Effects of pore-structure and Surface Acidities of Activated Carbon Electrodes on The Double-layer Adsorption

使用流动电容器（FTC）可以有效地去除稀溶液中的电解质，当使用多孔活性炭电极时，去除效率达到85%以上。结果表明，活性炭的去除率一般取决于活性炭的表面积和微孔体积。此外，表面官能团也有改善离子去除的作用，但官能团的数量有限，主要是由于离子运输的干扰。离子的去除机制包括：1)静电力吸附；2)施加电压时的电化学离子交换反应；3)电解质与活性炭接触的正常离子交换反应（特别是铜离子）；1)电极表面的电解（例如铜离子和锌离子）。在长时间的离子去除过程中，电解形成的金属会影响活性炭电极的孔结构。碱金属是最容易回收和浓缩的，但重金属是最难回收和浓缩的。后一种离子主要在电极界面处通过电解去除，金属在电极表面生成。因此，用这种方法无法浓缩和回收金属离子。阳离子的脱除和解吸程度由低到低依次为：碱性金属>碱土金属>过渡金属。对硫酸和硝酸盐的循环特性进行了研究，获得了较高的回收率。在单层和电双层中都不容易解吸。为了增加污水处理量，进行了大规模的污水处理。确定了高效优于小效的最佳运行条件。

It was possible to efficiently remove electrolytes from dilute solution using the flow-through capacitor (FTC), and a greater then 85% removal efficiency was achieved when porous activated carbon electrodes were used. It was confirmed that the amount of removal is generally dependent on the surface area and micropore volume of the activated carbon. Also, surface functional groups had the effect of improving ion removal, but there is a limit to the amount of groups mainly due to the interference of the transport of ions. The mechanisms for removal of the ions is proposed to include 1) adsorption by electrostatic force, 2) electrochemical ion exchange reactions when voltage is applied, and 3) normal ion exchange reactions by contact between the electrolyte and the activated carbon (especially for copper), and 1) electrolysis on the surface of the electrode (for example, for copper and zinc ions). The metal formed by electrolysis affected the pore structure of the activated carbon electrodes during prolonged ion removal. Alkali metals could be recovered and concentrated the easiest, but heavy metals were the most difficult. The latter ions were removed mainly by electrolysis at the interface of the electrode and the metals were being produced on the electrode surface. Therefore it was impossible to concentrate and recover the metal ions by this method.Cations have been demonstrated to be removed and desorbed in the following descending order of ease: alkaline metal > alkaline earth metal > transition metal. A high recovery rate has been obtained in the cycle characteristics of sulfuric acid and nitrates. In both one- and electric double layer are not easily desorbed.In order to increase volume of wastewater treatment, the FTC was large scaled. The optimum running conditions were determined for high efficiency better than small ones.