Sustainable Approaches for Pharmaceutical Pollutant Removal: Advances in Chitosan-Based Nanocomposite Adsorbents

The growing presence of pharmaceutical pollutants in aquatic environments poses significant threats to both human health and ecosystems. Despite their crucial role in healthcare, pharmaceuticals enter water systems through various sources, making them some of the most critical environmental contaminants. Traditional wastewater treatments, which are classified into physical, chemical, and biological techniques, often struggle to effectively remove pharmaceuticals. Among these methods, adsorption stands out as a reliable and versatile approach for removing organic pollutants and enhancing the efficiency of wastewater treatment processes. Biopolymers, particularly chitosan, are gaining attention due to their numerous advantages, including biocompatibility, biodegradability, affordability, high adsorption capability, non-toxicity, and availability from diverse natural sources. Chitosan, a hydrophilic biopolymer, can be chemically modified by incorporating various nanoparticles (e.g., metal oxides, carbon-based materials, and magnetic particles) to boost its adsorption efficiency. These advancements enable chitosan-based nanocomposites to effectively remove a range of pharmaceuticals, including antibiotics, analgesics, and hormones, from water. This review examines the latest developments in chitosan-based nanocomposite adsorbents, emphasizing their fundamental adsorption mechanisms, optimization conditions, kinetic behaviors, and isotherm models. These factors collectively determine the efficiency of nanocomposites in capturing pharmaceutical pollutants. Moreover, the review underscores the potential of these materials for environmental remediation, offering valuable insights into their application and future research directions. Ultimately, the aim of this review is to provide insight into chitosan-based nanocomposite adsorbents, which offer an innovative and effective solution to the challenge of pharmaceutical contamination in water. By addressing key challenges and utilizing advanced material designs, these adsorbents hold great promise for the sustainable and efficient removal of pollutants in environmental systems.