Evac EcoOcean
Moving bed bioreactor biological wastewater treatment systems

Evac MBBRs  (moving bed bioreactors), biological wastewater treatment systems, deliver effluent quality for cruise ships and other vessels that exceeds the world’s most stringent marine discharge standards with the lowest life cycle costs in the industry.

The moving bed bioreactor process is certified according to IMO MEPC.159(55) and MEPC.227(64) regulations . This means that the process fulfills the requirements of the amendments to MARPOL Annex IV in MEPC.200(62) for passenger ships in restricted areas, such as the Baltic Sea and Alaska.

Incorporating proven components and a patented process, the Evac MBBR wastewater treatment system delivers environmental performance specifically designed to meet the tough demands of long-term shipboard operation. Every MBBR system is customized for the vessel in question to ensure optimum functionality. The Evac MBBR process can efficiently treat any blend of marine wastewater streams, including black and gray water streams from cabins, galleys food waste reject water, and laundry facilities. An optional nutrient removal module is also available if MEPC 227(64) §4.2 limits are required by a shipyard or a ship owner.

A significant advantage of the Evac MBBR process is its ultra-low annual chemical consumption, which reduces operating costs and the need to store and handle chemicals on board space-constrained vessels.






  • Compact design with small footprint
  • Fully automatic operation with minimal operational and maintenance requirements
  • Low operating costs due to highly efficient dissolved air floatation (DAF) and ultra-low chemical consumption
  • Easy to expand capacity by increasing the fill fraction of the biofilm carriers
  • Single-pass process means no return-activated sludge stream is required
  • Actively sloughed biofilm automatically responds to load fluctuations
  • No food-to-mass (F/M) ratios or mixed liquor suspended solids (MLSS) levels to maintain
  • Excellent effluent results
  • Long lifetime of equipment

Marketing material

  • Evac EcoOcean MBBR leaflet

    Type: Leaflet Language: English Industry: Marine

  • Without limitations: Evac MBBR

    Type: Article Language: English Industry:

Operating principle of Evac MBBR

The treatment process consists of the following phases:

Primary screening

The next stage is the removal of coarse solids and debris from the wastewater using a rotating drum. The screening unit incorporates an automatic spaying system that ensures the screen surface remains clean and free of solids build-up.

Influent mixing

Collecting and blending the influent waste streams in a mixing tank and equalizing the flow and load to the bioreactors is an important process in the MBBR system. The gray water collection system discharge pumps are controlled to optimally blend the wastewater.


The MBBR process is based on the biofilm principle using polyethylene carrier elements. The carrier elements are less dense than water and provide a large protected surface for bacteria culture. Bacteria degrade the organic matter in the wastewater to produce clean water, carbon dioxide, and sludge. The biofilm thickness is maintained and controlled through continuous sloughing created by the aeration mixing process.

Dissolved air flotation (DAF)

Following the MBBR process, DAF removes the sludge by dissolving air in the water under pressure and then releasing the air at atmospheric pressure in a flotation tank. The released air forms micro bubbles that adhere to the suspended matter, causing it to float to the surface of the water where it is removed with mechanical paddles.

Tertiary filtration

The tertiary polishing system provides a positive barrier to ensure that the total suspended solids discharge requirement is met in higher-than-normal loading events. The polishing filter is a compact filter system with an automated backwash cycle.

Ultraviolet (UV) disinfection

UV light is used to disinfect the treated wastewater in high-intensity, low-pressure, multi-lamp UV reactors. No cleaning chemicals are needed since the reactors are equipped with automated wiper mechanisms that automatically clean the quartz sleeves. The multiple-lamp configuration provides redundancy to ensure that sufficient levels of UV radiation are maintained even if a lamp fails.

Only available for the marine industry customers.

See our other wastewater treatment solutions suitable for your industry.

Wastewater treatment systems


Only available for the marine industry customers.

See our other wastewater treatment solutions suitable for your industry.

Wastewater treatment systems


Related products

Evac Optima 5

Advanced vacuum toilets

Read more
Evac EcoVac

Vacuum tanks

Read more
Evac MBR

Membrane bioreactor, biological wastewater treatment systems

Read more
Fresh water generation systems

Custom-made reverse osmosis desalinators

Read more
Evac cyclone incinerator

Advanced waste handling

Read more
Evac food waste management system

Collection and treatment

Read more