Removal of copper (II) from aqueous solutions by organic polymer-modified TiO2/bentonite nanocomposites

In order to investigate the effect of pectin and dextran polymers on the adsorptive capacity of TiO2/bentonite nanosorbents, two nanocomposites of TiO2/pectin/bentonite and TiO2/dextran/bentonite were made by sol-gel method. Their investigation by FT-IR spectroscopy confirms the expected microstructure, and XRD results confirm the formation of anatase titania crystalline phase and also crystalline structure of bentonite. FESEM images showed the formation of TiO2 nanoparticles. These two nanocomposites were used for removing copper (II) ion from water and the effective factors on removal were investigated that maximum removal for both nanocomposites is in pH=7, adsorption dosage of 0.04g and temperature of 25°C, but contact times for two composites of TiO2/pectin/bentonite and TiO2/dextran/bentonite were equal to 20 and 30 minutes and adsorptive capacity for them were 40.16 and 22.12 mg Cu2+ per gram of adsorbent, respectively. Investigating the effect of interference ions had no considerable influence on removal efficiency. The results show that adsorption of Cu2+ by TiO2/pectin/bentonite and TiO2/dextran/bentonite nanocomposites follows Langmuir and Freundlich isotherms.