In a rectangular basin, which type of collector uses suction pipes or submersible pumps for sludge withdrawal?

• A. Floating-bridge siphon collector
• B. Chain scraper
• C. Submersible pump collector
• D. Gravity collector

Answer: (A)

In the context of sludge withdrawal from a rectangular basin, the type of collector that utilizes suction pipes or submersible pumps is indeed the floating-bridge siphon collector. This method employs a system where suction is created to remove sludge, which is particularly effective for maintaining the cleanliness and efficiency of water treatment operations.

The floating-bridge siphon collector operates by having a floating structure that adjusts with the water level, allowing for continuous and effective collection of sludge. The suction pipes are typically positioned below the water surface to draw in the sludge without significantly disturbing the treated water above. This design helps in minimizing the resuspension of solids and ensures that the sludge is systematically removed.

Other options may involve different mechanical processes or gravity-fed systems, but in terms of suction and submersible pump usage specifically for sludge removal, the floating-bridge siphon collector is the suitable choice due to its operational efficiency and effectiveness in handling variable flow conditions in the basin.