Abstract
This study demonstrates the synthesis of titanium oxide-magnetite/chitosan nanocomposite (TiO2-MNPs/CT) where TiO2 nanoparticles were precipitated onto prepared MNPs followed by immobilization onto CT. The prepared nanocomposite was investigated using scanning electron microscopy, X-ray diffraction spectrometry, and Fourier transform infrared spectrometry. The nanocomposite was applied for adsorptive removal of naphthalene, which is the most prevalent compound of the most hazardous polycyclic aromatic hydrocarbon, from aqueous solutions. The parameters assumed to considerably controlling the removal process was optimized The highest removal efficiency (98%) with the maximum adsorption capacity (49.7 mg/g) was obtained at pH 7, adsorbent concentration 2 g/L, and contact time 24 h. The experimental results were analyzed using isotherm models including Langmuir, Freundlich, and Dubinin-Radushkevich, which revealed multilayer adsorption with maximum adsorption capacity of 60.48 mg/g. The kinetic studies showed good fit for the experimental results with pseudo-second order model referring to the presence of chemical adsorption. Furthermore, the spent adsorbent particles were regenerated via shaking with ethanol for 60 min and studied in repeated adsorption cycles. Slight decrease after the fifth adsorption-regeneration cycle was observed, indicating good stability of the nanocomposite against regeneration.