// multi-utility computation suite · offline · instant · precise
┌──────────────────────────┐
│ [c] calcalyst_ │
│ computation suite │
└──────────────────────────┘
// select a module to initialize
/ search↵ open firstesc close
// adsenseEMPTY_LEADER_SLOT728×90
// adsenseMOBILE_ANCHOR_SLOT320×50
// keyboard_shortcuts
/focus search
↑↓navigate module list
Enter
open first result from search
open highlighted
compute when module is open
compute when focused in a field
Escclose module · clear selection
⌫
sci.activated-sludge-SRT Calculator
Calculates activated sludge solids retention time (SRT = θc) = total system solids / daily wasted solids, and mixed liquor suspended solids from the design equation. SRT determines the microbial community — nitrification requires SRT > 8–10 days at 20 °C; full denitrification and enhanced phosphorus removal require still longer SRT.
Inputs
Q M3 Day
Reference formula or conversion factor shown for context.
S0 Mg L
Amount per unit of time or per unit quantity. Check the denominator before interpreting.
Se Mg L
Amount per unit of time or per unit quantity. Check the denominator before interpreting.
Y Coeff
Reference formula or conversion factor shown for context.
Kd Per Day
Reference formula or conversion factor shown for context.
X Mg L
Amount of solute per unit volume. Higher concentration = more solute dissolved.
Results
sludge retention time SRT (days)
The computed duration or time value.
waste sludge production Px (kg VSS/day)
The result of multiplying all input values together.
required aeration tank volume V (m³)
The computed three-dimensional volume.
substrate removal ΔS (mg/L)
The value at the specified point or condition.
1/SRT = Y·μ − kd
Reference formula or conversion factor shown for context.
process classification
Category assigned based on where the computed value falls on a defined scale. Check which standard or guideline defines these boundaries.