Analysis of Wastewater Membrane Pollutants in Joint Station and Research on Biological Control Technology

Abstract

In view of the serious membrane pollution and short stable operation period of the existing heavy oil wastewater treatment process in a combined station of an oil field, the organic pollution is determined to be the main cause of the membrane pollution on the basis of the analysis of the wastewater quality and membrane pollutants. In view of the characteristic pollutants in heavy oil wastewater, the efficient degrading bacteria were screened by restrictive culture technology, and the strains were identified as Pseudomonas and Bacillus. The effects of environmental conditions on the growth of bacteria and the degradation of heavy oil by bacteria were investigated. In the existing process, biological treatment unit was added, simulation process was established, and long-term operation experiment was carried out. The results show that after biological treatment, the oil content of wastewater is less than 1 mg/L, COD is less than 100 mg/L, suspended matter is less than 1 mg/L, and the median particle size is 0.92 um, which is better than the first kind of water injection index (SY/T 5329-2012). Biological treatment effectively degraded organic pollutants in heavy oil wastewater and delayed membrane fouling. The loss rate of membrane flux was less than 15%. The microscopic morphology of membrane surface also showed that membrane fouling was effectively suppressed.