Kinetic and isotherm studies of Cu(II) adsorption by beads and film of alginate/zeolite 4A composites

Abstract

Abstract Beads and film of alginate/zeolite 4A composites were synthesized to adsorb Cu(II) from aqueous solution. Furthermore, the kinetic and isotherm modelling of the adsorption experiment data were investigated. The adsorption equilibrium of 0.5 mM Cu(II) by beads and film of alginate/zeolite 4A composites was achieved at 24 h and 60 min, respectively. The removal efficiencies at equilibrium adsorption time were 88.31 % for beads and 99.69 % for film. Subsequently, the linear form of pseudo-first-order and pseudo-second-order models were used to study the adsorption kinetics. Pseudo-second-order model was the fittest model to described the adsorption kinetics for both beads (R2 =0.999) and film (R2 =0.998). Furthermore, the linear form of Langmuir and Freundlich isotherm models were used to investigate the adsorption equilibria data. Langmuir was the fittest isotherm model for both beads (R2 =0.9992) and film (R2 =0.9977), with the value of monolayer coverage capacity of 0.9929 mmol/g and 1.2773 mmol/g, respectively. The results indicated that alginate/zeolite 4A film had better adsorption rate and capacity compared to alginate/zeolite 4A beads.