Realtime Monitoring of Ballast Water with Flow Cytometry

Project summary

IMO's ballast water convention entered into force in September 2017, and instructs all ships to purify their ballast water prior to discharge. This to reduse the spread of potentially invasive species via ships ballast water. Knutsen OAS Shipping AS has therefore developed their own ballast water treatment system, called KBAL. KBAL combines pressure vacuum technology with UV irradiation for ballast water disinfection. KBAL is type approved by IMO, and was initially installed onboard M/T Gijon Knutsen. The main aim of the BallastFlow project has been to improve KBAL's competetivness nationally and internationally. The type approval and the sale of KBAL systems to new vessels are important steps in this regard.

Analysis and monitoring of purified ballast water is important for several bodies, including: (I) Port state control for compliance control; (II) Producers of ballast water treatment systems for improvement and monitoring their systems; (III) Shipping industry for self-control before ballast water discharge.

The BallastFlow project has developed new methods for ballast water analysis based on flow cytometry. This ensures rapid information about compliance, which is important to further develop KBAL and for control of KBAL. We have mainly focused on UV-treated ballast water, since KBAL uses UV-technology.

Our studies has focused on development of new analysis methods for treated ballast water, by studying the connections between UV-dose and vitality, as well as vitality over time after irradiation. As an indicator organism we have used Tetraselmis suecica, a robust microalge that can easily be grown under laboratory conditions. In addition to rapid results, flow cytometry has the possibility to combine with stains for live/dead-detection.