Comprehensive review on the environmental remediation of pharmaceuticals in water by adsorption

Pharmaceuticals in polluted water can harm humans, animals, and marine life. Pharmaceuticals undergo degradation and give secondary products that are more toxic, so their infiltration becomes life-threatening and life-saving if not properly disposed of. Among various processes such as membrane filtration, advanced oxidation processes, biodegradation, etc, adsorption is considered the most appropriate for efficiently removing pharmaceuticals from water. This review summarises different adsorbents and recent advances to enhance the adsorption capacity of the adsorbents, including carbon-based material, zeolites, metal-organic frameworks, and polymers. Every adsorbent is evaluated based on different parameters like removal capacity, removal efficiency, pH, temperature, and mechanism of action. The parameters like pH range and temperature depend on the adsorbent-adsorbate system and the experimental conditions. There was a wide variation in removal efficiencies: 28%-99.7% for carbon-based adsorbents, 37% - 100% for zeolites, 86%-99.3% for metal-organic frameworks, and 70-98.2% for polymers. The possible interactions between pharmaceuticals and adsorbents are included for further improvements to increase the adsorption. The outcome of this study highlighted the use of adsorbents and demonstrated how their modification can improve the adsorption of pharmaceuticals from water bodies.