太湖氮素出入湖通量与自净能力研究

为了探索太湖氮素迁移转化过程,对2009～2010水文年环太湖25条主要河流及太湖梅梁湾、东太湖等典型区域的各形态氮素进行分析,并利用太湖出入湖水量、蓝藻人工打捞量和鱼产量等相关数据,分析计算太湖氮素流动和转化潜力.结果表明太湖全年河道输入氮素总量约7.00×104t,河道出湖氮素总量约4.01×104t.整个水文年中,太湖氮素自净量约3.22×104t,其中反硝化约3.02×104t,沉积物吸附约0.20×104t.在反硝化潜力上,太湖西湖区(如梅梁湾)反硝化潜力远高于东部湖区(如东太湖),而夏季太湖反硝化潜力又高于其它季节.因此,太湖氮素自净作用在湖泊氮素迁移转化中发挥重要作用.

Nitrogenous Fluxes and Its Self-Purification Capacity in Lake Taihu

The various forms of nitrogen in 25 rivers surrounding Lake Taihu as well as in some typical lake zones such as Meiliang Bay and East Lake Taihu were analyzed during the hydrological year of 2009-2010. Furthermore, the nitrogenous self-purification capacity of Lake Taihu was studied in combined with the investigation of water flow, cyanobacteria salvages and aquatic product outputs. In the whole hydrological year, the inflow and outflow fluxes of total nitrogen (TN) were 7.00×10⁴ t and 4.01×10⁴ t, respectively. About 3.02×10⁴ t and 0.20×10⁴ t nitrogen in water body were removed by denitrification and sediment adsorption during this hydrological year, respectively, suggesting a strong nitrogen self-purification capacity of Lake Taihu. The potential denitrification is stronger in western Lake Taihu (e.g., Meiliang Bay) than that in eastern Lake Taihu (e.g., East Lake Taihu), and is stronger in summer than that in other seasons. Thus, the nitrogenous self-purification capacity plays an important role in nitrogenous transference and transformation in Lake Taihu.