Removal of organic dyes in the hybrid photocatalysis/nanofiltration system

The removal of azo dyes acid red 18 (ARIS), direct green 99 (DG99) and acid yellow 36 (AY36) in hybrid photocatalysis/nanofiltration (NF) system was investigated. The photocatalytic reactions were conducted ill the flow reactor with immobilized photocatalyst bed. A commercially available titanium dioxide (Aeroxide (R) P25, Degussa, Germany) was used as a photocatalyst. The solution after the photocatalytic reaction was applied as feed for NF process. The changes of various parameters, including concentration of dyes, pH and conductivity of the Solution, total organic carbon (TOC) and total dissolved solids (TDS) content were analyzed during the process. It was found that azo dyes AR18, DG99 and AY36 Solutions Could be successfully decolorized in the quartz labyrinth flow reactor with immobilized photocatalyst bed. The rate of color removal can range as follows: AR18 > DG99 > AY36. (C) 2009 Curtin University of Technology and John Wiley & Sons, Ltd.