电化学氧化降解蒽醌染料动力学研究

Study on electrochemical degradative kinetics of an anthraquinone dye

利用形稳阳极原位电生成活性氯对蒽醌型染料活性艳蓝KN-R进行氧化脱色。以该染料的2个特征波长处吸光度为主要指标,对染料脱色及其芳环结构氧化降解的过程进行同步分析。在电流密度15A/m2、0.1mol/L Na2SO4、0.2 mol/L NaCl、0.1 mmol/L活性艳蓝KN-R、初始pH值6.4、温度30℃的实验条件下,经4h的电解,可使染料100%脱色,45%左右的染料芳环结构被破坏,处理每千克染料的能耗为0.28 kWh。实验结果表明,电流密度、氯化钠浓度、染料浓度、温度对染料的脱色及其母体结构氧化降解有较强的影响;染料脱色及其芳环结构氧化降解过程遵循准一级动力学;在整个的电氧化过程中,电解液未发生矿化。

The simulated wastewater containing C.I.Reactive Blue 19 was treated by the electrochemical oxidation via electrogenerated active chlorine with metallic oxide coatings(DSA) as anode.The electrolysis for the wastewater was conducted at a constant current electrolysis.Absorbance at 592 nm and 255 nm were measured to follow the decolorization of the dye and the degradatin of its aromatic ring.After a 4-hour electrolysis with a current density of 15A/m^2,for a simulated wastewater containing 0.2 mol/L of NaCl,0.1 mol/L of Na_2SO_4,0.1 mmol/L of dye,with 6.4 of initial pH value,an 100% decolorization of the dye can be achieved and about 45% of its aromatic ring degrade,and every kilogram of dye consumes 0.28 kWh of energy.The experimental results have suggested that the decolorization of the dye and degradation of its aromatic ring were directly affected by current density,temperature,concentrations of the dye and NaCl;that the decolorization of the dye and degradation of its matrix was a pseudo first-order reaction,respectively;that indirect electrooxidation,using electrogenerated active chlorine,was predominately of the electrochemical oxidation; no obvious mineralization was observed in the oxidative degradation of the dye.