Abstract:
This research was carried out to produce hydrogen (H₂) simultaneously with the organic pollutant degradation from biodiesel wastewater using the coupled semiconductor photocatalysts. The investigated parameters were types and quantities of coupled semiconductors (Bi₂O₃, Nb₂O₅ and WO₃) and concentrations of H₂O₂ (0.1 - 0.7 M). The obtained results demonstrated that the Bi₂O₃/TiO₂ photocatalyst at the Bi₂O₃ content of 5% mole showed the highest H₂ production rate (948 µmol/h), while the WO₃/TiO₂ photocatalyst at the WO₃ content of 5% mole exhibited the highest COD removal (29.1%) using 3.3-fold dilution biodiesel wastewater, photocatalyst loading of 4 g/L and UV-Visible irradiation of 5.93 mW/cm² at temperature of 30 °C for 4 h. In addition, the addition of H₂O₂ can enhance the photocatalytic activity of the coupled semiconductor photocatalysts for simultaneous H₂ production and organic pollutant degradation. Addition of H₂O₂ at the concentration of 0.3 M in the presence of the Bi₂O₃/TiO₂ photocatalyst at the Bi₂O₃ content of 5% mole can enhance the H₂ production up to 6,316 µmol/h and can remove COD of 28.7%, oil and grease of 20.0%. The color of processed wastewater was around 15 Pt-Co unit.