Contaminant Removal Efficiency Calculator
Calculate the percentage removal efficiency of contaminants in water treatment, air filtration, or industrial purification systems based on influent and effluent concentrations.
mg/L
Formulas Used
Removal Efficiency (RE):
RE (%) = [(Cin − Cout) / Cin] × 100
Log Removal Value (LRV):
LRV = log10(Cin / Cout)
Per-Stage Efficiency (n equal stages in series):
REstage (%) = [1 − (1 − RE/100)1/n] × 100
Mass Load Removed:
Mass Removed = (Cin − Cout) × Q
Where: Cin = influent concentration, Cout = effluent concentration, Q = volumetric flow rate, n = number of treatment stages.
Assumptions & References
- Removal efficiency assumes steady-state conditions with uniform mixing (completely mixed flow reactor model).
- Per-stage efficiency assumes each stage achieves equal fractional removal (geometric series model).
- Log Removal Value (LRV) is widely used in drinking water treatment per WHO Guidelines for Drinking-water Quality (4th ed., 2017) and US EPA LT2ESWTR for pathogen removal.
- Mass load calculation assumes concentration and flow rate are measured at the same point and time (no storage effects).
- Unit conversions: 1 ppm ≈ 1 mg/L (for dilute aqueous solutions); 1 ppb ≈ 1 μg/L.
- Flow conversion: 1 MGD = 3.78541 × 10⁶ L/day.
- Applicable to water treatment (coagulation, filtration, disinfection), air filtration (HEPA, activated carbon), and industrial scrubbers.
- Reference: Metcalf & Eddy, Wastewater Engineering: Treatment and Resource Recovery, 5th ed., McGraw-Hill, 2014.
- Reference: US EPA, Guidance Manual for Compliance with the Filtration and Disinfection Requirements, 1991.