Two double-layer composite electrodes were fabricated by coating anion exchange resin (A520E) and carboxyl-functionalized multi-walled carbon nanotubes (MWCNTs-COOH) onto activated carbon electrodes. Subsequently, an asymmetric capacitive deionization reactor was assembled to evaluate performance of the selective electro-adsorption of nitrate in 2 mM chloride and 1 mM nitrate solutions. In the experiment, the total amount of anions adsorbed in reactor reached 48.80 mmol/m², with nitrate accounting for 54.07% in particular. It was confirmed that A520E/AC/GP electrode enhanced nitrate selectivity, and MWCNTs-COOH/AC/GP electrode increased the adsorption capacity. An investigation of desorption of anions showed nitrate was electrostatically adsorbed on electrode and then ion exchanged on the resin layer. When the applied voltage increased from 1.0 to 1.6 V, the total amounts of adsorbed anions increased, while the molar fraction of nitrate decreased. Desalination tests performed using different binary solutions of anions, revealed that the order of desalination capacities for anions is NO₃⁻ > SO₄²⁻ > F⁻ ≈ Cl⁻. A highly linear relationship between the amounts of total adsorbed ions and desorbed chloride ions on resin electrode indicated the same effect of changing solution conditions (i.e., concentration of ions) on adsorption by ion exchange and the electric field.

通过将阴离子交换树脂（A520E）和羧基官能化的多壁碳纳米管（MWCNTs-COOH）涂覆在活性炭电极上来制造两个双层复合电极。随后，组装不对称电容去离子反应器，以评估2mM氯化物和1mM硝酸盐溶液中硝酸盐选择性电吸附的性能。在实验中，反应器中吸附的阴离子总量达到48.80 mmol / m ^2。，其中硝酸盐占54.07％。证实了A520E / AC / GP电极增强了硝酸盐的选择性，MWCNTs-COOH / AC / GP电极提高了吸附能力。阴离子的解吸研究表明硝酸盐被静电吸附在电极上，然后离子在树脂层上交换。当施加的电压从1.0 V增加到1.6 V时，吸附的阴离子总量增加，而硝酸盐的摩尔分数降低。脱盐试验使用的阴离子的不同的二进制溶液进行，表明脱盐能力为阴离子的顺序是NO ₃ ^-  > SO ₄ ^2-  >˚F ^-  ≈氯^-。树脂电极上的总吸附离子和解吸氯离子之间的高度线性关系表明，改变溶液条件（即离子浓度）对通过离子交换和电场进行吸附具有相同的效果。