珠江口沉积物中磷的赋存形态

采用较为系统的化学提取法，对珠江口柱状沉积物中TP、各形态无机磷及有机磷进行分析，重点考虑了分离提取碎屑和自生钙结合磷。结果表明：在无机磷中以钙磷占主要地位（49％），其中又以碎屑磷含量较高（43％），有机磷含量在TP中占有一定比例（38．8％）。沉积物中TP及其不同形态无机磷在垂向上的分布变化规律为：TP、有机磷和Fe－P含量随深度增加而降低，而碎屑态磷含量随深度增加而增高，自生钙磷变化幅度不大。TP、有机磷和Fe－P含量自下而上增高，在一定程度上反映了近年来陆源环境污染加剧的趋势。结合调查区域各种理化条件，认为在珠江口仅有铁结合磷与有机磷为潜在的生物可利用P，自生钙结合磷与原生碎屑结合磷总的来说占沉积物中TP的49％，因此我们估计有将近一半的P不能为生物利用。

Species of phosphorus in sediments from Peal River Estuary

A modified sequential extraction method has been used to determine the depth dependent changes of different forms of phosphorus in three cores sediment from the Peal River Estuary. The results indicate that in the surveyed area, the inorganic form was the dominant portion of phosphorus, and detrital aptaite phosphate makes up of 73% of the total inorganic P. The organic P was also an important portion, it made up of 38.8% of total phosphorus (TP). TP, organic P and Fe bound phosphate (Fe P) had a negative correlation with the depth of sediments. On the contrary, detrital aptite P showed a positive correlation with the depth. The correlation between TP, organic P, Fe P and the depth can be used as an indicator of marine environment pollution. Finally, under the physical chemical condition of Peal River Estuary, organic P and Fe P were the potentially bioavailable phosphorus, and because Ca bound phosphate (authigenic P and detrital aptaite P) represent mean proportions of 49% of the total sedimentary phosphorus pool, it is considered that there is more than half of the sedimentary phosphorus pool represents an insoluble phase which should be ignored in terms of potential resource of the water column.