Evaluation of SO₂ removal efficiency using a series non-thermal plasma reactor coupled with TiO₂ and ZnO photocatalysts

SO₂ is one of the major air pollutants affecting both the environment and human health. Controlling its emissions has become a critical goal for many countries. This study evaluates the performance of a combined system utilizing non-thermal plasma and photocatalysts for SO₂ removal, with data analyzed through SPSS and R software. In this method, nano-photocatalysts of TiO₂ and ZnO were used in IPC form. The study examined the effects of concentration, flow rate, voltage, specific input energy, and residence time on removal efficiency, as well as their interactions. ANOVA results showed that both systems were highly effective in removing SO2, with the non-thermal plasma system paired with TiO2 photocatalyst performing slightly better. At a concentration of 500 ppm, SO₂ with a removal efficiency of 97.32% in the TiO₂-based system and 94.3% in the ZnO-based one. The best efficiency for both methods was achieved at a voltage of 15 kV and a flow rate of 3 Lit/Min. energy efficiency in optimal conditions was 6.6 g/kWh. A significant relationship was reported between Flow Rate (p-value ≤ 0.001), Voltage (p-value ≤ 0.001), Residence Time (p-value ≤ 0.001), and study factors. The findings indicate that this method seems to be very effective, efficient, and economical for the removal of sulfur dioxide (SO2).