Remediation of Ni2+ and Sr2+ ions from aqueous solutions by acacia gum/polyacrylic acid hydrogel reinforced with TiO2 nanoparticles

Abstract

Abstract Globally, the environment and public health are progressively threatened due to water resource contaminants. For this purpose, a unique polyfunctional nanocomposite is created to remediate heavy metals from aqueous media. The basis of it is TiO2 composite nanoparticles (NPs) manufactured via embedding titanium oxide (TiO2) into acacia gum/acrylic acid (AG/AAc). Nanocomposite hydrogels, bearing different functional groups, are constructed employing a gamma irradiation approach that would operate as adsorbents to remove strontium (Sr2+) and nickel (Ni2+) ions from their wastes. The structure of the prepared hydrogel and its nanocomposites were confirmed by FTIR, whereas the morphology was characterized by SEM. XRD and EDX analysis confirms that the TiO2 NPs are successfully encapsulated into the prepared hydrogel. The presence of TiO2 enhances the thermal stability of the prepared hydrogel. Adsorption extent is evaluated comprehensively concerning temperature, contact time, adsorbent dosage, metal ion concentration, and pH. The physical connection between the adsorbent surface and metal ions is strengthened once TiO2 NPs are included in a copolymeric matrix, which enhances adsorption. Pseudo-second-order kinetics accurately depict the adsorption process, and the Freundlich isotherm provides the most relevant explanation of the equilibrium data. There is a demonstration that sorption is a spontaneous, feasible, and endothermic chemisorption process by examining a variety of thermodynamic parameters, including ΔH, ΔG, and ΔS.