Green synthesis, characterization, and application of copper nanoparticles obtained from printed circuit boards to degrade mining surfactant by Fenton process

Abstract

The disposal of solid waste containing toxic metals in the composition is a problem of environmental and human contamination. The amount of waste as printed circuit boards has been increasing year by year. New processes that aim at recycling and subsequent application implementing a circular economy of this waste have been gaining importance. This study proposes the printed circuit boards characterization for the copper recycling by acid leaching in two steps, green synthesis of copper nanoparticles using ascorbic acid (vitamin C), and later application of nanoparticles into surfactant degradation through the Fenton-like process. Acid leaching proved a possible methodology for recycling copper, obtaining over 90% recovery. The printed circuit boards show to be a copper secondary source with a weight percentage of about 26 and recovery of 97% in two leaching stages. The synthesis of CuNPs was inferred through UV–Vis with absorption peak in 585 nm and modification of the coloration over time of solutions to dark brown. The syntheses were performed at 70 °C, 80 °C, and 90 °C and in 0.17, 0.5, 0.83, 1, 2, and 3 h, and the stability of copper nanoparticles was verified in 168, 720, and 960 h after syntheses. Stable nanoparticles were produced with different diameters, and they were applied as a catalyst in the Fenton reaction to degrade an amine-based surfactant used in the mining industry. The total carbon degradation found was 57%. It was possible to observe that the recycling of printed circuit boards is strategic to obtain copper from a secondary source, and the synthesis of copper nanoparticles could be used as a product to applicate in the circular economy using the Fenton process. © 2021 Elsevier Ltd