Binding of inorganic phosphate to dissolved metal humates
Jeremy Riggle1, Ray von Wandruszka
1Department of Chemistry, University of Idaho, Moscow, ID 83844-2343, USA.
Abstract:
A cobalt-wire electrode was used to determine the concentration of free phosphate (P) in solutions containing a series of metal humates (MHA). The results were used in Scatchard plots to determine the stability constants of the dissolved MHA-P complexes formed. The constants were found to be high, with logK values in the range 4.8-6.0. Solutions containing MHA-P complexes were found to be relatively inert to the addition of phosphate-precipitating cations, indicating that MHA has a solubilizing effect on P and may enhance its mobility in the environment.
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