Research Article
Hydrogeochemical Characteristics of Groundwater in the Prefecture of Bassar, Togo
Issue:
Volume 13, Issue 1, February 2025
Pages:
1-13
Received:
26 December 2024
Accepted:
27 January 2025
Published:
31 January 2025
DOI:
10.11648/j.ajche.20251301.11
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Abstract: This study aims to assess the factors and geochemical processes controlling groundwater quality in the prefecture of Bassar. It is a major yam tubers and pre-colonial West African iron production center in Togo but with limited investigations on groundwater chemistry. Conventional hydrochemical techniques with geochemical mass balance calculations, intervariables correlation, and factor analysis with principal component methods were applied to a chemical database of major ions and heavy metals concentrations of twenty borehole water samples. These groundwater samples were collected during the dry season and analyzed following AFNOR standard methods for the examination of water. The results showed fresh and circumneutral groundwater types with pH values between 6.7 and 7.5 with an average of 7.1 and EC between 280 and 1148 µS/cm and an average of 691 µS/cm. All the hydrochemical parameters comply with the WHO drinking water guideline value except Arsenic content for 5 % of the samples, suggesting potential health risks for residents relying on raw groundwater for drinking purposes. Anions and cations' contributions to groundwater mineralization are in the order of HCO3-> Cl- > SO42- > NO3- and Ca2+ > Mg2+ > Na+ > K+, respectively. The main hydrochemical facies were mixed cations-HCO3 water types, followed by accessory Ca-HCO3, Mg-HCO3, Ca-Mg-Cl, and Mg-Na-HCO3, under the control of water-rock interaction mechanisms and human activities influence from agriculture practices. The geochemical processes are silicate minerals hydrolysis, carbonate, and soil salts dissolution, sorption, and cations exchange with the thermodynamic equilibrium of groundwater with kaolinite, muscovite, K-feldspar, and smectites such as Mg-montmorillonite solid phases. Fe/Mn-(hydr)oxide phases in the aquifer matrix exert significant control on the mobility of As and Sb originating from geogenic sources in the study area. This study provides insight into the factors and geochemical processes controlling the groundwater quality, as a baseline tool for water security concerning major and trace constituents in the Bassar prefecture.
Abstract: This study aims to assess the factors and geochemical processes controlling groundwater quality in the prefecture of Bassar. It is a major yam tubers and pre-colonial West African iron production center in Togo but with limited investigations on groundwater chemistry. Conventional hydrochemical techniques with geochemical mass balance calculations,...
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