Abstract
A new method for disperse dye decolourization using the photochemically active silicadodecatungstic acid (H4SiW12O40) + isopropanol (electron donor) redox system has been described. Results of a series of control experiments have indicated that the one-electron reduced form of the silicadodecatungstic acid, SiW12O5-40, was responsible for reductive cleavage of disperse dye as evidenced by photochemical heteropoly blue generation upon H4SiW12O40 + isopropanol UV-illumination. A threshold (0.09 mM) and an optimum (0.5 mM) heteropoly acid dose existed for minimum and maximum decolourization rates, respectively. It was also evident that decolourization kinetics were first-order with respect to dye concentration for concentrations up to 75 mg/l, and the photochemical degradation rate became UV-light penetration limited (zero order) above 100 mg/l dye concentration.
| Original language | English |
|---|---|
| Pages (from-to) | 167-176 |
| Number of pages | 10 |
| Journal | Dyes and Pigments |
| Volume | 60 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Feb 2004 |
Funding
The financial support of Istanbul Technical University Research Foundation is acknowledged. The assistance of Mr Izzet Alaton (Head of R&D Department, Pisa Tekstil Dyeing Corp.) during the selection of dye assisting chemicals is deeply appreciated. The author also wishes to thank SETAS Kimya Corp. for the kind supply of disperse dye preparations.
| Funders | Funder number |
|---|---|
| Istanbul Technical University Research Foundation |
Keywords
- Decolourization
- Disperse dyes
- H SiWO
- Heteropoly acid
- Heteropoly blue
- Photochemical degradation