3 Confirmatory tests
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Circulars - Marine Environment Protection Committee - MEPC.1/Circular.677 – Guide to Diagnosing Contaminants in Oily Bilge Water to Maintain, Operate and Troubleshoot Bilge Water Treatment Systems – (22 July 2009) - Annex – A Guide to Diagnosing Contaminants in Oily Bilge Water to Maintain, Operate and Troubleshoot Bilge Water Treatment Systems - Annex 4 – Detecting Particulates: Biological, Soot and Rouge (Iron Oxide Compounds) - 3 Confirmatory tests

3 Confirmatory tests

 ▸ Biological – citric acid test

▸ Rouge – citric acid test and visual examination of reddish (rouge) particles. High amounts of iron oxide compounds will cause turbidity and lack of transparency of the water sample. The sample will look characteristically rouge or red. Lower concentrations of rouge can cause what appears to be discoloration of the water without apparent turbidity. The sample will look clear, but have reddish or rouge colour. This is simply because the human eye is not sensitive enough to detect the turbidity difference at these low concentrations.

▸ Soot – citric acid followed by ERT pH test, and visual evaluation of black or brownish particles. High amounts of soot will cause turbidity and lack of transparency of the effluent sample. The sample will look characteristically brown or black. Lower concentrations of soot can cause what appears to be discoloration of the water without apparent turbidity. The sample will look clear, but have a brownish or black colour. This is simply because the human eye is not sensitive enough to detect the turbidity difference at this low concentration. Confirmation may require laboratory analysis.

Sampling Instructions

  • Take a small container and draw bilge water before OWS. (To diagnose bilge water contamination.)

    Take a small container and draw bilge water at OWS outlet. (To diagnose OWS capability to handle contaminated bilge water.)

    Take a small container and draw bilge water after post-treatment polishing and particulate filters if installed. (To diagnose post-treatment capability to handle contaminated bilge water.)


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