Study on the adsorption behavior of modified persimmon powder biosorbent on Pt(IV)

Abstract

A glycine-modified persimmon powder was used as biosorbent for platinum adsorption in aqueous solution. The combined effects of modifying agent amount, modifying time and temperature on Pt(IV) adsorption by persimmon biosorbent were investigated, from which the optimum modification conditions with modifying agent amount of 50 %, temperature of 333 K and contact time of 4.0 h were determined. The influences of solution initial pH, solid-to-liquid ratio, contact time, temperature and initial concentration on the Pt(IV) adsorption were studied systematically by batch experiments. The optimum modification conditions were determined as follows: chemical reagent amount of 50 %, temperature of 333 K and contact time of 4.0 h. From the adsorption kinetic analysis, it was found that the adsorption kinetics of glycine-modified persimmon powder followed a pseudo-second-order kinetic model. The adsorption isotherms of the crude persimmon powder and glycine-modified persimmon powder were analyzed with the BET-type adsorption isotherm. The adsorption mechanism of Pt(IV) on the glycine-modified persimmon was considered to be adsorption-reduction mechanism. The results achieved from this study indicated that the novel persimmon adsorbent could be applied to recover trace Pt(IV) ions from a concentrated chloride solution.