A device that causes the wastewater in a vertical riser pipe to rise to an outlet using compressed air is called an

A device that causes the wastewater in a vertical riser pipe to rise to an outlet using compressed air is called an

• A. Air lift pump
• B. Siphon pump
• C. Submersible pump
• D. Centrifugal pump

Answer: (A)

Air lift pumps move wastewater by using compressed air injected at the bottom of a vertical riser. The air forms bubbles that mix with the liquid, lowering the overall density of the gas–liquid mixture. Because this lighter mixture is buoyant, it rises up the riser to the outlet, where the air disengages and escapes, and the liquid continues to flow out. This simple setup is useful in wastewater handling where you want to lift sludge or slurry without a submerged mechanical pump. This approach is different from a siphon, which relies on gravity and atmospheric pressure rather than injected air, and from submersible or centrifugal pumps, which use impellers and mechanical movement rather than buoyancy from air bubbles.

Air lift pumps move wastewater by using compressed air injected at the bottom of a vertical riser. The air forms bubbles that mix with the liquid, lowering the overall density of the gas–liquid mixture. Because this lighter mixture is buoyant, it rises up the riser to the outlet, where the air disengages and escapes, and the liquid continues to flow out. This simple setup is useful in wastewater handling where you want to lift sludge or slurry without a submerged mechanical pump.

This approach is different from a siphon, which relies on gravity and atmospheric pressure rather than injected air, and from submersible or centrifugal pumps, which use impellers and mechanical movement rather than buoyancy from air bubbles.