Preparation Of Mercapto-Modified Magnetic Silicon Oxide And Its Removal Of Heavy Metal Ions

Heavy metal have obvious harm to human.Excessive heavy metal in human bodies cause many kinds of diseases.Therefore, it is very hot to do research on removal of heavy metal in and out of China. Fe3O4 nanoparticle is widely used in many fields because of its magnetism and super small size.In this article, we cover it onto the surface with SiO2 and form a core-shell magnetic silica (MS).Then we modify MS with–SH to form a novel adsorbent support MMS. It's applied to adsorb heavy metal, and its structure,property and application were investigated as follows:1. Coupling agent TMMPS was used to modify MS to form MMS. IR and AFM were used as characterization methods. Granularity analytics indicated when dipersed in water,the granularity of MS and MMS were 240±90nm and 370±150nm respectively.VSM showed that after modification, the saturation magnetism (Ms) decreased,but they both had superparamagnetic properties.2. MMS were applied to adsorb the Pb2+ in the solution. The results turned to be: After reacting for 8h, the reaction reached an adsorption equilibrium. pH was proved to have great influence on adsorbing capacity, and pH=7 was the optimal condition. As Pb2+ concentration increased, supports ' adsorbent capability went up gradually This adsorption reaction was proved to be highly fitted with a Langmuir adsorption isotherm equation.In low concentration(14μg/mL), 30mg MMS can adsorb 96.25% of the Pb2+ . After the modification of–SH,MMS' s adsorbing capacity increased largely to be twice as much as the MS's. MMS which was used before then was soaked in 5% HNO3 so that they can be reused again,and their adsorbing capacity decreased .MMS has high adsorbing capacity of Hg2+ . Compared to Pb2+,Hg2+ was nearly adsorbed completely by the same amount of MMS.After adsorption,MMS was detected by XRF, its saturation adsorption capacity to Pb2+ and Hg2+ were respectively 18.46mg/g and 25.8mg/g.