A circular settling tank with diameter d, water depth H, and hourly sewage inflow Q features a detention time equal to________________?
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Answer: A. d² (0.011d + 0.785H)/Q
Explanation
Hydraulic design formulas for circular settling tanks relate diameter, depth, and inflow to determine detention time. Calculating surface area and liquid volume yields the precise mathematical expression for holding duration. The derived equation integrates tank geometry parameters with volumetric flow rates to evaluate performance. Circular sedimentation tanks utilize radial or central feed mechanisms to clarify wastewater flows. Detention time represents the average duration liquid remains inside the clarification basin. Mathematical modeling of settling basins ensures effective removal of suspended solid particles.
Environmental engineers use settling tank equations to size wastewater treatment plant clarifiers. Proper hydraulic design prevents short-circuiting and ensures adequate solid-liquid separation. Municipal design standards require specific detention times to achieve regulatory effluent quality. Option B features incorrect coefficients that fail to match standard circular tank volume geometry. Option C alters the placement of diameter and depth variables, producing erroneous hydraulic results. Option D contains incorrect numerical constants that deviate from standard settling tank formulas.
- Subject
- Engineering
- Category
- Civil Engineering
- Topic
- —
- Difficulty
- medium
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