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地下水中硫酸盐的34S和18O在探寻地下水的水质演化规律、赋存环境特征方面具有重要的研究意义,笔者选取保定—河间—沧州—黄骅剖面采集深层地下水水样,分析测试了其主要阴阳离子含量、δ18O、δD、14C及δ34SSO42-和δ18OSO42-各项指标,在此基础上首次探讨了河北平原地下水中硫酸盐的硫、氧同位素分布特征与演化机理。研究发现研究区地下水硫酸盐的δ34SSO42-值沿地下水流向增大,δ18OSO42-值则在一个较小的范围内波动,最终接近一个常数值,二者间呈现较好的负相关关系;δ34SSO42-值随地下水14C年龄的增加而增加,δ18OSO42-则随地下水14C年龄的增加而趋于稳定;34SSO42-值与r(SO42-)/r(Cl-)的值呈负相关关系,δ18OSO42-值与r(SO42-)/r(Cl-)的值则呈正相关关系。在研究区地下水中硫酸盐的34S和18O同位素的分布演变特征主要由SO42-和水之间的同位素交换反应、微生物硫酸盐的还原作用、硫化氢的再氧化作用所影响,其中微生物硫酸盐的还原作用的结果使地下水中的硫酸盐富集34S,SO42-和水之间的同位素交换反应是影响地下水的δ18OSO42-值的主导因素,使地下水的δ18OSO42-取决于地下水的氧同位素组成。
Groundwater in the sulfate 34S and 18O in exploring the evolution of groundwater quality rules, the occurrence of environmental characteristics has an important research significance, the author selected Baoding - Hejian - Cangzhou - Huanghua profile acquisition of deep groundwater samples, analysis and testing of its main yin and yang Ion content, δ18O, δD, 14C, δ34SSO42- and δ18OSO42-, on the basis of which, the distribution characteristics and evolution mechanism of sulfate and oxygen isotopes of sulfate in the groundwater of Hebei Plain were discussed for the first time. The results show that the δ34SSO42- value of groundwater sulfate increases along the groundwater flow direction and the δ18OSO42- value fluctuates within a small range and finally approaches a constant value, showing a good negative correlation between the δ34SSO42 value Δ18OSO42- tends to be stable with the increase of groundwater 14C age; the 34SSO42-value is negatively correlated with the value of r (SO42 -) / r (Cl-), the δ18OSO42- value is positively correlated with r (SO42 -) / r (Cl-) values showed a positive correlation. The evolution of the distribution of 34S and 18O isotopes of sulfate in groundwater in the study area is mainly affected by the isotopic exchange reaction between SO42- and water, the reduction of microbial sulfate, and the reoxidation of hydrogen sulfide. Among them, the microbial sulfate As a result of the reduction, sulfate-enriched groundwater 34S, the isotopic exchange reaction between SO42- and water, is the dominant factor affecting the δ18OSO42-value of groundwater, making δ18OSO42- of groundwater dependent on the oxygen isotope composition of groundwater.