Advanced adsorbents for ibuprofen removal from aquatic environments: a review

The presence of pharmaceuticals in ecosystems is a major health issue, calling for advanced methods to clean wastewater before effluents reach rivers. Here, we review advanced adsorption methods to remove ibuprofen, with a focus on ibuprofen occurrence and toxicity, adsorbents, kinetics, and adsorption isotherms. Adsorbents include carbon- and silica-based materials, metal-organic frameworks, clays, polymers, and bioadsorbents. Carbon-based adsorbents allow the highest adsorption of ibuprofen, from 10.8 to 408 mg/g for activated carbon and 2.5-1033 mg/g for biochar. Metal-organic frameworks appear promising due to their high surface areas and tunable properties and morphology. 95% of published reports reveal that adsorption kinetics follow the pseudo-second-order model, indicating that the adsorption is predominantly governed by chemical adsorption. 70% of published reports disclose that the Langmuir model describes the adsorption isotherm, suggesting that adsorption involves monolayer adsorption.