División de Ciencias Ambientales del Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, Col. Lomas 4(a) sección, San Luis Potosí, S.L.P, Mexico.
Universidad de Guanajuato, Departamento de Ingeniería Geomática e Hidráulica, Av. Juárez 77, Zona Centro, C.P. 36000, Guanajuato, Mexico.
J Hazard Mater. 2020 Jun 15;392:122349. doi: 10.1016/j.jhazmat.2020.122349. Epub 2020 Feb 18.
In this work, the influence of oxygen-containing surface groups of activated carbon electrodes on the charge efficiency of electro-assisted adsorption of As(V) was investigated. It was distinguished between activated carbons modified through acidic (oxidation) and thermal (reduction) treatments, starting with a granular pristine commercial activated carbon of bituminous origin. The textural characterization of the three materials showed that the treatments did not produce significant changes in the surface area and in the distribution of pores. The three carbon samples were used to fabricate packed electrodes with stainless-steel mesh as electric current collector. This work report that the application of anodic potentials (1.01 and 1.41 V vs. NHE) increased the adsorption capacity and rate of arsenate uptake in solutions containing only this contaminant (2.5 mg L) at pH 7. The oxidized carbon electrode presented the lowest capacitance and adsorption capacity during electroadsorption (0.33 mg g), compared to pristine material (1.77 mg g). On the other hand, the reduced electrode displayed the highest adsorption capacity of arsenate (3.14 mg g) when applying a potential of 1.01 V. The results were correlated with the potential of zero charge values. In addition, for this material, the rate of kinetics increased 26.7 % compared to experiments without applied potential.
在这项工作中，研究了活性炭电极含氧表面基团对电辅助吸附 As(V) 的充电效率的影响。研究区分了通过酸性（氧化）和热（还原）处理改性的活性炭，起始材料为颗粒状原始商业沥青基活性炭。三种材料的结构特征表明，处理并没有在表面积和孔分布上产生显著变化。三种碳样品被用于制造带有不锈钢网作为电流收集器的填充电极。本工作报告，在仅含有这种污染物（2.5 mg L）的溶液中（pH 7），施加阳极电势（1.01 和 1.41 V 相对于 NHE）会增加吸附容量和砷酸盐的摄取速率。与原始材料（1.77 mg g）相比，氧化碳电极在电吸附过程中表现出最低的电容和吸附容量（0.33 mg g）。另一方面，当施加 1.01 V 的电势时，还原电极显示出最高的砷酸盐吸附容量（3.14 mg g）。结果与零电荷电位值相关。此外，与没有施加电势的实验相比，对于这种材料，动力学速率提高了 26.7%。
