‎A Review on Natural Clay Application for Removal of Pharmaceutical Residue in Wastewater

Clay minerals are eco-friendly adsorbent materials that are abundant in nature. The usage of nano-clay for the cleanup of contaminated water has grown recently due to its distinctive physicochemical properties and characteristics. Emerging contaminants, such as pharmaceutical residue, are not typically monitored in the environment and are not controlled in our wastewater. However, due to environmental dangers and their influence on human and aquatic life, removing pharmaceutical residues and their metabolites from wastewater has piqued attention. Several researchers have investigated the application of natural clay, clay-carbon, and clay-polymer composites, among others, to remove this specific pollutant. In addition, to enhance the adsorption efficiency of natural clay minerals, the adsorption sites can be improved by acid activation, thermal treatment, or incorporation of functional groups into the clay mineral layers, which have a strong affinity for the adsorption of pharmaceutical resides. The literature review findings show that modified clays are better adsorbents for the remediation of pharmaceutical residues in wastewater than natural clays and represent an economically viable and efficient option for the cleanup of wastewater containing this contaminant. Consequently, this review gives an inclusive overview of current trends in employing clay minerals for the remediation of pharmaceutical residues in wastewater and outlines the research gaps for future research.