Morillo D, Uheida A, Pérez G, Muhammed M, Valiente M
Universitat Autònoma de Barcelona, Centre GTS, Department of Chemistry, 08193 Bellaterra (Barcelona), Spain.
Royal Institute of Technology (KTH), Functional Materials Division, 16440 Kista (Stochkolm), Sweden.
J Colloid Interface Sci. 2015 Jan 15;438:227-234. doi: 10.1016/j.jcis.2014.10.005. Epub 2014 Oct 16.
In the present work, superparamagnetic iron oxide nanoparticles (SPION) surface-coated with 3-mercaptopropanoic acid (3-MPA) were prepared and their feasibility for the removal of arsenate from dilute aqueous solutions was demonstrated. The synthesized 3-MPA-coated SPION was characterized using transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Fourier transform infra-red spectrometry (FTIR). Separation efficiency of the coated nanoparticles and the equilibrium isotherm of arsenate adsorption were investigated. The obtained results reveal the arsenate adsorption to be highly pH-dependent, and the maximum adsorption was attained in less than 60 min. The resulting increase of 3-MPA-coated SPION adsorption capacity to twice the adsorption capacity of SPION alone under the same conditions is attributed to the increase of active adsorption sites. An adsorption reaction is proposed. On the other hand, efficient recovery of arsenate from the loaded nanoparticles was achieved using nitric acid (HNO3) solution, which also provides a concentration over the original arsenate solution.
在本研究中，制备了表面包覆3-巯基丙酸（3-MPA）的超顺磁性氧化铁纳米颗粒（SPION），并证明了其从稀水溶液中去除砷酸盐的可行性。使用透射电子显微镜（TEM）、热重分析（TGA）和傅里叶变换红外光谱（FTIR）对合成的3-MPA包覆的SPION进行了表征。研究了包覆纳米颗粒的分离效率和砷酸盐吸附的平衡等温线。所得结果表明，砷酸盐吸附高度依赖于pH值，并且在不到60分钟内达到最大吸附量。在相同条件下，3-MPA包覆的SPION吸附容量增加到单独SPION吸附容量的两倍，这归因于活性吸附位点的增加。提出了吸附反应。另一方面，使用硝酸（HNO3）溶液实现了从负载纳米颗粒中高效回收砷酸盐，这也使得砷酸盐浓度高于原始溶液。
