Research on Occurrence of Phosphorus in Sediments of Nansihu Lake and Its Main Inflow Rivers Based on Analysis of Scientifc Materials

Abstract

Phosphorus content and its species were studied for the surface sediments of Nansihu Lake and its main inflow rivers, and the core sediments of Dushan Lake and Weishan Lake, using the SMT sequential extraction method. The phosphorus contents in the surface sediment are 465.5-13068.3 mg/kg, with the maximum value in Laoyun River, which was due to the waste water pollution from Jining City. The enrichment factors of organic phosphorus (OP) and NaOH-P are 6.5 and 9.0, respectively. The contents of phosphorus in other surface sediments are relatively lower, and are mainly composed of HCL-P. The enrichment factors of NaOH-P and OP are 1.0-3.7 and 1.3-6.0, indicating a minor human pollution. The phosphorus in the core sediment of Dushan Lake and Weishan Lake are mainly composed of HCL-P and OP. The increasing content of TOC in the core sediments was due to the growth of aquatic productivity and organic matter decomposition during the early diagenesis process, which also induced the increase of OP in the sediments since late 1960s. The higher content of OP and NaOH-P in the sediments of 6-0cm and 5-0cm for Cores DU3 and WS4 also indicated the human contamination since mid 1980s.