Physico-metallic characteristics of waters from gold mining in the locality of Djouzami (Adamawa, Cameroon) and adsorption of iron(II) by a filter made from sand coated with bimetallic iron–manganese oxide: modeling and theoretical analysis
摘要
This study aims to remove the iron(II) contained in the water of the semi-mechanized gold mine of Djouzami (Adamawa, Cameroon) by a filter made from sand coated with bimetallic iron manganese oxide. The evaluation of the physico-metallic properties of water in the study area reveals the presence of heavy metals with concentrations above the thresholds set by the World Health Organization (WHO) in particular for iron(II) and lead(II). The one-dimensional advection–dispersion equation is established to describe the spatiotemporal distribution of the Fe(II) ion concentration inside the filter and the water quality at the filter outlet. Thus, the Laplace transform method and the finite difference with the fourth-order Runge–Kutta method (RK4) are used to, respectively, obtain an analytical and a numerical solution of the governed equation. The analyses of the obtained graphics show a gradual decrease in pollutant concentration throughout the filter. The length that the water travels to reach an almost zero concentration threshold is 48 cm. Filter life is an increasing function of filter depth. This proves on the one hand the performance of bimetallic iron manganese oxide in adsorbing iron(II) in water and on the other hand the proper sizing made for the filter.