Chlorophenols are persistent organic pollutants with high toxicity. Dichlorophenols (DCPs) include six isomers due to different substituted position of chlorine atoms. Self-made Pd/polypyrrole(sodium dodecylbenzene sulfonate)/Ti electrode (Pd/PPy(SDBS)/Ti electrode) was employed to dechlorinate six DCP isomers. The effects of electrolysis current

initial pH and the initial concentration of target pollutant on the dechlorination process of 2

5-DCP were investigated. Under the selected conditions

i.e.

applied current of 5 mA

initial pH of 2.5 and temperature of 25℃

dechlorination experiments of 2

3-DCP

2

5-DCP

2

4-DCP

2

6-DCP

3

4-DCP and 3

5-DCP with the same DCP concentration of 100 mg·L-1 were conducted

respectively. Phenol was the main product and a small amount of monochlorophenol could be detected during the dechlorination of six DCPs. The reaction rate constants of six DCPs were 4.735×10-2 min-1

4.609×10-2 min-1

4.845×10-2 min-1

4.317×10-2 min-1

3.973×10-2 min-1 and 3.770×10-2 min-1

respectively. It showed that the degradation rates of DCPs were affected by pKa

protonation and pH. The degradation difficulty of six DCPs was 2

4-DCP<2

3-DCP<2

5-DCP<2

6-DCP< 3

4-DCP<3

5-DCP.