Treatment phenolic compounds in coal gasification wastewater by hydrolytic acidification-AO process

Using hydrolytic acidification-AO process treating coal gasification wastewater, the COD, total phenols in the effluent and the removal efficiencies were studied. The start-up period was separated to two stages with influent COD concentration of 1500 and 2500mg/L. After 59 days operation, the COD and total phenols removal efficiencies were 80.3% and 72.9%, respectively. The COD and total phenols increased to 925.4 and 238.7mg/L when the HRT was reduced to 6h with the corresponding concentrations of influent were 2512.9 and 493.4mg/L. When the HRT in hydrolytic acidification was reduced to 100%, the removal of total phenols dropped from 75.4% to 57.6%. The bigger circle ratio of 500% didn't have obviously effect on total phenols removal of the process.