| 摘要: |
| 对国家海洋局第二海洋研究所1998年5月调查过程中采集的长江口外东海特定海区表层沉积物综合运用了EDEX、ASPILA和李悦方法进行了系统的总磷及其磷赋存形态分析。把磷分为5种赋存形态: 吸附态、铁结合态、钙结合态、碎屑态和有机态。同时, 结合其他沉积物性质和化学组分以及海水环境特征,讨论了磷的地球化学特征及其环境意义。研究表明, 表层沉积物中总磷(TP)、有机磷(OP)和铁结合态磷(Fe-P)的含量主要受控于物质来源；吸附态磷(Ad-P)与Fe-P和OP同属于沉积物中生物可利用磷范畴, 其在沉积物中的循环主要与铁氧化物有关, 钙结合态磷(Ca-P)主要来源于海洋浮游生物。
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| 关键词: 东海特定海区,表层沉积物,磷的分布,环境意义 |
| DOI：10.11693/hyhz200303006006 |
| 分类号: |
| 基金项目:国家十五(973)重点基金项目(地球圈层相互作用中的深海过程和深海记录———海水与海底的物质能量交换), G2000078503号和中日合作项目, 1997 |
附件 |
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| DISTRIBUTION OF DIFFERENT FORMS OF PHOSPHORUS IN SEABED SEDIMENTS FROM EAST CHINA SEA AND ITS ENVIRONMENTAL SIGNIFICANCE |
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ZHENG Li-Bo1, YE Ying2, ZHOU Huai-Yang3, WANG Huai-Zhao2
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1.Geographical Department, East China Normal University;2.Department of Earth Science, Zhejiang University;3.Second institute of Oceanography, State Ocean Administration
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| Abstract: |
| In recent years, eutrophication becomes a serious environment problem in the Changjiang River estuary and adjacent East China Sea due to large nutrient discharge from the Changjiang River. In this study, total phosphorus and its related forms in the sediment is analyzed by means of SEDEX, ASPILA and XRF methods, to determine the geochemistry characters of phosphorus in this region. There are five types of phosphorus: Absorbed-phosphorus(Ad-P), iron-phosphorus (Fe-P), organic-phosphorus (OP), calcium-phosphorus (Ca-P) and detritus-phosphorus (De-P). They differ from each other in occurrence, origin and geochemical features. The TP (Total phosphorus) content in sediment varies from 416.5—697.4μg/g, and its distribution in geographic space is similar with the variation of OP and Fe-P′s distribution. TP, OP and Fe-P contents decrease regularly from the estuary to seaward, corresponding to the pattern of dissolved P. Fe-P includes ferric phosphorus and aluminum phosphorus, known as potential variable component in sedimentary phosphorus. In the seabed sediment, Fe-P can be used to determine the source of phosphorus and to indicate the extent of environment pollution. The variation of OP distribution is plicated, for the sources of OP can stem from matters inherited from both terrestrial source and the marine planktons. Ca-P, including authigenic carbonate, fluorapatite, CaCO3-associated P and biogenic apatite, represents an oceanic sink for reactive P. In the study area, distribution of Ca-P has no relation with CaO in sediment cores, but exhibits an excellent positive correlation with primary productivity and chlorophyll-a content in seawater. Ca-P is mainly in the form of autoclast created by marine plankton, independent of terrigenous supply. As reactive phosphorus, Ad-P in sediment is one of the important forms of inorganic phosphorus and can easily be released to water and be uptook by photoplankton. In our study, the distribution of Ad-P in sediment is slightly dependent on iron-oxides and seems independent on aluminum oxides, indicating that the Ad-P content is mainly controlled by iron-oxides, rather than clay minerals. In the study area, De-P makes up a great mass of TP, varied from 64.9%—79.9%, but its distribution shows no clearly correlation with TP′s. The De-P content is vulnerable to environment factors, such as changes in pH, temperature and salinity conditions. Ad-P, OP and Fe-P are bio-usable phosphorus, but only Ad-P can be directly used by organisms. The interface exchange of phosphorus between sediment and seawater is determined by the phosphorus forms in sediment. However, there is possibility for other forms of phosphorus being transformed into Ad-P. Hence, to understand under what conditions phosphorus can be changed from one type into another, and phosphorus in sediment can be released into seawater is essential.
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| Key words: East China Sea, Seabed sediment, Phosphorous distribution, Environment significance |
