VALORIZATION OF RAW CLAY FROM GOULMIMA, MOROCCO, AS A LOW-COST MINERAL ADSORBENT FOR EFFICIENT CATIONIC DYE REMOVAL

Abstract

The present study evaluates the effectiveness of raw Goulmima clay from Morocco in removing malachite green from aqueous media. Experiments were carried out to examine the impact of different factors on the adsorption process, including thermodynamic, kinetic, and adsorption isotherm analyses. The findings indicate that the mass of adsorbent, initial solute concentration, stirring speed, temperature, and contact time affect how well malachite green adsorbs onto the clay. Increasing adsorbent of mass from 10 to 50 mg leads to a decrease in the adsorbed quantity from 60 to 13 mg/g. Conversely, raising the initial malachite green concentration from 5.10-6 to 10-4 M increased the quantity adsorbed from 2.60 to 39.86 mg/g within five minutes. Adsorption equilibrium was reached within 40 minutes. Both temperature and stirring speed had a slight positive effect, indicating the endothermicity of the process, as supported by the thermodynamic results. The isothermal and kinetic model evaluations indicated a strong fit between the experimental data and the non-linear forms of the Langmuir model and the pseudo-second-order model. Comparative analysis with other mineral materials shows that raw Goulmima clay demonstrates superior adsorption efficiency for malachite green. This positions it as a more effective and cost-efficient adsorbent than many other commonly used mineral materials. These findings suggest that the studied clay holds significant promise for practical applications in cleaning water loaded with malachite green dye.