This study interrogated straightforward ball-milling (BM) of powdered activated carbon (AC) to intensify the selective separation by capacitive deionization (CDI) primarily for SO₄²⁻ with potential eco-toxicity. Depending on the BM duration (20 to 60 h) of coconut-derived AC, the prevalent shift in pore size distribution or surface charge/moieties was observed for BM-20 and BM-60, respectively, whereas synchronous modifications were noted for BM-40. In single-pass experiments (1.2/0 V) with symmetric electrodes, BM-40 notably elevated the selectivity factor of SO₄²⁻ by 36 % from equimolar SO₄²⁻/Cl⁻ mixture (2 mM each). Enumerated effective pores for SO₄²⁻ (0.76–1.1 nm) and shorted diffusion length of reduced grain accelerated replacement of pre-sorbed Cl⁻ by divalent SO₄²⁻ under the alleviated ion-sieving effects. Comparison with asymmetric cells with the pristine negative electrode further evinced that ameliorated co-ion repulsion from the oxidized (with augmented potential of zero charge) negative electrode could secure driving potential on the positive electrode to strengthen the energetic-affinity-based ion swapping. In addition, quasi-absolute selectivity for NO₃⁻ sorption (with a partial inversion behavior for Cl⁻) was observed in the asymmetric cell receiving equimolar SO₄²⁻/Cl⁻/NO₃⁻ composite. Consequently, the BM effectively regulated not only the perm-selectivity, but also the surface charge and/or specific interaction.

本研究询问了粉末活性炭 (AC) 的直接球磨 (BM) 方法，以通过电容去离子 (CDI) 加强对具有潜在生态毒性的 SO ₄ ^{2-的选择性分离。}根据椰子衍生 AC 的 BM 持续时间（20 至 60 小时），BM-20 和 BM-60 分别观察到孔径分布或表面电荷/部分的普遍变化，而 BM- 40. 在使用对称电极的单程实验 (1.2/0 V) 中，BM-40 将等摩尔 SO ₄ ^2- /Cl ^-混合物（各 2 mM）的 SO ₄ ^2-选择性因子显着提高了36% 。_{SO 4} ²⁻的枚举有效孔（0.76-1.1 nm）和缩短的颗粒扩散长度加速了二价SO ₄ ^{2-对预吸附Cl -}的替代，从而减轻了离子筛分效应。与具有原始负极的不对称电池的比较进一步表明，改善来自氧化（零电荷电位增加）负极的共离子排斥可以确保正极上的驱动电位，以加强基于能量亲和力的离子交换。此外，在接收等摩尔 SO ₄ ^2- /Cl ^- /NO的不对称电池中观察到NO ₃ ^{-吸附的准绝对选择性（Cl -}具有部分反转行为）₃ ^-复合。因此，BM 不仅有效地调节了渗透选择性，还有效地调节了表面电荷和/或特定的相互作用。