Radiation Synthesis and Characterization of Poly (vinyl alcohol)/acrylamide/TiO2/SiO2 Nanocomposite for Removal of Metal Ion and Dye from Wastewater

PVA-co-AAm/TiO2/SiO2 nanocomposites adsorbents synthesized by gamma-irradiation copolymerization of polyvinyl alcohol (PVA) and acrylamide (AAm) incorporated TiO2/SiO2 nanopowders, aiming to enhance the removal of basic blue 3 dye (BB3) and Cu (II) ions from aqueous solutions. Properties of nanocomposites were analyzed by different techniques. FTIR results showed successful incorporation of nanoparticles and copolymerization of PVA and AAM. SEM/EDS confirm the peaks belonging to C, O, Si, and Ti. TEM investigation illustrated that TiO2/SiO2 nanoparticles were well dispersion, uniform, and homogeneous shape of particle size of 60-70 nm. XRD data specified characteristic diffraction peaks of TiO2 and the calculated crystalline size was 43 nm. Adsorption results confirm that PVA-co-AAm/TiO2/SiO2 nanocomposites provide better adsorption capacities of both BB3 and Cu (II) was three-folds rather than PVA-co-AAm-30. The nanocomposite prepared at 30 kGy (PVA-co-AAm/TiO2/SiO2-30) showed high swelling, gelation, and highest adsorption capacity and it was selected as the best adsorbent for batch experiments. The optimum adsorption was achieved using 0.4 g PVA-co-AAm/TiO2/SiO2-30 adsorbent dosage. The adsorption capacity of BB3 and Cu (II) was 140.9 and 190.3 mg/g with a removal efficiency of 93.5 and 95.2% after 7 h and 6 h, pH 11 and pH 6, and initial concentration of 150 and 200 mg/L, respectively. The adsorption of BB3 or Cu (II) was endothermic and spontaneous, well described by the pseudo-second-order adsorption kinetic and fit Langmuir isotherm. The results revealed that the as-synthesized PVA-co-AAm/TiO2/SiO2 nanocomposites could be employed as effective adsorbents for the adsorption of BB3 and Cu (II) ions from wastewater with high adsorption capacity and recovery.