The effects of particulates on the ultrafiltration of bilge (oily) wastewater containing new or used lubrication oil.

Abstract

As a result of increasing environmental regulations, navies and the marine industry have been required to install effective Oily Water Separation (OWS) systems capable of providing an effluent containing no more than 15 parts per million (ppm) oil and grease. However, due to the complex nature of bilge water it has proven difficult to develop a system capable of achieving these environmental standards while also addressing the marine constraints of compactness, robustness and automation. This work has investigated the particulate loading of bilge water and the impact of its various components on the effectiveness of a membrane based treatment system. Additionally, various means of minimizing the decline in trans-membrane flux associated with the particulate loading of bilge water were examined. Pilot scale testing was performed to better simulate shipborne conditions. Two membranes were tested: a ceramic membrane with a pore diameter of 0.005 microns and a polyacrylo nitrite membrane with a Molecular Weight Cut-off of 50,000 Daltons. The average run lasted 24 hours and the membranes were cleaned after each run. Backflushing was tested as a means of trans-membrane flux enhancement. (Abstract shortened by UMI.)