Alum Dosing Phosphorus Inactivation
Calculate candidate stoichiometric reagent mass for supplied water/sediment labile phosphorus and calibrated Al:P ratio; not dosing advice, and alkalinity, pH, toxicity, reagent hydration and delivery constraints need specialist assessment.
Description
Phosphorus inactivation calculations distinguish the target phosphorus mass from aluminum and formulated reagent mass.
Phosphorus inactivation calculations distinguish the target phosphorus mass from aluminum and formulated reagent mass. A supplied Al:P molar ratio converts that phosphorus estimate into candidate stoichiometric quantities.1
The tool returns candidatePhosphorusInactivationKg, stoichiometricAluminumKg, candidateReagentMassKg. The computation uses supplied observations and parameters rather than acquiring measurements.
When to use Alum Dosing Phosphorus Inactivation
Use this for the following task: Calculate candidate stoichiometric reagent mass for supplied water/sediment labile phosphorus and calibrated Al:P ratio; not dosing advice, and alkalinity, pH, toxicity, reagent hydration and delivery constraints need specialist assessment. Prepare observations and calibration parameters on the same unit and reporting basis.
How to use Alum Dosing Phosphorus Inactivation and understand its results
- Prepare the measured quantities and supplied model parameters. Match the units and align paired lists before calculating.
- Enter labileSedimentPhosphorusKg, waterVolumeM3, currentWaterPhosphorusMicrogramsPerLiter, targetWaterPhosphorusMicrogramsPerLiter, aluminumPhosphorusMolarRatio, aluminumMolarMassGramsPerMol, phosphorusMolarMassGramsPerMol, reagentAluminumMassFraction according to the field table, then run the tool.
- Read candidatePhosphorusInactivationKg, stoichiometricAluminumKg, candidateReagentMassKg. Use the calculation below to interpret the selected mean or the model’s signs, units and comparison flags.
- Review the supplied assumptions and calibration before comparing or reporting the result.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| labileSedimentPhosphorusKg | Labile sediment phosphorus kg | number | Required |
| waterVolumeM3 | Water volume m3 | number | Required |
| currentWaterPhosphorusMicrogramsPerLiter | Current water phosphorus micrograms per liter | number | Required |
| targetWaterPhosphorusMicrogramsPerLiter | Target water phosphorus micrograms per liter | number | Required |
| aluminumPhosphorusMolarRatio | Aluminum phosphorus molar ratio | number | Required |
| aluminumMolarMassGramsPerMol | Aluminum molar mass grams per mol | number | Required |
| phosphorusMolarMassGramsPerMol | Phosphorus molar mass grams per mol | number | Required |
| reagentAluminumMassFraction | Reagent aluminum mass fraction | number | Required |
Use nonnegative sediment mass, volume and water concentrations with positive molar parameters and reagent aluminum fraction in (0,1]. Add only the positive water-column excess and calculate both masses.
candidateP=labileSedimentP+volume×max(0,current−target) µg/L/1000000; Al=candidateP×molarRatio×AlMolarMass/PMolarMass; reagent=Al/aluminumMassFraction The symbols and boundary conditions refer to the supplied fields and the implementation described above.
| Output field | Meaning | Value type |
|---|---|---|
| candidatePhosphorusInactivationKg | Candidate phosphorus inactivation kg | number |
| stoichiometricAluminumKg | Stoichiometric aluminum kg | number |
| candidateReagentMassKg | Candidate reagent mass kg | number |
{
"input": {
"labileSedimentPhosphorusKg": 10,
"waterVolumeM3": 1000,
"currentWaterPhosphorusMicrogramsPerLiter": 30,
"targetWaterPhosphorusMicrogramsPerLiter": 10,
"aluminumPhosphorusMolarRatio": 2,
"aluminumMolarMassGramsPerMol": 27,
"phosphorusMolarMassGramsPerMol": 31,
"reagentAluminumMassFraction": 0.1
},
"output": {
"candidatePhosphorusInactivationKg": 10.02,
"stoichiometricAluminumKg": 17.454193548387096,
"candidateReagentMassKg": 174.54193548387096
}
}Limitations and assumptions
This is candidate mass arithmetic rather than dosing advice. Site-specific pH, alkalinity, toxicity, competing reactions, reagent hydration and delivery conditions are not assessed.
Numerical inputs must be finite. Input-shape and calculation checks do not establish measurement quality or the validity of a supplied calibration.
Alternative or Complementary methods
Choose Vollenweider Phosphorus Load Limit when you need its operation: Invert a caller Vollenweider-form steady retention relation for target areal external phosphorus load; not an authoritative load limit or site-specific ecological guarantee. Choose Gran Titration Alkalinity for the complementary operation: Fit the post-equivalence acid Gran function (Vs+Va)·10^(−pH) and extrapolate a nonnegative endpoint for monovalent acid alkalinity; activity corrections and endpoint validity require laboratory assessment.
Background reference: Monitoring Lake and Reservoir Restoration: phosphorus inactivation.
References
-
Monitoring Lake and Reservoir Restoration: phosphorus inactivation — U.S. Environmental Protection Agency
Similar or alternative tools
- Vollenweider Phosphorus Load Limit
Invert a caller Vollenweider-form steady retention relation for target areal external phosphorus load; not an authoritative load limit or site-specific ecological guarantee.
- Gran Titration Alkalinity
Fit the post-equivalence acid Gran function (Vs+Va)·10^(−pH) and extrapolate a nonnegative endpoint for monovalent acid alkalinity; activity corrections and endpoint validity require laboratory assessment.