Thiourea resole polymers for recovery of noble element

The recovery of noble elements from secondary source, industrial effluent, which are classified as high concentrated noble elements solution are very essential. Liquid-solid extraction systems are an attractive process used for the separation and purification of noble elements. For this purpose, a solid-phase extraction system was investigated for the recovery of noble metals (Au(III), Pd(II), and Rh(III)). Chelating resins were synthesized by a polycondensation reaction between phenolic thiourea monomers and formaldehyde under alkaline conditions. The resulting polymers were characterized and evaluated for their chelating properties with regard to noble metal sorption. Also, the selectivity of sorption of noble elements was studied in the presence of competitive elements that can be present in effluent waste, such as Zn, Cu, Ni, Fe, and Al. Here, we present a promising materials based on formo-phenolic thiourea resins as a potential candidate for high-capacity (> 350 mg/g for Au; > 50 mg/g for Pd; > 30 mg/g for Rh) and high-selectivity solid-liquid sorption of noble elements, particularly for Au.