Charged filter aid material and ion exchange bed

摘要

A method for preparing an improved filter material, together with the improved material prepared thereby and an improved method for removing impurities from a liquid. The filter material comprises a mixture of ion exchange resin particles and treated filter aid material. In the preferred embodiment, the ion exchange resin particles comprise a mixture of anion and cation exchange resin particles, and the filter aid material is treated with a chemical compound to produce a positive surface charge thereon. The filter aid material may be further treated with a second compound to produce an enhanced negative surface charge.