Preparation of TiO2/cellulose nanocomposites as antibacterial bio-adsorbents for effective phosphate removal from aqueous medium.

The design of environmentally benign bio-adsorbents for the removal of phosphate from aqueous medium was an economic and effective way for controlling eutrophication. Herein, we prepared three kinds of TiO2/cellulose (CE-Ti) nanocomposites by a facile hydrolysis-precipitation method, and used them as antibacterial bio-adsorbents for the removal of phosphate from aqueous medium. Multiple techniques including Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and thermogravimetric analysis (TGA) were employed to characterize the nanostructure and characteristics of the prepared CE-Ti nanocomposite. The adsorption capacity of the CE-Ti was 19.57 mg P g-1 according to the Langmuir model, which was 6 times higher than that of CE. Importantly, the bacterial inhibition zone of the CE-Ti was 2.88 mm (that of CE was 0 mm), indicating that CE-Ti had good antibacterial activity that could reduce the attachment of the microorganism to the surface of CE-Ti, which was suitable for long-term phosphate removal. Moreover, the CE-Ti had good adsorption selectivity and anti-interference capability, according to interfering ions and ion strength experiments. Furthermore, Ti4+ leakage tests suggested that CE-Ti was highly stable under acidic, neutral and alkali conditions. These results indicated that the CE-Ti nanocomposite could be utilized as a promising antibacterial bio-adsorbent for effective phosphate removal from aqueous medium.