The domestic sewage of ships mainly includes bathroom sewage, kitchen waste water, and laundry waste water. The marine domestic sewage treatment device (biochemical method) is used to treat sewage from the toilet sewers to meet international discharge standards and to be discharged outboard. It can also be used as a disinfectant for greywater on board (refers to galley washing water, bathroom bath water, toilet water and washing machine drain water, etc.).

The biochemical marine life sewage treatment device (marine domestic sewage treatment system) adopts biological contact oxidation and physical treatment disinfection principles to treat the domestic sewage of ships. It consists of five cabinets: aeration cabinet, contact oxidation cabinet, settling cabinet, and disinfection cabinet. In the aeration cabinet, activated sludge bacteria mainly composed of aerobic bacteria form a cotton-like floc with sticky flocculant to adsorb organic substances and become harmless carbon dioxide and water under the conditions of oxygenation, and active pollution at the same time. Mud is propagated; soft fillers are hung in the contact oxidation cabinet to serve as biofilms, and organic matter is further digested; the activated sludge deposits accumulated in the precipitation cabinet are returned to the aeration cabinet for bacterial propagation and reprocessing. The sewage that has been treated by the sinking and sinking process is finally sterilized with a chlorine-containing drug in a sterilizing cabinet and then discharged by an exhaust pump to the outboard side.

The maintenance of marine sewage treatment equipment, and the protection of the pump, motor and electric box are very important.