Solids Loading Rate
Calculates the solids loading rate (SLR) — pounds of solids per day applied per square foot of secondary clarifier area. SLR is the limiting variable for clarifier thickening capacity and is essential when running the basin at higher MLSS or higher RAS ratios.
Solids Loading Rate
Check how many pounds of solids per day are applied per square foot of clarifier area.
Enter all values above to calculate.
When you'd use this
Calculates the solids loading rate (SLR) — pounds of solids per day applied per square foot of secondary clarifier area. SLR is the limiting variable for clarifier thickening capacity and is essential when running the basin at higher MLSS or higher RAS ratios.
Category
Clarifier & SolidsMixed liquor suspended solids entering the clarifier.
Mixed liquor flow to the clarifier = forward flow + RAS flow.
Plan area of the clarifier in square feet.
Run the math behind this reference.
Each calculator opens onto its own page with the formula, variable definitions, a worked example, and related operator math.
Surface Overflow Rate (SOR)
Check clarifier settling performance by dividing flow by surface area.
Weir Overflow Rate
Check the flow rate per foot of weir length in a clarifier.
Required RAS Rate
Estimate the return activated sludge rate needed to maintain a target MLSS.
F/M Ratio
Compare the organic load entering the aeration basin to the biomass available to treat it.
WEF Manual of Practice No. 8 — Clarifier Design and Solids Flux.
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