Sewage Treatment on Ships

The video tutorial explains the sewage treatment requirements for ships with 400 gross tonnage and above, engaged in international voyages and carrying at least 15 persons. It describes the sewage treatment plant (STP) fitted in the engine room, which processes black and gray water before discharge. The STP consists of three main chambers: the aeration chamber, where aerobic bacteria decompose sewage; the settling chamber, where sludge settles and clear liquid is separated; and the sterilization chamber, where the liquid is disinfected with chlorine before being discharged overboard or to a settling tank, depending on the ship's location.

What is the minimum gross tonnage for ships required to have a sewage treatment system?

• 500 gross tonnage

• 400 gross tonnage

• 300 gross tonnage

• 200 gross tonnage

Where is the sewage treatment plant typically located on a ship?

• In the cargo hold

• In the captain's cabin

• In the engine room

• On the deck

What is the primary function of the aeration chamber in the STP?

• To filter solid waste

• To sterilize the sewage

• To decompose sewage using aerobic bacteria

• To store sewage

How is air supplied to the aerobic bacteria in the aeration chamber?

• Through natural ventilation

• Using blowers and diffusers

• By manual pumping

• Through chemical reactions

What happens to the sludge in the settling chamber?

• It is burned as fuel

• It is used as fertilizer

• It is sent back to the aeration chamber

• It is disposed of immediately

What is the purpose of the third chamber in the STP?

• To store drinking water

• To collect rainwater

• To filter solid waste

• To sterilize the liquid with chlorine

What is used to disinfect the liquid in the final chamber of the STP?

• Ultraviolet light

• Ozone

• Boiling

• Chlorine

Where can the treated liquid be discharged from the STP?

• Into the captain's cabin

• Into the ocean or a settling tank

• Into the ship's fuel tank

• Into the ship's drinking water supply

What determines whether the treated liquid is discharged overboard or into a settling tank?

• The number of passengers on board

• The ship's speed

• The ship's size

• The geological position of the ship