Electrochemical treatment of simulated anthraquinone dye wastewater with in situ electrogenerated active chlorine at constant potential
The electrochemical oxidation of C.I.Reactive Blue 1 9 with in situ electrogenerated active chlorine was carried out in a divided f low-by cell using metallic oxide coatings(DSA) as anode.At a constant potential,measurements of the absorbance at 592 nm and 255 nm were u sed to follow the discoloration of the dye and degradation of its aromatic ring. The experimental results suggested that the discoloration and degradation were s trongly affected by electrode potential,initial pH,concentration of dye and NaCl ,while slightly affected by supporting electrolyte concentration and temperature .After 4 h electrolysis at an electrode potential of 1.13 V(vs SCE), for a simulated wastewater composed of 0.5 mol·L  -1 NaCl, 0.1 mol· L -1 Na_2SO_4, 0.1 mmol·L -1 dye, the diseoloration of the dye and degradation efficiencies of its aromatic ring were 100%,ca.40%,respectively,wh ile no obvious change of TOC was observed. Indirect electrooxidation by using el ectrogenerated active chlorine was predominant in the electrochemical oxidation.