IDENTIFICATION OF TRACE ORGANICS IN A TREATED LUBRICATING OIL REFINERY WASTE-WATER

Organic substances in the influent and in the effluent of a fixed bed biology located at a lubricating oil refinery were characterized by ga s chromatography/mass spectrometry (GC/MS). Totals of hydrocarbons wer e 0.8 mg/l (influent) and 0.1 mg/l (effluent) indicating a biological removal of nearly 90% of the hydrocarbons. High temperature gas chroma tography/high resolution mass spectrometry of 1,1,2-trichlorotrifluoro -ethane extracts revealed that monocycloalkanes were the major group o f hydrocarbons in the influent (590 mu g/l) as well as in the effluent (65 mu g/l) of the biological stage. A small amount of me hydrocarbon s in the influent were aromatic compounds (mainly alkyl benzenes aid b enzocycloalkanes) which were degraded in the bioreactor to a lower ext ent than the aliphatic compounds. In dichloromethane extracts of the 6 0-fold concentrated effluent of the biological stage only few organics were identified gas chromatographically. Besides 1-methyl-2-propyl-cy clohexane a couple of ethers and nitrogen-containing heterocycles were the main components detected in the dichloromethane extracts. The dat a presented here confirm that aerobic fixed bed biology is an efficien t final treatment step for refinery wastewaters.