A.P. Moller-Maersk (Maersk) has indicated that ballast water treatment system (BWTS) based on mechanical filtration and disinfection with UV and ozone represents a good solution for container vessel retrofits. Both ozone water treatment and UV are excellant disinfection technologies for a wide range of applications.
Maersk says that the containerization of the BWTS is a viable way of overcoming space problems in crowded engine rooms as well as it gives the advantage of easy and short installation time.
The system works in fresh, brackish, or salt water and can provide flow rates up to 500 cubic meters per hour in a 20-foot container or and up to 3,000 cubic meters per hour in a configuration with two 40-foot containers placed on top of each other.
The International Maritime Organisation (IMO) has called on ship owners to adopt treatment technologies to prevent the spread of invasive species, although the 2004 convention on the issue has not yet received enough support to go into force.
Maersk Line is the global containerized division of the A.P. Moller – Maersk Group. The first Maersk Line vessel sailed in 1904 and has become the world’s largest ocean carrier.
In previous posts we have noted work on the use of ozone in ballast water treatment. IMO rules will require ships to treat ballast water to prevent the transport of invasive species across the globe. As an example of invasive species brought to the US via ballast water are zebra mussels.
The new rules will require the use of ozone, UV or other chemicals to treat the water. The US EPA ETV project has already identified ozone and UV as viable technologies. Currently, a few hundred ships have been equipped with such systems including ozone water treatment systems, but in the next decade over 50,000 systems will be needed at a cost of up to $1,000,000.
To be accepted for this application, manufacturers need to pass IMO certification for their systems. An expensive and time consuming process that can cost millions of dollars. Many ozone generator manufacturers and others are aggressively pursing this course.
If ozone becomes the primary biocide for this application, it is likely to be the largest single application for ozone.
Ozone News recently reported about the EPA ETV (Environmental Technology Verification) program for ballast water. the program does not approve or endorse technologies, but simply provides objective data on various technologies so stakeholders can evaluate the technologies themselves.
As noted in previous posts, there are concerns that ballast water may allow invasive species to move from one body of water to another via ships. Ozone has been proposed as one of the treatment technologies for this application because it is a well know and effective disinfecting agent.
The EPA program (www.epa.gov/etv) began in June 2011 with land based testing protocols. Sea based testing will follow. The protocol includes the organisms to be tested. For ozone based technologies brackish and non-brackish water must be tested.
The testing will take place at three testing centers: Great Ships Initiative (Superior, WI), maritime Environmental Resource Center (Chesapeake Bay, MD) and Golden Bear (San Francisco, CA).
The testing will include: biological treatment efficacy, O&M issues, cost factors, environmental acceptability and safety. the process must be able to treat 200 m3 in one hour.
Mitsui O.S.K. Lines, Ltd. (MOL) announced that an ozone-based ballast water treatment system earned a certificate of compliance from the Japanese government. The system was audited based on guidelines set out in the International Convention for the “Control and Management of Ships’ Ballast Water and Sediments (G8),” adopted by the International Maritime Organization (IMO).
Certification required a full-scale on-land test of the system and an onboard test. Both tests verified the system’s complete conformity to the ballast water treatment standard. The system also acquired the final approval under the “Procedure for Approval of Ballast Water Management Systems that Make Use of Active Substances (G9)” by the IMO.
Ozone is an extremely powerful biocidal agent that is produced on site by electric discharge using air. The ozone is mixed with the water to be treated and the micro organisms are killed by oxidation.