Synthesis, Characterization And Adsorption Properties Of A Chelating Resin Incorporating Mercapto Functional Groups Via Hydrophilic PEG Spacer Arms

Three kinds of chelating resins （PS-PEG200-SH、PS-PEG400-SH、PS-PEG600-SH） weresynthesized by incorporating mercapto functional groups into macroporous crosslinkedpoly-styrene via a hydrophilic spacer arm of polyethylene glycol, using chloromethyl methylether, polyethylene glycol200, polyethylene glycol400, polyethylene glycol600, thiourea asmaterials. Those chelating resins were characterized by Fourier transform-infrared spectra（FTIR）, scanning electron microscopy （SEM）, elemental analysis and porous structureanalysis. Adsorption properties of PS-PEG200-SH、PS-PEG400-SH、PS-PEG600-SH forHg²⁺、Ag⁺in aqueous were investigated in detail.The results showed that the resins had higher selectivity to Hg²⁺、Ag⁺.The optimum pH value of PS-PEG200-SH、PS-PEG400-SH、PS-PEG600-SH for Hg²⁺was3, The kinetic adsorption experimental results showed that the adsorption process ofPS-PEG200-SH、PS-PEG400-SH、PS-PEG600-SH for Hg²⁺were controlled by film diffusionand followed pseudo-first-order rate model. The adsorption thermodynamics experimentsrevealed that the Langmuir model was confirmed the adsorption process to Hg²⁺, belonging tomonolayer sorption. Spacer arms can effectively enhance the adsorption kinetics.Thermodynamic analysis proved that the adsorption of Hg²⁺onto adsorbents werespontaneous, endothermin and chemical adsorption in nature. Three chelating resins showedwell desorption and regeneration capacities.The optimum pH value for Ag⁺was1, The kinetic adsorption experimental resultsshowed that the adsorption process of PS-PEG200-SH、PS-PEG400-SH、PS-PEG600-SH forAg⁺were controlled by film diffusion and followed pseudo-first-order rate model. Theadsorption thermodynamics experiments revealed that the Langmuir model was confirmed theadsorption process to Ag⁺, belonging to monolayer sorption. Spacer arms can effectivelyenhance the adsorption kinetics. Thermodynamic analysis proved that the adsorption of Ag⁺onto adsorbents were spontaneous, endothermin and chemical adsorption in nature. Threechelating resins processed well desorption and regeneration capacities.