Abstract: Keeping the stable quality of high concentrated wastewater is the key to reach the discharge standards for refinery wastewater. The operation results of high pollutant wastewater treatment system indicate that the wastewater shock has a severe influence on alkaline residue wet-air oxidation process and oil-removing process, resulting in more phenol, sulfide and oil than design requirement in treated wastewater and low dissolved oxygen in bio-chemical process under the wastewater shock conditions. It becomes the bottleneck for effluent to meet the discharge standards. Solutions were put forward to solve the problems.

Key words: wastewater treatment, alkaline residue, sequencing batch reactor, biological aerated filter, wet-air oxidation