Handling wastewater on larger ships is becoming an increasing challenge due to tighter environmental legislation and customers’ growing demand for green solutions. Danish JD-Contractors, which operates several large ships, has experienced significant problems with their maritime purification systems.

Bjarne Sørensen, Marine Superintendent at JD-Contractors, says:

“On our ship CABLE ONE, we had two purification systems worn out after just a few months of use. The combination of chlorination and saltwater for toilet flushing caused leaks in the steel tanks, resulting in unpleasant odors on the ship.”

In 2023, Bjarne Sørensen contacted Gertsen & Olufsen Bioreactors. Instead of merely providing a quote, Thomas Højbo Hansen, Head of Sales at Gertsen & Olufsen Bioreactors, visited JD-Contractors.

“We went to inspect the ship and talked to the crew to understand the project,” says Thomas Højbo Hansen. The visit was important to identify the specific requirements and challenges faced by the ship and crew.

Development of a customized solution

Gertsen & Olufsen Bioreactors took these challenges seriously and designed a customized solution:

“We proposed a solution with fresh water for toilet flushing and our bioreactor system. Freshwater is less corrosive, and our unique bioreactor ensures optimal biological degradation of the wastewater,” says Thomas Højbo Hansen. The solution was tailored to the ship’s needs, including space optimization for cable storage, which is critical for operations on a cable-laying ship like CABLE ONE.

The system is designed to treat 3,700 liters of wastewater per day, which suits a crew of approximately 20 people.

Switch to a more environmentally friendly solution

A key feature in the new solution was the switch from chlorine to UV light for disinfection. The UV disinfection system is effective at eliminating pathogens like E. coli without use of chemicals, reducing the risk of corrosion in the system and impact on the marine environment.

UV treatment is supplemented with aeration and bacterial degradation, resulting in a residual product with minimal environmental impact, which complies with the IMO’s emission standards for ships regulated by the UN.

“We are increasingly measured on our environmental footprint by customers. The switch to biological purification supplemented with UV light shows that we are committed to our green profile,” says Bjarne Sørensen.

Fast implementation process

The implementation process proceeded smoothly and quickly, thanks to the close collaboration between G&O Maritime Group and JD-Contractors.

“Once JD-Contractors approved the design, we began production. Bjarne came to inspect both the welding of the tanks and the painting work,” explains Thomas Højbo Hansen. JD-Contractors were involved throughout the process, ensuring a high degree of transparency and satisfaction.

The quick delivery and implementation were crucial for JD-Contractors, as it is important that their ship is not at the dock for a long time. The entire process took only a couple of months.

“We constantly try to keep the ships operational, both for planned tasks and those that come up. Repair time should not take longer than necessary,” says Bjarne Sørensen.

Advantages of local production and support

One of the significant advantages of choosing Gertsen & Olufsen Bioreactors was the level support and documentation. Bjarne Sørensen notes: “It is definitely easier for us to work with a supplier in nearby. We can visit each other, and we received good documentation in the form of technical drawings, specifications, and thickness measurements, as well as reports and documentation of electrical and control systems. We probably wouldn’t have received the same high service from other suppliers.”

The new bioreactor solution from Gertsen & Olufsen Bioreactors has been a success for JD-Contractors. The customized approach, focus on environmentally friendly solutions, and close customer dialogue have ensured that the ship now has a reliable solution that meets today’s requirements and is ready for future challenges.