Hi friend, in this blog we are going to discuss about softening plant working and its uses. The quality of the makeup water can be adjusted by a water softener, a dealkalizer, or an ion exchange unit. In areas where only hardness reduction is required, a water softener is used and where only alkalinity reduction is required, a dealkalizer is used. In areas where combined treatment is required, an ion exchange unit is used.
Water softeners replace unwanted magnesium and calcium ions with sodium ions, which have none of the negative effects of hard water. To do this, hard water runs through a bed of small plastic beads that have sodium ions attached to them. As the water flows through, the sodium ions—which also occur naturally in water—are released into the water, and are replaced with the magnesium and calcium ions on the resin beads. Eventually, the beads in a water softener contain nothing but calcium and magnesium ions and stop being effective. To refresh the system, water softeners periodically go through a process known as regeneration. In regeneration, a brine solution of sodium chloride—made from salt pellets or block salt—is flushed through the system, which replaces all calcium and magnesium in the system with sodium. The calcium and magnesium, along with the remaining brine, is then drained into the wastewater system. A water softener is easy to operate and maintain. These are also called single bed ion-exchange unit.
Dealkalizer units operate the same as water softeners, but use different resin bed materials and require strong caustic or acid regeneration. The makeup water is passed through a treated resin bed where the contaminants in the water are collected through a chemical exchange process. When the bed becomes saturated with contaminants, the bed is backwash, treated with a concentrated electrolyte, rinsed, and placed back in service. For critical or continuous operations, treatment units may be dual-column units that allow switching from a saturated column to a regenerated standby column so that service is not interrupted for routine column regeneration.
The ion exchange process is to remove calcium and magnesium ions by replacing them with an equivalent amount of sodium ions. Unlike simple water softener, these are mixed bed ion-exchange unit consisting of cation and anion exchanger. The cation exchanger section removes metals, such as calcium and magnesium (hardness), and the anion exchanger section controls alkalinity and may remove bicarbonates (corrosion and embrittlement), sulfates (hard scale), chlorides (foaming), and soluble silica (hard scale).
