Evac’s EcoOcean moving bed bioreactor (MBBR) is a biological wastewater treatment system that delivers effluent quality for cruise ships, exceeding the most stringent marine standards and at the lowest lifecycle cost, according to Toni Saira, product manager.

“Our MBBR can efficiently treat any blend of marine wastewater streams, including black and gray water from cabins, galley food wastewater and laundry facilities,” said Saira. “The maximum design capacity is 120 cubic meters per hour.”

He said that typically the share of black water in a mixture to be treated is 5 to 10 percent and about 90 percent is gray water. This will result in 98 to 99 percent clean water and 1 to 2 percent sludge, with the sludge going into holding tanks.

Most of the effluent is discharged into the ocean. However, some of the clean effluent is also used for de-foaming and as washing water of the different units of the wastewater treatment equipment.

Saira said that the EcoOcean MBBR is designed for ships with more than 3,000 people onboard.

Smaller vessels can be outfitted with Evac MBR plants, which also have Rhine River certification and U.S. Coast Guard- type approval.

Other system features include low operating costs due to efficient dissolved air floatation and low chemical consumption, and the single-pass process, which means that no return-activated sludge stream is required.