【摘要】：本研究采用萊州灣沿岸含水層中的沉積物,通過滲濾實驗?zāi)M鐳的解吸過程。結(jié)果表明,在典型的地下水流速范圍內(nèi)(0.02~0.30 cm/min),鐳同位素(~(223)Ra、~(224)Ra、~(226)Ra)的解吸沒有顯著變化。在海水與淡水的混合過程中,解吸的鐳比活度與水的鹽度呈顯著的線性正相關(guān)關(guān)系。當(dāng)鹽度超過海水鹽度時(如S=80的鹵水中),解吸的鐳比活度則趨于最值平臺。對比模擬估算的地下水中鐳的比活度與萊州灣沿岸實測間隙水中鐳的比活度,~(223)Ra和~(224)Ra的結(jié)果基本一致,而~(226)Ra的實測結(jié)果較模擬估算結(jié)果偏小。可能由于含水層中~(226)Ra經(jīng)反復(fù)解吸后得不到母體核素及時補充所致。本研究將為更好地理解鐳同位素在含水層中的地球化學(xué)行為提供科學(xué)依據(jù),為合理地選擇量化海底地下水排放(submarine groundwater discharge,SGD)模型的鐳端元值提供新的參考視角。
[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.
【作者單位】： 中國海洋大學(xué)海洋環(huán)境與生態(tài)教育部重點實驗室;中國海洋大學(xué)環(huán)境科學(xué)與工程學(xué)院;中國海洋大學(xué)海洋化學(xué)理論與工程技術(shù)教育部重點實驗室;中國海洋大學(xué)化學(xué)化工學(xué)院;
【基金】：山東省自然科學(xué)基金資助項目(ZR2012DQ002,ZR2011DM010) 高�；究蒲袠I(yè)務(wù)項目(201262014,201213030)
【分類號】：P736.4
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本文編號：2394413