Amino-Functionalized Urea–Formaldehyde Framework Mesoporous Silica for U(VI) Adsorption in Wastewater Treatment
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- 作者：Kegang Wei ; Qingliang Wang ; Long Huang ; Lei Sun
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2016
- 出版时间：December 7, 2016
- 年：2016
- 卷：55
- 期：48
- 页码：12420-12429
- 全文大小：649K
- ISSN：1520-5045
文摘
A mesoporous silica prototype (MSP) was produced by attaching SiO2 colloid to urea formaldehyde resin. Treatment of the MSP using different grafting methods yielded three different amino-functionalized mesoporous silica samples. The materials were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, 13C nuclear magnetic resonance, zeta potential measurements, and isothermal N2 sorption/desorption. For a 1:2000 solid-to-liquid ratio, all adsorbents could almost completely remove uranyl from sulfate and carbonate solutions of 3.6 mg L–1 U(VI) at pH 3.5 to 5.5 and pH 6.5 to 9.5, respectively. The adsorption equilibrium time was less than 30 min. The adsorption equilibrium curve showed that the maximum sorption capacity was 117 mg L–1 at pH 4.0. Through the experimental adsorption, it was found that the most effective sample could reduce the U(VI) concentration from 3.6 mg L–1 to 0.79 μg L–1 with 99.98% removed. In desorption experiments, 0.1 mol L–1 nitric acid could desorb U(VI) almost completely from the adsorbent. However, this kind of adsorbent is unsuitable for use in high acid or alkaline environments.