真空紫外活化亚氯酸盐降解酸性红G的机理

Mechanism of Acid Red G Degradation by VUV-activated Chlorite

采用真空紫外(VUV)活化亚氯酸盐(ClO_(2)^(-)),研究其对偶氮染料酸性红G(ARG)的氧化降解机理,考察不同体系、ClO_(2)^(-)浓度、初始pH值、ARG初始浓度、无机阴离子和印染助剂对ARG降解效能的影响。结果表明:在ARG初始质量浓度为50 mg/L、ClO_(2)^(-)投加浓度为0.4 mmol/L的条件下,反应10 min时,VUV/ClO_(2)^(-)体系中ARG去除率可达98.3%。ARG去除速率随pH值的增大而降低,Cl-会促进ARG氧化分解,HCO_(3)^(-)有微弱的抑制作用,NO_(3)^(-)、SO_(4)^(2-)影响较小,柠檬酸钠和十二烷基苯磺酸钠抑制作用显著。VUV/ClO_(2)^(-)体系中主要氧化物质为·OH、1O_(2)、Cl·和ClO·,ARG降解机理为偶氮键断裂和萘环被破坏。

The oxidative degradation mechanism of azo dye acid red G by vacuum ultraviolet(VUV)activated chlorite(ClO_(2)^(-))was studied,and the effects of different systems,ClO_(2)^(-)concentration,initial pH value,initial concentration of acid red G,inorganic anions,printing and dyeing auxiliaries on the degradation efficiency of acid red G were explored.The results showed that when the initial mass concentration of acid red G was 50 mg/L,the concentration of ClO_(2)^(-)was 0.4 mmol/L and the reaction time was 10 min,the removal rate of acid red G in VUV/ClO_(2)^(-)system could reach 98.3%.The removal rate of ARG decreased with the increase of pH value.Cl-promoted the oxidative decomposition of ARG.HCO_(3)^(-)had a weak inhibitory effect,while NO_(3)^(-)and SO_(4)^(2-)had a minor impact.Sodium citrate and SDBS had a significant inhibitory effect.The main oxidizing substances in VUV/ClO_(2)^(-)system were·OH,1O_(2),Cl·and ClO·.The mechanism of ARG degradation was the fracture of azo bond and the destruction of naphthalene ring.