黑河金盆水库表层沉积物中磷的形态和分布特征

水源水库沉积物生源要素形态显著影响上覆水体水质,为给深水型水源水库水质修复提供科学依据,应用淡水沉积物中磷形态的标准测试程序(SMT),对西安市黑河金盆水库库区和上游入库6个代表性沉积物样的理化特征及磷赋存形态进行研究。结果表明:金盆水库表层沉积物中总磷(TP)含量范围为987~1326 mg·kg~(-1),从上游入库至库区,总磷含量逐渐增加;无机磷(IP)是沉积物中磷的主要成分,占总磷(TP)的比例为62.5%~78.9%;Ca-P是IP的主要组成成分,占IP的比例为72.0%~90.5%。沉积物-水界面存在明显的磷浓度梯度,当氧化还原条件变化时溶解性磷易从间隙水扩散到上覆水中,从而在一定程度上影响金盆水库整体的营养水平。TP与IP变化趋势基本一致,且TP的变化主要由IP决定,IP的增减因Ca-P和Fe/Al-P而改变。

Forms and distribution of phosphorus in surface sediments of Jinpen Reservoir

Biological elements harbored in sediment of drinking water reservoir have an important influence on the quality of the overlaying water. In this work, standard measurement and test(SMT) procedure of phosphorus forms in the freshwater sediments was used to determine surface sediments geochemical characteristics, the forms and distribution of phosphorus in Jinpen Reservoir located in Xi''an City. The results showed that total phosphorus(TP) content in sediments ranged from 987~1326 mg·kg^-1, from upstream storage to reservoir area, and the total phosphorus content increases. Meanwhile, inorganic phosphorus(IP) was the main component in sediment and accounted for 62.5%~78.9% of the total phosphorus(TP), and Ca-P accounted for 72.0%~90.5% of IP. A gradient of the soluble reactive phosphorus(SRP) occurred at the sediment-water interface, which indicated the SRP in the sediment could release to the overlying water and deterioriate the water quality. Variation trends of IP and TP are basically the same, and the change of TP is primarily determined by IP, but IP content was regulated by Ca-P and Fe/Al-P. The results from this work can provide scientific data for the water quality restoration in the deep drinking water reservoir.