Physicochemical characterization of new natural clay from south west of Algeria: Application to the elimination of malachite green dye

Volcanic clay from Ain Ouarka south west of Algeria (CA) was used to remove malachite green (MG). This material was purified and sodified (CA-Na+). They were characterized by different analysis techniques such as BET, SEM, XRD, ATG-ATD, FTIR, and the cation-exchange capacity (CEC). Batch adsorption tests were performed to examine the effect of several parameters such as contact time, pH of solutions, initial concentration, and temperature. The present study is the first to be carried out hitherto regarding natural clay, where the obtained results show that the clay contains two phases, Sericite 2M1 and Clinochlore, with good crystalline, very compact and layered structure. The adsorption of MG dye reached its maximum at pH close to 6. Kinetic and isothermal experiments were studied to establish the equilibrium time and adsorption capacity of the two clays. Two kinetic models; the pseudo-first and pseudo-second order models were used. Two isothermal equations, Freundlich and Langmuir were applied for the modeling of adsorption isotherms by the linear method. The maximum adsorption capacities calculated from Langmuir equation of CA and CA-Na+ are 166 and 126 mg g(-1), respectively. A significant variation of temperature demonstrated that the adsorption phenomenon was an endothermic process. (c) 2019 American Institute of Chemical Engineers Environ Prog, 38:e13152, 2019