Advanced oxidation of synthetic dyehouse effluent by O3,H2O2/O-3 and H2O2/UV processes

Ozonation, hydrogen peroxide combination with ozone, and UV light processes were investigated for the treatment of synthetic dyehouse effluent contain ing six reactive dyestuffs and their assisting chemicals. The decrease in D OC, UV absorbance at 254 nm, decolourization kinetics, and acute toxicity t owards the bioluminescent marine bacteria Vibrio fischeri were used to exam ine the treatment performance of these oxidation processes. Data indicated that in all examined processes rapid and complete decolourization could be achieved, but optimum oxidation conditions such as H2O2 dose and reaction p H had to be established for effective treatment. Toxicity of the samples de creased abruptly to non - detectable levels during the first minutes of all advanced oxidation processes. However, none of the oxidation combinations was able to bring about effective mineralization of the wastewater within 6 0 min reaction period. For comparative purposes, the electrical energy requ irements per order of pollutant removal were calculated for all treatment s ystems.