Ti/IrO_2-Pt电极电化学降解酸性橙II染料废水研究

ELECTROCHEMICAL DEGRADATION OF ACID ORANGE II WITH TI/IRO_2-PT ANODE

研究采用Ti/IrO2-Pt电极为阳极,对酸性橙II染料废水进行电化学降解研究。讨论了电解质、电流密度、溶液pH等工艺条件对酸性橙II降解的影响,对污染物的电化学降解过程进行了分析,并通过重复试验和电极表面形态比较等手段对电极耐用性进行了考察。结果表明,以氯化钠为电解质有助于酸性橙II的快速降解;加大氯化钠添加量和电流密度能缩短降解时间,但过高的电流密度会引起溶液中氯含量的流失;中性pH更有利于酸性橙II的降解。电化学降解过程中,Ti/IrO2-Pt电极可将各种中间产物无选择性的同步矿化。在氯化钠浓度为0.005 mol.L-1、电流密度10 mA.cm2、初始pH为6.8的条件下,质量浓度为50 mg.L-1的酸性橙II在30 min内被完全降解,电解2 h后TOC去除率达到45%左右。

In this study,the Ti/IrO2-Pt anode was used to electrolyze the synthetic wastewater containing acid orange II.The effects of electrolyte,current density and the pH of the solution on the degradation efficiency were discussed,the degradation process of acid orange II was analyzed with the UV-Vis spectra,and the durability of the anode was estimated with the repeated tests and the comparison of surface morphology.The results showed that,the degradation efficiency of acid orange II could be promoted significantly by adding NaCl electrolyte.The required time for complete degradation of acid orange II could be shortened by increasing the dosage of NaCl and the current density.However,the loss of chloride in the solution could be enlarged at the too high current density.The optimum pH for electrochemical degradation was at the neutral range.During the electrolytic process,all of the intermediates could be mineralized unselectively with the Ti/IrO2-Pt anode.At the current density of 10 mA·cm-2,NaCl concentration of 0.005 mol·L-1 and initial pH of 6.8,the acid orange II of 50 mg·L-1 was degraded completely within thirty minutes,and 45% of TOC was removed after two hours electrolysis.