Adsorption of fexofenadine and diphenhydramine on dehydrated and activated carbons from date palm leaflets

Dehydrated carbon (DC) was prepared from date palm leaflets via sulfuric acid treatment at [GRAPHICS] C in the presence of air. Acidified DC was converted to activated carbon (AC) at [GRAPHICS] C under nitrogen atmosphere. DC shows low surface area (48m(2)g(-1)), whereas activated carbon possesses high surface area (405m(2)g(-1)). Both carbons were tested for the adsorption of fexofenadine (FEX) and diphenhydramine (DPH) at different initial pH, concentration and temperature. Maximum adsorption took place at pH 4.0 for FEX and pH 8.0 for DPH. Adsorption kinetics was found to follow well pseudo second-order kinetic model with increased adsorption as temperature increased within the range of 25-