Study on phosphorus releasing and releasing kinetics of sediments in Dongping Lake

Abstract

Dongping Lake is an adjusting and important water storage lake on the east route of the South-to-North Water Diversion Project, and its water quality has an important influence on the quality of diversion water. To find out the phosphorus distribution characteristics and its releasing risk of the lake sediments, the phosphorus pollution and static release of phosphorus in sediment of Dongping Lake were investigated. The results showed that the release contents of soluble reactive phosphorus (SRP), TP and COD from the sediments on the static condition achieved maximum values with 0.03∼0.23 mg/L, 0.01∼0.15 mg/L and 18∼33 mg/L, at the 21, 33 and 28 day, respectively. With the increase of time, the SRP and TP in the sediment showed an increasing trend, while the change trend of COD was unstable. SRP, TP release was obvious in each area of the sediments, and the release rates of S4 and S9 were high, respectively, and the release rates of S1 and S7 were low. The adsorption-desorption experiment showed that, the risk of nutrient release would happen at the sediment-water interface.