Two-stage SBR for treatment of oil refinery wastewater

Water Sci Technol. 2004;50(10):243-9.

Abstract

A two-stage sequencing batch reactor (SBR) system was used for treatment of oily wastewater with COD and oil and grease (O&G) concentrations ranging from 1,722-7,826 mg/L and 5,365-13,350 mg/L, respectively. A suitable start-up protocol was developed using gradual increase in oily wastewater composition with methanol as the co-substrate. This strategy enabled a short acclimation period of 12 days for the sludge in the two-stage SBR to adapt to the oily wastewater. After acclimation, the 1st stage and 2nd stage SBRs were able to achieve COD removals of 47.0+/-2.4% and 95.3+/-0.5%, respectively. The 1st stage SBR was able to achieve 99.8+/-0.1% of O&G removal and effluent O&G from the 1st stage SBR was only 6+/-2 mg/L. The 2nd stage SBR was used to further remove COD in the effluent from the 1st stage SBR. The final effluent from the 2nd stage SBR had a COD concentration of 97+/-16 mg/L with no detectable O&G content. Thus, a two-stage SBR system was shown to be feasible for treating high strength oily wastewater to meet the local discharge standards.

MeSH terms

  • Bioreactors*
  • Industrial Waste / prevention & control*
  • Methanol / chemistry
  • Oxygen / isolation & purification
  • Oxygen / metabolism
  • Petroleum*
  • Sewage / chemistry
  • Sewage / microbiology*
  • Soil Pollutants / metabolism
  • Time Factors
  • Waste Disposal, Fluid / methods*

Substances

  • Industrial Waste
  • Petroleum
  • Sewage
  • Soil Pollutants
  • Oxygen
  • Methanol