巢湖水体氮磷营养盐时空分布特征

在不同汛期对巢湖水体进行了网格化样品采集,研究了巢湖水体中氮磷营养盐的含量与时空分布规律,确定了巢湖水体的主要污染因子.结果表明,巢湖入湖河流中TP、TN和NO-3-N指标均超过了Ⅴ类水标准,南淝河和十五里河中TP、TN、NH+4-N和NO-3-N表现出丰水期低于平水期、枯水期的季节性变化特征,在其他河流则呈现出丰水期高于枯水期、平水期的特征;巢湖湖体氮磷营养盐浓度的分布存在时空差异,西部湖区中氮磷营养盐含量远高于东部湖区;TP、TN和NH+4-N表现出在枯水期高于平水期和丰水期的变化特征,而NO-3-N在丰水期的含量较高;巢湖水体的主要污染因子为TN和NH+4-N,这些污染物从西往东质量浓度不断减少.

Spatial and Temporal Distributions of Nitrogen and Phosphate in the Chaohu Lake

In order to determine the concentrations, spatial and temporal distributions of nitrogen (N) and phosphorus (P) nutrients in Chaohu Lake, the surface water samples were collected systemically in different flood seasons by grid sampling methods. Meanwhile, the predominant pollution factors and priority control area were confirmed. The results showed that the concentrations of TP, TN and NO₃^--N in the inflowing rivers were higher than the V class water standard, the concentrations of nutrients in wet season were lower than those in normal season and dry season in Nanfei River and Shiwuli River, while the levels of nutrients in the other selected rivers were higher in wet season. The variations of spatial and temporal of nutrients were observed in the Chaohu Lake. The concentrations of N and P nutrients in the western part of Chaohu Lake were higher than those of the eastern part. The elevated concentrations of TP, TN and NH₄⁺-N were found in the dry season, while the elevated content of NO₃^--N was observed in the wet season. The predominant pollution factors in Chaohu Lake were TN and NH₄⁺-N, the concentrations of these nutrients were decreasing from the western part of the Chaohu Lake to the eastern part of the Chaohu Lake.