Selective Capture of Palladium from Acid Wastewater by Thiazole-Modified Activated Carbon: Performance and Mechanism

Abstract

As palladium is a kind of scarce metal that is widely used in industry, it is essential to recover palladium from secondary resources, especially acidic mediums. Chemically modified carbon materials not only have the advantage of activated carbon but also achieve the precise removal of specific pollutants, which is a kind of adsorption material with broad application prospects. In this direction, we report a solid carbon material named AT-C, which is obtained by one-step synthesis of 2-aminothiazoles grafted to the carbon surface by amidation. The present adsorbent delivers a huge porosity and specific surface area of 1022.749 m2 g-1, a high palladium adsorption capacity of 178.9 mg g−1, and desirable thermal and chemical stability. The uniform presence of abundant sulfur atoms and C=O in the porous network enables AT-C to achieve selective absorption and rapid adsorption kinetics (56.7% removal within 60 s) of Pd2+ in the complex water mixture containing many competing metal ions in the acidic pH range. In addition, AT-C showed a superior anti-interference ability to the presence of other anions in water. This work realizes an efficient, rapid, and selective removal of palladium under acidic conditions, and provides a reference for complex industrial water treatment and resource recovery of precious metals.

Keywords: Chemical modification, Carbon material, Precious metal, Acid wastewater, Selective adsorption