Bioaugmentation as a tool to enhance the removal of refractory compound in coke plant wastewater

Pollution caused by coal conversion wastewater has been a severe problem for decades in China due to the use of coal as the main energy source. An aerobic-anoxic-oxic (A1-A2-O) system was developed for treating coke plant wastewater and good results were obtained. GC/MS analysis indicated that the main ingredients of the effluent were aromatic and heterocyclic compounds, alkanes and plithalic acid esters etc. Bioaugmentation with specialized microorganism could be a powerful tool to improve the wastewater treatment processes. In this study, quinoline, which was poorly removed by the A1-A2-O system, was chosen as a target pollutant, and a quinoline-degrading bacterium, identified as Burkholderia pickettii was used as bioaugmentation microorganism. The feasibility of bioaugmentation in combination with A1-A2-O system was investigated. The performance of the A1-A2-O system and the contribution of each stage to COD removal were investigated. The contribution of anaerobic, anoxic and oxic reactors to COD removal was 25, 16 and 59%, respectively. The results of bioaugmentation experiments showed that the oxic reactor, to which the aerobic microorganism was added, was the best location of bioaugmentation in the A1-A2-O system. Bioaugmentation could be used as an efficient and effective method of improving the removal efficiency of recalcitrant organic compounds from industrial wastewater. (C) 2002 Elsevier Science Ltd. All rights reserved.