新型氯离子活化过氧单硫酸盐的非自由基系统去除水中扑热息痛的研究

Acetaminophen degradation with non-radical based reactive oxidants generated by chloride activated peroxymonosulfate system

摘要:

提出了基于过氧单硫酸盐(PMS)的非自由基氧化法降解水中典型药物污染：利用常见的氯离子(Cl-)活化PMS降解水中典型药物扑热息痛，并同传统次氯酸钠氧化降解扑热息痛系统进行比对. 对比研究了两系统中氧化剂投量、底物浓度和pH值对扑热息痛去除的影响. 实验结果表明PMS/Cl-系统对扑热息痛的去除符合典型零级反应动力学模型，而NaClO系统对扑热息痛的去除符合拟一级动力学模型. 当扑热息痛初始浓度为10 mg/L时，0.4 mM PMS和50 mM Cl-在120 min内对其去除率最大可达76.7%. 结果表明在PMS/Cl-和NaClO系统中，提高氧化剂浓度、降低底物浓度、降低系统pH值均利于目标物的去除. PMS/Cl-和NaClO系统均以HClO为主要活性因子降解污染物，但是PMS/Cl-系统中活性因子的产生更为缓慢，今后可考虑在基于PMS的高级氧化系统中投加氯离子以实现消除残余氧化剂并保证系统的持续消毒能力.

Abstract:

The degradation of acetaminophen with non-radical based reactive oxidants generated by chloride activated peroxymonosulfate system was investigated. The performance of PMS/Cl- system was also compared with traditional NaClO system in respect of oxidant dosage, pollutant concentration and pH values. Results showed that pseudo-zero-order kinetic model is more suitable to describe the degradation of acetaminophen in PMS/Cl- system nevertheless pseudo-first-order kinetics model is more suitable to NaClO system. A maximum removal of 76.7% was achieved in 120 min when m(APAP)0 was 10 mg/L, [PMS]0 was 0.4 mM and [Cl]0 was 50 mM. In either PMS/Cl- or NaClO system, higher oxidant dosage, lower acetaminophen concentration and lower pH favored removal efficiency. HClO was the main oxidant responsible for organic pollutant removal in both PMS/Cl- and NaClO system, while the HClO was produced more slowly in PMS/Cl- system. In the future, chloride anions would be an alternative choice for elimination of residual oxidant and continuously disinfection in PMS based oxidation processes.