研究报告
吴奕潼,刘红,李志学,范先媛.掺杂镍的纳米铁及其转化产物—FeOOH耦合去除对氯硝基苯及其还原产物效能与机制[J].环境科学学报,2022,42(4):122-130
掺杂镍的纳米铁及其转化产物—FeOOH耦合去除对氯硝基苯及其还原产物效能与机制
- Efficiency and mechanism of coupling removal of p-chloronitrobenzene and its reduction products by Ni-doped n-Fe and its transformation produdct—FeOOH
- 基金项目:国家自然科学基金(No.41230638);湖北省环保厅科研项目(No.2017HB08)
- 吴奕潼
- 武汉科技大学,资源与环境工程学院,武汉 430081
- 刘红
- 武汉科技大学,资源与环境工程学院,武汉 430081;武汉科技大学,冶金矿产资源高效利用与造块湖北省重点实验室,武汉 430081
- 李志学
- 武汉科技大学,资源与环境工程学院,武汉 430081
- 范先媛
- 武汉科技大学,资源与环境工程学院,武汉 430081;武汉科技大学,冶金矿产资源高效利用与造块湖北省重点实验室,武汉 430081
- 摘要:以掺杂了Ni的纳米铁及其转化产物耦合去除对氯硝基苯及其脱氯产物,探讨了耦合去除的效能、历程和机制.结果表明,m(Ni)/m(Fe)分别为8%和12%的纳米铁/镍(n-Fe/Ni)不仅能在20 min内将对氯硝基苯的硝基还原产物—对氯苯胺近乎100%脱氯还原为苯胺,而且在反应36 h后,其转化产物可将苯胺的浓度降至接近于0 mg·L-1. X-射线衍射和透射电镜的表征结果表明,反应8 h后,Fe(0)主要被氧化为板条状 纤铁矿(γ-FeOOH)和针状的针铁矿(α-FeOOH).耦合去除历程与机制为:Fe(0)提供电子使对氯硝基苯被还原为对氯苯胺,其腐蚀产物H2在Ni催化下解离为活性氢原子(H*).H*进攻对氯苯胺的C—Cl键使其脱氯还原为苯胺,苯胺随后被Fe(0)的转化产物α/γ-FeOOH吸附固定,从而使对氯硝基苯及苯胺从水中彻底去除.
- Abstract:The coupling removal of p-chloronitrobenzene and its dechlorination products by Ni doped nano-iron (n-Fe), as well as its conversion products are investigated in this study. The efficiency, process and mechanism of coupling removal are also examined. The results show that the Fe/Ni nanoparticles (n-Fe/Ni) with m(Ni)/m(Fe) ratios of 8% and 12%, almost completely reduce the nitroreduction product of p-chloronitrobenzene to aniline within 20 min. In addition, the concentration of aniline is reduced to nearly zero(0) after 36 h of reaction. The X-ray diffraction spectra and transmission electron microscopy indicated the oxidization of the Fe(0) into lath-like lepidocrocite (γ-FeOOH) and needle-like goethite (α-FeOOH) after 8 h of reaction. The coupling removal process and mechanism are as follows, Fe(0) provides electrons to reduce p-chloronitrobenzene to p-chloroaniline, and its corrosion product H2 is dissociated into active hydrogen atom(H*) under the catalysis of Ni. H* attacks the C—Cl bond of p-chloroaniline to reduce it to aniline, which is then adsorbed and fixed by the Fe(0) conversion product (α/γ-FeOOH), thus removing p-chloronitrobenzene and aniline from the wastewater completely.