School of Chemistry and Material Sciences, Fujian Normal University, Fuzhou, Fujian Province, China.
Water Res. 2011 Jan;45(2):886-92. doi: 10.1016/j.watres.2010.09.025. Epub 2010 Oct 1.
Bentonite-supported nanoscale zero-valent iron (B-nZVI) was synthesized using liquid-phase reduction. The orthogonal method was used to evaluate the factors impacting Cr(VI) removal and this showed that the initial concentration of Cr(VI), pH, temperature, and B-nZVI loading were all importance factors. Characterization with scanning electron microscopy (SEM) validated the hypothesis that the presence of bentonite led to a decrease in aggregation of iron nanoparticles and a corresponding increase in the specific surface area (SSA) of the iron particles. B-nZVI with a 50% bentonite mass fraction had a SSA of 39.94 m(2)/g, while the SSA of nZVI and bentonite was 54.04 and 6.03 m(2)/g, respectively. X-ray diffraction (XRD) confirmed the existence of Fe(0) before the reaction and the presence of Fe(II), Fe(III) and Cr(III) after the reaction. Batch experiments revealed that the removal of Cr (VI) using B-nZVI was consistent with pseudo first-order reaction kinetics. Finally, B-nZVI was used to remediate electroplating wastewater with removal efficiencies for Cr, Pb and Cu > 90%. Reuse of B-nZVI after washing with ethylenediaminetetraacetic acid (EDTA) solution was possible but the capacity of B-nZVI for Cr(VI) removal decreased by approximately 70%.
采用液相还原法合成了膨润土负载纳米零价铁（B-nZVI）。采用正交法评价了影响 Cr(VI)去除的因素，结果表明 Cr(VI)初始浓度、pH 值、温度和 B-nZVI 负载量均为重要因素。扫描电子显微镜（SEM）的表征验证了膨润土的存在导致铁纳米颗粒聚集减少，铁颗粒的比表面积（SSA）相应增加的假设。当膨润土的质量分数为 50%时，B-nZVI 的 SSA 为 39.94 m(2)/g，而 nZVI 和膨润土的 SSA 分别为 54.04 和 6.03 m(2)/g。X 射线衍射（XRD）证实了反应前存在 Fe(0)，反应后存在 Fe(II)、Fe(III)和 Cr(III)。批处理实验表明，B-nZVI 去除 Cr(VI)符合准一级反应动力学。最后，B-nZVI 被用于修复电镀废水，Cr、Pb 和 Cu 的去除率均>90%。用乙二胺四乙酸（EDTA）溶液洗涤后，B-nZVI 可以重复使用，但 B-nZVI 去除 Cr(VI)的能力下降了约 70%。
