The solvents n-pentane, methylene dichloride, ethyl ether and dodecylbenzenesulphonic acid sodium
were used to regenerate exhausted activated carbon used in the process of treating coking wastewater,
and the efficiency, ability, and optimum conditions of the different solvents on this regeneration were
investigated. The results indicate that n-pentane could effectively remove refractory organic compounds
in the coking wastewater adsorbed on the surface of activated carbon and could repeatedly regenerate
the exhausted activated carbon to recover its adsorption activity. Under the conditions of a regeneration
time of 20 min, a regeneration temperature of 25 ◦C, an activated carbon drying time of 300 min, and
an activated carbon drying temperature of 150 ◦C, n-pentane had the best regeneration efficiency, at
98.27%, for exhausted activated carbon. Gas chromatography–mass spectrometry analysis results show
that the nature of the activated carbon regenerated by organic solvents had no remarkable change in
adsorption for the main types of organic compounds in coking wastewater. The good regenerative effect
of n-pentane on the activated carbon may be due its stronger desorption of esters embedded within the
internal structure of activated carbon