3rd TAGRA

Rapid industrialization, mining operations, fertilizer manufacturing, and dye synthesis have led to the extensive discharge of heavy metals and synthetic colorants into natural ecosystems. Due to their severe toxicity, environmental persistence, and non-biodegradability, these pollutants pose critical hazards to human health and ecological integrity. Conventional remediation strategies are frequently limited by high operational costs, intensive energy consumption, and the generation of secondary toxic sludge. Consequently, the pervasive contamination of aquatic and terrestrial matrices with heavy metals, synthetic dyes, and persistent organic compounds necessitates the development of cost-effective, sustainable, and indigenous remediation technologies. Clay minerals, characterized by their natural abundance, low cost, high specific surface area, substantial cation exchange capacity (CEC), and chemical stability, have emerged as highly efficient, eco-friendly adsorbents. Both pristine and surface-modified clays serve as viable, regenerative alternatives to commercial resins and activated carbon for effluent decontamination and toxic ion sequestration. In waste containment engineering and soil remediation, compacted bentonite liners and clay–cement stabilization/solidification (S/S) matrices exhibit ultra-low hydraulic conductivity, preventing leachate percolation and immobilizing hydrocarbon and metal contaminants via physicochemical entrapment. Furthermore, surface engineering techniques—such as acid activation, organoclay synthesis via surfactant intercalation, and nanocomposite fabrication—significantly enhance adsorption capacity and selectivity toward multi-pollutant systems. Overall, pristine and modified clay minerals offer a robust, sustainable, and green platform for environmental protection and waste management, provided that challenges regarding spent-adsorbent regeneration, safe disposal, and long-term desorption risks are effectively addressed.