Catalytic degradation of tetracycline hydrochloride by persulfate activated with nano Fe0 immobilized mesoporous carbon
Catalytic degradation of tetracycline hydrochloride by persulfate activated with nano Fe0 immobilized mesoporous carbon
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DOI：
10.1016/j.cej.2018.02.034
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发表时间：
2018-06-01
影响因子：
15.1
通讯作者：
Xie, Ruzhen
中科院分区：
文献类型：
--
作者：
Jiang, Xia;Guo, Yinghui;Xie, Ruzhen
本研究以聚乙烯醇（PVA）为原料，以MnCO3为模板，制备介孔碳（MC）负载的纳米Fe-0，并以其作为催化剂活化过硫酸盐（PS）去除水溶液中的盐酸四环素（TC）。采用液相还原法将纳米Fe-0固定在MC上，克服了纳米Fe-0在过硫酸盐（PS）活化中容易聚集和氧化的缺点。实验结果表明，纳米Fe-0/MC + PS体系的TC去除率为92.1%，而MC + PS体系和纳米Fe-0 + PS体系的TC去除率分别为78.5%和33.7%。纳米Fe-0/MC + PS体系的高去除率可归功于纳米Fe-0与MC的协同作用，使其具有较好的PS活化能力。为了更好地了解纳米Fe-0的去除率机理，在纳米Fe-0/MC + PS体系中考察了纳米Fe-0的负荷量(c)、投加量(m)、PS/TC摩尔比（R-m）和初始pH对TC去除率的影响。结果表明：随着纳米Fe-0负载量和投加量的增加，对TC的去除率提高，而随着PS/TC摩尔比的增加，对TC的去除率略有降低；在c = 20%, m = 0.8 g/L, 50/1, pH = 5的最佳条件下，TC的最大去除率为97.7%。自由基清除剂研究和中间体分析结果表明，纳米Fe-0和Fe2+在Fe-0/MC表面催化活化PS产生的SO4中心点-在纳米Fe-0/MC + PS体系中对TC的降解起着重要作用。Fe-0/MC + PS体系表现出优异的氧化去除水溶液中TC的能力，并具有良好的稳定性和可重复使用性。
In this study, mesoporous carbon (MC) supported nano Fe-0 was prepared from polyvinyl alcohol (PVA) using MnCO3 as template, which was used as the catalyst to activate persulfate (PS) for the removal of tetracycline hydrochloride (TC) from aqueous solution. The nano Fe-0 was immobilized on MC by liquid phase reduction to overcome the drawbacks of nano Fe-0 for persulfate (PS) activation, including being easily aggregated and oxidized. The experimental results showed that the nano Fe-0/MC + PS system achieved 92.1% of TC removal, while the MC + PS system and nano Fe-0 + PS systems showed 78.5% and 33.7% of TC removal, respectively. High removal efficiency in the nano Fe-0/MC + PS system could be attributed to the superior PS activation capability due to the synergistic effects of nano Fe-0 and MC. In order to better understand the removal mechanism, the effects of nano Fe-0 loading amount (c), dosage (m), PS/TC mole ratio (R-m) and initial pH on TC removal were evaluated in the nano Fe-0/MC + PS system. The results showed that the removal efficiency of TC was enhanced with the increase of nano Fe-0 loading amount and dosage, while slightly decrease with the increase of PS/TC mole ratio. The maximum removal of TC was 97.7% under the optimal conditions: c = 20%, m = 0.8 g/L, = 50/1 and pH = 5. According to the results of radical scavengers' studies and intermediates analysis, SO4 center dot-, which was produced from catalytic activation of PS by nano Fe-0 and Fe2+ on the surface of Fe-0/MC, plays a significant role for TC degradation in the nano Fe-0/MC + PS system. The Fe-0/MC + PS system exhibited a superior oxidation process for the removal of TC from aqueous solution with excellent stability and reusability of Fe-0/MC.