Chuck Hansen 3.7.13

Dissolved Inorganic Phosphorus (DIP) aka Soluble Reactive Phosphorus (SRP)

Disolved Organic Phosphorus (DOP) Particulate Phosphorus (PP) Total P = DIP + DOP + PP Found in the form of Phosphates (PO4

-3) Important to plants, animals, and

microbiota Growth – Limiting Nutrient

Weathering of ApatitePoint Sources

Sewage, Urban RunoffNonpoint Sources

Agriculture, Animal Waste, FertilizersModes of Entry to Aquatic Systems

Precipitation (dust in air), Groundwater Adsorption, Surface Runoff

Decreases Downstream

Can occur faster than needed for growth

Rate of uptake dependant upon how much organic matter there is to take it in, and the metabolism of those constituents

How does the solubility of Fe influence the phosphorus redox reactions?  As a result, explain how sulfur and iron trapping influences the concentration of phosphorus in the hypolimnion at overturn in a lake.

Others….

Iron trap for P   - In oxygenated

waters, iron is present as Fe3+ (ferric)

pH < 7 : Fe3+ + PO43-

: FePO4 (Vivianite) pH > 7 : Fe3+ + PO4

3- + OH- : Fe2, OH, PO4

Fe3+ conversion to Fe2+  releases PO4

3- Sulfur trap may lower iron

concentrations enough to allow some phosphate to remain at overturn

All these reactions mediated by bacteria