Heavy Metal Removal with NanoTiO2/Chitosan Modified Poly(Vinylidene Chloride)

Background: Heavy metal contamination of water resources has been identified as one of the most serious environmental issues. Chemical modification of hydrophobic polymer matrices is another approach for changing their surface properties for water treatment. The addition of nanoparticles to polymers alters surface characteristics such as adsorption capacity, adhesion, catalytic ability, and wettability to heavy metals in wastewater. Objective: Evaluation of the nanomodified polyvinyl chloride (PVC) polymer as a heavy metal adsorbent from wastewater. Methods: In the field of emission discharges from industries and domestic wastes that contain unknown inorganic pollutants by PVC using grafting chitosan/TiO2 nanocomposites. The characterization of different thin films was performed using TEM, XRD, and FTIR. The metal concentrations were measured by using inductively coupled plasma (ICP-OES). Results: Nanomodification of PVC was evaluated by infrared spectroscopy. The presence of chlorine in the PVC structure before and after the nanomodification is confirmed by the presence of a peak at 690 cm^-1 attributed to the axial deformation of the C-Cl bond. The nanomodified PVC showed an ion exchange capacity of 1.27 mmol^-1, and efficiently removed the heavy metals from aqueous solutions. The heavy metal removal effectiveness (R) was improved by increasing the concentration of TiO2 nanoparticles. The amount adsorbed per gram of adsorbent (Qe) was computed and revealed that the amount of adsorption increased for nanomodified PVC thin film as compared to 100% PVC thin film. The nanomodified PVC thin film showed high stability for 4 cycles of use. This improvement has been attributed to the nanomodified PVC polymer's large surface area (ranging from 0.3 to 282 m²/g). Conclusion: The modification of PVC with nanoparticles increases the cost of PVC thin film by 15%. However, it offers efficiency 3 times than the original PVC.