Improvement Effect of Bioaugmentation with Phenol Degrading Bacteria on Lurgi Coal Gasification Wastewater Treatment

Abstract

The improvement effect of bioaugmentation with phenol degrading bacteria (PDB) on pollutants removal and chemicals consumption was investigated in a full-scale Lurgi coal gasification wastewater (LCGW) treatment plant. Bioaugmentation with PDB applied in biological contact oxidation tank(BCOT) was carried out in summer to prevent the limitation of low temperature on the bacteria activity. After augmentation, the removal of COD and total phenol (TPh) was significantly enhanced, with efficiencies from 78.5% and 80% to 82.3% and 86.6% in BCOT, respectively. The improvement could also be detected in further processes, including anoxic-oxic, coagulation sedimentation and biological aerated filter, with COD and TPh removal efficiencies increment from 70.1%, 24.7% and 53.4% to 73.9%, 29.1% and 55.9%, from 67.1%, 20% and 25% to 72.5%, 25% and 32%, respectively. In addition, chemicals used for denitrification and coagulation sedimentation showed considerable reduction after bioaugmentation, with methanol, coagulant, coagulant aid and bleaching dosage from 100.0, 100.0, 80.0 and 60.0 mg/L to 85.0, 70.6, 57.8 and 45.7 mg/L, respectively. Therefore, bioaugmentation with PDB can be a viable alternative for LCGW treatment plant in pollutants removal and chemicals saving.