【摘要】 研究了以微波激发Kr/I2混合气体产生的206 nm准分子紫外光(microwave electrodeless excilamp,MWEL)作为光源,联合过氧化氢(H2O2)用于水相中喹啉和吲哚的降解。H2O2剂量达0.06 mol/L以上,50 mg/L的吲哚和喹啉光照45 min转化率达100%,但不能被完全矿化。延长光照时间、降低目标物初始浓度和增加H2O2剂量都会使吲哚和喹啉的矿化度提高。采用旋转蒸发顶空气质联用(RE-HS-GC/MS)分析降解后水溶液中的产物,并采用红外光谱分析了吲哚降解后的固体沉淀物,结果表明,吲哚降解过程中发生了聚合反应,产物为5H-萘酚[2,3-C]咔唑、脂肪烯烃和酯;喹啉降解后的中间产物为己醛、甲酸丁酯、间二甲苯、邻二甲苯和2-乙氧基乙烷基乙酸,说明喹啉发生开环、氧化降解。动力学方程推导了吲哚矿化的速率常数,得到两个结论:吲哚矿化符合拟一级反应;吲哚和H2O2直接反应及与其光解产生的.OH的间接反应两者的协同作用导致了吲哚的矿化。更多还原

【Abstract】 A novel 206 nm excilamp was generated with microwave-driven Kr/I2 mixtures as a light source,which was combined with H2O2(MWEL/H2O2)for indole and quinoline degradation in an aqueous solution.50 mg/L of indole and quinoline can be removed entirely after 45 min irradiation with H2O2 dosage over 0.06 mol/L,otherwise,it can not be mineralized utterly.The increasing of irradiation time and H2O2 dosage or the decreasing initial concentration of target compounds all resulted in the decline of mineralization degree.The intermediates were identified qualitatively by gas chromatography/mass spectrum(GC/MS)with headspace sampling after they were extracted by rotary evaporator.FTIR is used to analyze solid precipitated in indole degradation process.The results showed that aggregation reaction occurred during indole photodegradation,as a result,5H-naphtho carbazole,aliphatic alkene and ester compounds were formed.However,quinoline has gone through ring-open dissociation and oxidation degradation under MWEL/H2O2,and the products were hexanal,acetic acid butyl ester,1,3-dimethyl,o-xylene and 2-ethoxyethyl acetate,respectively.The rate constant of indole mineralization was inferred from kinetic equation.Two conclusions were suggested:the mineralization of indole can be approximated as apseudo-first order kinetics,and was resulted from a direct reaction with hydrogen peroxide and an indirect reaction with ?OH radical.更多还原