An ecofriendly pectin-co-montmorillonite composite hydrogel for the separation of contaminant metal ions from water

The aim of this study was to investigate the synthesis, characterization, and sorption performance of ecofriendly pectin-co-montmorillonite composite hydrogels for the separation of potentially toxic elements (PTEs) from water. Hydrogels were synthesized using an environmentally friendly method, incorporating montmorillonite (MMT) at proportions ranging from 0 to 10 % in the tridimensional pectin (PC) network. The composite hydrogels were characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Batch sorption studies were conducted to investigate the capacity to separate copper (Cu2+), nickel (Ni2+), manganese (Mn2+), zinc (Zn2+), cadmium (Cd2+), and hexavalent chromium (Cr6+) ions from water. Higher PTE separation efficiencies were found with hydrogels containing 1 % MMT, with greater selectivity for Cu2+ ions. An exhaustive sorption study revealed that the separation process of Cu2+ fits the pseudo-second-order kinetic model and Langmuir isotherm, with maximum sorption capacity (qmax) of ~36.8 mg of hydrogel per g of PTE. This indicates that PC-co-MMT composite hydrogels are efficient alternative sorbents for the selective separation of PTEs from water, with potential application in ecofriendly water purification systems. [Display omitted] •Hydrogels synthesized using an environmentally friendly method incorporating MMT•Advanced PC-co-MMT hydrogel as matrix for selective separation of pollutants•Physical and chemical interactions between hydrogel and PTEs•Eco efficient solid supports for the selective separation of PTEs from water