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.
Ozone is among the measures deployed by Östersund municipality in northern Sweden to try kill off the parasite (Cryptosporidium) which has afflicted the stomachs of thousands of residents and rendered the water undrinkable. More than 5,000 residents have taken ill after ingesting water from the city’s water supply, many suffering from diarrhea, vomiting, and severe stomach cramps.
Ozone is one of the few biocides proven to remove cryptosporidium from water at reasonable dosage levels. It also treats a wide range of other pathogens in water as part of a complete water disinfection process.
United Water completed a $100 million rehabilitation of the Haworth Water Treatment Plant including ozonation equipment. The improvements were the largest single capital investment for United Water during its 140-years of operation.
The project was driven by drinking water regulatory compliance issues. These were caused by pollution of the source water. Better protection of the reservoir would have probably resulted in a less costly solution, but the process improvements at the plant will bring the drinking water into compliance.
The upgrade included a new ozone system, which will reduce the energy needed to disinfect and remove unwanted tastes and odors from the water. Ozone is widely used in situations where both disinfection and taste/odor problems are present. The facility previously used ozone, so the investment shows that this method of water treatment worked well.