太湖东北部沉积物理化特征及磷赋存形态研究

对太湖东部和北部8个沉积物样品进行了理化性质及磷赋存形态分析，在此基础上探讨了沉积物各理化性质与磷赋存形态间的相关关系。研究结果表明：太湖沉积物的总磷含量为307.43～1454.39 mg/kg，阳离子交换量为15.18～22.68 meq/100g土，有机质含量为1.66%～3.45%；颗粒组成以粉砂级和粘粒级为主，占总量的54.39%～76.83%；主要矿物组成为石英和长石，粘土矿物以伊利石/蒙脱石混层为主，其次是伊利石、绿泥石和高岭石；沉积物中氧化物以SiO2、Al2O3和TFe2O3为主，且它们的含量随沉积物中总磷含量的不同变化较大。磷的形态以无机磷为主，污染较重沉积物中铁/铝磷的含量明显升高，有机磷的比例降低，钙磷变化不大。沉积物的各理化性质与磷赋存形态间关系密切，随着沉积物中总磷含量的增加， 阳离子交换量和有机质的含量都逐渐升高，细颗粒含量（<2 μm）逐渐增多，铁/铝形态的磷在总磷中所占比例也逐渐增大。

PHYSICAL-CHEMICAL CHARACTERISTICS AND FORM OF PHOSPHORUS SPECIATIONS IN THE SEDIMENTS OF NORTHEAST LAKE TAIHU

The physical and chemical characteristics, various phosphorous forms from 8 sites in Lake Taihu's sediments were analyzed, and their relations were discussed. The results showed that，the values of total phosphorous, cation exchange capacity and organic matter are 307.43～1454.39 mg/kg, 15.18～22.68 meq/100g, 1.66%～3.45% , respectively; the main mineral compositions of the sediments are quartz and albite; the main clay minerals（<2 μm）are montmorillonate, illite, chlorite and kaolinite. The common composition of the sediments are mainly made up of SiO2, Al2O3 and TFe2O3, and their contents change greatly as the values of total phosphorous change. Close relations between physical chemical characteristics and various phosphorous forms exist in the sediments of Lake Taihu. As the concentrations of total phosphorous increase, the values of cation exchange capacity, organic matter and clay increase, at the same time, the proportion of Fe/Al P in TP increase.