Calcium-alginate/carbon nanotubes/TiO2 composite beads for removal of bisphenol A

Abstract

In this study, composite calcium-alginate/carbon nanotubes/TiO2 beads were prepared and tested for their potential in the removal of bisphenol A (BPA) from aqueous solutions. The removal traits were inspected using a fixed-bed sorption column. By varying parameters such as bed height (15-20 cm), flow rate (2.0-6.0 mL.min-1) and inlet BPA concentration (10-30 mg.L-1) we assessed the removal capacity of these composites. The highest sorption capacity of 5.46 mg.g-1 was achieved at 10 mg.L-1 BPA concentration, 2.0 mL.min-1 flow rate and 20 cm bed height at saturation. Adams-Bohart, Yoon-Nelson and Dose-Response isotherm models were applied to evaluate the performance of the column at different inlet concentrations. The experimental data satisfactorily fit the Dose-Response model with high correlation (r2<0.97) across the breakthrough curve. Regeneration of the used adsorbent beads were performed by immersion in the desorption solvent followed by light irradiation. It was postulated that inclusion of TiO2 facilitates the desorbed pollutant degradation from the used adsorbent beads.