Adsorption of zinc and toluene by alginate complex impregnated with zeolite and activated carbon

Abstract

In this study, a novel alginate complex was developed for removal of mixed contaminants containing both organic and inorganic compounds. The alginate complex was generated by impregnating synthetic zeolite and powdered activated carbon (PAC) into alginate gel bead. The adsorption of zinc and toluene as target contaminants onto the alginate complex was investigated by performing both equilibrium and kinetic batch tests. Equilibrium tests showed that adsorption of two contaminants followed Langmuir isotherm and that the alginate complex was capable of removing zinc (maximum binding energy beta=4.3 g/kg) and toluene (beta= 13.0 g/kg) best compared to other adsorbents such as granular activated carbon (GAC), zeolite, and alginate impregnated with PAC (AG-AC bead). These values were higher than those of any other adsorbents for each contaminant. It was further revealed from kinetic tests that removal efficiency of zinc and toluene was 54% and 86% for the initial solution concentrations of 250 mg/L, respectively. This indicates that the alginate complex developed in this study can be used as promising adsorbents for simultaneous removal of organic and inorganic compounds from industrial wastewater or groundwater containing mixed contaminants. (C) 2008 Elsevier B.V. All rights reserved.