Synthesis, characterization and experimental assessment of a novel functionalized macroporous acrylic copolymer for gold separation from wastewater

Gold (Au) is one of the precious metals whose availability, use and recovery represent important problems from the economic and environmental point of view. The synthesis of the novel acrylic copolymer bearing dimethylaminobenzaldehyde functional groups (AS-5BA) was carried out in three stages. The structure of the synthesized material was evidenced by infrared spectroscopy (IR) and its morphology by scanning electron microscopy (SEM), while the elemental composition was determined through X-ray photoelectron spectroscopy (XPS). The AS-5BA functionalized copolymer was used for gold sorption from chloride solution by the batch method. The effects of HCl medium acidity, initial Au(III) concentration, and contact time on the Au(III) retention were studied. The maximum Au(III) sorption capacity was evaluated as 87.75 mg/g. The copolymer under study exhibited strong selectivity for the gold in the binary Au(III)-Co(II), Au(III)-Mn(II) and Au(III)-Cd(II) solutions. Gold could be quantitatively desorbed from the loaded sorbent with acidic solution of thiourea at ambient temperature. The developed AS-5BA copolymer was successfully applied to recover gold from a wastewater collected from a gold jewellery manufacturing plant. The AS-5BA functionalized acrylic copolymer with N as donor atoms has good durability as well as good efficiency for its repeated use for gold removal from aqueous solutions.