染色残液电化学处理碳素阴极材料性能比较

Performance Comparison of Carbonaceous Cathode Materials for Electrochemical Treatment of Dyeing Residual

为实现染色残液的高效处理及废水回用,鉴于染色残液良好的导电性,选用电化学处理技术,以模拟活性红X-3B染色残液为研究对象,在钌铱形稳电极为阳极和合适的电解条件下,比较石墨板、石墨毡、炭毡、ACF(活性炭纤维毡)、碳纤维电极[CFF(碳纤维布)、CFB(碳纤维刷)]等碳素阴极材料的电化学处理效能.结果表明:碳素阴极材料可实现染色残液的完全脱色,活性红X-3B的降解过程符合一级反应动力学特征,其中CFF为阴极时CODCr去除率达到86. 37%,一级动力学反应常数为0. 010 3 min-1,是石墨毡(0. 007 3 min-1)的1. 4倍.相比于石墨板电极,CFB显示出优异的二电子氧还原和产H2O2能力,单位面积产H2O2的浓度为10. 40μmol/L,是石墨板(1. 08μmol/L)的9. 7倍,产生的H2O2导致活性红X-3B的降解,30 min内实现完全脱色.循环伏安曲线表明,碳纤维电极(包括CFF和CFB)的析氧电位明显高于其他电极,可有效抑制析氧副反应,提高有机污染物降解过程中的电催化效率,有利于降低能耗.研究显示,碳纤维可作为阴极材料应用于电化学处理染色残液,具有良好的稳定性.

In order to treat dyeing residual liquid effectively and reuse wastewater and salt, electrochemical oxidation was applied due to its excellent conductivity. The present work focused on comparing the performance of different carbonaceous cathodes materials, including graphite plate, graphite felt, carbon felt, active carbon felt （ACF）, carbon fiber electrode （carbon fiber fabric （CFF）, and carbon fiber brush （CFB）） using Ru-Ir DSA as an anode. For simulated Reactive Red X-3B dyeing residual liquids, it was found that carbonaceous cathodes materials could achieve a complete decolorization and the degradation of Reactive Red X-3B followed the first-order kinetics. Using CFF cathode, the removal of COD Cr of dyeing residual liquid was 86.37%. The first-order kinetic reaction constant on CFF cathode was 0.0103 min -1 , 1.4 folds of that on carbon felt cathode （0.0073 min^ -1 ）. Comparing to the graphite plate cathode, the CFB cathode exhibited excellent efficacy for 2e - oxygen reduction reaction and H 2O 2 generation capacity, leading to the degradation of Reactive Red X-3B . The H 2O 2 generation per area of CFB cathode was 10.40 μmol L, which was 9.7 folds of that of graphite plate cathode （1.08 μmol /L ）. Based on CV examination, the oxygen evolution potential of carbon fiber electrodes, including CFF and CFB, was found to be higher than the other cathodes used in this work, which favors the inhibition of oxygen evolution and improves electro catalytic efficiency. The results of this study show that carbon fiber cathode with desirable stability may have potential industrial applications in dyeing residual liquid treatment.