长寿湖沉积物中磷形态的季节变化特征

Seasonal Variation Characteristics of Phosphorus Speciation in the Sediment of Changshou Lake

为进一步了解湖泊沉积物中磷形态的季节变化特征,采用沉积物磷形态SMT提取法,在2009年7月(丰水期)和11月(平水期)、2010年3月(枯水期)监测了长寿湖表层沉积物样品中不同形态磷的含量.结果表明,长寿湖沉积物中总磷(TP)含量基本表现为丰水期>枯水期>平水期,枯水期寿岛TP含量最高(2 960.29 mg/kg),平水期关家河最低(586.05mg/kg);铁/铝结合态磷(Fe/Al-P)和有机磷(OP)占TP的质量分数均为平水期>丰水期>枯水期,2种形态的最大质量分数分别出现在乐温(40.01%)和大坝口(72.44%);钙磷(Ca-P)占TP的质量分数为枯水期>平水期>丰水期,最大值出现在摆布荡(15.52%),说明长寿湖沉积物中磷形态呈现明显的时空变化特征.另外,Fe/Al-P受上覆水pH的影响,而OP受溶解氧(DO)影响不太明显.

To further know the seasonal variation characteristics of phosphorus species in lake sediment,the contents of different phosphorus species in the surface sediment sampling from Changshou Lake were determined by using the SMT sequential extraction method in July and November,2009,and March,2010.The contents of total phosphorus（TP） basically show an order of the low-water period,high-water period,and normal-water period from high to low,and the maximum appeared in Shoudao（2960.29 mg/kg） while the minimum in Guanjiakou（586.05 mg/kg）.The mass fractions of phosphorus associated with hydrous ferric/aluminum oxides（Fe/Al-P） and organic phosphorus（OP） in TP at all sampling sits are in an order of the normal-water period,high-water period,and low-water period from high to low,and the maximum of Fe/Al-P appeared in Lewen（40.01%） while that of OP in the dam mouth（72.44%）.The mass fraction of phosphorus bound to calcium salt（Ca-P） in TP is in an order of the low-water period,normal-water period,and high-water period,and the maximum appeared in Baibudang（15.52%）.These results suggested that the phosphorus speciation in the sediment of Changshou Lake shows obviously temporal and spatial distribution characteristics,and Fe/Al-P is mainly influenced by pH of the overlying water,while OP is not apparently influenced by dissolved oxygen（DO）.