砷酸根及铬酸根在低聚合羟基铁-蒙脱石复合体表面的竞争吸附

在模拟氧化及酸性土壤条件下，用制备的低聚合羟基铁-蒙脱石复合体进行了砷酸根、铬酸根离子的竞争吸附实验，研究了砷酸根离子和铬酸根离子不同用量及不同添加顺序对竞争吸附的影响，并与蒙脱石和含水氧化铁进行了对比。结果表明，低聚合羟基铁-蒙脱石复合体对砷酸根及铬酸根离子有不同的吸附能力，但在实验条件下砷酸根及铬酸根离子在低聚合羟基铁-蒙脱石复合体表面不发生竞争吸附。砷酸根和铬酸根的吸附顺序对其吸附量有一定的影响。竞争吸附实验的砷酸根、铬酸根吸附量均高于对其单阴离子的吸附量，此现象在复合体表面最为明显，说明复合体具有独特的阴离子吸附性能。

Competitive Adsorption of Arsenate and Chromate on Hydroxy-Fe-Montmorillonite Complex

The competitive adsorption of arsenate and chromate was conducted on the surface of hydroxy-Fe-montmorillonite complex. The effect of the initial concentration and the addition order of arsenate and chromate on their uptake by hydroxy-Fe-montmorillonite complex was investigated. The results show that competitive adsorption does not exist between arsenate and chromate on hydroxy-Fe-montmorillonite complex under experimental conditions. The addition of the secondary anion increases the adsorption of the first one to some extent and this increase is proportional to the initial concentration of the two anions. The addition order of arsenate and chromate influences their uptakes to a certain extent, especially on the surface of hydroxy-Fe-montmorillonite complex. This phenomenon is more obvious for chromate for its relative weak affinity for adsorption on these surfaces.