Highly adsorptive removal of oxytetracycline in water environment using polyanion modified alumina nanoparticles

In this study, adsorptive removal of an antibiotic oxytetracycline (OTC) using polyanion poly(2-acrylamide-2-methylpropane sulfonic acid), PAMPs modified α-Al2O3 nanoparticles (PAMNA) was investigated. Surface modification of α-Al2O3 nanoparticles by PAMPs enhanced the removal efficiency of OTC significantly from 35.5 to 90.7 %. The optimum conditions for adsorptive removal of OTC using PAMNA were found to be pH 4, contact time 120 min and adsorbent dosage 20 mg/mL. Under selected conditions, the removal efficiency of OTC using PAMNA was greater than 90 % while the maximum adsorption capacity reached 140.2 mg/g. After three regenerations, the removal efficiencies of OTC were still higher than 75 %. The results of adsorption isotherms of OTC on PAMNA and the surface charge change of PAMNA indicate that both electrostatic and non-electrostatic interactions control OTC adsorption on PAMNA.