Below I have provided a . You can copy this directly into Excel. It covers the primary calculation chain: Influent Loading $\rightarrow$ Reactor Sizing $\rightarrow$ Aeration $\rightarrow$ Sedimentation. How to Build the "Best" WWTP Design Calculator in Excel To make this functional, set up your Excel sheet with three columns: Parameter , Value/Unit , and Formula/Note . Sheet 1: Design Basis (Inputs) This is where you define the problem. Cjiang Sims 4 - Mostly Use Sims
| Row | Parameter (Column A) | Formula (Paste into Column B) | Unit | Explanation | | :-- | :--- | :--- | :--- | :--- | | 1 | | | | | | 2 | Surface Overflow Rate (SOR) | 24 | m³/m²/day | Typical Peak Flow value | | 3 | Required Surface Area | =B3_Sheet2 / B2 | m² | Peak Flow / SOR | | 4 | Diameter (if circular) | =SQRT(B3/3.14159)*2 | m | | | 5 | Weir Loading Rate | < 150 | m³/m/day | Check hydraulic flow | Where to Download Pre-Made Sheets If you prefer not to build this from scratch, the following sources offer high-quality spreadsheets (often better than generic search results): Siterip — Taylormadeclips Com
| Row | Parameter (Column A) | Formula (Paste into Column B) | Unit | Result Example | | :-- | :--- | :--- | :--- | :--- | | 1 | | | | | | 2 | Average Daily Flow (ADF) | =B2*B3*B5/1000 | m³/day | 12,000 | | 3 | Peak Hourly Flow (PHF) | =B2*B4 | m³/day | 30,000 | | 4 | Average Flow (m³/hr) | =B2/24 | m³/hr | 500 | | 5 | Peak Flow (m³/hr) | =B3/24 | m³/hr | 1,250 | | 6 | LOADING CALCULATIONS | | | | | 7 | BOD Load (kg/day) | =B2*B7/1000 | kg/day | 3,000 | | 8 | COD Load (kg/day) | =B2*B8/1000 | kg/day | 6,000 | | 9 | TSS Load (kg/day) | =B2*B9/1000 | kg/day | 3,600 | | 10 | TKN Load (kg/day) | =B2*B10/1000 | kg/day | 480 | Sheet 3: Aeration Tank (Activated Sludge) Design This is the heart of the calculation. We will use the F/M Ratio method as it is the most common for XLS sheets.