Description
Return grossReject = feed-permeate, netReject = grossReject-recycleReject and recovery = permeate/feed.
Membrane calculations distinguish feed, permeate and reject streams, gross recovery and recycle, and hydraulic from osmotic pressure. A local mass balance or pressure difference is only one part of membrane transport and operating performance.
Return grossReject = feed-permeate, netReject = grossReject-recycleReject and recovery = permeate/feed.
When to use this tool
Use Membrane Recovery Reject Base when checking a supplied membrane stream balance or driving-pressure term.
How to use the tool and how it works
- Enter feed, permeate, recycleReject. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read grossReject, netReject, recovery. Use the output convention below.
Require positive feed, permeate between zero and feed, and recycleReject between zero and feed-permeate. Return grossReject = feed-permeate, netReject = grossReject-recycleReject and recovery = permeate/feed. All flow or volume inputs must use the same basis.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| feed | Feed | Required. Finite number; strictly above 0. |
| permeate | Permeate | Required. Finite number; minimum 0. |
| recycleReject | Recycle Reject | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| grossReject | Gross Reject | Required. Finite number. |
| netReject | Net Reject | Required. Finite number. |
| recovery | Recovery | Required. Finite number. |
{
"input": {
"feed": 100,
"permeate": 60,
"recycleReject": 10
},
"output": {
"grossReject": 40,
"netReject": 30,
"recovery": 0.6
}
}Limitations and assumptions
- Recovery uses the supplied gross feed, not feed minus recycled reject. This one-pass balance does not solve a recirculating system, determine solute rejection or validate membrane performance.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a complete process and membrane model for recirculation, concentration polarization, fouling, energy use and operating constraints.
References
Similar or alternative tools
- Reverse Osmosis Permeate Recovery Salt Factor
Return permeateFlow = feedFlow*recovery, concentrateFlow = feedFlow*(1-recovery), permeateConcentration = feedConcentration*(1-rejection) and concentrateConcentration = feedConcentration*(1-recovery*(1-rejection))/(1-recovery).
- Membrane Recovery Concentrate Share
Partition measured feed volume into permeate and concentrate assuming a closed additive-volume balance.