\[SOR=\frac{Q}{A}\]
Variables
SORsurface overflow rate (m³/m²·time)
Qflow rate (m³/time)
Aclarifier surface area (m²)
Description
What is this formula?
Surface Overflow Rate (SOR) represents the hydraulic loading applied to the surface area of a clarifier or settling basin.
When to use it
Use it when designing or evaluating primary clarifiers, secondary clarifiers, sedimentation tanks, and water treatment settling basins.
Example
Data:
Q = 2400 m³/day
A = 120 m²
Formula:
SOR = Q / A
Substitution:
SOR = 2400 / 120
Result:
SOR = 20 m³/m²·day
Applications
Clarifier design, sedimentation basin sizing, wastewater treatment, drinking water treatment, process optimization, and hydraulic loading evaluation.
Note
Although SOR is calculated as a hydraulic loading rate, actual settling performance also depends on particle characteristics, turbulence, density differences, inlet design, and sludge accumulation.