Veolia reverse osmosis (RO) systems are on some 15 ships for Carnival, Aida and Costa, according to Andreas Rosebrock, special projects manager.

He noted that while most RO suppliers use the same standards of membrane, Veolia has developed its own pre-filtration disk-filter system replacing the typical media and multi-media filters.

“Our disk filter operates at 20 micrometers, which makes it equal to or better than media filters, and it’s more compact, fully automated, has a smaller footprint and weighs less. We have been using this technology for the past 10 years, also for our ballast water treatment system.

“We guarantee the performance of our RO system from 1 to 32 degrees Celsius seawater temperature,” Rosebrock continued. “In Arctic conditions, if there are ice crystals in the water, we recommend preheating, using low-level waste heat on the incoming water, which protects the membrane and also reduces the overall power consumption of the RO.”

Veolia’s cruise ship installations are rated at 100 to 500 tons of water per day per unit, and they can be scaled up, according to Rosebrock, who said there are no limits. The company has built units for up to 10,000 cubic meters of water per day and more for land-based applications.

“Our systems can be equipped with energy recovery technologies,” he added, “including hydrostatic pressure exchangers, bringing the overall specific power consumption down to below 3 kilowatt hours per cubic meter of water.”

At Veolia’s plant in Germany, RO systems are pre-assembled and shop-tested, Rosebrock explained, thus reducing the amount of commissioning work at the shipyard.