There are many considerations to make when selecting a ballast water compliance monitoring device (CMD). You have almost certainly already considered the simplest: Does this ballast water test provide the results required by the IMO D2 standards? What about the requirements set by relevant local authorities?
In this article, we dive into a trickier factor to consider – that is whether the CMD you are using is able to accurately test water treated by the specific ballast water treatment system (BWTS) used. There are a wide variety of USCG & IMO Type Approved BWTS in ships, and the different treatment types use methods ranging from chemical injections to ultraviolet (UV) light disinfection.
No chemicals, therefore no risk of interference between CMD and BWTS methods
When using a chemical-based CMD, you could need to be aware of potential Ballast water CMDs based on chemical reactions are for example ones using ATP or FDA methods. It is unknown whether there is interference between these chemicals.
However, it is possible to test ballast water compliance without adding any chemicals at all. In which case, you can be certain the test is not affected by any chemicals used for the ballast water treatment. One CMD without chemicals is BallastWISE, which instead uses a visual method for tracking movement of live organisms, much like an automated form of microscopy.
Fluorescence-based CMD after treatment with UV BWTS
With regards to testing compliance of ballast water that has been treated with UV light, you must consider compatibility with active fluorescence-based CMDs. Therefore, some ballast water testing methods, such as FDA, require longer holding times before they can be used.
These damaged organisms’ fluorescence will, however, be lower compared to healthy cells. BallastWISE takes this into account by only including organisms with active fluorescence over a certain threshold in the counts reported. Cells with a fluorescence below that threshold are damaged by UV treatment and are not considered viable.
We hope this helps you. Have any questions? Feel free to reach out
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