Invited feature articleTreatment of phenol in petrochemical wastewater considering turbidity factor by backlight cascade photocatalytic reactor

- Innovative cascade backlight photocatalytic reactor was studied for treatment of phenol in petrochemical wastewater considering turbidity factor.
- TiO2 nanoparticles were coated on Plexiglass plates using the slurry method.
- TiO2 concentration changes had a direct effect on output of phenol removal efficiency in the cascade photocatalytic reactor.
- Turbidity in the limits of the studied pH had no effect on phenol removal efficiency in the cascade photocatalytic reactor.

The toxicity of phenol is such that even in its low concentration in industrial wastewater, it should be removed. Photocatalytic treatment is an appropriate method for treating toxic and difficult to biodegrade organic materials. However, most phenol containing wastewaters such as petrochemical wastewater, contain turbidity that limits photocatalytic treatment usage. To remove phenol from petrochemical wastewater, a novel cascade photocatalytic backlight reactor is developed. In the developed reactor, the effect of four factors including initial phenol concentration, TiO2 concentration, turbidity, and pH on phenol removal efficiency is investigated using full factorial design. The best removal efficiency was 88% obtained after three hours when pH is 9, initial phenol concentration equals 50 mg/L, and TiO2 concentration equals 80 g/m2. The relationship of these parameters on phenol removal efficiency is statistically evaluated using analysis of variance. The significance of reaction parameters is shown as follows: time > initial phenol concentration > TiO2 concentration > pH. The ANOVA analysis also reveals that turbidity has no effect on phenol removal efficiency.

61