三维电极体系中苯酚降解效率的影响因素研究  

Influencing factors of phenol degradation efficiency using three-dimensional electrodes system

作　　者：王立章[1] 乔启成[1] 傅剑锋[2] 王哲晓[1] 

机构地区：[1]中国矿业大学环境与测绘学院,江苏徐州221008 [2]东南大学环境工程系,江苏南京210096

出　　处：《生态环境》2007年第3期850-854,共5页Ecology and Environmnet

基　　金：甘肃省中青年基金项目(ZS021-A25-021-G)

摘　　要：三维电极法用于处理含酚废水的影响因素研究报道较多,但并未充分在理论上阐述其影响方式及机理。采用自制的实验室小试电化学反应器对含酚自配废水进行了处理。试验结果表明:体系中苯酚降解遵循一级反应模式;通过电流效率的核算确定60min作为最佳反应时间,得到的苯酚去除率为64.3%,吨水处理能耗为14.29kW·h·t-1,实际电流效率与理论电流效率相等为0.68。对体系进水控制不同的苯酚起始质量浓度,当反应时间不变时,实际试验结果与法拉第定律一致,即电流密度与去除的污染物的量以及COD去除率与电量和进水质量浓度的比值均呈线性关系;体系中羟基自由基的产生量能够采用式[?OH]=0.1218×EC0进行计算。采用最佳反应时间t=60min、电流密度I=20A,在苯酚质量浓度为500mg·L-1时改变极板间距进行的试验结果表明电压随极板间距的增大而降低,最佳极板间距为0.21m时可获得最大去除率为78.5%,体系的启动电压为0.25V。Influencing factors of phenol degradation efficiency using three-dimensional electrodes system were reported so much, but how and why they influenced it were discussed so little. In this study, the electro-chemistry oxidation of phenol using lab-scale three-dimensional electrodes （TDE） reactor was conducted. Results from this experiment revealed that the degradable behaviors of phenol can be reasonably described by first-order kinetics and the optimize reaction time was obtained by value of 60 min with phenol removal rate 64.3% and energy consumption 14.29 kW·h per ton wastewater for phenol oxidation process. In addition, factual current efficiency was accordance with the theoretical one with the value of 0.68. Experiment at the condition of constant reaction time with different initial phenol concentration illustrated that there were linear relationship between current density, COD removal rate and phenol quantity removed, ratio of electric quantity and influent COD respectively. Concentration of hydroxyl radicals generated from electrode process could be calculated with the description of [·OH]=0.121 8×EC0. With the increasing of inter-electrodes distance, voltage for oxidation decreased at the reaction conditions of t=60 min, I=20 A and C0=500 mg·L^-1. From this study, the optimize inter-electrodes distance, maximum phenol removal rate and startup voltage were also obtained with the value of 0.21 m, 78.5% and 0.25 V respectively.

关 键 词：三维电极 羟基自由基 反应时间 起始质量浓度 启动电压 

分 类 号：X703.1[环境科学与工程—环境工程] TQ035[化学工程]