东平湖表层沉积物中磷的吸附容量及潜在释放风险分析

利用沉积物磷吸附指数（PSI）和磷吸附饱和度（DPS）研究了东平湖表层沉积物的磷吸附容量，并讨论了沉积物中磷的潜在释放风险。结果表明，表层沉积物的磷吸附指数变化范围为30.3～45.2[mg P·（100g）-1]·（μmol·L-1）-1，表现出从湖心、湖东向湖北、湖南逐渐增大的扇形特征；而磷吸附饱和度变化范围为6.5%～24.1%，与磷吸附指数变化趋势恰好相反。磷吸附指数与沉积物中草酸铵提取的铁（FeOX）含量呈极显著正相关，与草酸铵提取的铁铝总量呈显著正相关，磷吸附饱和度与沉积物中草酸铵提取的磷（POX）含量呈显著正相关。此外，磷释放风险指数（ERI）变化范围为14.9%～67.5%，表明东平湖表层沉积物中磷释放诱发富营养化的风险处于高度风险范围。

Phosphorus Sorption Capacity of the Surfical Sediment in the Dongping Lake and Risk Assessment of Potential Phosphorus Release

Phosphorus sorption capacity of the surface sediments are estimated by the phosphorus sorption index （PSI） and the degree of phosphorus saturation（DPS ） of the sediments in the Dongping Lake,China. And the risk of potential phosphorus release was also investigated. The results showed that the phosphorus sorption index ranged from 30.3 to 45.2[mg P·（100g）-1]·（μmol·L-1）-1, increasing gradually from the mid-lake and the east to the north and the south of the lake. However, the variation tendency of the degree of phosphorus saturation （DPS） was exactly opposite, ranging from 6.9% to 24.7%. The phosphorus sorption index was very significantly and positively correlated to iron（Feox） and summation of iron and aluminum extracted from sediment by ammonium oxalate. The degree of phosphorus saturation was significantly and positively correlated to phosphorus（Pox） extracted from sediment by ammonium oxalate. And iron extracted from sediment by ammonium oxalate might be played a major role in adsorbing phosphorus. Additionally, the results showed that the phosphorus release risk index（ER1） ranged from 15.9% to 69.3%. The results of the phosphorus release risk index indicated that the Dongping Lake might be in high potential eutrophication risk due to the release of phosphorus from the surfacial sediments.