Preparation of novel poly(sodium p-styrenesulfonate)/sodium alginate hydrogel incorporated with MOF-5 nanoparticles for the adsorption of Pb (II) and tetracycline

Novel alginate-based nanocomposite hydrogels with MOF-5 were prepared to remove Pb(II) and TC from water. The structure was characterized and analyzed by FTIR, XRD, TGA, SEM-EDS, BET, zeta, and XPS. Key factors, such as pH, adsorbent dosage, temperature, and coexisting salt ions were investigated in batch adsorption. The optimized MOF-5/PNaSS/SA demonstrated superior adsorption ability compared to SA and PNaSS/SA. In experimental tests, it exhibited maximum adsorption capacities for Pb(II) (189 mg/g) and TC (181 mg/g) at pH 6. The second-order kinetics model and the Langmuir isotherm model accurately described the sorption data of MOF-5/PNaSS/SA. Thermodynamic analysis indicated that the adsorption of MOF-5/PNaSS/SA was an exothermic and spontaneous process. MOF-5/PNaSS/SA also displayed excellent selectivity in adsorption and resistance to interference from salt ions. Moreover, the adsorption-desorption experiments demonstrated the recyclability of MOF-5/PNaSS/SA, as its adsorption capacity remained high level after ten cycles. The presence of O/S-containing groups and benzene rings played a crucial role in the adsorption mechanism, as confirmed by FTIR and XPS. In conclusion, MOF-5/PNaSS/SA has a high adsorption capacity and can effectively remove Pb(II) and TC from wastewater.