Water Quality Association

Water Treatment For Dummies

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30 Exchanging ions to make water softer Ion exchange water softeners are among the most common ways of softening water. The typical ion exchange system consists of a pres- sure tank filled with sulfonated, polystyrene beads that are capable of removing hardness ions from water, and replacing them with softer ions, such as sodium. These units are connected to a brine tank that's filled with salt, which periodically regenerates the resin beads. The unit's tiny beads attract and hold onto calcium and magnesium ions as water passes through them. When the beads become so saturated they can't hold any more, the unit rinses them with salt, which scrubs off the mineral deposits and gets them ready to absorb hardness ions again. If you've got this type of water softener, you can set it to regenerate at preset times, or if it's a bit more sophisticated, it can base regeneration on your actual water use. Systems that measure water use and regen- erate accordingly, called demand initiated regeneration (DIR), may be more efficient because they only regen- erate as needed. Systems that automatically regenerate on set time intervals, called time clocks, certainly sim- plify the process. But sometimes these regenerate more often than necessary, wasting salt, or they leave users with hard water when water demand is higher than normal. Filtration may be the answer you need Although water softeners get rid of some heavy metals along with hardness, water filtra- tion systems are the best way to remove These materials are the copyright of John Wiley & Sons, Inc. and any dissemination, distribution, or unauthorized use is strictly prohibited.

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