Selective removal of heavy metal ions from aqueous solutions with surface functionalized silica nanoparticles by different functional groups

KONG Xiang-feng(孔祥峰)^{1, 2, 3}, YANG Bin(杨斌)^{1, 3}, XIONG Heng(熊恒)^{1, 3}, ZHOU Yang(周阳)^{1, 3}, XUE Sheng-guo(薛生国)², XU Bao-qiang(徐宝强)^{1, 3}, WANG Shi-xing(王世兴)⁴

(1. National Engineering Laboratory for Vacuum Metallurgy (Kunming University of Science and Technology),
Kunming 650093, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
3. State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization, Kunming 650093, China;
4. Yunnan Institute of Product Quality Supervision and Inspection, Kunming 650223, China)

Abstract:The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as (3-Mercaptopropyl) triethoxysilane (MPTES) and (3-Amincpropyl) trithoxysilane (APTES). Some further modifications were studied by chloroaceetyl choride and 1,8-Diaminoaphalene for amino modified silica. The surface functionalized silica nanoparticles were characterized by Fourier transform infrared (FI-IR) and X-ray photoelectron spectroscopy (XPS). The prepared adsorbent of surface functionalized silica nanoparticles with differential function groups were investigated in the selective adsorption about Pb²⁺, Cu²⁺, Hg²⁺, Cd²⁺ and Zn²⁺ ions in aqueous solutions. The results show that the (3-Mercaptopropyl) triethoxysilane functionalized silica nanoparticles (SiO₂-MPTES) play an important role in the selective adsorption of Cu²⁺ and Hg²⁺, the (3-Amincpropyl) trithoxysilane (APTES) functionalized silica nanoparticles (SiO₂-APTES) exhibited maximum removal efficiency towards Pb²⁺ and Hg²⁺, the 1,8-Diaminoaphalene functionalized silica nanoparticles was excellent for removal of Hg²⁺ at room temperature, respectively.

Key words:industrial silica fume; surface functionalization; heavy metal ions; selective removal