环境因素对长江口水域沉积物吸附磷酸盐的影响研究

The Influence of Environmental Factors on the Adsorption Behavior of Phosphate by Suspended Sediments from Changjiang Estuary

研究了pH、盐度、沉积物浓度和温度等环境因素对长江口水域悬浮沉积物吸附磷酸盐的影响规律.实验结果表明:不同沉积物对磷酸盐的吸附都存在一个明显的“稳定pH范围”,而且该范围基本一致,均在6.5—9.5之间;几种沉积物的最大吸附盐度值均在6左右,范围为5—7;单位重量沉积物上的磷酸盐吸附量随沉积物浓度的增加呈明显下降趋势,而沉积物对磷酸盐的绝对吸附量则随着沉积物浓度的增加呈直线上升趋势;大部分沉积物样品对磷酸盐的吸附量随温度的升高而升高,呈现出吸热反应的特征,但有的沉积物样品却呈现出放热吸附反应的特征.

The influences of environmental factors on adsorption behavior of phosphate by suspended sediments from Changjiang estuary were studied. The results show that: the adsorption capacities of different sediment samples have fixed values within the pH range from 6.5 to 9.5, which is called “stable pH scope”; the maximum adsorption capacity of different sediment samples occurs at salinity 6; the relative adsorption capacities decrease obviously but the absolute adsorption capacities increase linearly with the increase of sediment concentrations; the phosphate adsorption capacities on most of the sediments increase with the increasing of temperature, showing the characteristics of endothermic reactions while some samples show the characteristics of exothermic reactions.