河口水中Cd(Ⅱ)在Fe_2O_3·nH_2O(am.)上的特性吸附及界面电性研究

Study of Specific Adsorption of Cd(Ⅱ) on Fe_2O_3·nH_2O(am.) and Interface Electroproperties in Estuary Water

本文叙述了盐度为5％。的河口水中Cd（Ⅱ）在Fe2O3·nH2O（am）上的吸附等温线以及pH，盐度对吸附百分率的影响，着重讨论了吸附对固-液界面电性的影响和不同盐度（s＝2.5‰;5.0‰;7.5‰）时吸附Cd（Ⅱ）后变化的等电点。结果表明：Cd（Ⅱ）在Fe2O3·nH2O（am.）上的吸附为特性吸附，固液界面的电性变化及等电点移动与体系的pH和Cd（Ⅱ）的吸附量有关。盐度上升，吸附量降低，由吸附～pH曲线和海水中锅的溶存状态可知吸附机理为离子交换～表面络合沉淀过程。

This paper studied the adsorption of Cd(Ⅱ) on the amorphous Fe2O3. nH2O in estuary water as the solution salinity was 5‰, It described adsorption isotherm, the influence of pH and salinity, perticularly in effect of adsorption on electroproperties at solid-liquid interface, and varied isoelectropoint after its adsorption of Cd(Ⅱ) at various salinity (2.5‰, 5‰, 7.5‰)respectively. The results are: The adsorption of Cd(Ⅱ ) on Fe2O3·nH2O(am.) is specific adsorption. The changing of electroproperties of solid-liquid interface and the varying of isoelectropoint have so mething to do with the pH of the system and the adsorption quantity. As the salinity increased, the adsorption quantity decreased. From the adsorption-pH curve and the state scheme of Cadmium in sea water, we could conclude the adsorption mechanism is" ion-exchange adsorption-surface complexion precipitation.