A feasibility study of magnetic separation of magnetic nanoparticle for forward osmosis

摘要

It was recently reported that a UK company has developed a naturally non-toxic magnetoferritin tonact as a draw solute for drawing water in forward osmosis process. The gist of this technology is thenutilization of the magnetic nanoparticle and high-gradient magnetic separation for draw solutenseparation and reuse. However, any demonstration on this technology has not been reported yet. Innthis study, a feasibility test of magnetic separation using magnetic nanoparticle was thereforenperformed to investigate the possibility of magnetic separation in water treatment such asndesalination. Basically, a magnetic separation system consisted of a column packed with a bed ofnmagnetically susceptible wools placed between the poles of electromagnet and Fe3O4 magneticnnanoparticle was used as a model nanoparticle. The effect of nanoparticle size to applied magneticnfield in separation column was experimentally investigated and the magnetic field distribution in anmagnet gap and the magnetic field gradient around stainless steel wool wire were analyzed throughnnumerical simulation. The amount of magnetic nanoparticle captured in the separator columnnincreased as the magnetic field strength and particle size increased. As a result, if magneticnseparation is intended to be used for draw solute separation and reuse, both novel nanoparticle andnlarge-scale high performance magnetic separator must be developed.