电催化氧化法处理阳离子染料废水的试验研究

以结晶紫作为阳离子染料,采用电催化氧化法对阳离子染料溶液进行了电解脱色处理试验,研究了电流密度、电解质种类、电解质浓度、pH值等对该溶液脱色率的影响,测定了电解时溶液中生成的余氯浓度和溶液的紫外-可见吸收光谱曲线,并对不同电解时间的溶液的吸光度进行了归一化计算。结果表明:随着电解时间的延长,水溶液中活性氯浓度不断上升,经一定时间后达到最大值;在电催化和活性氯的协同作用下,阳离子染料结晶紫分子中的大π共轭体系被破坏、苯环结构基本瓦解,溶液快速脱色;在电流密度为5.1mA/cm2、NaCl浓度为4g/L、pH值为9.41的条件下,初始浓度为100mg/L的结晶紫溶液经过20min的电解,其脱色率可高达98.31%。

Experimental Study on Treating the Cationic Dye Wastewater by Electro-catalytic Oxidation

The electro-catalytic oxidation method is adopted to decolor the dyes in aqueous solution by using crystal violet as cationic dye.The effect of current density,electrolyte type,electrolyte concentration and initial pH on the decoloration rate of cationic dye solutions is investigated,the chlorine concentration and the ultraviolet-visible absorption spectral curves at different electrolysis times in the solution are measured,and the normalization of spectrophotometry of different times is calculated.The experimental results indicate that the concentration of dissociative chloring increases continuously and reaches the maximum after a certain time in the process of electro-catalytic oxidation;the big π bond conjugate system of crystal violet is destroyed and the structure of benzene ring collapses under the synergy action of dissociative chloring and electro-catalytic oxidation,so dye wastewater is decolored rapidly.The decoloration rate of dye wastewater with the initial concentration of 100mg/L crystal violet is up to 98.31% after 20 minutes of electrolysis under the conditions of current density of 5.1 mA/cm2,NaCl concentration of 4 g/L and pH of 9.41.