Adsorption of chlorpheniramine and ibuprofen on surface functionalized activated carbons from deionized water and spiked hospital wastewater

Activated carbon (AC) was prepared from date palm leaflets via KOH activation. AC was oxidized with HNO₃ to produce oxidized activated carbon (OAC) that was surface functionalized using ethylene diamine to produce basic surface (BAC-EDA) and ethylamine to produce hydrophobic carbonaceous surface (HAC-EA). Details of preparation and characterization was published earlier. The adsorption of chlorpheniramine (CP), a basic drug, and ibuprofen (IBU), an acidic drug, on these carbons was investigated at different initial pH, contact time, drug concentration and temperature. Drug adsorption depends mainly on solution pH and the adsorbent surface nature, and initial pH 7 was found optimal for the removal of both drugs. Equilibrium adsorption was reached faster on HAC-EA, OAC and BAC-EDA than on AC with kinetic adsorption data following well pseudo second order model, and enhanced performance as temperature rises. Activation energy (E_a) was found to be in the range of 11.7-29.1 kJ/mol. Equilibrium adsorption data follow well the Langmuir model with better performance as temperature rises. CP uptake follows the order: HAC-EA > OAC > AC > BAC-EDA whereas the adsorption of IBU follows the order: OAC > AC>HAC-EA > BAC-EDA. Thermodynamic parameters showed that drug adsorption is endothermic and spontaneous. Drug adsorption from spiked hospital wastewater showed slightly less capacity than that from deionized water. Dominant adsorption forces between the drugs and the carbons varied from carbon to another depending on their surface nature and solution pH.