Wastewater math
Wastewater Math Calculators
Five calculators for exam math that comes up on plant rounds. Each one shows the formula, a worked example and the mistakes that cost points on the exam.
Detention Time Calculator
How long wastewater stays in a tank, in hours, from the tank volume in gallons and the flow in MGD.
Surface Overflow Rate Calculator
Clarifier surface overflow rate in gpd/ft², from the flow in MGD and a circular clarifier's diameter in feet.
Chlorine Dose and Feed Calculator
Chlorine dose in mg/L from demand and residual, and the feed rate in lb/day from the flow and the product's purity.
F/M Ratio Calculator
Food-to-microorganism ratio from the flow in MGD, BOD in mg/L, aeration volume in MG and MLVSS in mg/L.
Sludge Volume Index (SVI) Calculator
SVI in mL/g from the 30 minute settled sludge volume in mL/L and the MLSS in mg/L.