CTAB调控绿色合成纳米氧化铁及去除亚硝酸盐

采用阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）改性绿色合成纳米氧化铁（IONP），提高其稳定性和分散性，并应用于去除水中亚硝酸盐。实验结果表明，亚硝酸盐初始浓度为20 mg·L-1，反应温度 30 ℃时，0.4 mmol·L-1 CTAB改性的绿色合成纳米氧化铁（CTAB-IONP）去除亚硝酸盐的效率最高，为 97.32%，比IONP增加了 23%。通过扫描电镜（SEM）和傅里叶变换红外光谱（FTIR）表征可知，经CTAB改性提高了IONP的稳定性和分散性，同时使其带正电，从而提高了反应活性。IONP对亚硝酸盐的去除反应遵循伪一级动力学，而CTAB-IONP则更符合伪二级动力学。

Surface modification of green synthesized iron oxide nanoparticles by CTAB and its adsorption of nitrite

In this study, the cationic surfactant cetyl trimethyl ammonium bromide (CTAB) was used at different concentrations as both a stabilizing and dispersing agent to improve the function of IONP and to remove nitrite in an aqueous solution.The removal efficiency of nitrite using 0.4 mmol·L-1 CTAB was 97.32% at an initial nitrate concentration of 20 mg·L-1, which was 23% higher than that of IONP.The results from SEM and FTIR indicated that CTAB improved the dispersion and stability of IONP, thereby enhancing the latter's reactivity.A kinetic study, conducted in this work, showed that the adsorption of nitrite by IONP fit the pseudo-first order, while the adsorption of nitrite by CTAB-IONP fit the pseudo-second order.