The treatment of dye wastewater by the revised electro-Fenton method

An electrochemical apparatus was set with electro-Fenton Method to treat dye wastewater.In the eletrolytical bath,the Na_2SO_4 was used as the supported electrolyte,the carbon was used as the cathode and the iron was used as the anode.When the dye wastewater was electrolyzed,air was exported on the cathode.With the electrochemical methods,H_2O_2 was produced on the cathode in the electrolytic cell,then H_2O_2 reacted with Fe~(2+) dissolved on the anode to produce Fenton reagent.Fenton reagent was used as an oxidant in the treatment of dye wastewater.Several factors affecting the COD removal ratio and color removal of the dye wastewater,such as electrolysis volt,PH values,electrolysis time were given respectively.The results showed that the COD removal ratio was about 50%-70% and the color removal rat was 98% in condition of PH=6,electrolysis volt=15V,and electrolysis time=1h,temperature=25℃.Based on the above electrolysis conditions,the 0.2g/L MnSO_4 or 0.5g/L Zn(NO_3)_2 was added to the dye wastewater,the results showed that COD removal ratio was raised to 91%.It has not been reported earlier that using MnSO_4 or Zn(NO_3)_2 can improve COD removal ratio dramatically in electro-Fenton method.It was exploited in our laboratory.