三峡入库河流大宁河回水区沉积物和消落带土壤磷形态及其分布特征研究

应用淡水沉积物中磷形态的标准测试程序（SMT）对三峡入库河流大宁河回水区表层沉积物、消落带土壤不同形态P进行了分级测定，分析了各形态磷之间以及各形态磷与样品理化性质如有机质、主要氧化物组成之间的相关性.结果表明，沉积物总磷含量在483.4～848.4 mg/kg之间，平均为569.0 mg/kg，与长江中下游浅水湖泊表层沉积物总磷含量相比，大宁河回水区表层沉积物TP含量处于中下游水平，而消落带土壤中总磷含量在488.9～1 487.7 mg/kg之间,平均含量为813.3 mg/kg，远远高于沉积物样品总磷含量，显示了人类活动对消落带土壤P含量的影响.各种形态P在河流沉积物与岸边消落带土壤中分布特点不同: ① 河流沉积物中IP/TP（平均值55.7%）略高于消落带土壤（平均值49.4%）；② 河流沉积物中IP以Ca-P为主（平均比例为83.5%）， Fe/Al-P占IP比例仅为15%；消落带土壤Ca-P占IP平均比例为73.9%， 而Fe/Al-P占IP比例上升至22%；③ 河流沉积物中活性磷组分（OP+Fe/Al-P）平均含量为261.8 mg/kg，在TP中所占比例平均值为49%，而消落带土壤活性磷组分（OP+Fe/Al-P）平均含量为405.7 mg/kg，在TP中所占比例平均达到54%.消落带土壤中活性磷组分在适宜的环境条件下会成为水体的二次污染源，因此消落带土壤P对水体富营养化的潜在影响不容忽视.

Phosphorus Forms and Its Distribution Characteristics in Sediments and Soils of Water-Level-Fluctuating Zone of the Backwater Reach from Input River of Three Gorges Reservoir

The contents of different phosphorus forms in surface sediments and the soils of water-level-fluctuating zone of the backwater reach from input river of Three Gorges Reservoir were measured,using the standard measurement and test(SMT) procedure of phosphorus forms in freshwater sediments.Correlation coefficients between phosphorus forms and sample geochemical characteristics,such as organic matter and major components were analyzed.The results indicated that the TP content in surface sediments varied from 4...