CHARACTERIZATION OF A BIOLOGICALLY TREATED WASTE-WATER FROM OIL RECLAIMING - RECORDING OF LOW-MOLECULAR-WEIGHT ORGANICS AND ESTIMATION OF HUMIC SUBSTANCES

Wastewater originating from oil reclaiming (COD about 300 mg/l, TOC ab out 70 mg/l) which was pretreated by equalization, neutralization, ads orption to activated sludge from a publicly owned treatment work, floc culation, and flotation and finally oxidized in an activated sludge pr ocess was analyzed for humic acids and gas chromatographically detecta ble organic compounds. The humic acid concentration was estimated to r epresent about 15% of the COD. Hydrocarbons were detected in activated sludge, but no hydrocarbons were identified gas chromatographically. In the two analyzed wastewater samples ethers (mainly containing polye thoxy structures), carboxylic acids and carboxylic acid esters were fo und. In one sample several nitrogen compounds (amines and amides) were detected. Except for 1,1'-oxybis-(2-methoxy)-ethane, which was a cons tituent of both samples, the organic gas chromatographically detectabl e compounds differed completely