Wastewater management and treatment onboard ships is a complex problem. Oily bilge water, black water and grey water have different characteristics and require different treatment technologies. This approach complicates the crew’s job, increasing the overall knowledge required to properly operate and maintain each unit.  

WETT is a novel wastewater treatment technology based on a highly effective electrochemical approach that adapts to different wastewaters to be cleaned.  The core treatment process employed is a proprietary self-cleaning ElectroCoagulation (EC) unit. Pre-treatment and polishing units are added to the process, as needed. For highly contaminated streams, the EC unit is followed by a Boron Dopped Diamond (BDD) based electrochemical oxidation unit that provides further treatment and full disinfection of the treated water.  

WETT does not require heating, filters, membranes or polishing adsorbent media. Therefore, it requires significantly less maintenance than many other commercially available treatment systems, while being effective, compact and robust. Its operation requires only small amount of electricity and inexpensive aluminum plates that need to be replaced every few months. 

The WETT technology performance for treatment of oily bilge water and mixed black water and greywater was evaluated onboard of CCGS Earl Grey. A WETT-O unit for treatment of bilge water was installed in October 2019, and a WETT-S unit for treatment of black and grey water, in January 2023. Following an excellent collaboration between the Terragon and CCG teams, the units were easily installed onboard during refit periods. The systems were commissioned and the crews received extensive training on operation and maintenance of the technology.  

The WETT-O and WETT-S units are constantly able to treat the wastewater generated onboard, with effluent quality exceeding discharge requirements. System improvements were also performed during the testing period.