\[WLR=\frac{Q}{L_w}\]
Variables
WLRweir loading rate (m³/m·time)
Qflow rate (m³/time)
Lwtotal weir length (m)
Description
What is this formula?
Weir Loading Rate (WLR) represents the flow applied per unit length of clarifier weir.
When to use it
Use it when designing or evaluating clarifiers, sedimentation basins, circular settling tanks, and water treatment units equipped with outlet weirs.
Example
Data:
Q = 5000 m³/day
Lw = 125 m
Formula:
WLR = Q / Lw
Substitution:
WLR = 5000 / 125
Result:
WLR = 40 m³/m·day
Applications
Clarifier design, sedimentation basin design, wastewater treatment, drinking water treatment, hydraulic analysis, and process optimization.
Note
Excessive weir loading rates can produce uneven flow distribution and hydraulic disturbances near the outlet. Design guidelines typically specify maximum allowable WLR values depending on clarifier type and treatment objectives.