O_3/UV降解含氮杂环化合物喹啉

Degradation of the Nitrogenous Heterocyclic Compound Quinoline by O_3/UV

本研究采用O_3/UV工艺降解喹啉溶液,系统地探讨了喹啉初始浓度、反应后置时间、初始pH、HCO_3^-浓度等因素对降解过程的影响.通过测定降解过程中的中间产物,分析了喹啉的降解机制及途径.结果表明随着喹啉初始浓度增加,反应表观速率常数和去除率都降低;pH(7~9)碱性条件时降解效果最好;HCO_3^-的存在明显降低了喹啉的去除率,加入100 mg·L^(-1)HCO_3^-喹啉去除率降低了42.01%;反应后置时间对喹啉的去除率及矿化率基本没有影响.喹啉的降解中间产物主要为8-羟基喹啉、5-羟基喹啉、2(1H)-喹啉酮、2-吡啶甲醛等,喹啉在O_3/UV体系中的降解途径主要由羟基自由基(·OH)、O_3氧化剂发生的加成反应、取代反应、亲电反应等.

The influences of various factors including initial concentration of quionline solution,static duration after reaction,initial pH,HCO3- on the degradation of quinoline by O3/ UV were analyzed in this study. In addition,the degradation mechanism and pathways were also analyzed. The results showed that reaction rate constants and removal rate of quinoline decreased with the increase of the initial concentration of quinoline. The best degradation efficiency of quinoline was achieved under the alkaline conditions（ pH 7-9）. Removal rate of quinoline was obviously influenced by HCO3-,and was reduced by 42. 01% within 6 min when the concentration of HCO3- was 100 mg·L- 1. There was neglected effect of static duration after reaction on the removal rate and mineralization rate of quinolone. The intermediate products of quinoline were mainly 8-hydroxyquinoline,5-hydroxyquinoline,2（ 1H）-quinoline ketone,2-pyridinecarboxaldehyde and so on. The main degradation pathways of quinoline in the O3/ UV system were addition reaction,substitution reaction and electrophilic substitution mediated by O3 and ·OH.