Photocatalytic Treatment of Linear Alkylbenzene Sulfonate (LAS) in Water

The photocatalytic degradation of aqueous linear alkylbenzene sulfonate (LAS) was studied. Two different photocatalysts, Degussa P25 TiO₂ and Hombikat UV 100 TiO₂, were used to degrade aqueous linear alkylbenzene sulfonate in slurry batch photoreactors. For a 100 mg/L LAS solution based on first–order rate constants, the optimum photocatalyst loading for Degussa P25 TiO₂ was 4.0 g/L, while for Hombikat UV 100 TiO₂ it was 2.0 g/L. The photoactivity of Degussa P25 TiO₂ it was higher than that of Hombikat UV 100 TiO₂ for the treatment of LAS. A mixture of both photocatalysts did not improve the LAS degradation rates in batch experiments. Combination of Degussa P25 TiO₂ and 600 mg/L H₂O₂ along with irradiation with UV light at either 254 or 365 nm did not improve the LAS degradation rates over the photocatalytic or photolytic processes individually.

Key Words :

• Surfactants
• Linear alkylbenzene sulfonate
• LAS
• Titanium dioxide
• Advanced oxidation processes
• Hydrogen peroxide
• Water and wastewater treatment.

ACKNOWLEDGMENTS

The financial support of the Natural Sciences and Engineering Research Council of Canada (NSERC) for this project is gratefully acknowledged.