EDTA, oxalate, and phosphate ions enhanced reactive oxygen species generation and sulfamethazine removal by zero-valent iron
EDTA, oxalate, and phosphate ions enhanced reactive oxygen species generation and sulfamethazine removal by zero-valent iron
复制标题
EDTA、草酸根和磷酸根离子增强活性氧的产生和零价铁对磺胺二甲嘧啶的去除
DOI：
10.1016/j.jhazmat.2020.122210
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发表时间：
2020-06-05
影响因子：
13.6
通讯作者：
Zhang, Ying
中科院分区：
文献类型：
--
作者：
Pan, Yuwei;Zhou, Minghua;Zhang, Ying
零价铁（Fe⁰）对氧气的活化速率很低。在本研究中，采用乙二胺四乙酸（EDTA）、草酸盐（Ox）和磷酸根离子（Na₂HPO₄）来增强零价铁对氧气的活化作用，以去除磺胺二甲嘧啶（SMT）。添加这些配体能够显著促进SMT的降解。SMT的去除率从Fe⁰体系中的10.5%（360分钟）分别提升至Fe⁰/EDTA体系中的70.3%（60分钟）、Fe⁰/Ox体系中的85.2%（180分钟）以及Fe⁰/磷酸盐体系中的77.8%（360分钟）。记录了不同体系中零价铁的扫描电子显微镜 - 能量色散X射线光谱（SEM - EDX）、傅里叶变换红外反射光谱（FTIR）、接触角以及X射线光电子能谱（XPS）。螯合剂的存在使零价铁发生羟基化，抑制了零价铁表面氧化铁的形成，并促进了铁离子从固体中的释放。此外，这些试剂提高了表面Fe²⁺的回收率，进而增强了对O₂的活化，产生更多的H₂O₂和活性氧自由基以去除SMT。在这三种体系中，主要通过H₂O₂分解产生的·OH自由基是去除SMT的主要原因。添加螯合剂的Fe⁰体系是一种处理含配体废水的全新且有前景的方法。
The activation rate of oxygen by zero-valent iron (Fe degrees) was very low. In this study, ethylenediaminetetraacetic acid (EDTA), oxalate (Ox), and phosphate ions (Na2HPO4) were used to enhance the oxygen activation by Fe degrees for sulfamethazine (SMT) removal. The addition of these ligands could significantly enhance the SMT degradation. SMT removal was improved from 10.5 % in the Fe degrees system (360 min) to 70.3 %, 85.2 % and 77.8 % in the Fe degrees/EDTA (60 min), Fe degrees/Ox (180 min) and Fe degrees/phosphate (360 min) systems, respectively. Scanning electron microscopy with energy dispersive X-ray (SEM-EDX), Fourier transform infrared reflection (FTIR), contact angle and X-ray photoelectron spectra (XPS) of Fe degrees in different systems were recorded. The presence of chelating agents hydroxylated Fe degrees, inhibited the iron oxide formation on the Fe degrees surface and promoted iron ion release from the solid. Moreover, the agents improved the recovery of surface Fe2+ which could subsequently enhance the activation of O-2 to produce more H2O2 and reactive oxygen radicals for SMT removal. (OH)-O-center dot radical produced mainly through H2O2 decomposition was primarily responsible for removing SMT in all three systems. The Fe degrees system added with chelating agents is a new and promising approach for treating wastewaters containing ligands.