Enter Calculation Inputs
Example Data Table
| Scenario | Influent | Background | Flow | Duration | Removal | Influent Load | Effluent Load |
|---|---|---|---|---|---|---|---|
| Cooling water cleanup | 18 mg/L | 2 mg/L | 35 m³/h | 8 h | 70% | 4.48 kg | 1.34 kg |
| Trace solvent rinse | 2500 µg/L | 300 µg/L | 120 L/min | 12 h | 50% | 0.1901 kg | 0.0950 kg |
| High strength batch drain | 0.08 g/L | 0 g/L | 5 L/s | 2 h | 90% | 2.88 kg | 0.288 kg |
Formula Used
Net concentration = Influent concentration − Background concentration
Effective flow = Flow per stream × Parallel streams × Uptime fraction
Mass rate (mg/s) = Net concentration (mg/L) × Effective flow (L/s)
Total load (kg) = Mass rate (mg/s) × Duration (s) ÷ 1,000,000
Removed load = Total load × Removal efficiency
Effluent load = Total load − Removed load
Effluent concentration = Net concentration × (1 − Removal efficiency)
ppm is treated as mg/L for dilute aqueous systems. Unit conversions are handled automatically before the final contaminant load is calculated.
How to Use This Calculator
- Enter the influent concentration and choose its unit.
- Optionally add background concentration for net loading analysis.
- Enter flow rate per stream and select the correct flow unit.
- Set operating duration, parallel streams, and uptime percentage.
- Add treatment removal efficiency and any discharge limit.
- Click the calculate button to view results above the form.
- Review the summary table, compliance result, and Plotly chart.
- Use the CSV or PDF buttons to export your results.
Frequently Asked Questions
1. What is contaminant load?
Contaminant load is the total contaminant mass carried over time. It combines concentration, flow, and duration into a mass value such as kilograms.
2. Why subtract background concentration?
Subtracting background concentration isolates the process contribution. That helps you evaluate added pollution instead of total ambient contamination already present in the source water.
3. Which concentration units are supported?
The calculator supports µg/L, mg/L, g/L, kg/m³, and ppm. All values are converted internally to mg/L before load calculations.
4. How does removal efficiency affect results?
Removal efficiency reduces the calculated influent load to estimate removed mass and remaining effluent mass. Higher efficiency lowers effluent concentration and discharge load.
5. What does uptime percentage mean?
Uptime adjusts the operating flow to reflect real equipment availability. A lower uptime reduces the effective total processed flow and total contaminant load.
6. Can I use ppm for wastewater screening?
Yes. For dilute water systems, ppm is commonly treated as mg/L. For dense or unusual fluids, laboratory density corrections may be needed.
7. Why can effluent concentration exceed the limit?
That happens when the net influent concentration remains too high after treatment. Increase removal efficiency, reduce feed concentration, or lower flow to improve compliance.
8. Do the export buttons save my data automatically?
No. The export buttons download a result file only when you click them. They do not store records on the server.