大亚湾表层沉积物中磷的形态分布特征

Distribution Characteristics of Phosphorus Forms in Surface Sediments in the Daya Bay

沉积物中不同形态的磷具有不同的生物有效性和地球化学行为,它们的含量和分布特征包含着许多环境地球化学信息。因此,对沉积物中磷的地球化学形态的研究具有重要的环境地球化学意义。采用SEDEX法将大亚湾表层沉积物中不同形态的磷分离开,继而分析表层沉积物中不同形态磷的含量、分布特征及其影响因素。结果表明,表层沉积物中总磷的含量较高,平均高达341.87 mg/kg;无机磷所占的比例很高,平均达85.11%,平均含量为290.81 mg/kg;有机磷的平均含量为51.05 mg/kg。表层沉积物中的碎屑态磷是无机磷的主要赋存形态,平均占无机磷的47.67%;其次为自生磷灰石及钙结合态磷,平均占无机磷的34.79%;铁结合态磷和吸附态磷分别仅占无机磷中的10.23%和7.31%。其中,潜在的生物有效性磷(包括Ads-P、Fe-P和OP)平均占总磷的29.40%。在空间分布上,各站间不同形态磷的含量差异与污染物的陆源输入、沉积物性质等因素有关。

Different forms of phosphorus have different bioavailability and geochemical behavior.Their contents and distribution contain much environmental geochemistry information.Therefore,researches on geochemical forms of phosphorus have important significance of environmental geochemistry.In this paper,different forms of phosphorus in surface sediments were separated by SEDEX method,and the contents,distribution characteristics,influencing factors of different forms of phosphorus were analyzed.The results indicated that the content of total phosphorus was relatively higher in the surface sediments with an average value of 341.87 mg/kg,in which inorganic phosphorus averaged 290.81 mg/kg,comprising 85.11% of the total phosphorus,and organic phosphorus averaged 51.05 mg/kg.The content of De-P was the highest in all inorganic phofsphorus forms of the surface sediments in the Daya Bay,accounting for 47.67%.Ca-P,the second part of inorganic phosphorus,accounted for 34.79%.Fe-P and Ads-P,the small parts of inorganic phosphorus,accounted for 10.23% and 7.31% respectively.The potential bioavailable phosphorus,including Ads-P,Fe-P and OP,accounted for 29.40%.The contents of different forms of phosphorus in different sites were mainly influenced by terrigenous input,the nature of sediments,etc.