Abstract: A process and apparatus employing nylon 4 for the purification of water comprising the steps of contacting the water with iodine in a first treatment zone; nylon 4 complexed with iodine rather than elemental iodine is preferably used and is contacted by the water in the first treatment zone where it releases iodine at levels sufficient to purify the water. The treated and purified water is then contacted with nylon 4 in a second treatment zone where the iodine is removed from the water. The apparatus comprises a conduit having an inlet and an outlet, with a first treatment zone containing nylon 4 material complexed with iodine and a second downstream treatment zone containing nylon 4. The nylon 4 material used in both treatment zones can be in any form, preferably a form having a high surface area. A suitably restrained moistened fine powder may be used as may be textured or untextured, drawn or undrawn, staple fiber, knitted or non-woven fabrics or pulp (fibrils).