Anoxic and oxic removal of humic acids with Fe@Fe2O3 core-shell nanowires: a comparative study.
Anoxic and oxic removal of humic acids with Fe@Fe2O3 core-shell nanowires: a comparative study.
复制标题
DOI：
10.1016/j.watres.2013.12.041
复制
发表时间：
2014-04
期刊：
影响因子：
12.8
通讯作者：
Hao Wu;Zhihui Ai;Lizhi Zhang
中科院分区：
文献类型：
--
作者：
Hao Wu;Zhihui Ai;Lizhi Zhang
本文比较研究了Fe@Fe2O3core -壳纳米线在缺氧和缺氧条件下对腐植酸的去除效果。利用三维激发发射基质荧光光谱和气相色谱质谱技术对腐植酸与Fe@Fe2O3core -壳纳米线在缺氧和缺氧条件下反应后的产物进行了详细的研究。研究发现，Fe@Fe2O3core -壳纳米线在缺氧条件下对腐植酸有吸附去除作用。Langmuir吸附等温线适用于描述吸附过程。腐植酸在Fe@Fe2O3core -壳纳米线上的吸附动力学遵循伪二阶速率方程。相比之下，Fe@Fe2O3core -壳纳米线对腐植酸的氧去除涉及到对腐植酸的吸附和随后的氧化，因为Fe@Fe2O3core -壳纳米线可以激活分子氧产生活性氧来氧化腐植酸。腐植酸的后续氧化可将氧去除率提高到缺氧去除率的2.5倍，同时矿化率约为8.4%。本研究为腐植酸的去除提供了一种新的方法，也揭示了腐植酸对纳米零价铁去除污染物的影响。
In this study we comparatively investigate the removal of humic acids with Fe@Fe2O3core–shell nanowires under anoxic and oxic conditions. The products of humic acids after reacting with Fe@Fe2O3core–shell nanowires under anoxic and oxic conditions were carefully examined with three-dimensional excitation emission matrix fluorescence spectroscopy and gas chromatography mass spectrometry. It was found that humic acids were removed by Fe@Fe2O3core–shell nanowires via adsorption under anoxic condition. Langmuir adsorption isotherm was applicable to describe the adsorption processes. Kinetics of humic acids adsorption onto Fe@Fe2O3core–shell nanowires was found to follow pseudo-second-order rate equation. By contrast, the oxic removal of humic acids with Fe@Fe2O3core–shell nanowires involved adsorption and subsequent oxidation of humic acids because Fe@Fe2O3core–shell nanowires could activate molecular oxygen to produce reactive oxygen species to oxidize humic acids. This subsequent oxidation of humic acids could improve the oxic removal rate to 2.5 times that of anoxic removal, accompanying with about 8.4% of mineralization. This study provides a new method for humic acids removal and also sheds light on the effects of humic acids on the pollutant removal by nano zero-valent iron.