Gerold-Janssen-Straße 2
28359 Bremen, Germany
Phone: +49 421 53705 - 0
Fax: +49 421 53705 - 440

Biological sewage treatment

Sewage Treatment onboard every ship in accordance with MEPC-227(64)

Sewage treatment with no efforts

Clean Sewage

CleanSewage Bio is designed to put all efforts with wastewater treatment to the lowest level possible. The accessibility from one side allows ship designers to plan space in the engine room on a whole new level.

Operators and crew are pleased with a hygienic no-touch-cleaning system, an intuitive status control allows checking at a glance, whether the system is running or intervention is necessary. Thereby CleanSewage Bio works with a proven 3-chamber-treatment concept that ensures highest water quality according to MEPC.227(64).

Main Advantages

CleanSewage Logo


  • Integrated mechanical pre-treatment
  • no harmful or flammable chemicals
  • Certified by German Authority BG Verkehr

Easy to operate

  • No-touch-system for hygienic sludge discharge
  • 100% control through individual switches for every aggregate
  • Integrated high-quality PLC


  • No holding tank necessary
  • Up to 25% less space demand through unique one-side access
  • Considerably low maintenance-space

Suitable for both black & grey water

Compatible with all vacuum systems

How it works

RWO CleanSewage Bio works with a 3-chamber process. The three different steps are described below the scheme.

CleanSewage How it works

The working principle of CleanSewage Bio

In the Moving-Bed Biofilm Reactor (MBBR) organic matter is degraded into carbon dioxide and water by microbial activity. Biofilm carriers inside are fixed in cages, which significantly eases handling and maintenance. Aeration stabilises the biomass and prevents harmful and dangerous gases from forming.

In the Clarifier compartment residual solids are separated by sedimentation and returned back into the Bioreactor compartment. The treated wastewater flows into the Disinfection chamber.

Here a chlorine-based disinfection chemical is added. The clean water then is pumped overboard. To meet the limit values set for the chlorine content, a special neutralising agent, LC35, is dosed prior to the discharge pump.

Treated excess sludge, reduced in volume, can be discharged or collected in an external tank. Due to the biomass retained by the MBBR process, sludge discharge does not interfere with the performance of the plant.