Hydrochemical framework of groundwater in the Ankobra Basin, Ghana

Abstract

Hydrochemical and stable isotope ( 18 O and 2 H) analyses of groundwater samples were used to establish the hydrochemistry of groundwater in the Ankobra Basin. The groundwater was generally mildly acidic, low in conductivity and undersaturated with respect to carbonate phases. Major ions except bicarbonate were low and dissolved silica was moderately high. Silicate minerals weathering is probably the main process through which major ions enter the groundwater. Groundwater samples clustered tightly along the Global Meteoric Water Line suggesting integrative, smooth and rapid recharge from meteoric origin. The majority of the boreholes and a few hand dug wells cluster towards the Ca-Mg-HCO 3 dominant section of the phase diagram, in conformity with the active recharge and short residence time shown by the isotope data. Aluminium, arsenic, manganese, iron and mercury were the only trace metals analysed with concentrations significantly above their respective detection limits. Approximately 20%, 5%, 40% and 25% respectively of boreholes had aluminium, arsenic, iron and manganese concentrations exceeding the respective WHO maximum acceptable limits for drinking water. The relatively large percentage of boreholes with high concentration of aluminium reflects the acidic nature of the groundwater.

Assessment of Groundwater Quality and its Suitability for Drinking and Agricultural Uses in the Oshnavieh Area, Northwest of Iran

“…The results of calculation saturation index show that the nearly all of the water samples were saturated to undersaturated with respect to carbonate minerals (calcite, dolomite and aragonite) and undersaturated with respect to sulfate minerals (gypsum and anhydrite). In the study area, the dominant hydrochemical facieses of groundwater is Ca-HCO 3 and Ca-Mg-HCO 3 . Distribution of the groundwater samples in rectangular diagram reveals that all of the groundwater samples fall under the calcium-magnesium-bicarbonate category.…”

“…A further illustration of this is shown in Figure 5 where the median values of HCO 3 exceeded 50% of total anions in milli-equivalent unit. The abundance of the major ions in groundwater is in following order: Ca > Mg > Na > K and HCO 3 > SO 4 > Cl > NO 3 > CO 3 . Minimum, maximum and average values of physical and chemical parameters of groundwater samples are presented in Table 3.…”

“…In the study area, the major groundwater type is Ca-HCO 3 and Ca-Mg-HCO 3 (Figure 8). Chadha [32] has proposed new diagram for geochemical data presentations.…”

“…Generally, the motion of groundwater along its flow paths below the ground surface increases the concentration of the chem. ical species [1][2][3]. Hence, the groundwater chemistry could reveal important information on the geological history of the aquifers and the suitability of groundwater for domestic, industrial and agricultural purposes.…”

Hydrochemical characteristics and quality assessment of groundwater in Amaravathi river basin of Karur district, Tamil Nadu, South India

“…In general, the motion of groundwater along its flow paths below the ground surface increases the concentration of the chemical species (Kortatsi 2007). Hence, the groundwater chemistry could reveal important information about the geological history of the aquifers (Elkrail et al 2004).…”