Treatment of a Petrochemical Wastewater in an Anaerobic Packed Bed Reactor

Wastewater from a used oil rerefinery was tested in laboratory scale anaerobic packed bed reactors for TOC removal, gas production and control of volatile organic emissions. The raw wastewater had a TOC ranging from 3,250 to 5,800 mg/L of which 40 to 45% consisted of total phenolics, acetone, methanol, ethanol and volatile fatty acids. The remaining TOC was not analyzed but was expected to contain potentially harmful constituents. Treatment of the undiluted wastewater achieved acidogenisis but methane production appeared to have been inhibited. A 1:2 dilution of the wastewater produced reasonably good treatment with 52 to 67% TOC reduction, over 75% removal of acetone and total phenolics and vigorous methane production. Operational parameters were characterized by an organic loading of 1.4 kg COD/m3.d and HRT of 3.0 days. Implications for full-scale operation and airborne contaminant control are discussed