桑稳姣,李志轩,黄明杰.羟胺强化过渡金属活化过硫酸盐降解磺胺甲恶唑[J].环境科学学报,2019,39(6):1772-1780
羟胺强化过渡金属活化过硫酸盐降解磺胺甲恶唑
- Enhanced transition metal oxide based persulfate activation by hydroxylamine for the degradation of sulfamethoxazole
- 基金项目：国家自然科学基金（No.51108360，21677055）
- 桑稳姣
- 武汉理工大学土木工程与建筑学院, 武汉 430070
- 李志轩
- 武汉理工大学土木工程与建筑学院, 武汉 430070
- 黄明杰
- 华中科技大学环境科学与工程学院, 武汉 430074
- 摘要：以典型磺胺类抗生素-磺胺甲恶唑（SMZ）为降解对象，选取赤铁矿（α-Fe2O3）、氧化钴（Co2O3）和氧化铜（CuO）3种过渡金属氧化物（MxOy），研究了羟胺（HA）对3种过渡金属氧化物活化过硫酸盐（PDS）降解SMZ的强化效果及机理.结果表明，HA对MxOy/PDS体系降解SMZ具有明显的促进作用，初始HA、PDS、MxOy和SMZ浓度均对SMZ的降解具有重要影响.电子顺磁共振（EPR）实验结果证实，α-Fe2O3/HA/PDS和Co2O3/HA/PDS体系中的主要活性自由基是·OH，而CuO/HA/PDS体系中SMZ的降解并不依赖于自由基的生成，表面活化态PDS是降解SMZ的主要活性物种.此外，采用高效液相色谱-离子阱质谱联用仪（HPLC-ESI-MS）检测了SMZ在Co2O3/HA/PDS体系中的降解产物.结果表明，SMZ主要通过3条路径进行降解矿化，分别为氨基官能团的硝基化、不饱和碳碳双键的羟基加成及磺胺键的断裂.
- Abstract：The enhanced persulfate (PDS) activation and sulfamethoxazole (SMZ) degradation performances and mechanisms by hydroxylamine (HA) in the presence of three transition metal oxides (MxOy), i.e., hematite (α-Fe2O3), cobalt oxide (Co2O3) and copper oxide (CuO) were comprehensively studied. The results demonstrated that the extra addition of HA could greatly enhance the degradation of SMZ in the three MxOy/PDS system. The effects of initial HA, PDS, MxOy and SMZ concentrations on the degradation of SMZ were studied. The electron paramagnetic resonance (EPR) results indicated that·OH was the main reactive species in the α-Fe2O3/HA/PDS and Co2O3/HA/PDS systems, while in the Co2O3/HA/PDS system, the degradation of SMZ was not relied on the generation of free radicals, and the activated-PDS on the surface of CuO was determined to be responsible for SMZ degradation. What's more, the degradation pathways of SMZ in the CuO/HA/PDS system was studied by a high performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS). The results indicate that SMZ could be degraded in three pathways, i.e, the nitration of the amino functional group, the hydroxylation of unsaturated carbon-carbon bonds, and the breakdown of sulfonamide bonds.
