Comparative study for removal of potentially toxic metals from the groundwater of Lakhanpur Area, Odisha, India by using two different hydrogels

In this work, we collected eight groundwater samples from various important locations from Lakhanpur area, Odisha, India. The concentration of various metal ions (Fe^3+, Ni^2+, Cd^2+, and Zn²⁺) present in the collected water samples was analyzed through an atomic absorption spectrometer (AAS). Two hydrogels, such as PVA/CH and PVA/AA, are synthesised by adopting sol–gel polymerization technique using CH, AA, and PVA. Both the hydrogels were characterized by using FT-IR, XRD, SEM/EDS, XPS, and TGA. We adopted suitable methodology to carry out studies on the antibacterial properties, swelling behaviour, and adsorption of the water samples. The adsorption study was done for the separation of potentially toxic metal ions at various intervals of time using two hydrogels. It was observed that the capability of adsorption rate increases with increases in adsorbent dosage and the rate of adsorption, which is faster at the initial time and then gradually decreases up to 180 min. The adsorption capacity of both hydrogels follows the order Zn²⁺ > Ni²⁺> Fe³⁺> Cd²⁺ ions. The results revealed that the adsorption capability of the PVA/CH hydrogel is higher than that of PVA/AA, signifying their use efficiently for the elimination of potentially toxic metal ions from metal-contaminated water.