超声激发碘自由基降解水中磺胺嘧啶

以H2O2和KI作为分子碘(I2)的来源,研究超声/H2O2/KI体系对磺胺嘧啶(SD)的降解效果.考察超声/H2O2/KI体系中溶液初始pH值、H2O2和KI添加浓度等因素的影响.采用碘自由基抑制剂甲硫咪唑对体系中的活性物质进行分析.结果表明,超声/H2O2/KI体系显著提高了磺胺嘧啶的降解效果,磺胺嘧啶的去除率随溶液初始pH值(2.6~5.2)的升高而降低; H2O2和KI的添加浓度对磺胺嘧啶的去除率影响较大,磺胺嘧啶的去除率随其初始浓度的增大而降低.碘自由基(I·和I2-·)是超声/H2O2/KI体系降解磺胺嘧啶的主要活性物质.HPLC图谱表明,磺胺嘧啶降解的同时生成4种产物,磺胺为降解产物之一.

Sulfadiazine degradation through iodine radicals excited by ultrasound

The ultra-degradation of sulfadiazine (Sulfadiazine, SD) enhanced by molecular iodine under ultrasound/ H2O2/KI system was investigated. The experimental parameters such as initial solution pH, KI and H2O2 adding concentration were discussed. The main active species in ultrasound/H2O2/KI system were evaluated by adding methimazole, the scavenger of iodine radicals. The experimental results indicated that SD degradation was enhanced significantly under the ultrasound/H2O2/KI system. The SD removal efficiency decreased with the initial pH value, and was influenced considerably by the concentration of H2O2 and KI. The radical inhibition experiments indicated that I· and I2-· were the main active species contributed to SD degradation. HPLC analysis showed that four intermediate products formed during SD degradation under ultrasound/H2O2/KI system, and one was sulfanilamide.