Selective removal mechanism of the novel Zr-based metal organic framework adsorbents for gold ions from aqueous solutions

Abstract

A novel metal organic framework absorbent was synthesized by one step method using 2,2′-dithiodibenzoic acid as organic linker for efficient and selective recovery of Au(III) from aqueous solution. The adsorbent were detected by scanning electron microscope, X-ray diffraction and zeta potential instruments. Its performance was tested by batch experiments. The adsorption isotherm conforms to the Langmuir model, demonstrating that the adsorption process is the uniform monolayer adsorption. The kinetic model is well fitted to the pseudo second-order dynamics model. The maximum adsorption capacity was 1119 mg/g at pH = 2. High temperatures can promote the absorption process. The five adsorption and desorption cycles indicate that the adsorbent has good repeatability for Au(III) adsorption. It could selectively adsorbed Au(III) from wastewater. The adsorption derivefromchelation and reduction. The DFT and XPS results show that Au(III) is mainly adsorbed on the adsorbent by coupling with the S atom. These results indicate that it has a high potential to remove Au(III) from industrial wastewater.