In the dynamic of drinking water supply in rural populations, water pollution by cyanide is one of challenges that impacts the process in the mining areas of Burkina Faso. The objective of this work was to assess the efficiency of laterite soils to remove cyanide from water. To do this, two laterites were prepared and characterized by spectroscopic and analytical techniques to serve as adsorbent. The cyanide removal was carried out using batch experiments with cyanide aqueous solutions. The characterization of laterites using analytical techniques showed a specific surface area of 42.39 and 24.55 m2.g-1. The crystalline phases were mainly kaolinite, goethite, hematite, quartz, and alumina. The optimization of the operating parameters indicated a strong influence of operating conditions on the adsorption process. Indeed, the optimum stirring speed was 150 rpm corresponding to an adsorption capacity of 0.14 and 0.34 mg/g using raw (LB) and treated (LT) laterites, respectively. By assessing the influence of the contact time, the adsorption capacities were 0.35 and 0.19 mg.g-1 at 40 and 75 min respectively using LT and LB corresponding to a treatment rate of 53% and 28%. The optimal doses were 28 and 45 g.L-1 at the optimal temperature of 30°C using LB and LT. Results concluded the efficiency of treated laterite comparatively to the raw laterite. The isotherm modelling concluded on Freundlich isotherm indicating a multilayer adsorption following a pseudo-second order kinetic. Therefore, these laterites would be good filters for the treatment of cyanide enriched waters and other heavy metals in dynamic experiments.

Adsorption, Characterization, Cyanide, Laterite, Water Resources