超声协同铁氧化物/草酸光Fenton like体系降解磺胺类药物及铁循环演变机制

Pharmaceuticals and personal care products (PPCPs) residuals in the environment is becoming one of the most concerned issues. It is essential to develop novel physical-chemical technologies of high efficiency for PPCPs treatment. As a novel advanced oxidation process, photochemical Fenton-like (UV/IO-Ox) system based on iron oxides-oxalate complexes, has been concerned due to the in-situ generation of hydrogen peroxide in this system. However, the application of this technology is limited due to mass transfer barrier of the solid-liquid surface reactions and relative high concentration level of dissolved iron in the effluent. Therefore, the ultrasound assisted photochemical Fenton-like system (US/UV/IO-Ox) is proposed in this project for the degradation of sulfonamides, a kind of typical PPCPs. The objectives of this project are to: (1) study the degrdation mechanism of sulfonamides in the US/UV/IO-Ox system, based on the qualitative analysis of the degrdation intermediates and the quantum calculation of sulfonamides molecular structure, (2) study and clarify the synergistic mechanism of US for the sulfonamides degradation in the system, combining the promotional roles in the solid-liquid interphase reactions and the bulk solution radical reactions, and (3) reveal the complete iron cycling mechanism in the system, by evaluating the evolution of iron species during the whole reaction and the regeneration process of iron oxides. The research work of this project is expected to provide theoretical and technical support for the application of US/UV/IO-Ox system in the treatment of sulfonamides pollutants.

药物和个人护理品（PPCPs）的环境污染已成为国内外关注的热点，研发高效的物化处理技术迫在眉睫。铁氧化物-草酸光Fenton like（UV/IO-Ox）体系是一种新型高级氧化技术，因其可原位产过氧化氢而受到研究者的青睐，但存在固液界面传质慢和出水总铁浓度偏高等问题。为此本项目提出超声协同IO-Ox非均相光Fenton like体系（US/UV/IO-Ox），以典型PPCPs磺胺类药物为对象，首先研究其在US/UV/IO-Ox体系中的降解规律，通过产物定性分析与分子结构量化计算相结合，阐述磺胺类药物的结构位点开环及降解机理；其次比较性研究液相自由基反应和固液界面反应的US强化机制，综合阐释体系中US协同强化机理；最后研究US作用下铁氧化物的草酸配位溶解—液相失稳—再生成过程，揭示体系中铁循环演变机制。本项目研究成果可为US/UV/IO-Ox体系应用于PPCPs的处理提供理论依据。

药物和个人护理品（PPCPs）的环境污染已成为国内外关注的热点，研发高效的物化处理技术迫在眉睫，本项目研究了超声协同铁氧化物-草酸非均相光Fenton like体系（US/UV/IO-Ox）对典型PPCPs的降解行为及反应机理，并进一步探索了典型PPCPs在超声/零价铁/过硫酸盐（US/Fe0/PS）体系和超声电化学（US/EC）体系中的降解过程。主要研究工作包括：1）研究了诺氟沙星（NOR）在UV/IO-Ox体系中的降解行为，获得了最佳参数条件，阐述了体系中的均相/异相反应机理，结合实验和理论计算，对NOR的降解路径进行了全面阐释。2）建立US/UV/IO-Ox体系实现了对磺胺二甲嘧啶（SMX）的强化降解，考察了重要实验参数的影响，阐述了SMX的降解路径。3）深入剖析了US/UV/IO-Ox体系中US的强化机理，一方面US能加快固液传质和活化再生表面活性位点，另一方面也能促进自由基反应和有机污染物热解矿化。4）研究了US辐射下无定形铁氧化物的强化结晶规律，并结合铁离子溶出规律，完整的揭示了体系中US作用下铁氧化物的草酸配位溶解—液相失稳—再生成过程。5）研究了US/Fe0/PS体系中磺胺嘧啶（SD）的降解行为，采用响应曲面法优化了重要的实验参数，研究了废水中典型杂质无机离子和有机配体对体系降解SD的影响及机理，并研究了US/Fe0/PS体系在高浓度天然有机物和高电导率环境下对有机物的氧化降解能力。6）研究了US/EC体系中磺胺甲噁唑（SMZ）的降解规律，得到了最佳参数条件，剖析了电化学体系中US的强化降解机理，同时发现当以NaCl为电解质时，US/EC比EC体系能产生更少的含氯中间产物，说明声电联用体系能有效缓解含氯废水处理过程中消毒副产物（DPBs）的影响。