ABSTRACT
The incorporation of functionalized micro- and nanoparticles into conventional water treatment technologies, such as adsorption, advanced oxidation processes, or membrane filtration techniques, has significantly improved the efficiency of these processes. However, the recovery of these small materials after the treatment process is very challenging due to their small size. One interesting approach is the inclusion of magnetic materials in their formulation, so that their recovery can be achieved through the use of magnetic fields. Nevertheless, the magnetic separation step, which represents one of the most important stages of these processes, should be carefully designed to facilitate the successful design of magnetic particle applications. In this chapter, the principles of magnetic separations are reviewed, the forces acting on the particles during separation are analyzed, and the effect of different variables and parameters is discussed. Recent advances in the development of different separators are presented (high gradient magnetic separation systems, open gradient magnetic separation columns, and low gradient magnetic separation devices) along with their main advantages and practical limitations. Finally, continuous microfluidic magnetic separators are introduced as a promising alternative for water quality monitoring at the point-of-need, with the potential to be employed for water treatment when using parallelized microfluidic devices.
