Website Navigation

Website Search

Our technologies

Softening and Ion Exchange

Products & Services
>
Technologies
>
Water Treatment Technologies
>
Softening and Ion Exchange

General Description

Water softening is a technique used for the removal of the ions that cause water to be hard. Typically, the removed ions, referred to as "hardness minerals", are calcium and magnesium ions. Hard water is generally responsible for pipe clogging and for complicating soap and detergent dissolution in water.

A water softener collects hardness minerals within its conditioning tank and from time to time flushes them away to drain.

Ion exchangers are often used for water softening. When an ion exchanger is applied for water softening, it will replace the calcium and magnesium ions in the water with other ions, for instance sodium or potassium. The exchanger ions are added to the ion exchanger reservoir as sodium and potassium salts (NaCl and KCl).

Advantages – Benefits of the Technology

Water treated with a water softener has many benefits over untreated hard water:

Soft water preserves the life of all water-using appliances such as clothing washers, dishwashers, coffee and icemakers. A water heater protected by a water softening system will also reduce the yearly energy cost of that appliance.
Maintenance costs for water-using appliances are also reduced as a result of reduced pipe clogging due to scale build-up.
Hard water made soft through a water softener restores the rich lathering of soaps, shampoos and detergents, thus reducing the usage and costs of these products.
Fabrics are softer without hard minerals trapped in them. Fabrics laundered with soft water last longer, are softer and their colours look brighter.
Silverware and glassware, washed up with soft water are cleaner and shinier.

Applications

Water softeners are widely used in various applications, both industrial and residential.

Houses, apartments, hotels, restaurants, hospitals, health clubs, car washes and any other application that consumes water can benefit from the use of a water-softening unit. Hardness and minerals in water burdens the annual budget of residences and businesses in various ways such as early replacement of equipment, plumbing repairs, maintenance and greater consumption of chemicals and detergents.

Basic Process Stages

Ion exchange softening is a physical and chemical process that filters the water through an exchange media known as resin or zeolite. Typically, the resin is a synthetic or natural, sand-like material coated with positively charged sodium ions. As calcium and magnesium dissolve into positively charged ions, an ion exchange environment is created. As water flows through the ion exchange unit the resin releases its sodium ions and readily trades them for the calcium and magnesium ions. As a result of the exchange, the water flowing out of the ion exchange unit is soft.

Obviously, the resin is not an inexhaustible exchange site. When all the sodium exchange sites are replaced with hardness minerals, the resin is spent and will no longer soften water. At this point, the water softener will need to be run on an alternate cycle called regeneration. During this cycle, resin is backwashed with a salt solution. The brine is reverse flushed through the system taking with it the calcium and magnesium ions that had been adsorbed on the resin. Once backwashing is complete, the softener can be returned to use. Some water softeners will automatically switch to the operation cycle. Others are manually operated via a switch.