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P Partitioning

Tue, 01/11/2005 - 2:06pm — Eric
I have a question about phosphorus partitioning. I am modeling a large reservior in the Southwest desert. I am trying to determine the effect of internal and external phosphorus loadings on algal growth. I have large loads of suspended sediments in the inflow, which I think might have an effect on the amount of available phosphorus. I am still using version 3.1, and I noticed in the manual that it is not recommended to allow phosphorus to sorb onto inorganic suspended solids, so [PARTP] should be zero. I was wondering why this was so. Have any models used phosphorus partioning? Thanks
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Water Quality
Wed, 01/26/2005 - 12:20pm — Tom

The problem with setting PARTP to a value other than zero is that SRP specified in the inflow will immediately sorb onto any ISS present in the inflow and then will settle out, thus becoming unavailable for algal growth. In reality, most of the sorbtion sites on ISS are already taken up by inorganic P and are generally only available for desorption rather than absorption. The state variable really should be particulate inorganic phosphorus that ebbs and flows between the PIP state and DIP state. This is something on the TO DO list, but just hasn't been done yet.