Silver(I) recovery on thiomorpholine - modified functional polymer

Abstract

The functional polymer containing heterocyclic ligands was synthesized by microwave modification of a crosslinked poly(vinylbenzyl chloride–divinylbenzene) matrix with thiomorpholine. The modification yield was 89.3%. The sorbent was used to recover Ag(I) from the synthetic and real chloride solutions. The maximum sorption capacity of Ag(I) was approximately 180 mg Ag/g. The sorption kinetic data were well-fitted to the pseudo-first-order kinetic model. The degree of silver desorption was approximately 50.0% using a 1.0% potassium cyanide solution in a 0.50% hydrogen peroxide solution. The resin retained its capacity toward Ag(I) in five consecutive sorption/desorption cycles. The thiomorpholine modified resin was highly selective toward Ag(I) in relation to Cu(II), Pb(II), Co(II), Ni(II), and Zn(II) from the real chloride leaching solution.

Removal of silver from chloride solutions using new polymer materials

“…For Resin I, this value was lower than the qmax calculated from the linear regression. The maximum sorption capacity of AgCl4 3-obtained by the Dubinin-Radushkevich isotherm model is 151.3, 120.4, 131.6, and 85.2 [mg Ag(I)/g] for functional polymers containing heterocyclic ligands, i.e., thiomorpholine, 4-tert-butylpyridine, pyrrolidine, and 3-morpholinopropylamine ligands, respectively (Pilśniak-Rabiega and Wolska, 2021;Pilśniak-Rabiega and Wolska, 2022). The OCS-ET-TU adsorbent based on a natural corn stalk modified by grafting epithiochlorohydrine and thiourea could selectively adsorb AgCl4 3-from the Ag(I) single and Ag(I)-Cu(II)-Ni(II) simulate nickel electrolyte system (Li et al, 2018).…”

“…The recovery of Ag(I) from chloride solution was studied using sorbents containing heterocyclic functional groups (Pilśniak-Rabiega and Wolska, 2020;Pilśniak-Rabiega and Wolska, 2021;Pilśniak-Rabiega and Wolska, 2022). Kinetic studies indicated that the adsorption reaction follows the pseudofirst-order kinetics.…”

“…The functional polymers with heterocyclic ligands, i.e., thiomorpholine, 4-tertbutylpyridine, pyrrolidine, and 3-morpholino-propylamine, were stable in subsequent sorption and desorption processes of Ag(I) ions from their surface (Pilśniak-Rabiega and Wolska, 2021, Pilśniak-Rabiega andWolska, 2022). The sorption capacity of functional polymers for Ag(I) ions increased significantly after the first adsorption-desorption cycle (by 49-64% for the second cycle).…”

“…MC-PYS is more efficient and selective than MC-PYO at pH 2.2, where the total sorption capacity reaches 88.5 mg Ag(I)/g. The thiomorpholine modified resin is an advanced material for the selective removal of Ag(I) ions from a multicomponent system (Pilśniak-Rabiega and Wolska, 2022). The value of the selectivity coefficient (αsel.)…”

“…The thiomorpholine modified resin is characterized by a high affinity to Ag(I) from chloride solution (Pilśniak-Rabiega and Wolska, 2022). The maximum sorption capacity of Ag(I) was approximately 1.67 mmol/g.…”