Photocatalytic decolorization and mineralization of textile dyes by nanophotocatalysis from aqueous solutions

Degradation of Basic Blue 41 (BB 41) and Direct Yellow 28 (DY 28) were investigated by nanophotocatalysis using immobilized titania (TiO ) nanoparticles. A simple and effective method was developed for the immobilization of 2 titania nanoparticles. Photocatalytic degradation processes were performed using pilot scale (7 L) colored dye solutions. The effects of operational parameters governing the efficiency of the photocatalytic processes such as H2O2 , initial dye concentration and anions (Cl- and CO3-2 ) were investigated. UV-Vis, Ion Chromatography (IC) and total organic carbon 3 (TOC) analyses were employed to obtain the details of the photocatalytic decolorization and mineralization of BB 41 and DY 28. Kinetics analysis indicates that the photocatalytic decolorization rates can usually be approximated first-order model for both dyes. 90% total organic carbon of both dyes can be eliminated after 240 min of irradiation time. The nitrate and sulfate anions were detected as photocatalytic mineralization products of BB 41 and DY 28. Results show that the employment of optimal operational parameters may lead to decolorization and mineralization of BB 41 and DY 28 at pilot scale.

کلیدواژه ها:

decolorization ، immobilized titania nanoparticle ، mineralization ، nanophotocatalysis ، pilot scale