Sweden: Ballast purification treatment technique passes initial test program

BenRad Marine Technology's new ballast purifier prototype system is going through its paces at a test facility in Gothenburg harbor, Sweden.

Th 120172

Jennifer Pallanich Hull
Special Reports Editor

BenRad Marine Technology's new ballast purifier prototype system is going through its paces at a test facility in Gothenburg harbor, Sweden. Process inventor Professor Rune Söremark said this prototype is the company's first system developed specifically to purify ballast water. Performance tests have been carried out within the European Union's onboard treatment of ballast water project, Martob, spearheaded by Newcastle University in the UK. Initial operational tests have yielded good results, with 800 cu m/hour pumped through hydraulically, according to Peter Svensson, BenRad Marine's technical support manager.

Th 120172
BenRad Marine has installed this plant on a passenger cruiser to purify condensate water from the A/C plant for use in the laundry.
Click here to enlarge image


Following the tests, the BenRad Marine prototype system will be installed in one of the Wallenius vessels during February-April. Wallenius Lines is a sister company to BenRad Marine Technology.

"All the major tests for the new ballast system will be on our own ships," Svensson said.

Bacteria into H2O and CO2

BenRad Marine's fully automatic water purifier eliminates microorganisms and other organic matter. The company's patented advanced oxidation technology combines ozone and ultraviolet (UV) systems with different wavelength spectra, and one or more catalysts. In this combination, ozonolytic, photolytic, and photo catalytic redox processes operate simultaneously within a reactor. The result is large amounts of radicals, mainly hydroxyl (OH) radicals, generated within the reactor.

These radicals destroy and eliminate microorganisms; unlike strictly UV systems, microorganisms cannot re-grow because everything decomposes into carbon dioxide and water. The UV light, which has a 9,000-hour life expectancy, breaks down any generated ozone immediately to form OH radicals. The radicals take electrons from contaminant molecules, starting a chain reaction that stops only when everything decomposes to water and carbon dioxide.

Th 120171
A sieve and a filter take away everything larger than 100 microns in the water entering the ballast water purification system. Three processes work in parallel inside the reactor to produce radicals. The titanium purifiers have no moving parts, and the energy consumption and operation costs are low for the units. The modular units can be placed in parallel to accommodate larger flows of water.
Click here to enlarge image


No chemicals are used in the process, and no byproducts are formed during water treatment. The OH radicals generated in the titanium reactor have a lifetime of a few nanoseconds, so no radicals remain in the water exiting the purifying unit.

Ballast water

danger prevention

BenRad Marine formed its ballast water treatment process in response to what has become known as the ballast water problem. Invasive marine flora and fauna transported from one region to another have threatened native marine ecosystems. Ships' ballast water, at an estimated rate of 10 billion metric tons a year, transports marine species from their native environs. When discharged into new waters, they may become invasive, disrupting the ecology in the area.

"That is a tremendous problem," Söremark said.

Th 120173
Click here to enlarge image

The new process can be used during both ballasting and de-ballasting, i.e., water must be run through the purifier system before the ballast water is returned to the ocean, Svensson said. The process also reduces corrosion in ships' ballast tanks, he claimed, by limiting the amount of oxygen and by eliminating bacteria.

Other applications

The water purifying process can also provide usable water offshore for tasks ranging from injection to laundry, to showers and use of gray water for cleaning the decks. Existing water running through the purifying system is less expensive for these jobs than producing "new" water through a desalination plant, Svensson said.

For more information contact Patrick Dahl, BenRad Marine Technology. Tel: +46 8 772 05 88, fax: +46 8 772 07 88, email: patrick.dahl@benradmarine.com, website: www.benradmarine.com.

More in Home