Filtration systems for iron removal use the principle of iron oxidization (or rusting) to cause iron to separate from water molecules and gather into particles (precipitation) that are big enough for a filter medium to catch. Water is passed through a filtering medium, such as birm (chemical-coated beads) or greensand. If the iron is ferric (oxidized, making the water reddish) these filters will catch the particles, but if the iron is ferrous (unoxygenated, making the water clear), then water must be aerated and the air given time to react with the iron. More time is better, but allow at least 15 minutes.

On the Other: Complicating Factors

The precipitation process can be thwarted if the pH value of the water is too high or low. See the system specifications for your requirements, but the range can be as narrow as 7.5 to 8.5. Birm systems suffer if the water contains hydrogen sulfide, oil or organic matter. Finally, be aware that these systems require one hour daily for a self-cleaning cycle.

Bottom Line

Many iron-removal systems are in operation today, but do your homework. Simply installing a system may not help if your water has other complicating issues. Fortunately, those issues usually can be resolved with chemical additives.

Source:

U.S. Patent & Trademark Office

Environmental Protection Agency

Environmental Expert

Resource:

Adsorptive Iron Removal from Groundwater