Selective adsorption of Au~(3+) from aqueous solutions using persimmon powder-formaldehyde resin

摘要

A new adsorption resin has been developed by immobilizing persimmon powder with formaldehyde, and its adsorption properties to Au~(3+) were investigated in detail. The resin exhibited outstanding selective adsorption capacity towards Au~(3+) from acidic aqueous solutions (pH 2.0), which the equilibrium adsorption capacity was high up to 3025.20 mg g~(-1) at 323 K. The resin exhibited 100% adsorption of Au~(3+) within 8 h, and the experimental data were well fitted with the pseudo-first/second-order rate model. The adsorption isotherms could be well described by Freundlich equation. The column studies suggested that the resin was effective for the adsorption of Au~(3+) from aqueous solutions, and the loaded Au~(3+) could be easily desorbed by acidic thiourea solution. The adsorption of Au~(3+) was an endothermic reductive adsorption process. This suggested that the resin can be used as an active biosorbent for the recovery of Au~(3+) from aqueous environment.