A Novel Rotary Drum Filtering Photoreactor for Wastewater Treatment Using Titanium Dioxide Nanoparticles

A rotary drum filtering photoreactor using titanium dioxide (TiO₂) as photocatalyst could eliminate the problem of catalyst loss by elutriation with the effluent stream. The effects of operating conditions, namely, rotating speed and filtration velocity on phenol removal were investigated. The experimental results revealed that the rates of phenol decomposition and total organic carbon (TOC) depletion decreased against the increased rotating speed. The suitable speed of the drum was 5 rpm. As for the filtration velocity, the phenol decomposition and TOC depletion rates achieved their maxima when the filtration velocity was 0.73 cm min^-1. To obtain the intrinsic capacity of TiO₂ cake in degrading phenol, the photolysis of phenol was also studied. The results indicated that the photolysis efficiency of phenol after 360 min was 4.96% while the decomposition efficiency of phenol was 21.47%. They indicated that the presence of TiO₂ cake was a key factor for degrading phenol. In addition, the dark adsorption of phenol on TiO₂ cake after 30 min was insignificant at about 0.95%.