Binary biopolymeric beads of alginate and gelatin as potential adsorbent for removal of toxic Ni2+ ions:: A dynamic and equilibrium study

Binary biopolymeric beads of alginate and gelatin were prepared and characterized by IR spectral and scanning electron micrograph techniques. On to the surfaces of the prepared beads were performed static and dynamic adsorption studies of Ni2+ ions at fixed pH and ionic strength of the aqueous metal ion solutions. The adsorption data were applied to Langmuir and Freundlich isotherm equations and various static parameters were calculated. The dynamic nature of adsorption was quantified in terms of several kinetic constants such as rate constants for adsorption (k(J)), Lagergreen rate constant (k(ad)), interparticle diffusion rate constant (k(p)), and pore diffusion coefficient (15). The influence of various experimental parameters such as solid to liquid ratio, pH, temperature, presence of salts, and chemical composition of biopolymeric beads on the adsorption of nickel ions was investigated. Various thermodynamic parameters were also calculated. (c) 2006 Wiley Periodicals, Inc.