真空紫外活化过硫酸盐降解偶氮染料酸性红G

Vacuum Ultraviolet Activation of Persulfate Degradation of Azo Dye Acid Red G

该文研究了真空紫外/过硫酸盐(VUV/PDS)体系降解偶氮染料酸性红G(ARG)的反应机制。在ARG初始质量浓度为60 mg/L、PDS为0.5 mmol/L条件下,VUV/PDS体系下反应5 min时ARG的去除率可达96.7%。溶液pH对反应速率影响不大,额外投加NO_(3)^(-)、HCO_(3)^(-)和Cl时会对反应产生抑制作用,而额外投加SO_(4)^(2-)对ARG降解率几乎没有影响。由自由基捕获实验及电子顺磁共振(EPR)得出,VUV/PDS体系中所存在的氧化物种主要包括硫酸根自由基(SO_(4)^(-)·)、羟基自由基(·OH)、单线态氧(^(1)O_(2))。根据紫外可见光谱分析,初步推断ARG降解主要通过偶氮键断裂、萘环开环。经总有机碳(TOC)分析,30 min时ARG矿化度可达到56.8%。

The reaction mechanism of vacuum ultraviolet/superordinate(VUV/PDS)system for the degradation of azo dye Acid Red G(ARG)was investigated.The removal rate of ARG was up to 96.7%at 5 min in the VUV/PDS system under the conditions of an initial mass concentration of ARG of 60 mg/L and PDS of 0.5 mmol/L.The pH of the solution had little effect on the reaction rate.The addition of NO_(3)^(-),HCO_(3)^(-)and Cl^(-)inhibited the reaction,while the addition of SO_(4)^(2-) had little effect on the ARG degradation rate.From the free radical trapping experiment and electron paramagnetic resonance(EPR),the oxidized species present in the VUV/PDS system mainly included sulfate radicals(SO_(4)^(-)·),hydroxide radicals(·OH),and single linear oxygen(^(1)O_(2)),which were the main oxides in the VUV/PDS system.Based on the UV-visible spectral analysis,it was initially inferred that the ARG degradation was mainly through azo bond breaking and naphthalene ring opening.After total organic carbon(TOC)analysis,ARG generalization could reach 56.8%at 30 min.