Study on the removal capability of trinitrotoluene in water using the UV/WO₃/H₂O₂ photo oxidation method

Abstract

The paper presents the results of synthesizing WO₃ by the chemical precipitation method, along with an evaluation of its physicochemical properties, morphology, crystal structure, and chemical characteristics. In addition, preliminary results are introduced regarding the removal efficiency of TNT from aqueous solution by photocatalytic oxidation, in which •OH and h⁺ play the main role as oxidizing species. The results indicate that the synthesized WO₃ possesses a hexagonal crystal structure, a density of 7.920 g/cm³, an absorption intensity of 1.45 a.u at a wavelength of λ = 285 nm, and a band gap energy of approximately 3.3 eV. The protonation process favors the widening of the energy band gap and enhances the oxidation potential of WO₃, thereby improving its photocatalytic performance and increasing its ability to absorb UVB light. The UV/WO₃/H₂O₂ photocatalytic oxidation process, with a fixed H₂O₂ concentration of 2.94 × 10⁻³ M, an optimal catalyst dosage of 300 mg WO₃, and a UV lamp power of 10 W, achieved a TNT removal efficiency of 98.7% at an initial concentration of 100 mg/L after 60 minutes of reaction under ambient temperature.