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Bloemfontein, South Africa

Atangana A.,Institute for Groundwater Studies | Baleanu D.,King Abdulaziz University | Baleanu D.,Cankaya University | Baleanu D.,Romanian Space Science Institute
Romanian Journal of Physics

The groundwater flow equation is used to simulate the movement of water under the confined aquifer. In this paper we study a modification of the groundwater flow equation within a newly proposed derivative. We numerically solve the generalized groundwater flow equation with the Crank-Nicholson scheme. We also analytically solve the generalized equation via the method of separation of variable. © 2015, Editura Academiei Romane. All Rights Reserved. Source

Atangana A.,Institute for Groundwater Studies | Alabaraoye E.,University of the Free State
Water Science and Technology: Water Supply

We described a groundwater model with prolate spheroid coordinates, and introduced a new parameter, namely t the silhouette influence of the geometric under which the water flows. At first, we supposed that the silhouette influence approaches zero; under this assumption, the modified equation collapsed to the ordinary groundwater flow equation. We proposed an analytical solution to the standard version of groundwater as a function of time, space and uncertainty factor α. Our proposed solution was in good agreement with experimental data. We presented a good approximation to the exponential integral. We obtained an asymptotic special solution to the modified equation by means of the Adomian decomposition and variational iteration methods. © IWA Publishing 2015. Source

Gomo M.,Institute for Groundwater Studies | van Tonder G.J.,Institute for Groundwater Studies
Environmental Earth Sciences

An investigation was conducted to assess the hydrogeochemical processes of an alluvial channel aquifer located in a typical Karoo Basin of Southern Africa. The investigation was aimed at identifying and describing the groundwater chemistry evolution and its contribution to the overall groundwater quality. X-ray fluorescent spectrometry (XRF) and X-ray diffractometry (XRD) analyses were performed on geological samples to identify and quantify the major element oxides and minerals. The study utilises the conventional Piper diagram, bivariate plots and PHREEQC hydrogeochemical model to analyse groundwater chemistry data obtained during the wet (February and May) and dry seasons (August and December) of 2011. The XRF and XRD results show that the channel deposits are dominated by SiO2 element oxides and quartz minerals, thus elevated concentrations of silicon (Si4+) were found in the groundwater. Dolomite and calcite minerals were also detected in the unconsolidated aquifer sediments. The detailed study of the alluvial aquifer system has shown that dissolution of dolomite and calcite minerals and ion exchange are the dominant hydrogeochemical processes influencing the groundwater quality. The groundwater evolves from Ca2+-Mg2+-HCO3 - recharge water that goes through ion exchange with Na+ in the clay-silt sediment to give a Na+-HCO3 - water type. The groundwater is supersaturated with respect to quartz, dolomite and calcite minerals. The study shows the potential usefulness of simple bivariate plots as a complimentary tool to the conventional methods for analyzing groundwater hydrogeochemical processes. © 2012 Springer-Verlag Berlin Heidelberg. Source

Gomo M.,Institute for Groundwater Studies | Vermeulen D.,Institute for Groundwater Studies
Journal of African Earth Sciences

An investigation was conducted to statistically compare the influence of non-purging and purging groundwater sampling methods on analysed inorganic chemistry parameters and calculated saturation indices. Groundwater samples were collected from 15 monitoring wells drilled in Karoo aquifers before and after purging for the comparative study. For the non-purging method, samples were collected from groundwater flow zones located in the wells using electrical conductivity (EC) profiling. The two data sets of non-purged and purged groundwater samples were analysed for inorganic chemistry parameters at the Institute of Groundwater Studies (IGS) laboratory of the Free University in South Africa. Saturation indices for mineral phases that were found in the data base of PHREEQC hydrogeochemical model were calculated for each data set. Four one-way ANOVA tests were conducted using Microsoft excel 2007 to investigate if there is any statistically significant difference between: (1) all inorganic chemistry parameters measured in the non-purged and purged groundwater samples per each specific well, (2) all mineral saturation indices calculated for the non-purged and purged groundwater samples per each specific well, (3) individual inorganic chemistry parameters measured in the non-purged and purged groundwater samples across all wells and (4) Individual mineral saturation indices calculated for non-purged and purged groundwater samples across all wells. For all the ANOVA tests conducted, the calculated alpha values (p) are greater than 0.05 (significance level) and test statistic (F) is less than the critical value (Fcrit) (F Source

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