Amorphous titanium dioxide: a recyclable dye remover for water treatment

Decolorization of dye solutions, crystal violet and congo red, were investigated using the synthesized amorphous titanium dioxide and compared with commercial titanium dioxides: Degussa P25 and anatase. Results showed that amorphous TiO₂ had good adsorptivity that could decolorize the dye polluted water effectively mainly by adsorption. Decolorization by photocatalytic property was also detected but was very low. Concentrations of dye solutions used in this work were about ten times higher than normally used in other reports. After use, the particle surface was completely covered with dye molecules but this could be regenerated and the cleaned particles could be reused several times. Hydrogen peroxide and ultraviolet irradiation were used in the regeneration process.