酸性红B染料的阴极氧化降解机理

Degradation Mechanism of Acid Red B by Cathodic Oxidation

以Pt/C气体扩散电极为阴极,对pH=3的60mg/L酸性红B溶液进行双室电解,8V下电解80min后,酸性红B溶液在阴极室的脱色率和COD去除率分别为94.2%和66.8%,而酸性红B溶液在阳极室的脱色率和COD去除率分别为73.3%和56.6%,表明O2能在阴极室还原为H2O2和.OH来氧化降解酸性红B.通过红外光谱和GC-MS对酸性红B在阴极室的降解中间产物进行了分析,检测出20种中间产物,包括14种酯、3种酸和3种含—NO2或N—OH基团的物质,给出了酸性红B染料在阴极室的可能降解路径.

Acid red B （ARB） solution with pH=3 was electrolyzed in a two-chamber cell using Pt/C gas diffusion electrode （GDE） as cathode. The color and COD removal ratio in cathode chamber were 94.2 96 and 66.8 96 respectively; and the color and COD removal ratio in anode chamber were 73.3% and 56.6% respectively, which indicated that O2 can be reduced to H2O2 and ·OH in the cathode chamber, then ARB was degraded. Through IR and GC-MS analysis for the intermediates of ARB in the cathode chamber, 20 intermediates have been detected, including 14 esters, 3 acids and 3 compounds with-NO2 or N-OH groups and the probable degradation pathway of ARB in the cathode chamber was given.