UTILIZATION OF FENTON REACTION FOR THE DE GRADATION OF CONVENTIONALLYUSED DYES AND COLORED WASTE-WATERS

Water solutions of the some dayes produced by Bayer and Sandoz and was te waters from three plants were decolourized with Fenton's reagent. T he reduction in chemical oxygen demand ranged from 60 to 89 % and from 24 to 94 % for individual dyes and waste waters, respectively. The me an decolourization of dye solutions was above 98 % and that of waste w aters from Duslo, Sala and Merina, Trencin was 100 %. The decolourizat ion of pulp-mill waste waters (Sturovo) was inefficient. The found eff icient conditions of the treatment were: pH 3.0, H2O2-to-FeSO4 ratio 1 .75 : (1.00-2.00), Fenton reaction time at 24 degrees C 1 hour, pH for coprecipitation 7.0. Better results are obtained by addition of a flo cculant during neutralization. Fenton's reagent is efficient in decolo urizing waters that also contain dissolved organics.