Enhanced Removal of Eriochrome Black T in Wastewater by Zirconium-Based MOF/graphene Oxide

The zirconium-based MOF/graphene oxide (UiO-66-NH2/GO) composites were prepared by ultrasonic dispersing different amounts of graphene oxide (GO) in a well-dissolved zirconium tetrachloride/H2BDC-NH2 mixture, obtaining 2 wt% (UiO-66-NH2/GO-1), 5 wt% (UiO-66-NH2/GO-2), and 10 wt% (UiO-66-NH2/GO-3) GO composites. The products were characterized by XRD, FTIR, SEM, BET, Raman, UV, XPS, and Zeta potential. Adsorption experiments on simulated Eriochrome Black T (EBT) printing and dyeing wastewater were carried out using UiO-66-NH2/GO, and the optimal conditions for adsorption were obtained by exploring the effects of initial EBT concentration, time, pH, and salt ionic strength. Adsorption isotherms, kinetics, mechanism, and regeneration were also researched. The adsorption behavior was consistent with the Langmuir isotherm and fully compliant with pseudo secondary dynamics model. The adsorption capacity of UiO-66-NH2/GO-2 was found to be the highest of the three products, which was 263.158 mg/g. Therefore, the UiO-66-NH2/GO-2 composite was considered to be an excellent adsorbent for the adsorption of EBT from organic dye wastewater.