Catalytic degradation of 3 , 5 - dimethylphenol with goethite and hydrogen peroxide

Phenolic compounds are one class of organic contaminants with high toxicity. In the present work, we study the degradation of 3,5-dimethylphenol (3,5-DMP) in heterogeneous phase with Fe(III)(hydr)oxides (goethite). The transformation of 3,5-DMP in aqueous suspension has been investigated under monochromatic irradiation at 365 nm. The disappearance of 3,5DMP was efficient upon irradiation of 3,5-DMP-goethite ( 10 mol/l , 1 g/l ) suspension. The effects of pH, oxygen, initial concentration of DMP and goethite are demonstrated. The involvement of HO radicals has been ruled out because of the non-influence of tertiobutanol used as a scavenger. The 3,5-DMPgoethite-H2O2 ( 10 -4 mol/l , 1 g/l, 10 g/l ) system was performed in dark before studying the photochemical reaction. It was found that the photodegradation of 3,5-DMP was significantly accelerated in comparison with the 3,5-DMP-goethite system. The optimal levels of H2O2 required for the process are also examined.