Rotating disk photocatalytic reactor: Development, characterization, and evaluation for the destruction of organic pollutants in water

This work focuses on the development, characterization and evaluation of th e TiO2 Rotating Disk Photocatalytic Reactor (RDPR) for the treatment of org anic pollutants in water. A commercial TiO2-based catalyst in the Form of c omposite ceramic balls was used as the immobilized photocatalyst on the rot ating disk. LiCl tracer studies conducted at different disk angular velocit ies, ranging from 20 to 5 rpm, proved that the mixing in the RDPR is close to that of an ideal CSTR. Two different techniques, an overflow method and the potassium ferrioxalate actinometry method were employed for determining the liquid holdup and turnover time of the rotating disk with glass beads substituted for TiO2 coated beads. The two methods were in agreement and on ly the overflow method was employed for determining the same parameters for the rotating disk when loaded with TiO2 composite ceramic balls. Power law correlations were obtained in all cases. TiO2-assisted photocatalytic degr adation of 4-chlorobenzoic acid (4-CBA) was investigated in the RDPR at a s pecified angular velocity of the rotating disk (4 rpm), initial pH = 3.0, a nd room temperature using near-UV radiation. (C) 2000 Elsevier Science Ltd. All rights reserved.