Eutrophication is an important environmental problem in urban lakes,and endogenous pollution is one of the main causes of eutrophication.In this paper,surficial sediment in a typically urban lake in Jiujiang City was collected to revealed the spatial distribution of sediment nutrients.The pollution risk of surface sediment before and during algae bloom was evaluated,and the sources of nutrients were also explored along the sediment vertical profile.The results showed that:1)the contents of total nitrogen(TN),total phosphorus(TP),and total organic matter(TOM)in sediments exhibited strong spatial consistency,vertically,the highest concentrations of TN,TP and TOM were found in the surface layer,with an overall decreasing trend as depth increased;horizontally,the surface sediments in the central lake area had higher TP and TN contents.2)Before the algal bloom,the surface sediments were generally in a moderately polluted state;during the algal bloom,the surface sediments were in a severely polluted state,with a significant increase in the risk of nitrogen and phosphorus pollution.3)TOC/TN and TOC/TP ratios of sediment indicating that the source of sediment was transformed from plankton residues to microorganisms due to eutrophication and algal bloom in recent years.
维普
万方数据