新型无极准分子光源深度处理水相中含N-杂环化合物

采用微波激发Kr/I2混合气体产生的206 nm准分子紫外光降解水相含N-杂环化合物,考察了206 nm准分子光直接光解模拟喹啉和吲哚废水的效果.结果表明,初始浓度为20 mg.L-1的吲哚溶液,光照80 min时去除率达62.0%,150 min时TOC去除达50.7%.光照时间、初始浓度和溶液的pH值对喹啉的降解有一定的影响.相同条件下,喹啉的去除率和TOC损失率都明显低于吲哚.光解后的溶液经旋转蒸发提取,顶空注射进入气相色谱/质谱联用仪(GC/MS)定性分析,结果表明,光照下喹啉发生开环降解,生成了甲苯、二甲苯、酸、醛和酯类化合物,而吲哚降解过程中发生了聚合反应.最后,根据中间产物,推断了206 nm准分子光源光解喹啉和吲哚的机制.

New-Type Electrodeless Excilamp for Advanced Treatment on Nitrogen-Heterocyclic Compounds (NHCs) in Aqueous Solution

A novel 206 nm excilamp generated by microwave-driven Kr/I₂ mixtures was employed for nitrogen-heterocyclic compounds (NHCs) degradation in aqueous solution. The photodissociation efficiencies of indole and quinoline with 206 nm excilamp were estimated on the basis of removal efficiency of targeted compounds and the loss of total organic carbon (TOC). The results indicated that removal efficiency of 20 mg·L^-1 indole was as high as 62.0% after 80 min and TOC loss efficiency of 50.7% for 150 min. The irradiation time, initial concentration and pH value had some influences on quinoline degradation. Indole removal efficiency and TOC loss was markedly higher than that of quinoline under the same condition. The intermediates were identified qualitatively by gas chromatography/mass spectrum (GC/MS) with headspace sampling after they were extracted by rotary evaporator. GC/MS analysis indicated that indole and quinoline underwent ring-open dissociation under 206 nm irradiation, as a result, benzene, xylene, acetate, aldehyde, as well as ester compounds were formed, while indole aggregation reaction occurred during indole photodegradation. At last, degradation mechanisms of quinoline and indole in aqueous media with 206 nm excilamp were proposed on the basis of intermediates.