Mineralogical and physicochemical assessment of Benue Cameroon Valley clays for trace metal adsorption potential

This study addresses an environmental concern through the potential of clayey materials as natural adsorbents. The studied samples come from the Benue Valley in northern Cameroon, where soils are characterized in terms of mineralogy and physicochemical properties. Results reveal a mineralogy dominated by kaolinite, illite, and smectite-group minerals. This mineralogy is consistent with the chemical composition rich in SiO₂ (53.83–77.61%wt) and Al₂O₃ (13.39–21.18%wt). The findings showed a strong link between mineral composition and physical properties. Correlation analysis (p < 0.05) confirmed that clay content is positively correlated with natural moisture content (ρ = 0.85), liquid limit (ρ = 0.82), and plasticity index (ρ = 0.80). Critically, the materials exhibit high cation exchange potentiality, illustrated by methylene blue values (MBV) up to 17, which also showed a strong positive correlation with the plasticity index (ρ = 0.78). In general, these properties are characteristic of smectite-rich, reactive clays. The results demonstrate that the Benue Valley clayey materials possess the key properties, high surface activity, and plasticity that underpin a high potential for sequestration of cationic pollutants. This research provides a vital scientific foundation for utilizing these local resources in sustainable environmental remediation strategies.