Our products

We deliver biological waste water treatment solutions for the maritime industry. We can treat both grey and black water before it is let out into the ocean. Our bioreactors live up to all rules and requirements, securing you operational flexibility while you protect marine eco systems where you operate.

What is grey and black waste water?

Grey water

Grey waste water from the vessel is all the water that comes from sinks, showers, cleaning, cooking etc.

Black water

Black waste water from the vessel is all the water that comes from toilets and medical treatments.

We have a solution for any challenge


We have the needed approvals and live up to all requirements in order to deliver to navies around the world.


Our systems can be delivered with all special features required offshore e.g. EEX/ATEX approvals.

Passenger vessels

We have systems that live up to and exceed the strictest requirements from IMO including those for passenger vessels and special areas.


We are experienced in custom building bioreactors and fit them into even the tightest spaces on existing vessels.

We deliver two types of bioreactors

Conventional bioreactor

Biological cleaning – removing E.coli

The bioreactor is a 100% biological treatment system, which uses a fixed biofilm combined with UV treatment for a sustainable solution. The system can handle all grey and black water from any vessel or offshore facility with no need for filters, dilution or chemicals during normal treatment.

This system lives up to IMO requirements.

Advanced bioreactor

Biological cleaning – removing E.coli, phosphorous, nitrogen and microplastic

With the advanced bioreactor, it is possible to go beyond regulations to protect the environment. It is a biological process in combination with a unique membrane treatment. In addition to this, phosphorous and nitrogen is removed, thereby living up to the rules for special areas in MEPC 227(64). The advanced solution is for those who face the toughest challenges, including cruise ships in protected waters and ship owners with an ambitious environmental agenda.

This system exceeds the strictest IMO regulations.

We can deliver auxiliary solutions or connect with existing systems

Grease separating units

A well dimensioned grease separation is essential for a well functioning water treatment system for both black and grey water. Besides reducing the organic load of the treatment plant, it also prevents grease from building up in the vessel tanks and piping.

Vacuum collection solutions

The majority of our treatment systems are delivered with a G&O vacuum collection integrated into the system control and structure.

Sludge handling solutions

Sludge handling procedures will become a requirement in future marine regulations. We can dewater the sludge to minimise the volume of tanks required for storing sludge, returning water to the sewage treatment plant for processing before discharge.

Sludge can be incinerated or disposed as solid waste.

Customer case

A2SEA Challengers story

Off the mainland coast, an offshore construction vessel, A2SEA’s Sea Challenger, found itself to have met the capacity of its biological sewage treatment plant. A four-month project caused an increase in personnel on board the vessel and meant a quick solution for waste water treatment was needed.

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