ABSTRACT
In aquatic systems, phosphorus occurs in a wide variety of inorganic and organic forms (McKelvie et al., 1995). While these may exist in the dissolved, colloidal, or particulate forms, the predominant species is orthophosphate in either the mono-or diprotonated forms HPO H PO4
− −, . The dissolved component is operationally dened by ltration, and for this reason, the term filterable is used in preference to either dissolved or soluble, both of which are used extensively and interchangeably in the literature.
