Phosphorus Adsorption and Desorption on the Surface Sediments of Yellow River Estuary

Adsorption-desorption behaviors of phosphorus (P) on the surface sediments of Yellow River estuary(Y) were investigated in the natural water (river water and seawater) . The results show that(1)The releasing P to the seawater of Y mainly occurs in 0~48h, which occupies 80% of total amount of releasing P. However, releasing P became slowly in 48~96h and according to this speed average kilogram sample releasing P is 70.956 mg /a, which is 11 times of that of Y compare to 1989; (2)P adsorption reaction of Y in the river water and the seawater mainly occurs in 12h, and during 0~0.5h, rapid adsorption is observed. Furthermore, the adsorption reaction is more rapid in the seawater, which has achieved the peak after 4h. The desorption P and adsorption P of process of Y is similar in seawater, 4h desorption has reached the maximum, then, desorption amount gradually decreased and reached a desorption equilibrium at 12h; (3)The zero equilibrium P concentration (EPC₀) of Y-BS and Y-HS in this study is are higher than the P concentration in their corresponding water, consequently, Y is a source to releases P to the water body under the experimental conditions.