达里诺尔湖磷赋存特征及底泥释放影响因素

Characteristics of Phosphorus Occurrence and Influence Factors of Sediment Release in Dali-Nor Lake

[目的]揭示封闭性内陆湖磷组成特点及底泥释放影响因素,为控制达里湖磷元素污染提供理论支持。[方法]对达里诺尔湖水体总磷(TP)、溶解性总磷(DTP)、溶解性无机磷(DIP),沉积物形态磷进行监测,并利用因子分析的方法对影响沉积物底泥释放的因素分类讨论。[结果]达里湖上覆水总磷(TP)均值2.00±0.02mg/L,间隙水TP均值2.50±0.02mg/L,沉积物TP在206.09~940.49mg/kg之间。沉积物中无机磷(IP)占TP的47.9%,是沉积物主要的磷形态之一。钙磷(Ca-P)是IP中含量最多的形态磷(217.76±47.01mg/kg),其次为铁铝结合态磷(Fe/Al-P,62.73±28.34mg/kg)和交换态磷(Ex-P,36.50±19.13mg/kg),有机磷(OP,200.28±135.13mg/kg)含量占TP的41.8%;通过因子分析法将影响底泥释放的因素分为三类:沉积物TP,Ca-P,Fe/Al-P和生物有效性磷含量归为沉积物磷因子;水体pH,DO,Eh值以及间隙水磷含量归为界面影响因子;湖水水深归为湖泊自身特征因子。[结论]达里湖存在沉积物磷底泥释放的风险,根据因子分析的结果可知,影响沉积物底泥释放的因素分为沉积物磷、水—沉积物界面理化指标和湖水水深3大类。

[Objective]In order to reveal the characteristics of phosphorus composition in closed inland lake,and the influencing factors of endogenous release.[Methods]The phosphorus content in different medium of Dali-Nor Lake was determined.Using factor analysis to classify the factors affecting sediment release.[Results]The average value of total phosphorus(TP)in the water on Dali-Nor Lake was 2.00±0.02 mg/L,and the mean value of interstitial water TP was 2.50±0.02 mg/L.The sediment TP is between 206.09 to 940.49 mg/kg.Inorganic phosphorus(IP)in sediments accounts for 47.9%of TP,which is one of the main forms of phosphorus in sediments.Followed by iron-aluminum bound phosphorus(Fe/Al-P,62.73±28.34 mg/kg)and exchangeable phosphorus(Ex-P,36.50±19.13 mg/kg)By using the factor analysis method to analyze the influence of 13 sediments release indicators,there are 4 main factors,the 13 indexes are divided into 3 categories:TP,Ca-P,Fe/Al-P and bioavailability of phosphorus content in sediments classified as phosphorus in sediments and interstitial water factor;phosphorus concentrations of pH,DO,Eh of the water as the interface influence factor;The third is water depth to lakes characteristic factor.[Conclusion]There is a risk of release of sediment phosphorus sediment in Dali-Nor Lake.According to the results of factor analysis,the factors affecting sediment release are divided into three categories:sediment phosphorus,water-sediment interface physical and chemical indicators and lake water depth.