Ankron Water Services GmbH keeps up to date with BWMS regulations and latest progressions. One of the current topics of interests is commissioning testing and the methods for its evaluation. As per BWM.2/Circ.42/Rev. 1 indicative tools (see Table 1 for overview of 10-50 µm indicator) can be used to determine whether a ballast water treatment system is performing properly during commissioning.
Therefore, Ankron Water Services is performing a survey with various indicative tools. This time Turner Designs Ballast-Check 2 was tested.
Untreated ballast water was collected upon uptake and treated ballast water during discharge. The samples were analyzed with one indicative method and compared to the lab method MPN (most probable number) and a Pulse-Amplitude-Modulation fluorometer measurement (PAM). The ballast water was treated with a low-pressure UV based treatment system. The performance of the Turner Designs Ballast-Check 2 can be seen in Table 2.
In order to be compliant with the D-2 discharge standard the number of viable organisms in the size range 10-50 µm has to be below 10 org/mL. The risk estimation of indicative tools gives an indication whether this threshold was met. Therefore, indicative methods are a great tool for a quick scan of the sample, but it should be noted that they won’t give an actual number of organisms in the sample. For that reason, they cannot be used for type approval shipboard tests but for quick evaluation during start-up of a system or inspection by port state control.
The results of the Turner Designs Ballast-Check 2 were in accordance with the lab method and the PAM measurement in 5 out of 6 trials. The uptake of test 3 represented a special challenge since the sample was taken during wintertime while algae activity was low and therefore more difficult to detect. The tested tool is also easy to use, robust, transportable and gives a result within a few minutes.
written by Dr. Claudia Dreszer