High Gradient Magnetic Separation as a

Means of Water Purification

Jonathan Lundt

This is a three dimensional graph of an arsenic filter’s magnetic field gradient. The filter utilizes the fact that arsenic binds to ferromagnetic particles which can be manipulated and separated by high magnetic gradients. Dr. Finlayson and I used COMSOL Multiphysics to model solutions to Maxwell’s equations for various two dimensional filter designs. The filter for the above graph can be seen in the xy-plane and should be visualized as a plate of steel with a 4x4 array of holes through which the ferrofluid/contaminated water mixture flows and where high local gradients are produced when an initially uniform field is established across the plate starting from the closest edge of the plate and going perpendicularly to the farthest.

Dr. Finlayson and I also considered the flow rate through the filter, were it to be comprised of close-packed spheres of radius around a third of a millimeter. For the modest dimensions we established and with ten feet of head (water pressure) the device could flow over one thousand liters per day.


Micro_W07 home