盐度对厦门筼筜湖疏浚物-海水界面上镉交换作用的影响

Influence of salt on exchange action of Cd on dredged materials-seawater interface from Yuandang Lake,Xiamen

本文报道了厦门筼筜湖疏浚物在不同盐度的天然海水中镉的溶出和被吸附的模拟研究结果。在相同条件下释放量(释放率)随介质盐度升高而增大,而被吸附能力降低。讨论了盐度的影响及溶出与再吸附所遵循的动力学规律。

This paper intends to find the factor influencing Cd chemical action on solid-liquid interface in the oceanic environment. The release and re-adsorption kinetics of Cd in seawater of different salinity of dredged sediments from Yuandang Lake has been studied in simulation. The results show that(1) In seawater of salinity from 8 to 34, Cd is released from dredged materials into seawater, with a release ratio of 60%～90% and re-adsorption ratio of 7.1%～27%, implying that Cd may transfer in marine environment mostly as dissolve species.(2) The intensity of media ion has evident influence on the exchange action of Cd on dredged materials-seawater interface. The release ratio increases and readsorption rate decreases with increasing salinity.(3) It has been demonstrated that the exchang-adsorption kinetic model of solid-liquid interface proposed by the authors can be used to explain the exchang action of Cd on dredged sediments-seawater interface and deal with the release-readsorption kinetics of Cd.