Investigating Salt Effect Correction for δ18O and δ2H in Saline/Brine Groundwater Samples

Authorsمحمد میرزاوند، هدی قاسمیه، سیدجواد ساداتی نژاد، رحیم باقری، Julien Walter
JournalInvestigating Salt Effect Correction for δ18O and δ2H in Saline/Brine Groundwater Samples
Page number81
Volume number12
IFثبت نشده
Paper TypeFull Paper
Published At2023-09-22
Journal GradeScientific - research
Journal TypeElectronic
Journal CountryIran, Islamic Republic Of
Journal IndexISC

Abstract

This study focuses on the Kashan Plain Aquifer (KPA), an emblematic case in Iran, where over-pumping groundwater intensifies salinity. Employing advanced isotopic techniques, specifically analyzing stable water molecule isotopes (δ18O and δ2H) through the Gasbench+DeltaPlusXP method, the current study addresses the intricate nature of saline waters by analyzing geochemistry and isotopes of 15 groundwater samples. It should be noted that the electric conductivity (EC) of the water samples varied from 2210 to 212000, with their mean value being 65499 μS/cm. The study also investigates the impact of salinity on isotopic values, considering ion hydration and salt effects that are crucial for accurate measurements. The results of the study revealed that δ18O values ranged between -8.4 to 6 and -8.38 to 6.48 % before and after salt effect correction, respectively. Moreover, it was found that the average δ18O values varied from -4.58 to -4.49 % before and after salt effect correction. In addition, the disparity between measured and corrected δ18O revealed the impact of MgCl2, and CaCl2 salts on δ18O in all collected samples. However, no difference was found between measured and corrected δ2H. Therefore, while the findings indicate the necessity of salinity correction for δ18O, it appears that salinity correction bears less significance for δ2H.

tags: Environmental Isotopes Activity Saline Groundwater Brine Isotope Hydrology