Notice of RetractionResearch on Harbor Oily Wastewater Treatment by Submerged Hollow Fiber Membrane Bioreactor

Submerged hollow fiber Membrane Bioreactor (MBR) was applied to treat harbor oily wastewater after coagulation-sedimentation process. When the influent COD was 327 mg L-1, average effluent COD from the MBR was 135 mg L-1, with the average removal efficiency of 60%. The COD removal capacity of MBR deteriorated with the increase of influent salt content, thus, the influent salt content should be limited below 8000 mg L-1 in terms of total dissolved solid (TDS). In addition, ammonia nitrogen was reduced from 20 mg L-1 to 1.2 mg L-1 by the MBR, with the remarkable average removal efficiency of 92%. Oil content was reduced from 4.3~8.0 mg L-1 to 1.4~4.1 mg L-1 , with the average removal efficiency of 57.9%. This study also suggested that the drop of particle size, mainly caused by the overgrowth of filamentous microorganisms and disintegration of floes due to hydraulic attrition, had direct responsibility to the increasing of specific resistance to filtration (SRF) and forming of cake layer, and finally contributed to more and more serious membrane fouling.