Membrane bioreactors for petrochemical and oil refinery wastewater treatment: a technology adequate to protect very sensitive water bodies?

Full scale centralised MBRs are growing in large chemical and petrochemical areas, especially where the receiving water bodies are very sensitive and involve very stringent limits for discharge. In addition, in numerous areas of the developed countries the industrial petrochemical production is under irreversible crisis and the related wastewater are consequently under-loaded and very variable for quantity and chemical-physical characteristics. This paper present a two-year-long pilot study where a MBR (reaction volume 4.2m3) is continuously applied to optimize the treatment of a drastically under-loaded petrochemical wastewater coming from a large industrial petrochemical area. The mechanisms of removal for macro and micropollutants was investigated and different operating conditions were tested to find the best strategy to operate the full scale MBR plant.