Identification of hydrogeochemical processes in groundwater using major ion chemistry: a case study of Yenagoa and environs, southern Nigeria

Abstract

Hydrogeochemical studies were carried out in Yenagoa city and environs, Southern Nigeria in order to assess the chemistry of the groundwater and identify the dominant hydrogeochemical processes and mechanisms responsible for the evolution of the chemical composition of the groundwater. The study approach includes detailed geochemical analysis of groundwater samples collected from domestic boreholes for major constituents such as Ca 2+ , Mg 2+ , Na + , K + , HCO 3 , Cl-, SO 4 2-, and NO 3 and the hydrochemical data was subjected to multivariate statistical analysis and conventional graphical plots. The results show that most groundwater quality parameters are within World Health Organization acceptable limits for drinking water. The chemical relationships of the ions in Piper diagram identify Ca-Cl, Ca-HCO and Na-HCO 3 as most prevalent water types. The alkalis exceed the alkaline earths and weak acids exceed the strong acids. The contribution of (Ca + Mg) and (Na + K) to total cations and HCO 3 indicates the dominance of silicate weathering as the major source of cations. The plot of Na vs Cl indicates higher Na, derived from silicate weathering process which was also supported by higher HCO 3 values. Reverse ion exchange process is also significant in the study area which is indicated by negative Schoeller indices and shifting to the left in the plot of Ca 2+ + Mg 2+ vs HCO 3 + SO 4. Furthermore, the plot of Na-Cl vs Ca+Mg-HCO 3-SO 4 confirms that Ca, Mg, and Na concentrations in groundwater are derived from aquifer materials. Saturation index of silicate and carbonate minerals indicate undersaturation to oversaturation

Vertical and spatial evaluation of the groundwater chemistry in the Central Nile Delta Quaternary aquifer to assess the effects of human activities and seawater intrusion

“…In the intermediate zone, they have a moderate to strong correlation with Ca + Mg and HCO 3 , whereas, in the deep zone, they have a strong to very strong correlation with Ca + Mg and HCO 3 . This suggested the contribution of the carbonate dissolution process to the content of Ca, Mg, and HCO 3 in the groundwater (Kumar et al, 2009;Okiongbo and Akpofure, 2015).…”

Assessment of Groundwater Quality in Coastal Region a Case Study of Qayyumabad, Karachi, Pakistan

“…Main reason of increasing potassium in groundwater seems due to agricultural activities [15] and the sewage mixing. Moreover, K might have come from the weathering of feldspar and clay minerals from the aquifer matrix as feldspars are more susceptible to weathering and alteration than quartz in silicate rocks [16].Calcium and magnesium contents range between 75-800 and 48.6-2217 mg/L respectively. The mean value of calcium (231 mg/L) is double of the permissible limit by WHO 100 mg/L Table 3.…”