Here it is reported the electrosorption of fluoride in the presence of competing anions of environmental relevance (chloride, nitrate, sulfate, phosphate and arsenate) by two activated carbon electrodes impregnated with La(III), La-0.5% and La-1.5% (w/w %). The electrosorption kinetics were evaluated using equimolar initial concentrations (0.263 mM of each studied anion) in both binary solutions (F⁻ vs. anion) and in a complex mixture comprising all anions simultaneously. For La-0.5%, the presence of nitrate and chloride did not significantly modify its fluoride removal (q = ∼19.25 µmol g⁻¹), while these same anions decreased the fluoride removal of La-1.5% from 32.85 to 17.2 and 13.95 µmol g⁻¹, for nitrate and chloride, respectively. In general, the divalent anions competed the most during the kinetics, decreasing the fluoride removal in both carbons; the lowest capacity values were 5.75 and 4 µmol g⁻¹ for La-0.5% and La-1.5%, respectively. The increases in the pH of the solution corroborated that all anions anchored to the modified surface by a ligand-exchange mechanism involving the exposed hydroxyls from the La(III) clusters. The discussion of the results was not centered on the charge and the hydrated radius of the anions, but it was also expanded to other thermodynamic parameters that also denote selectivity, such as the hydration energies and mass-transport parameters. Electrochemical impedance spectroscopy was performed as a characterization technique in two electrolytes: 0.1 M NaF and the working solution, 0.263 mM NaF (5 ppm F⁻ solution). The information obtained from the latter correlated the most with the electrosorption performance of the electrodes.

据报道，在存在与环境相关的竞争性阴离子（氯离子、硝酸根、硫酸根、磷酸根和砷酸根）的情况下，通过两个浸渍有 La(III)、La-0.5% 和 La-1.5% 的活性炭电极电吸附氟化物（重量/重量％）。^{在二元溶液（F -} 对阴离子）和同时包含所有阴离子的复杂混合物中，使用等摩尔初始浓度（每种研究阴离子的 0.263 mM）评估电吸附动力学。对于 La-0.5%，硝酸盐和氯化物的存在并没有显着改变其氟化物去除率 (q = ∼19.25 µmol g ^-1 )，而这些相同的阴离子将 La-1.5% 的氟化物去除率从 32.85 降低到 17.2 和 13.95 µmol g ^-1，分别为硝酸盐和氯化物。一般来说，二价阴离子在动力学过程中竞争最激烈，降低了两种碳中氟化物的去除率；最低容量值为 5.75 和 4 µmol g ^-1分别为 La-0.5% 和 La-1.5%。溶液 pH 值的增加证实了所有阴离子通过配体交换机制锚定到改性表面，该机制涉及来自 La(III) 簇的暴露羟基。对结果的讨论不是集中在阴离子的电荷和水合半径上，而是扩展到其他也表示选择性的热力学参数，例如水合能和传质参数。在两种电解质中进行电化学阻抗谱作为表征技术：0.1 M NaF 和工作溶液 0.263 mM NaF（5 ppm F ^-溶液）。从后者获得的信息与电极的电吸附性能最相关。