首页  |  本刊简介  |  编委会  |  投稿须知  |  订阅与联系  |  微信  |  出版道德声明  |  Ei收录本刊数据  |  封面
超声强化金刚石膜电极电化学降解效率的机制
摘要点击 3699  全文点击 2301  投稿时间:2007-09-07  修订日期:2007-10-10
查看HTML全文 查看全文  查看/发表评论  下载PDF阅读器
中文关键词  电化学氧化  金刚石膜电极  超声  传质  吸附量  平均电化学氧化能量利用率
英文关键词  electrochemical oxidation  BDD electrode  ultrasound  mass transport  adsorption amount  average electrochemical oxidation energy efficiency
DOI    10.13227/j.hjkx.20080729
作者单位
沈世豪 同济大学化学系上海 200092 
赵国华 同济大学化学系上海 200092 
吴梅芬 同济大学化学系上海 200092 
雷燕竹 同济大学化学系上海 200092 
刘梅川 同济大学化学系上海 200092 
中文摘要
      从电化学氧化的传质过程、吸附与脱附、电极反应3个步骤,考察了超声强化金刚石膜电极(BDD)电化学降解效率的机制.超声对上述3个步骤都有显著影响.超声增强了污染物的传质过程,苯酚和邻苯二甲酸的传质系数分别由5.410-6 m/s和6.710-6 m/s增大至2.010-5 m/s,提高了270%和199%.污染物在BDD电极表面的电化学吸附特性决定了超声对吸附与脱附过程的作用.苯酚的吸附量大,但中间产物难于脱附,超声虽然使得吸附量由6.4910-10 mol/cm2减小至1.3910-10 mol/cm2,但促进了产物的脱附,产生了正效应,有利于直接氧化,氧化峰电流提高了32%;邻苯二甲酸的吸附能力弱,超声使得吸附量由1.2510-11 mol/cm2进一步减小至3.1110-12 mol/cm2,产生了负效应,导致直接氧化消失.超声可以显著提高BDD电极的降解效率,而且对苯酚降解的促进作用更为明显.苯酚的平均电化学氧化能量利用率提高了287%,高于邻苯二甲酸的224%,这主要是因为超声可以同时强化苯酚的直接氧化和间接氧化,但对于邻苯二甲酸,间接氧化得到了加强,却不发生直接氧化.
英文摘要
      Mass transport process, adsorption and desorption, and electrochemical reaction were analyzed to investigate the mechanism of enhancement on boron-doped diamond (BDD) electrode electrochemical degradation efficiency by ultrasound (US). US has considerable influences on the above steps of electrochemical oxidation. Mass transport coefficients of Ph and PA reach 2.010-5 m/s with US, from 5.410-6 m/s and 6.710-6 m/s in EC process, increasing by 270% and 199%, respectively. The effect of US on adsorption and desorption has relationship with electrochemical adsorption properties of pollutants on BDD electrode surface. The adsorption amount of Ph decreases from 6.4910-10 mol/cm2 to 1.3910-10 mol/cm2, with the desorption of polymer intermediates promoted, so US makes positive effect with benefit to direct oxidation and oxidation peak current increases by 32%. For PA, the adsorption amount decreases from 1.2510-11 mol/cm2 to 3.1110-12 mol/cm2 with US, and no direct oxidation happens in US-EC process. US can improve degradation efficiency of BDD electrode and the enhancement on Ph degradation is more effective. Average electrochemical oxidation energy efficiency (AEE) of Ph increases by 287%, more than 224% of PA. This is because both direct and indirect oxidation for Ph can be enhanced by US, while for PA, direct oxidation almost disappears.

您是第83078283位访客
主办单位:中国科学院生态环境研究中心 单位地址:北京市海淀区双清路18号
电话:010-62941102 邮编:100085 E-mail: hjkx@rcees.ac.cn
本系统由北京勤云科技发展有限公司设计  京ICP备05002858号-2