Research on the Treatment of Dyeing Wastewater with Fenton Process

The factors which influence the the removal efficiency of COD and chromaticity including the initial pH, dosage of Fe, the Fe/C ratio ,the dosage of H_2O_2, the type of activator and the reaction time were studied in the process of electro-Fenton treatment to the dyeing wastewater. The test results showed that the internal electrolysis optimal initial pH was 3.0, dosage of Fe was 25 g/L and the Fe/C ratio was 1 :13. The Fe~(2+) from the internal electrolysis can be used in Fenton oxidation process, so can save the application amount of the reagent. The optimal terms of Fenton oxidation processes were as follows: the reaction time was 50 min, the dosage of H_2O_2 was 30 mmol/L, and the pH was the internal electrolysis dying (the pH was about 4.0). The maximum removal efficiency of COD_(Cr) may reach to 58% and the removal efficiency of chromaticity can be more than 95% as well as the ratio of BOD_5/COD_(Cr) can be raised from 0.08 to 0.36 under above conditions.