水源水库沉积物磷形态分布及其释放特征

采用淡水沉积物中磷形态的标准测试方法（SMT），分析测定了西安市汤峪水库表层沉积物中总磷及各形态磷的含量分布特征，并对该分级测定结果与间隙水水质及沉积物其他理化性质进行了相关性分析．结果表明，该水库表层沉积物中总磷（TP）含量为1215．03～1592．83μg／g；铁铝结合态磷（Fe／Al-P）平均值为241．34μg／g，其余形态磷中，钙结合态磷（Ca—P）为7111．98μg／g，有机磷（OP）为301．54μg／g．相关性分析方面，Fe／Al-P含量与间隙水中TOC浓度显著相关．环境变化会导致Fe／Al-P释放进入水体，当氧化还原条件降低时，结合态的磷会由于2价铁的溶出而释放到间隙水和上覆水中，是水库富营养化的潜在威胁．

Phosphorus Forms and Its Distribution in Source Water Reservoir Sediment

Total phosphorus （TP）and distribution of phosphorus speciation in surface sediments collected from Tan- gyu Reservoir in Xi＇an were analyzed, using the standard measurement and test （SMT） procedure of phosphorus forms in the freshwater sediments. Correlation coefficients between phosphorus forms and some water qualities of pore water and some other sediment geochemical characteristics were analyzed. The TP content in surface sediment of this reservoir varied from 1 215.03- 1 592.83μg/g. The average content of Fe/Al-bound phosphorus（Fe/A1-P） was 241.34 μg/g. Among the other speciations of phosphorus, the content of Ca-bound phosphorus （Ca-P）was 711.98 μg/g and organic-phosphorus （OP）was 301.54μg/g. From the correlation analysis, TOC was significantly and posi- tively correlated to Fe/A1-P. The Fe/AI-P, which can be released into the overlying water when environment changes, is the potential threat to the reservoir eutrophication. When the oxidation-reduction potential decreases, the phosphorus which was once bonded with ferrous will be released into the pore water and the overlying water because of the dissolution ofFe （ II ）.