摘要
采用单过硫酸氢钾复合粉(Oxone)作为氧化剂,对甲氧苄啶(TMP)进行氧化降解试验。研究了Oxone去除TMP的降解机制和主要作用的活性物种,考察了Oxone浓度、pH值、温度对TMP降解效果的影响,并对降解反应过程中的消毒副产物进行测定。试验结果表明,Oxone溶于水后,PMS与Cl^-发生非自由基反应生成活性氯(Cl_2和HOCl),活性氯作为主要活性物种降解TMP。降解过程符合拟一级反应动力学模型,反应动力学常数为9.15×10^(-2)min^(-1)(R^2>0.99);随着Oxone的投加量增加,反应速率常数k_(obs)增大;初始pH值在5.1~9.2,随着pH增大,TMP的去除率先减小后增大,中性条件下去除率较小,但仍可达62.4%;温度在15~55℃,温度越高,反应速率常数越大。根据阿伦尼乌斯方程,得到TMP的反应活化能E_a为34.12 kJ/mol;Oxone降解TMP过程中产生的DBPs主要是CHCl_3,反应开始时的生成量最高并随着时间逐渐减小。
This experiment investigated the kinet ics and mechanisms of TMP degradation by oxone, a new type of drinking water disinfectant. The active subustance generated in the reaction was identified using the indirect method. Some important operating parameters,such as dosages of oxone,initial pH of solution, temperature,were systematically investigated. The results showed that oxone generated active chlorine species by non-radical reaction at room temperature. TMP degradation fit well with the pseudo-first- order kinetics. The pseudo-first-order-constant was 9. 15x10 2 min 1 （R 2〉 0 . 9 9 ） , increased with the increasin g of the initial oxone concentration. Different initial pH environment had certain effect on the degradation of TMP. When the initial pH value was changed from acidic to alkaline,the degradation rate of TMP had a tendency to drop and then elevate,which could reach 62. 4%. Elevating solution temperature would efficiently accelerate degradation of TMP,when temperature was 15 ？55 丈.The reaction activation energy was 34. 12 kJ/mol. The results of disinfection byproduct analysis showed that the DBPs produced during the degradation of TMP by oxone （mainly CHQ 3）. Results from this study showed oxidation of TMP by oxone might be an efficient approach to remove TMP from waters.
出处
《净水技术》
CAS
2018年第2期17-23,37,共8页
Water Purification Technology
基金
国家科技重大专项(2012ZX07403-001)
国家科技重大专项(2014ZX07406-002)
国家自然基金(51608372)
关键词
单过硫酸氢钾复合粉
甲氧苄啶
活性氯
反应动力学
消毒副产物
oxone trimethoprim （TMP） active chlorine reaction k in et ic s dis infection by-products （DBPs）
