High Gradient Magnetic Separation as a Means of Water Purification

In Bangladesh, like many developing nations, the drinking water is unsafe. Traditionally, the population acquired its water from ponds and reservoirs laden with a myriad of unpleasant contaminants including cholera, botulism, typhoid, hepatitis A, dysentery, and polio. In an attempt to remedy this problem, Bangladeshis drilled shallow wells but soon found the water to be contaminated with high levels of naturally occurring arsenic. The level present in some aquifers is several hundred micrograms per liter (∝g/L). The World Health Organization currently sets the allowable concentration at .05 ∝g/L. The effects of chronic arsenic exposure include cancer of the skin, lungs, urinary bladder, and kidney as well as other skin disorders. With an estimated 25% of the population chronically exposed to unsafe levels of arsenic and 200,000-270,000 deaths related to arsenic poisoning, the situation has captured the attention of the National Academy of Engineering which offered the Grainger Challenge Prize to encourage research and foster a viable solution to this massive public health problem. 1