Mineralogical and Physicochemical Characterization of Natural and Heat‐Treated Kaélé Clay Pellets for Pollutant Removal from Tannery Wastewater in Cameroon

Abstract

Abstract Water pollution is a critical challenge in developing countries, including Cameroon, necessitating innovative solutions for environmental remediation. This study investigates the formulation and characterization of clay pellets derived from Kaélé clay, focusing on both natural and heat‐treated samples subjected to temperatures of 600, 800, and 1000 °C. Comprehensive mineralogical and physicochemical analyses were performed using FT‐IR, SEM ‐ EDS, TGA/DTG, XRF, and XRD techniques. Results revealed montmorillonite‐type smectite 2:1 as the predominant mineral, highlighting the potential of these clay pellets as effective adsorbents for water purification. Proposed mechanism of pollutant adsorption involves a two‐step process characterized by rapid external diffusion followed by weak interactions between pollutants and the pellet surface, influenced by pH and ionic conditions. Geochemical analysis indicated a high silica (SiO2) content of 44.01%, significant alumina (Al2O3) content of 27.77%, and lower levels of iron oxides (Fe2O3) at 4.55%, along with minimal alkaline (K2O) and alkaline earth (CaO, Na2O, MgO) contents. Rapid elimination of COD by both control and P800 pellets reached equilibrium within 30 minutes, with elimination rates of 86.09% and 98.99% for COD, respectively. This research underscores the innovative use of local clay materials for environmental applications, contributing to sustainable practices in water treatment and pollution control.