INDUSTRIAL-WASTE WATER-TREATMENT - LARGE-SCALE DEVELOPMENT OF A LIGHT-ENHANCED FENTON REACTION

The feasibility of a large scale application of the light-enhanced Fen ton reaction has been investigated for the treatment of a highly conta minated industrial waste water containing toxic aromatic amines (dimet hyl anilines or xylidines) as the main pollutants. The Fenton reagent, a combination of hydrogen peroxide and a ferrous salt, is a potent ox idizing agent of organic compounds in acidic aqueous solution, and UV/ visible irradiation may significantly enhance the degradation rates. P reliminary laboratory rests on the model compounds, 2,4- and 3,4-xylid ine have been performed for selecting appropriate experimental conditi ons. Subsequent experimentation on the industrial waste water at a lar ge scale level (3000 mg Cl-1, 500 l) has been carried out using an exp erimental design methodology for the simulation and the evaluation of the effects of the two critical factors, hydrogen peroxide and ferrous ion concentrations. The results indicate that the light-enhanced Fent on reaction is a most effective treatment process under acidic conditi ons and is a realistic alternative to adsorption of xylidines on activ ated carbon as used at present. (C) 1997 Elsevier Science S.A.