What is the maximum weir loading for light alum floc in solids-contact basins?

• A. 5 gpm/ft
• B. 10 gpm/ft
• C. 15 gpm/ft
• D. 20 gpm/ft

Answer: (B)

The correct choice indicates that the maximum weir loading for light alum floc in solids-contact basins is 10 gpm/ft. This is an important operational guideline in water treatment processes, particularly for maintaining effective flocculation and sedimentation.

Understanding the maximum weir loading is critical because it directly impacts the efficiency of the solids-contact basin. If the loading exceeds this limit, it can lead to poor separation of solids from the water, resulting in higher turbidity levels in the effluent and potential violations of water quality standards. Adequate weir loading ensures that the floc remains buoyant and can successfully adhere to and settle with other particles, enhancing the overall treatment efficiency.

Choosing the wrong maximum loading could compromise the coagulation process; thus, recognizing that a value of 10 gpm/ft provides a safe operational threshold is essential for proper system function and water quality management. Knowing these parameters helps operators design and adjust treatment processes in a way that optimizes performance and meets regulatory requirements.