Daneshvar N, Sorkhabi H Ashassi, Kasiri M B
Water and Wastewater Treatment Research Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
J Hazard Mater. 2004 Aug 9;112(1-2):55-62. doi: 10.1016/j.jhazmat.2004.03.021.
This study was performed to investigate the variables that influence the efficiency of decolorization of a solution containing an azo dye (Acid Red 14) by electrocoagulation (EC) in order to compare the efficiency of different electrode connections for color removal. Current density, time of electrolysis, interelectrode distance, and pH of the solution were the variables that most influenced color removal. Initially, a simple electrochemical cell was prepared with an anode and a cathode. Then the effect of each variable was studied separately using synthetic wastewater in a batch mode. The efficiency of the method tested was determined by measurement of color removal and reduction of Chemical Oxygen Demand (COD). For dye solutions with COD of approximately 30 ppm and dye concentrations less than 150 ppm, high color removal (93%) was obtained when the pH ranged from 6 to 9, time of electrolysis was approximately 4 min, current density was approximately 80 A/m2, the temperature was approximately 300 K, and interelectrode distance was 1 cm. During the EC process under these conditions, the COD decreased by more than 85%. In the second series of experiment, the efficiency of EC cells with monopolar electrodes in series and parallel connections and an EC cell with bipolar electrodes were compared with results using a simple electrochemical cell. The experimental results showed that an EC cell with several electrodes was more effective than a simple electrochemical cell in color removal. The results also showed that an EC cell with monopolar electrodes had a higher color removal efficiency than an EC cell with bipolar electrodes. Furthermore, within an EC cell, the series connection of the monopolar electrodes was more effective for the treatment process than the parallel connection in color removal.
本研究旨在探究影响电凝聚（EC）法对偶氮染料（酸性红14）溶液脱色效率的变量，以比较不同电极连接方式在脱色方面的效率。电流密度、电解时间、电极间距和溶液pH值是对脱色影响最大的变量。最初，制备了一个带有阳极和阴极的简单电化学电池。然后，以分批模式使用合成废水分别研究每个变量的影响。通过测量脱色和化学需氧量（COD）的降低来确定所测试方法的效率。对于COD约为30 ppm且染料浓度低于150 ppm的染料溶液，当pH值在6至9之间、电解时间约为4分钟、电流密度约为80 A/m²、温度约为300 K且电极间距为1 cm时，可实现较高的脱色率（93%）。在这些条件下的电凝聚过程中，COD降低了85%以上。在第二系列实验中，将串联和并联单极电极的电凝聚电池以及双极电极电凝聚电池的效率与简单电化学电池的结果进行了比较。实验结果表明，带有多个电极的电凝聚电池在脱色方面比简单电化学电池更有效。结果还表明，单极电极的电凝聚电池比双极电极的电凝聚电池具有更高的脱色效率。此外，在一个电凝聚电池内，单极电极的串联连接在脱色处理过程中比并联连接更有效。
