哈素海表层沉积物中内源磷的释放研究

Phosphorus Release from Surface Sediment of the Hasuhai Lake

以浅水湖泊哈素海为研究对象,开展了上覆水质、温度、pH、溶解氧、扰动和光照等环境要素对湖泊沉积物内源磷释放的影响试验研究。结果表明,温度升高、碱性条件、厌氧和强烈的扰动作用等均有利于内源磷的释放,而照度则间接地限制了沉积物释磷对上覆水中磷浓度的影响。HSH-2、HSH-5和HSH-6等3个站位TP的最大释放量在自然光照条件下分别为1.53、1.39和1.27mg·kg-1,避光条件下分别为1.77、1.52和1.52mg·kg-1;静置条件下分别为1.42、1.38和1.68mg·kg-1,R=60r·min-1时分别为1.75、1.50和2.00mg·kg-1,R=120r·min-1时分别为2.52、2.64和4.02mg·kg-1;在pH=11时释放量最大,分别为10.82、6.83和16.68mg·kg-1。各环境因子中,以pH和扰动对哈素海沉积物内源磷的释放影响最大。哈素海为浅水湖泊,在湖水咸化程度逐渐增高的条件下,将会导致湖泊沉积物内源磷的大量释放,从而将进一步加剧水体的富营养化。

Based on the releasing experiment of sediment phosphorus（P）, the effects of environmental factors such as overlying water, temperature, pH values, dissolved oxygen levels, turbulence and illumination on the release of sediment phosphorus was studied in the Hasuhai Lake in the paper. The results showed that temperature increasing, alkalescence condition, anaerobic and strong turbulence could improve the release capacity of sediment P, but illumination indirectly limited the release of P from sediment to overlying water. Under the condition of illumination, the maximum release capacity of sediment P in HSH-2 ,HSH-5 and HSH-6 stations were 1.53,1.39 and 1.27 mg·kg^-1 respectively; While were 1.77,1.52 and 1.52 mg·kg^-1 in the dark condition. When enhanced the turbulence strength（R=120 r·min^-1 ）, the maximum release capacity of sediment P in the three stations were 2.52 mg·kg^-1,2.64 mg·kg^-1 and 4.02 ·kg^-1 respectively. At pH= 11, the maximum release capacity of sediment P in the three stations were 10.82,6.83 and 16.68 mg·kg^-1 respectively.In all the environmental factors, pH and turbulence were the key ones. With the increase of salinity of the overlying water, more sediment P will release to overlying water, resulting in lake eutrophication improvement.