New activated carbon derived from Gundelia tournefortii seeds for effective removal of acetaminophen from aqueous solutions: Adsorption performance

Abstract

Pharmaceuticals as one of the emerging pollutants in water systems are a global environmental concern. This study aims to synthesize a new activated carbon from Gundelia tournefortii seeds (ACGT) for effective removal of acetaminophen (ACT) from aqueous solutions. The synthesized adsorbent was characterized by different techniques, namely FESEM, EDX, XRD, FTIR, BET, TGA, and pHpzc. The effects of experimental parameters such as pH, adsorbent dosage, initial concentration, contact time and ionic strength on the ACT adsorption were investigated. Optimization studies revealed that the maximum removal (98.31%) of ACT was obtained at 30 min of contact time, 0.25 g/L adsorbent, 20 mg/L Ca2+, pH 4.0 and temperature 25˚C. For predicting ACT adsorption on synthetized adsorbent, isotherm, kinetic, and thermodynamic characteristics were determined. The equilibrium data were well represented by Freundlich model (R2 = 0.97) and kinetics data were well fitted by the pseudo-second order model. The thermodynamic analysis discovered that the adsorption process was endothermic and spontaneous. Overall, the development of the ACGT can be a promising adsorbent for ACT removing from aqueous solutions.