CHARACTERIZATION OF TEXTILE EFFLUENTS TREATED BY ELECTROCHEMICAL TECHNIQUES

In a previous paper, the electrochemical oxidation of textile effluents was reported as an efficient method to remove color, especially when the wastewater contains reactive dyes. However, before applying industrially this technique, some controls should be carried out in order to verify that no exceeding amount of toxic products are generated during the treatment.In the present work, effluents treated by electrochemical oxidation are characterized by gas chromatography-mass spectrometry (CG-MS) techniques to determine the content of volatile compounds.After applying several electrochemical treatments to the reactive dye containing wastewaters, some volatile organic compounds are detected in the treated effluents: 3-methylpentane, hexane, methylcyclopentane, cyclohexane, dichloromethane, chloroform (trichloromethane), carbon tetrachloride, tricholoroethylene, bromodichloromethane, trichloronitromethane and dibromochloromethane. Its concentration depends on the electrolyte employed during the dyeing.When chloride ion is present in a dyeing wastewater, an electrochemical treatment can achieve a good decolorisation of reactive dyes with a reasonable cost. Then, current density must be low and flow rate must be high in order to reduce the formation of chloroform and other trihalomethanes.In the absence of chloride, the amount of volatile compound generated is low and almost independent on the fixed experimental conditions.