Model daily organic feed and reactor stress. Compare COD, BOD, volume, and treatment efficiency easily. Plan stable operations using practical outputs for design decisions.
Use the form below to estimate loading, retention time, removal, and indicative methane potential.
This sample shows a practical wastewater digester scenario and the type of output generated by the calculator.
| Parameter | Example Value | Unit | Comment |
|---|---|---|---|
| Reactor Type | Anaerobic Digester | - | Generic screening range used. |
| Organic Basis | COD | - | Typical wastewater strength basis. |
| Daily Flow | 850 | m³/day | Average influent flow. |
| Organic Concentration | 2200 | mg/L | Equivalent to 2.2 kg/m³. |
| Reactor Volume | 1500 | m³ | Working liquid volume. |
| Removal Efficiency | 72 | % | Estimated average removal. |
| Recycle Ratio | 0.15 | decimal | Hydraulic recycle only. |
| Peak Factor | 1.25 | - | Used for peak hydraulic check. |
| Methane Yield | 0.35 | m³/kg removed | Screening estimate. |
| Design Range | 1.00 to 4.00 | kg/m³-day | Example reference band. |
| Example Output | Value |
|---|---|
| Organic Mass Load | 1,870.00 kg/day |
| Organic Loading Rate | 1.247 kg/m³-day |
| Base HRT | 1.765 days |
| Effective HRT with Recycle | 1.535 days |
| Removed Organics | 1,346.40 kg/day |
| Effluent Concentration | 616.00 mg/L |
| Methane Estimate | 471.24 m³/day |
| Status | Within reference range |
If unit is mg/L: Concentration (kg/m³) = Concentration (mg/L) ÷ 1000
Organic Mass Load (kg/day) = Flow Rate (m³/day) × Concentration (kg/m³)
OLR (kg/m³-day) = Organic Mass Load (kg/day) ÷ Reactor Volume (m³)
Base HRT (days) = Reactor Volume (m³) ÷ Influent Flow (m³/day)
Effective HRT (days) = Reactor Volume ÷ [Flow × (1 + Recycle Ratio)]
Removed Organics (kg/day) = Organic Mass Load × Removal Efficiency ÷ 100
Effluent Concentration = Influent Concentration × (1 − Removal Efficiency ÷ 100)
Methane Estimate (m³/day) = Removed Organics (kg/day) × Methane Yield (m³/kg removed)
Organic loading rate measures how much biodegradable material enters each unit of reactor volume per day. It helps compare feed strength against available treatment volume and operational stability.
Reactor volume is the denominator of OLR and HRT. A larger working volume lowers loading intensity and usually increases contact time, which can improve treatment performance.
No. Higher loading can improve throughput, but excessive loading may reduce stability, lower removal efficiency, increase washout risk, and create odor or gas management problems.
Use the same basis as your design standard or monitoring program. COD is common for anaerobic design, while BOD is often used for aerobic systems and compliance tracking.
Recycle ratio does not add new organic mass in this tool. It changes effective hydraulic flow, which reduces effective HRT and helps screen hydraulic stress separately from true organic loading.
It is a screening estimate based on removed organics and the yield you enter. Actual gas production depends on substrate type, temperature, retention time, and digester health.
Yes. The formula structure still works. However, the reference design range should match the selected process type, site conditions, and your own engineering standards.
That means the computed OLR is lower than the minimum value in your selected reference band. It may indicate conservative feeding, oversized volume, low influent strength, or an unsuitable benchmark.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.