In order to illuminate pollutants distribution characteristics in sediment of Shanmei Reservoir, sediment samples at 47 sampling stations were collected (include 8 column samples), and concentrations of total nitrogen, total phosphorus and organic matter in the sediment of each station were measured. C/N and the correlation of TN, TP and OM were also analysed. Finally, pollution assessment for contaminated layer sediments was conducted. The results showed that the average contents of TN, TP and OM (mass fraction) were 1,180 mg kg?¹, 642 mg kg?¹ and 3.30% in the contaminated layer of sediments. Concentrations of total nitrogen and total phosphorus were low and stable at the depth of the normal layer. C/N of the contaminated layer of sediments was much higher than those in normal lakes, which showed that large part of OM came from natural land-based sources. Besides, a small part of OM came from phytoplankton, zooplankton and algae. Any two of TN, TP and OM were significantly correlated. The authors concluded that these findings showed that most of the nitrogen and phosphorus were in the organic form, and they came from similar sources. Evaluation results showed that both organic index and organic nitrogen belonged to the clean category. TP was at a moderate pollution level but not far from the category of heavy pollution.
Authors: Qiu ZK, Hu XZ, Yao C, Zhang WH, Xu QJ, Huang TY. ;Full Source: Huan Jing Ke Xue. 2016 Apr 15;37(4):1389-96. ;