『Abstract
　The Daliao river system in China has been seriously affected by long-term intensive industrial, urban and agricultural activities. The objectives of this study were to determine the total phosphorus (TP) content and forms of phosphate in the sediments and investigate geochemical relationships between P forms and sediment mineral phases. Twenty-seven samples of surface sediments were collected and analyzed for P and major elements. Chemical forms of phosphate in the sediments were measured by sequential selective extraction method. Results indicate that TP in the sediments of the Daliao river system averaged 703 mg kg^-1, in the range from 206 to 1,342 mg kg^-1. The sediments in the tributaries and near cities contained high TP, due to discharge of municipal and industrial effluents. The distribution of phosphate in the various mineral phases followed the order: Ca-P＞RES-P＞RS-P＞Fe-P＞Al-P＞S/L-P for the Hun river and Taizi river, and Ca-P＞Fe-P＞RES-P＞RS-P＞Al-P＞S/L-P for the Daliao river. Fe and Ca contents in the sediments were positively correlated to Fe associated P (Fe-P and RS-P) and Ca-P, respectively. In addition, sediment organic matter, Fe and Ca contents were positively correlated to TP in the sediments. However, al content was not correlated to Al-P or TP in the sediments. Generally, the sediments contaminated by effluents and in tidal zone contained more bioavailable P. Possible release of P from these sediments to overlying water might pose potential risk on estuarine eutrophication.

Keywords: Daliao river; Sediment; Phosphorus; Fractionation; Bioavailability』

Abbreviations
　S/L-P　Soluble and loosely bound P
　Al-P　Al bound P
　Fe-P　Fe bound P
　RS-P　Reductant soluble P
　Ca-P　Ca bound P
　RES-P　Residual P
　SOM　Sediment organic matter
Introduction
Materials and methods
　Sediment sampling and analysis
　Phosphorus fractionation
Results and discussion
　General properties of the sediments in the Daliao river systems
　Chemical forms of P in the sediments of the Daliao river system
　Relationships between P and mineral phases in the sediments of the aliao river system
Conclusion
Acknowledgments
References

• Pierzynski,G.M.(Ed.)(2000): Methods of phosphorus analysis for soils, sediments, residuals, and waters. Southern Cooperative Series Bulletin No. # 396、110p．〔2009年版はこちら〕【見る→】
  『土壌と堆積物と残留物と水のリン分析法』
  Zhang（2000）による連続抽出法を使用。