Highly efficient and selective recovery of Au(III) by cellulose microspheres bearing nucleobase and their applications in gold slag treatment

Abstract

Gold recovery from secondary resources involves tremendous environmental and economic implications. In this work, four nucleobase (guanine, xanthine, hypoxanthine and adenine) modified cellulose microspheres were synthesized via radiation method for Au(III) capture from actual gold slag solution. The adsorption rapidly achieved equilibrium within 4 h. It was discovered that the pseudo-second-order and Langmuir model provided a superior match for the Au(III) adsorption process on adsorbents. At the optimal pH, the four adsorbents exhibited the outstanding adsorption capacities for Au(III) with a range of 307.69–510.20 mg/g. Furthermore, cellulose microspheres bearing nucleobase were able to selectively adsorb trace Au(III) with recovery efficiencies of 62 %–70 % from gold slag leaching solution. In addition, the column separation approach was utilized to better assess the applicability of adsorbents, proving that cellulose microspheres bearing nucleobase exhibited great benefits and prospects in industrial applications. The N-containing groups on adsorbents captured Au(III) by ion exchange, chelation and oxidation–reduction. The low-cost nucleobase-bearing adsorbents offer a new prospect for nucleobase in environmental remediation and water treatment.