Dewatering Polymer Dose Calculator

Polymer is dosed per dry ton of solids. Enter your sludge feed and dose rate to get daily polymer feed in pounds of active polymer, pounds of product, and gallons per day.

Sludge feed to dewatering (gpd)

Feed solids (% by weight)

Polymer dose (lb active per dry ton)Belt presses typically run 5–15 lb/dry ton.

Product active polymer (%)Emulsion products are often 30–50% active.

Product density (lb/gal)Default 8.6 for emulsion polymer.

Polymer Feed Rate

Item	Value

How the calculation works

Formulas
Dry solids (lb/day) = flow (gal/day) × 8.34 (lb/gal) × TS% ÷ 100
Dry tons/day = dry solids (lb/day) ÷ 2000
Active polymer (lb/day) = dose (lb/dry ton) × dry tons/day
Product (lb/day) = active polymer (lb/day) ÷ (active% ÷ 100)
Product (gal/day) = product (lb/day) ÷ density (lb/gal)

Notes & limitations

The lb-per-dry-ton dosing convention is standard across dewatering equipment vendors and WEF references. Optimum dose is equipment- and sludge-specific — confirm with jar or pilot testing, not rules of thumb alone.

Enter the dose as active polymer. If your vendor quotes dose as product, convert first or set active% to 100.
Overdosing wastes money and can blind belts and filtrate quality; underdosing drops capture and cake solids. Watch capture %, not just the dose number.
Make-down concentration and aging time affect performance but do not change the mass balance — this tool covers the mass side only.
For dry polymer, density does not apply — use the lb/day product figure and your feeder calibration.

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