Factors and Processes That Influence Chemical Interactions Between Phosphorus and Iron Oxides.

To obtain optimal efficiency in treating runoff waters using mineral adsorbents requires a good understanding of the factors and processes that influence the P and mineral interaction. This presentation reviews the mechanisms of P sorption by a variety of materials that have potential for use in P treatment applications. Factors such as pH, ionic strength, ion composition and presence of natural organic matter play a crucial role in the effectiveness of P adsorption by minerals. The interplay between these factors shows a complicated pattern and can sometimes lead to controversial results, As a consequence, it makes selection of optimal conditions for P removal not straightforward. With the help of mechanistic modeling, the net macroscopic effect of single and combined factors can be understood and can be predicted. Recent progress of mechanistic modeling of P adsorption to mineral adsorbents will be reviewed and examples in modeling P adsorption under the influence of solution chemistry will be presented.