荣成天鹅湖沉积物磷的赋存形态和时空分布特征

Phosphorus Fractions and Temporal-Spatial Distribution Characteristics in Sediments from Rongcheng Swan Lake

采集了荣成天鹅湖表层和柱状沉积物,研究了沉积物中磷的赋存形态、空间及垂向变化特征,并对沉积物的理化性质与磷形态间的关系进行了初步分析。结果表明,天鹅湖表层沉积物中总磷水平不高,变化在79.15～565.12mg/kg之间。不同区域沉积物中总磷和各形态磷的含量差异较大,从西北至东南呈高-低-高-最低的变化趋势,外源污染和沉积物颗粒组成是影响其分布的主要因子。垂向分布上,总磷和各形态磷的含量均表现为自表层向下递减,8-10cm深度含量最低。相关性分析表明,总磷与各形态磷之间均呈较好的正相关关系,其中与无机磷的相关性最好,无机磷是总磷的主要赋存形态,占总磷含量的42.24%～82.04%;钙结合态磷是无机磷的优势组分,其含量远高于铁铝结合态磷;铁铝结合态磷在表层有明显的富集,与近几十年来入湖污染的增加有关。在天鹅湖湖水碱性条件下,湖区西北部及西端沉积物具有较大的释磷潜力。

The surface and core sediments from Rongcheng swan lake were collected to study the spatial and vertical distribution of different phosphorus forms,and the relationship between physico-chemical characteristics and phosphorus forms of sediments was also analyzed.Results showed that the concentrations of total phosphorus（TP） of sediments were not high,ranging from 79.15 mg/kg to 565.12 mg/kg.High space diversity of TP and phosphorus forms in sediments among different regions was observed.From the northwest to southeast of swan lake,the changing trend of TP was high-low-high-the lowest,whose primary factors were external pollution and sediment grain size.Concentrations of TP and different phosphorus forms decreased with the depth,and reached the lowest at the depth of 8-10 cm.The correlation between TP and various phosphorus forms was very good,and high significant correlation was observed between TP and inorganic phosphorus（IP）.IP was the dominant form of total phosphorus in sediments,accounting for 42.24%to 82.04% of TP.Calcium-bound phosphorus（Ca-P） was the largest part of TP,and much higher than Fe/Al-bound phosphorus（Fe/Al-P）.The concentrations of Fe/Al-P in top sediments were high,which was related to the increase of anthropogenic inputs in recent years.The sediments in the northwest and west end had great potential for phosphorus release in the alkaline water of swan lake.