Two-Step Elution Recovery of Cyanide Platinum Using Functional Metal Organic Resin

Abstract

A novel functional ion-exchange/adsorption metal organic resin (MOR), TEBAC-HKUST-1, was prepared and characterized. Ethanedithiol was used as the grafting agent to introduce thiol groups onto HKUST-1, and 4-vinylbenzyl chloride was then grafted onto SH-HKUST-1 using thiol groups. Finally, the quaternary ammonium functional group was immobilized onto the carrier by performing a quaternization reaction. The structure and property of TEBAC-HKUST-1 MOR were characterized by TGA, N2 adsorption–desorption, FTIR, SEM, and XRD. TEBAC-HKUST-1 MOR was used to remove metal cyanide complexes from wastewater. The adsorption was rapid, and the metal cyanide complexes including Pt(CN)42−, Co(CN)63−, Cu(CN)32−, and Fe(CN)63− were removed in 30 min. TEBAC-HKUST-1 MOR exhibited a high stability in neutral and weak basic aqueous solutions. Furthermore, Pt(II) could be efficiently recovered through two-step elution. The recovery rate of Pt(II) for five cycles were over 92.0% in the mixture solution containing Pt(CN)42−, Co(CN)63−, Cu(CN)32−, and Fe(CN)63−. The kinetic data were best fitted with the pseudo second-order model. Moreover, the isothermal data were best fitted with the Langmuir model. The thermodynamic results show that the adsorption is a spontaneous and exothermic process. TEBAC-HKUST-1 MOR not only exhibited excellent ability for the rapid removal of metal cyanide complexes, but also provided a new idea for the extraction of noble metals from cyanide-contaminated water.

Faujasite-Type Zeolite Obtained from Ecuadorian Clay as a Support of ZnTiO3/TiO2 NPs for Cyanide Removal in Aqueous Solutions

“…Positive entropy values (∆S • ) indicate that the randomness at the solution-solid interface increased during the adsorption process. These results are consistent with previous studies reported by other authors [74].…”

Controllable Nitric Oxide Storage and Release in Cu-BTC: Crystallographic Insights and Bioactivity

“…The Cu-BTC MOFs before and after loading NO showed weak bands at 488 and 721 cm −1 , which are attributed to the bending and stretching modes of Cu–O, respectively. The higher intensity absorption peaks at 1368, 1445, and 1640 cm −1 are assigned to the stretching modes of the carboxylate moiety of BTC; specifically, the stretching mode of C–O, and the asymmetric and symmetric stretching modes of C=O, respectively [ 34 , 35 , 54 ]. However, in this study, a new peak representing the coordination of NO to Cu in the 1890–1900 cm −1 range did not appear after NO loading.…”

“…Moreover, MOFs have been considered the best candidates for controlled NO release as they can physically capture NO in their inner pores, bond with NO via their open metal sites (OMSs), or amine functional group of the linkers comprising the frameworks [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. Cu-BTC, formulated as Cu 3 (BTC) 2 (MOF-199, copper(II)-benzene-1,3,5-tricarboxylate), is one of the most studied MOFs and is commonly used as a sensor or for gas sorption, gas storage, and catalysis [ 34 , 35 , 36 , 37 , 38 , 39 ]. For example, Xiao et al investigated Cu-BTC as an NO donor due to its high crystallinity and varied porosity and reported that this material could store as much as 9 mmol·mg −1 of NO at 196 K but released only 1 nmol·mg −1 —a very small fraction of the loading—upon exposure to a stream of wet nitrogen gas.…”

One-step synthesized 3D-structured MOF foam for efficient and convenient catalytic reduction of nitrogen-containing aromatic compounds

“…The band in the range of 500-1600 cm -1 region can be attributed to HKUST-1 consisting of H3BTC and -OH group at >3000 cm -1 [36]. Hence, the band at 770 cm -1 was attributed to Cu-O stretching vibration [37] and the band at 1370cm -1 was assigned to the symmetric vibrations center [36]. The bands at 1450-1560cm -1 were attributed to carboxylic group of H3BTC [38].…”