湿地沉积物磷的吸附与解吸研究

Desorption and Sorption of Phosphorus by Wetland Sediments

采用恒温培养法研究美国纽约Pelham Bay Park6种典型淡水湿地沉积物中磷的吸附与解吸行为及其动力学过程。结果表明：湿地沉积物具有强烈吸附溶液中磷的功能，随着溶液中磷浓度的增加，吸附量增大；但是湿地沉积物也有释放磷到溶液中去的功能．释放量为0～41．19mg／kg，与沉积物吸附磷量的关系不大，沉积物释放磷与沉积物的特性有关。衡量一种淡水湿地沉积物的除磷能力，可根据沉积物最大吸附磷量和吸附解吸附平衡浓度（EPC0）来衡量．6种沉积物中，磷的最大吸附能力强弱依次是：S1〉S2〉S3〉S6〉S5〉S4；S1沉积物吸附磷的最大量为500mg／kg。各沉积物的平衡浓度相差很大，S4的吸附与解吸附平衡浓度最高，其值为166．00μg／L，而S2的吸附与解吸附平衡浓度最低，其值为0．36μg／L。低的EPC0值表明，沉积物有很强的吸附磷的能力，故S2湿地生态系统有非常强的除磷能力。

The objectives of this study were to determine the ability of six wetlands site sediment to release and sorption P. Sorption characteristics and kinetics equations were obtain by incubating sediments collected from Pelham Bay Park wetlands, New York, USA. Sediments had the strong ability to sorb P from the solution, and more sorption amount by the increase of amount of P in the solution. However, the sediments released P to the solution, the amount of released P ranged from 0 to 41.19 mg/kg. Maximum P sorption capacity （Smax） and Equilibrium P concentration （EPC0） can determine the removal of P by wetland. Smax was the highest for S1 wetland sediment, and its value for 500 mg/kg. EPC0 was lowest in S2 sediments, indicateing a high capacity of these sediments to sorb P. EPC0 ranged from 0.36 to 166.00 μg/L from six wetlands sediment.