra and ~ (224) Ra are basically consistent, but the measured results of ~ (226) Ra are smaller than those of simulation. This may be due to the repeated desorption of ~ (226) Ra in the aquifer and the lack of timely replacement of the parent nuclide. This study will provide a scientific basis for a better understanding of the geochemical behavior of radium isotopes in aquifers and provide a new reference angle for the rational selection of radium end-member values in the model of quantifying the discharge of groundwater from the sea floor by (submarine groundwater discharge,SGD.
【作者单位】： 中国海洋大学海洋环境与生态教育部重点实验室;中国海洋大学环境科学与工程学院;中国海洋大学海洋化学理论与工程技术教育部重点实验室;中国海洋大学化学化工学院;
【基金】：山东省自然科学基金资助项目(ZR2012DQ002,ZR2011DM010) 高校基本科研业务项目(201262014,201213030)
【分类号】：P736.4
，
本文编号：2394413
[Abstract]:In this study, the desorption process of radium was simulated by leachate experiments using sediments from the littoral aquifer of Laizhou Bay. The results show that the desorption of radium isotope (~ (223) Ra,~ _ (224) Ra,~ (226) Ra) has no significant change in the typical range of groundwater velocity (0.02 ~ 0.30 cm/min). In the process of mixing seawater with fresh water, the specific activity of radium desorbed has a significant linear positive correlation with the salinity of water. When the salinity exceeds the salinity of seawater (such as in the brine of Sch 80), the desorption specific activity of radium tends to the maximum platform. The specific activity of radium in groundwater estimated by comparison and simulation is basically consistent with the measured specific activity of radium in interstitial water along the coast of Laizhou Bay. The results of ~ (223) Ra and ~ (224) Ra are basically consistent, but the measured results of ~ (226) Ra are smaller than those of simulation. This may be due to the repeated desorption of ~ (226) Ra in the aquifer and the lack of timely replacement of the parent nuclide. This study will provide a scientific basis for a better understanding of the geochemical behavior of radium isotopes in aquifers and provide a new reference angle for the rational selection of radium end-member values in the model of quantifying the discharge of groundwater from the sea floor by (submarine groundwater discharge,SGD.
【作者单位】： 中国海洋大学海洋环境与生态教育部重点实验室;中国海洋大学环境科学与工程学院;中国海洋大学海洋化学理论与工程技术教育部重点实验室;中国海洋大学化学化工学院;
【基金】：山东省自然科学基金资助项目(ZR2012DQ002,ZR2011DM010) 高校基本科研业务项目(201262014,201213030)
【分类号】：P736.4
，
本文编号：2394413
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