Photocatalytic removal of naphthalene (C۱۰H۸) from aqueous environments using sulfur and nitrogen doped titanium dioxide (TiO۲-N-S) coated on glass microbullets in presence of sunlight

Background and aims: Due to their toxicity and carcinogenic effects, polycyclic aromatic hydrocarbons (PAHs) such as naphthalene(C۱۰H۸) are regarded as hazardous compounds for both humans and the environment, and it is essential to remove these contaminants fromthe environment. The present study aimed to remove naphthalene from a synthetic aqueous environment using sulfur and nitrogen dopedtitanium dioxide (TiO۲-N-S) nanoparticles (NPs) immobilized on glass microbullets under sunlight.Methods: In this experimental study, TiO۲-N-S NPs were synthesized using sol-gel process. The structure of NPs was investigated usingX-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray (EDX), and differential reflectance spectroscopy(DRS). In addition, using statistical analyses, the effects of parameters such as the initial concentration of naphthalene, pH, contact time,and the optimal conditions on naphthalene removal were investigated.Results: XRD patterns and SEM images of the samples confirmed the size of synthesized particles in nanometer. The EDX and DRS spectraanalysis showed the presence of two elements (sulfur and nitrogen) and the optical photocatalytic activity in the visible region, respectively.The maximum level of naphthalene removal in the presence of sunlight was obtained to be about ۹۳.۵۵% using a concentration of ۰.۲۵ gof thiourea immobilized on glass microbullets at pH=۵ and contact time of ۹۰ minutes.Conclusion: The rate of naphthalene removal using the immobilized TiO۲-N-S on glass microbullets was ۹۳.۵۵% in optimal conditions.Therefore, this method has an effective potential for naphthalene removal, and can be used to remove naphthalene from industrialwastewater.

Keywords:

Sunlight , Aromatic hydrocarbons , Naphthalene , Glass microbullets , TiO۲-N-S nanoparticles