Comparison of Iron-carbon microelectrolysis and Fenton oxidation on treatment of dyeing wastewater

【Objective】 Dyestuff wastewater is a typical kind of biorefractory wastewater with high concentration,high chroma,complicated components and low degradability.【Method】 Dyeing wastewater from the Second Printing and Dyeing Mill of Xianyang,Shaanxi was chosen as experimental material to study the optimal conditions of for Iron-carbon microelectrolysis and Fenton oxidation using the single-factor experiments.The treatment effects of the two methods were compared as well.【Result】 In disposing printing and dyeing waste water,optimum reaction conditions of Iron-carbon microelectrolysis were as follows:exposure time was 30 min,pH value was 3-4,volume ratio of iron to carbon was 1,and chroma and COD removal efficiency were 80% and 60%,respectively.Optimum reaction conditions of Fenton oxidation were as follows:pH value was 3,exposure time was 45 minutes,the dosage of hydrogen peroxide was 20 mL/L and ferrous sulphate was 25 mL/L,the hydrogen peroxide was added in the reaction system three times,and chroma and COD removal efficiency were 79% and 80%,respectively.【Conclusion】 Treatment of dyeing wastewater by Iron-carbon microelectrolysis and Fenton oxidation showed good effects.It suggests that Iron-carbon microelectrolysis can be used in combination with Fenton oxidation to improve the treatment efficiency.