Buffering characteristics of sediments phosphorus in Daming Lake, China

Water quality of Daming Lake, located at the central district of Jinan City of China, can be obviously affected by the external nutrients loading. There are about 8.07x10(7) kg seriously contaminated loosing sediment with 1.30x10(5) kg phosphorus in the lake sediment. The buffering effect of the sedimentary phosphorus plays a critical role in the lake water quality. Under natural conditions, sedimentary phosphorus in Daming Lake is usually release phosphorus to the lake overlying water. Our results showed that when concentration of the phosphorus in sediment exceeds a certain level, it can absorb phosphorus in lake overlying water. However, this can hardly happen under natural conditions.