Synthesis and characterization of new composite sponge combining of metal-organic framework and chitosan for the elimination of Pb(II), Cu(II) and Cd(II) ions from aqueous solutions: Batch adsorption and optimization using Box-Behnken design

Abstract

By using a one-step hydrothermal process in an acidic environment, an unique Ag-MOF/chitosan composite sponge (Ag-MOF/CSC composite sponge) was effectively created. Chitosan synthesis has been studied for more than half a century, but its Use for adsorption of heavy metals (HM) is presently being researched. As Particularly with regard to adsorbents constructed of metal organic framework, to increase an adsorbent material's adsorption capacity, its composition is commonly changed. Pb(II), Cu(II), and Cd(II) adsorption and elimination were examined in this study in relation to the composite Ag-MOF/CSC sponge. Following thorough analysis including measurements of the surface area using Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and SEM and Fourier transform infrared spectroscopy (FTIR) (BET).The Ag-MOF/CSC composite sponge exhibits an impressive large surface area of 1496.58 square meters per gram, besides having the best capacity for adsorption (qmax) for various ions: 1.80, 1.49 and 1.72 mmol per gram for Pb(II), Cu(II) and Cd(II), respectively. Consider the factors that influence the adsorption characteristics, such as temperature, pH, metal concentration, and adsorbent dosage. The kinetic isotherm and the adsorption isotherm were fitted using the pseudo-second-order equation and the Langmuir equation, respectively. It was shown that the adsorption process was endothermic and spontaneous in accordance with adsorption thermodynamics. With rise in temperature, more metal were absorbed. With good efficiency, no change in chemical composition, and similar XRD and XPS data before and after reuse, the Ag-MOF/CSC composite sponge was repurposed six times. Investigate the mechanism of interaction between the heavy metals and the Ag-MOF/CSC composite sponge. Utilizing Box-Behnken design, the adsorption outcomes were optimized (BBD).