Oscillating-tank experiments for quantification of water-sediment phosphorus exchange

Phosphorus exchange between sediment-water system was observed under molecular diffusion and turbulent condition. Some experiments were focused on adsorption behavior under common environmental factors (e.g., temperature, salinity and pH). The sediment suspension was found to have a significant effect on phosphorus movement to the upper layer water. Higher temperature increased the release of phosphorus from kaolinite and lake sediments, and the effect was almost nil for bentonite. Temperature effect was pronounced on kaolinite where relatively higher release of phosphorus observed. Salinity effect on lake sediments was not significantly important for release or adsorption. Bentonite showed a release of phosphorus after addition of salts. Adsorption on kaolinite was found higher at pH 4.7-5.0. The study was also focused on the estimation of phosphorus partitioning due to molecular diffusion and turbulent mixing. The observed behavior of the phosphorus exchange under different conditions showed an agreement with the observations by the other investigators.