Mercury Removal From Solution by High Gradient Magnetic Separation With Functional Group Modified Magnetic Activated Carbon

Environmental pollution of mercury is growing into a serious problem on a worldwide scale. In particular, the toxicity of the mercuric compound like methylmercury is so high that the development of the purification technology is strongly demanded. In order to eliminate mercury efficiently from the aquatic environment, we have newly developed several kinds of functional group modified magnetic activated carbon (MAC). We have studied their adsorption and desorption properties of methylmercury and the magnetic separation ability. The magnetic seeding for activated carbon was done by both chemical synthetic procedure and physical adsorption of nano-size magnetite. An oxidized magnetic activated carbon (Ox-MAC) having acid functionalities and a SH radical-decorated magnetic activated carbon (SH-MAC) were synthesized. The mercury adsorption performance depends on the fabrication process, for example 44.8 mg methylmercury adsorption per 1 g of MAC was achieved in high concentration solution. MAC was possible to be collected at high speed of 1 m/s by a high gradient superconducting magnetic filter even in low magnetic fields under 2 T.