基于Ti/SnO_2阳极氧化法的典型染料废水电化学氧化规律

Electrochemical oxidation rule of representative dye wastewater with Ti /SnO_2 as anode

采用Ti/SnO2电极间接阳极氧化法处理直接深棕M和活性艳蓝KNR模拟染料废水,研究电解质种类、pH、电压、NaCl投加量及电解时间对其降解效果的影响;在最佳组合条件下,通过分析UV-Vis光谱以及降解过程中氮元素的存在形式,研究上述2种染料的降解规律。结果表明,在pH为3,电压20 V,NaCl投加量为2.5 g/L的条件下,电解30 min后,直接深棕M和活性艳蓝KNR的脱色率分别达到80%和95%,60 min后直接深棕M的COD去除率可达75%,活性艳蓝KNR的COD去除率达到90%;电解60 min后,直接深棕M的偶氮双键完全破坏,萘环和苯环结构被逐步降解,活性艳蓝KNR溶液电解2 min,其分子结构中的蒽醌共轭体系被破坏,随反应的进行,蒽醌结构逐渐被破坏,染料逐步降解。

Ti/SnO2 was employed as anode to electrolyze simulated dye wastewater containing Direct Dark Brown M （DDB-M） and Reactive Brilliant Blue KNR （RBB-KNR） by the method of indirect anode oxidation. The influences of the type of electrolytes, pH value, voltage, NaC1 dosage, and electrolysis time on the degrada- tion performance were explored. Under the optimal condition, degradation rule of the two dyes was analyzed by investigating the existance form of nitrogen and UV-Vis spectra. After being electrolyzed for 30 min （at the pH value of 3, the voltage of 20 V, the concentration of NaC1 2.5 g/L）, the decolourization of DDB-M and RBB- KNR reached 80% and 95% , respectively; 60 min later, the COD removal of DDB-M and RBB-KNR achieved 75% and 90% , respectively. The azo double bond of DDB-M was completely broken, the benzene ring and naphthalene ring were gradually broken during electrolytic oxidation process. As the electrolysis process contin- ued, the anthraquinone conjugated structure of RBB-KNR began to be gradually broken at 2 min, and then the dye was degraded step by step.