CTMP模拟废水在铂电极上循环伏安特性的研究

为探索电化学法脱除桉木CTMP废水色度的机理，以鞣酸模拟CTMP废水作为研究对象，自行设计组装了循环伏安系统，考察了鞣酸在铂电极上的循环伏安特性。结果表明：在pH=4．0的柠檬酸钠-盐酸缓冲溶液中出现-灵敏的氧化峰，峰电位为-1．1V左右；随着鞣酸浓度的增加，峰电位开始逐渐增大，到一定浓度后略有下降，最后基本达到稳定值，而对于峰电流密度，则是随着鞣酸浓度的增加而不断增大；在铂电极上进行的鞣酸缓冲溶液体系的电化学氧化，同时涉及扩散和吸附两种过程；在鞣酸的结构式中，苯环上的取代基为-OH，其Hammet常数为负值，根据Hammet常数理论，推测鞣酸发生的是电化学氧化反应，与实验结果相一致。

Study on Characteristics of CTMP Model Effluent Cyclic Voltammetry on Platinum Electrode

In this paper,tannic acid was chosen as CTMP model effluent.In order to investigate the mechanism of electrochemically removing chroma of CTMP wastewater,the characteristics of tannic acid were studied on platinum electrode with the methods of cyclic voltammetry.The results showed that tannic acid had an obvious oxidation peak at about-1.1V in C6H5Na3O7-HCl buffer solution(pH=4.0);with the increasing of tannic acid concentration peak voltage began to go up and then slightly declined after getting to certain concentration and basically became steady in the end,but the current density increased as the concentration of tannic acid was up;the tannic acid electrochemical reaction on platinum electrode was an oxidation process composed of diffuse and adsorption at the same time.Because the substituted group of phenyl is-OH in the structure of tannic acid and its Hammet constant is minus,according to the theory of Hammet constant,electrochemical oxidation reaction should take place,which is in accordance with the result of this experiment.