Effect of Particulate Size on Membrane Performance in Bilge Water Treatment Systems


  1. Nottegar, M.
  2. Tremblay, A.Y.
Corporate Authors
Ottawa Univ, Ottawa ONT (CAN) Dept of Chemical Engineering;Defence Research Establishment Atlantic, Dartmouth NS (CAN)
Environmental regulations now preclude all ships, including naval vessels, from the direct overboard discharge of bilge water, primarily owing to hydrocarbon contamination. Acceptable limits for hydrocarbon contamination levels for overboard discharge in various areas have been establishment. However, due to the complex composition of bilge water and onboard restrictions, including available space and ship's motion, the identification of purification systems that can produce discharge fluids which meet these new acceptable low limits of contamination is extremely difficult. Many different types of systems have been tried, including coalescers and parallel plate separators, but all have problems purifying the discharge to the new low levels of contamination required. Membrane based systems can surmount these difficulties and provide an effective onboard bilge water treatment system. A major factor affecting the quality and quantity of a membrane's permeate is the presence of emulsified oil and particulates in bilge water. Specifically, emulsions and particulates in the 0.01 to 0.1 micrometer size range accumulate readily at the surface of the membrane. In this range, particles are too large to back diffuse and too small to be swept away from the surface of the membrane. They accumulate in a layer on the surface of the membrane and greatly reduce its flux. TRUNCATED
Bilge water
Report Number
DREA-SR-1999-162-PAP-12 — CONTAINED IN CA000150
Date of publication
01 Oct 1999
Number of Pages
Hardcopy;Document Image stored on Optical Disk

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