Use of Hydrochemistry and Stable Isotopes as Tools for Groundwater Evolution and Contamination Investigations

Abstract

Hydrochemical and isotopic studies in groundwater was attempted in a basin to gain knowledge on geochemical evolution and water quality status. The results of the chemical analysis indicate the sources of ions into the groundwater are from dissolution and leaching from source rocks, cation exchange and anthropogenic activities. The saturation index calculated specify oversaturation of carbonate species and undersaturation of amorphous silica indicating groundwater chemical evolution controlled by water rock interactions. Water type alters from Ca-HCO 3 to Na-Cl indicating groundwater chemistry controlled by rock-water interaction and anthropogenic activities. The plots of various ionic ratios point out groundwater chemistry affected by ion exchange process, silicate and carbonate weathering along with anthropogenic activities. The isotopes of δ 2 H versus δ 18 O signify ionic concentration increases along the groundwater flow direction along lower elevations. The water type's classification designate 5 distinct groups ranging from low EC and highly depleted isotopes to very high EC with enriched stable isotopic composition indicating longer residence time of groundwater.

Application of environmetrics statistical models and water quality index for groundwater quality characterization of alluvial aquifer of Nalagarh Valley, Himachal Pradesh, India

“…The applications of fertilizer such as anhydrous ammonium chloride have main elemental components of N and Cl. The negative loading of pH is associated with organic matter oxidation related to anthropogenic activities (Krishnaraj et al 2011). PC3 was strongly negative weighted on Ca 2?…”

The Investigation of the Dorfak Karstic Aquifer

“…The displacement of points to the right side and below the 1:1 line indicates that the ion exchange has occurred. Conversely, the displacement of points to the left side and above the 1:1 line shows the reverse ion exchange [24]. The Investigation of the Dorfak Karstic Aquifer DOI: http://dx.doi.org /10.5772/intechopen.85337 Information about the stoichiometric process existence in groundwater provides the evaluation of Ca + Mg against HCO 3 .…”

Use of Hydrochemistry, Stable Isotope, Radiocarbon, 222Rn and Terrigenic 4He to Study the Geochemical Processes and the Mode of Vertical Leakage to the Gambier Basin Tertiary Confined Sand Aquifer, South Australia

“…In a similar study, Chae et al [46] report two distinct groundwater types, a Ca-HCO 3 type and a Na-HCO 3 type, with the former indicating strong influence by surface processes and the Na-HCO 3 type water indicating the attainment of a chemically more stable state. The plot of (Ca + Mg) versus (HCO3 + SO4) shows (Figure 5a) that the majority of data points cluster around a 1:1 stoichiometry of (Ca + Mg) to (HCO3 + SO4), indicating that Ca, Mg, SO4 and HCO3 are derived from simple dissolution of calcite, dolomite and gypsum [47][48][49]. Minor ion exchange takes place at TLA and the Mepunga Formation at VIC 3, as the data plot below the 1:1 line, which reflects that portion of the anion balances of Na and K produced by silicate weathering.…”

“…The plot of (Na + K) versus Cl (Figure 5b) shows that the majority of data clusters around, but sits above the 1:1 line, particularly at the SA 2 , VIC 1 and VIC 3 sites, where excess (Na + K) over Cl is found. Since the salinities of the samples are low (1551, 718 and 533 mg•L −1 , respectively) and have The plot of (Ca + Mg) versus (HCO 3 + SO 4 ) shows (Figure 5a) that the majority of data points cluster around a 1:1 stoichiometry of (Ca + Mg) to (HCO 3 + SO 4 ), indicating that Ca, Mg, SO 4 and HCO 3 are derived from simple dissolution of calcite, dolomite and gypsum [47][48][49]. Minor ion exchange takes place at TLA and the Mepunga Formation at VIC 3, as the data plot below the 1:1 line, which reflects that portion of the anion balances of Na and K produced by silicate weathering.…”

“…EC profiles are considered useful indicators to identify possible pathways of freshwater from point recharge sources [46,47] and are used to track possible groundwater flow pathways. EC profiles are considered superior to mid-screen water sampling alone as the sonde records EC of water at 0.05-m intervals, thus enabling identification of EC changes at short depth intervals.…”