With levels of 2 ppm of residual chlorine or chloramines, the resin life will double with a prefiltration system. With municipal and occasionally well water supplies relying on chlorine for microbial control, a carbon filter is highly recommended ahead of a water softener. Manganese fouls resin in the same manner as iron. This restricts the flow of water over the resin to specific arteries that form over time in the resin tank, reducing the exchange capacity of the tank to as low as 10%. The beads will stick to one another, causing channeling. The iron is oxidized as air is introduced into the system, and the now-ferric iron attaches itself to the surface of the bead as well. However, a brine solution alone will not dislodge iron ions from resin beads. Ferrous iron exchanges ions and attaches itself to resin the same way as hardness minerals. In situations in which iron or manganese is present, organic fouling is accelerated. At this stage, cleaning the resin can return some of the lost capacity, but the ability to remove silica and carbonic acid will be lost. If these organics remain on the resin, they break down the strong base of the beads until they are no longer active. These contaminants plug the interiors of beads, causing a fish eye effect. The most typical natural contaminants include tannins, oils, tannic acid and fulvic acid. Natural organics are formed from decaying materials and are usually acidic and have an odor. Well water is typically low in organic materials, but surface waters contain hundreds of parts per million of natural and manmade organic matter. Organic fouling is the most common and expensive form of resin fouling and degradation. Most newer models only allow for slow-rinse cycles to prevent this from occurring. As the beads break down into smaller sizes, they are flushed more easily down the drain during regeneration. In a fast-rinse scenario, water enters the beads at such a quick pace that it causes them to swell and crack. In situations in which the brine has more than 45% salinity, water is drawn out of the bead due to osmosis and the bead shrinks. Over-brining and fast rinses with freshwater also can cause resin to foul. The results include pressure loss and resin that is so mushy it can be crushed easily between two fingers. As DVB breaks down, the pores and channels inside the beads break down and close up. DVB is the ingredient in resin that gives it a hard, porous shape. The presence of 2-ppm residual chlorine in a water system can cut the life expectancy of a standard resin for water softeners in half.Ĭhlorine and chloramines attack the divinylbenzene (DVB) in resin, which causes it to swell and take on moisture. Because cation resin is essentially porous plastic beads, it is highly susceptible to chloramines and chlorine degradation. Some resin manufacturers see gel-type, 8% softening resin life as a 10- to 15-year event. Resin life varies based on several factors, such as the type of resin used, the minerals or oxidants present in the source water and the regeneration cycle. This allows a sodium-rich brine solution (or potassium permanganate for greensand applications) to rinse away the minerals stuck to the resin beads and restore them to peak efficiency-at least in theory. Just before the resin becomes completely saturated with calcium or magnesium, the unit should be set to regenerate. In the exchange, the resin bead loses sodium and/or potassium ions. Resin for water softeners is designed to change the chemical makeup of minerals, which makes them cling to the resin beads. Resin for water softeners could last much longer in these hostile environments with a few fairly inexpensive solutions. Resin beads, ranging in size from 16 to 50 mesh, are abused daily during the backwash process and by contaminants in the source water. Surprisingly, 99% of ion exchange actually happens in the interior of the bead. Water softener resin is extremely porous, which is beneficial because it allows for more surface area to capture calcium and other metals in source water. About the author: Justin Ramsey is marketing manager for Pro Products LLC.
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