Water • Wastewater

Wastewater Calculators

Biological process sizing, starting with the aeration basin. This vertical is being built one tool at a time, and the tools below are the ones whose engines exist and are verified.

Water Live Tool

Activated Sludge Sizing Calculator

Size an aeration basin from the applied COD load, the F/M loading and the MLVSS, then audit your stated SRT, HRT and volume against each other. Reports oxygen demand as demand only, never as air flow.

load = Q × S₀ ÷ 1000 · V = load ÷ (F/M × X) on the APPLIED load · Px = Yobs × load removed · θc = VX ÷ Px · wasting = inventory ÷ θc · O₂ = 8/7 × COD removed, +4.57 per kg NH₄-N removed · air flow is not calculated

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Why this vertical starts with one calculator

Wastewater sizing is where an assumed number does the most damage. A yield, a temperature and an oxygen-transfer coefficient each look like small entries in a table, and each one changes the answer substantially. Rather than publish a family of calculators with defaults in them, this vertical begins with the tool whose governing numbers must all be stated by you, and reports what it cannot close.

The tools that exist are listed above. Where a calculation needs a settling velocity, a transfer model or a toxicity correction that this platform does not have, the engine says so instead of returning a number.