Assessment of the Environmental Safety of the Ship Ballast Water Treated by Ozone

The aspects of purification of discharged ballast water from non-indigenous species of microorganisms in ballast water by the ballast water management systems (BWMS) installed on ships are considered. As a method of water treatment, the technology chosen is to influence the microorganisms with gaseous ozone introduced into the flow of ballast water when it is received onto the ship. A design diagram for a prototype BWMS unit for treating the ballast water during intake and deballasting has been developed. The results of studies of the prototype on the inactivation of microorganisms in water of various salinities (0, 18 and 36‰) are presented and its effectiveness is shown. Biotesting methods were used to assess the toxicity of ozone-treated waters. Using organisms of three trophic levels, it was shown that water neutralized using this technology is not toxic and can be discharged into a receiving reservoir.