摘要
本文通过自由基聚合反应合成了一种带永久正电荷的磁性阳离子水凝胶,评价了该水凝胶对水体中六价铬的吸附去除效果.结果表明,磁性阳离子水凝胶具有较强的热稳定性和磁性,水凝胶中的磁性粒子γ-Fe2O3约占总质量10%,红外光谱测试表明水凝胶表面含有酰胺基和季铵基团.在pH 3—12,磁性阳离子水凝胶具有较好的化学稳定性,其表面Zeta电位在+30 mV以上.吸附实验表明,磁性阳离子水凝胶对六价铬的吸附量较高,最大吸附量达到285 mg.g-1,吸附等温线可用Freundlich方程和Langmuir方程模拟.解吸实验表明,NaCl对水凝胶上六价铬的解吸效果优于NaOH.磁性阳离子水凝胶在对六价铬4次吸附再生后,仍保持高达85%以上的吸附容量,说明该磁性阳离子水凝胶具有较好的应用前景.
Magnetic cationic hydrogel with permanent positive charge was synthesized via radical polymerization.Its adsorption capacity for chromium（Ⅵ） was evaluated.It was found that magnetic cationic hydrogel had strong thermostability and magnetism.The weight percentage of magnetic γ-Fe2O3 in cationic hydrogel was about 10%.FTIR spectroscopic analysis showed the existence of amide and trimethyl amine on the surface of magnetic cationic hydrogel.In the range of pH 3 to 12,high chemical stability and low swelling property were observed,and the zeta potential on its surface was above ＋30 mV.Adsorption experimental results showed that a high adsorption capacity for chromium（Ⅵ）（maximum 285 mg · g-1） was found.Adsorption isotherm of chromium（Ⅵ） on the hydrogel fitted both Freundlich model and Langmuir model well.NaCl had a stronger ability in desorbing chromium（Ⅵ） from the magnetic cationic hydrogel than NaOH.Over 85% recovery rate was attained after four consecutive adsorption-desorption cycles,indicating good perspective for real applications.
出处
《环境化学》
CAS
CSCD
北大核心
2011年第11期1858-1863,共6页
Environmental Chemistry
基金
上海市自然科学基金项目(10ZR1412600)
上海市教委科研创新项目(12YZ153
11ZZ176)资助
关键词
磁性
阳离子水凝胶
六价铬
合成
吸附去除
magnetism
cationic hydrogel
hexavalent chromium
synthesis
adsorption removal.
