Activated Sludge FM Ratio Calculator
Calculates daily BOD5, CBOD5, or COD loading divided by active MLVSS inventory derived from volume and MLVSS, volume and MLSS with a volatile fraction, or a directly entered MLVSS mass.
Chemical Dose Feed Rate Calculator
Calculates required dry or liquid chemical feed from flow and target dose, or back-calculates achieved dose from an actual feeder rate, with optional user-entered capacity screening.
Chlorine CT Contact Time Calculator
Calculates achieved chlorine CT from a minimum residual and direct or process-unit T10, solves the T10 required for a user-entered CT target, or sizes a minimum effective volume from peak flow and a user-entered baffling factor.
Clarifier Surface Solids Loading Calculator
Calculates surface overflow rate and solids loading rate for in-service clarifiers using explicit geometry, flow, unit-system, and solids-stream choices.
Sludge Volume Index Settleability Calculator
Calculates standard 30-minute sludge volume index and companion settling indicators from either one 30-minute observation or a fixed 5-60 minute settling curve.
Solids Retention Time MCRT Calculator
Calculates actual SRT/MCRT from system inventory and measured solids exits, or solves the nonnegative waste flow required for an entered target SRT on a consistent total- or volatile-solids basis.