Capacity of Two Clays to Clean Up Water from an Illegal Gold Mining Site

The intensive development of illegal gold mining, with the uncontrolled use of chemicals, has a strong impact on the environment in Côte d'Ivoire. This study aims to clean up contaminated water from the illegal gold mining site of Angamankro in the Daoukro department using two clays from Ivory Coast. To achieve this goal, physicochemical parameters such as pH, conductivity, turbidity and metal contents in water were measured. The levels of most of the metals studied in wastewater are higher than their various limit values recommended by the WHO. In order to depollute the water, adsorption treatment on Bingerville (BIN) and Katiola (KAT) clays were used. The treatment of wastewater with clays showed a significant reduction in metal contents. The elimination of different metals in water has decreased in the direction Cu >Hg > Zn> Mn > Ni > Co > Cd > Cr > As > Pb. KAT clay adsorbs metals better than BIN clay. This greater adsorption capacity that KAT clay possesses is due to its mineralogical composition (20.14% smectite) and its greater surface properties.