Hydrogeochemical characterization and water quality assessment in parts of Indo-Gangetic Plain: An insight into the controlling processes

This study provides a comprehensive evaluation of groundwater chemistry, with a specific emphasis on characterizing the primary hydrogeochemical mechanism that is acting on the groundwater system in parts of Shahjahanpur, Uttar Pradesh (U.P.), India. For the said purposes, 54 groundwater samples from shallow and deep wells and 7 river water samples were examined for physico-chemical parameters in pre-monsoon (PRMS) and post-monsoon (POMS) seasons, 2019. The analysis of seasonal variations in the physico-chemical parameters conducted through one-way ANOVA statistical approach, unveiled that most of the parameters do not depict any significant seasonal fluctuations. Hydrogeochemically, groundwater was predominantly of Ca + Mg-HCO type. Gibbs and other bivariate plots elucidated that silicate weathering dominantly influences the groundwater chemistry with ion exchange process also affecting it. The results of silica geothermometry revealed that groundwater descending from deeper depth have higher silica content, thus reflecting greater rock-water interaction at relatively higher temperature as compared to the one with lesser silica content. Relationship of SiO with Cl and TDS indicates the involvement of both anthropogenic causes and geogenic mechanisms in regulating groundwater chemistry. Schoeller semi-logarithmic diagram illustrates similar fluctuations in concentrations of most of the major ions between river and groundwater suggesting the likelihood of interaction. The groundwater quality evaluation through water quality index indicates that water sourced from deeper wells is preferable for drinking. The evaluation of Sodium Adsorption Ratio, Kelley’s Ratio and Residual Sodium Carbonate for irrigational use and Larson-Skold Index for industrial use indicates the appropriateness of both surface and groundwater for respective applications.