River sediment typically acts a 'sink' or 'source' of phosphorus for the overlying water owing to the adsorption of phosphorous by the sediment or release of phosphorous to the water, respectively. In this study, a method is proposed for the determination of the equilibrium concentration of the total phosphorus (ECTP) and total phosphorus release rate (Rr). Phosphorus release experiments were conducted on natural river sediments in flowing water with a low velocity under different water temperatures. An empirical equation was established for the correlation between ECTP and Rr at an arbitrary temperature and at 20 °C. The results indicate that an increase in the water temperature significantly enhances the phosphorus release. In comparison with total phosphorus, dissolved phosphorus and particulate phosphorus in the overlying water do not change with the water temperature. Thus, the results of this study aid in understanding the contaminant exchange between sediments and water in flowing rivers.
Keywords: Flowing water; Phosphorus; Release; Sediment; Temperature.
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