MARCH 9, 2016 — In MARPOL Special Areas such as the Baltic Sea, ships will soon be required to remove nutrients like nitrogen and phosphorous before returning water to the sea.
To met these requirements, the two new LNG fueled ferries on order for Sweden's Rederi AB Gotland at China's Guangzhou Shipyard International (GSI) (see earlier story) will be equipped with a range of Evac equipment.
Each vessel will carry about 1,700 passengers and crew and will be equipped with two membrane bioreactors (MBRs), solids screening, 233 vacuum toilets, two buffering tanks, two macerating food waste feeding stations, and one bone shredder.
Each MBR unit is also equipped with a nutrient removal system.
Evac Product Manager Mats Riska says that in the past wastewater treatment was viewed as "one more piece of mechanical equipment on board."
But due to compliance requirements for wastewater treatment, all that has changed.
"Nutrient removal is a complicated biological and chemical process," says Mr.Riska. "Thanks to Evac's systems this process can be fully automated so that only a basic process understanding is required from our customers."
As not all vessels are destined for SA waters, and because not all shipowners demand it, nutrient removal is not standard on Evac MBR systems. But because compliance regulations will require it in the future, all Evac MBR systems are built to allow an easy upgrade to nutrient removal.
"Our standard MBR is easy to retrofit to meet compliance requirements, with nutrient removal supplied as a one skid installation," says Mr. Riska.
Factoring in future compliance costs, an Evac MBR with upgrade capability makes Evac MBR systems the most competitively priced on the market. "It's much more cost effective to upgrade than to do a full retrofit," says Mr. Riska.
Another feature found on the Rederi AB Gotland vessels' MBR units is a touchscreen control panel.
"We gave a total facelift to our MBRs at the beginning of 2015," says Riska. "We went from mechanical switches to a touchscreen with a great user interface. Rederi AB Gotland will be using the first ones we've shipped."
The touchscreen system offers data logging for all parameters. The user can check process values, and make log data available to Evac for easy service.
Huang Sheng Ming, the Guangzhou Shipyard International (GSI) piping engineer responsible for the design management work on the two vessels, is charged with signing technical agreements with systems makers like Evac.
Nutrient removal is an area of growing concern to Mr. Huang.
"Nutrient removal is a requirement for the near future," he says. "MBR and nutrient removal is our first contact, and with this trend we're still in the learning stage. But by working with Evac, we are slowly getting to know the rules and the importance of MBR."