Removal of tetracycline hydrochloride from wastewater by Zr/Fe-MOFs/GO composites

Zirconium-iron metal–organic frameworks (Zr/Fe-MOFs) and Zr/Fe-MOF/graphene oxide (GO) composites were prepared via solvothermal synthesis using ferrous sulfate heptahydrate, zirconium acetate, and 1,3,5-benzenetricarboxylic acid. The MOFs and composites were measured using scanning electron microscopy (SEM), infrared spectrometry (IR), and thermogravimetric analysis (TGA). In this study, we explored the ability of Zr/Fe-MOFs and Zr/Fe-MOF/GO composites to adsorb tetracycline hydrochloride from an aqueous solution. Additionally, we optimized the adsorption performance by varying the ratio of MOFs and MOF composites to tetracycline hydrochloride solution, the concentration of tetracycline hydrochloride solution, and the pH of the solution. The results were investigated and fit to both pseudo-first-order and pseudo-second-order kinetic models. The results of the Freundlich and Langmuir isotherm models indicate that Zr/Fe-MOFs and Zr/Fe-MOF/GO composites have heterogeneous adsorption surfaces and that tetracycline hydrochloride is adsorbed over Zr/Fe-MOFs and Zr/Fe-MOF/GO by multilayer adsorption. Overall, our findings indicate that Zr/Fe-MOFs and Zr/Fe-MOF/GO composites can effectively treat wastewater, providing an inexpensive alternative to other methods.