Photocatalytic removal of toluene from gas stream using chitosan/AgI-ZnO Nanocomposite fixed on glass bed under UVA irradiation

In this study, AgI-ZnO/chitosan nanocomposite was synthesized and then was coated on 2×40×200 glass plates under UVA irradiation for the removal of toluene from air streams. The AgI-ZnO/chitosan Nanocomposite was characterized using XRD, SEM, FTIR and BET techniques. The analyses showed Zn and Ag were added to the composite structure with weight percentages of 32.02 and 7.31, respectively. The results confirmed that the AgI-ZnO/chitosan nanocomposite was successfully synthetized. According to the results, the photocatalytic process was able to remove 74.6% of toluene at an air flow rate of 1 L/min after 3.3 min. Also, by increasing the passing flow rate from 0.3 to 1.5 L/min through the photocatalytic reactor, the process efficiency for toluene removal increased. The toluene removal efficiency decreased with increasing relative humidity with respect to time. Moreover, increasing relative humidity decreased the photocatalyst capacity for the removal of the target pollutants. The results implied that the initial toluene concentration in the inlet stream played a key role on the photocatalysis of toluene and by further increase in the pollutant concentration higher than 20 ppm, its performance decreased dramatically. Therefore, the proposed process can be used and an effective technique for the removal of toluene from the polluted air stream under UV irradiation and increasing temperature up to 60 °C could increase its performance.