Dehalogenation of chlorophenol to give chloride ion had been found to take place in an aqueous solution by contact with high temperature He-treated activated carbons (ACs). In the present study, the influence of the surface chemistry of activated carbon and solution pH was examined to study the dehalogenation mechanism. The dehalogenation reaction was inhibited by electron-withdrawing groups and by nitrogen introduced on the graphite edge on ACs, whereas the reaction took place for ACs that had been outgassed and introduced to electron-donating groups. In addition, the greater the increase in pH, the greater the dehalogenation for the outgassed ACs.
