2-Mercaptobenzimidazole derivative of chitosan for silver sorption – Contribution of magnetite incorporation and sonication effects on enhanced metal recovery

The recycling of precious and strategic metals from secondary resources (including E-wastes) is critical importance for the recovery scarce widely used in High-Tech devices. Therefore, development efficient selective sorbents great importance. grafting 2-mercaptobenzimidazole onto chitosan microparticles allows developing highly sorbents. incorporation magnetite particles also a aspect facilitating use microparticles. Sonication (at two different frequencies: 37 kHz 80 kHz) shows high potential improving both kinetic thermodynamic aspects associated with silver uptake on 2-MBI-chitosan materials. Sorption capacities as 3 mmol Ag g?1 can be obtained contact times low 20–30 min. sorption isotherms are successfully fitted by Langmuir Sips equations, while profiles modeled using pseudo-second order rate equation resistance to intraparticle diffusion. process exothermic: sonication (and frequency sonic generator) strongly changes parameters. speeds up metal desorption, which acidic thiourea solutions: reducing concentration eluent required complete elution. sorbent remarkable stability terms or desorption five successive runs. acid leachates printed circuit board efficiently treated recovery, enrichment separation (Ag, Au Pd) base (major elements: iron copper, aluminum, tin).