The Potential of Chitosan-TiO_2 Nanocomposite for Methyl Orange and Rhodamine B Removal

摘要

The overall objective of present work was to prepare and use chitosan-titanium dioxide (CS-TiO_2) nanocomposite as an adsorbent to remove two toxic dyes, namely Methyl Orange (MO) and Rhodamine B (RhB) from the aqueous solution. This work consists of two main parts, namely adsorption and characterization studies. For adsorption studies, several experimental parameters were studied such as the effect of initial concentration, solution pH and adsorbent dosage. Meanwile, Scanning Electron Microscope (SEM), Thermogravimetric Analyser (TGA), and X-ray Diffractometer (XRD) were used for characterization studies. The outcomes have shown that the equilibrium data correlated well to Freundlich isotherm model with adsorption capacity at equilibrium (K_F) was determined as 1.608 mg/g for MO and 7.646 mg/g for RhB, respectively. Based on SEM analysis, the rod- and needle-like deposits on the surface of CS-TiO_2 nanocomposite were disappeared following interaction with MO and RhB. There were cube-like deposits observed on the surface of CS-TiO_2 nanocomposite after adsorption of MO, while a dense and uneven surface texture were observed after adsorption of RhB. From TGA analysis, CS had two degradation stages, while CS-TiO_2 nanocomposite had three steps of decomposition. Furthermore, XRD results observed diffraction peaks for CSTiO_2 at 2θ = 34.075°, 29.235°, 25.47° and 20.26°.