Mass transfer kinetics of Cd(II) ions adsorption by titania polyvinylalcohol-alginate beads from aqueous solution

Abstract

Kinetic assessment of the photoreduction of Cd(II) ions in aqueous solution is of interest and thus can most definitely help us make better measures of the scientific concepts to improving the environmental performance. This study showed that the use of titania polyvinylalcohol-alginate beads (TPVA-ABs) as photocatalyst could be effective to remove Cd(II) ions from aqueous solution. The efficiency of Cd(II) ions removal can be expected at 100% for an initial Cd(II) concentration of 50 mg L−1, compared with the efficiencies of 91.2 and 83.6% for the initial Cd(II) concentrations of 100 and 200 mg L−1, respectively, after 3-h reaction time under sunlight irradiation. The desorption capacities of Cd(II) ions in TPVA-ABs were verified for five consecutive cycles of adsorption/desorption to be less than 3% of the reduced Cd(II) ion removal efficiency. Photoreduction of Cd(II) ions by the TPVA-ABs can be used repeatedly at least for five cycles of adsorption/desorption and showed very little loss of its initial properties. The present study scrutinised mass transfer kinetics of Cd(II) ions adsorption by the TPVA-ABs promotes a rapid method to strengthening the adsorption process of treating Cd-contaminated wastewater in the future.