Monday, June 05, 2006

"How does a water softener work?": "The idea behind a water softener is simple. The calcium and magnesium ions in the water are replaced with sodium ions. Since sodium does not precipitate out in pipes or react badly with soap, both of the problems of hard water are eliminated. To do the ion replacement, the water in the house runs through a bed of small plastic beads or through a chemical matrix called zeolite. The beads or zeolite are covered with sodium ions. As the water flows past the sodium ions, they swap places with the calcium and magnesium ions. Eventually, the beads or zeolite contain nothing but calcium and magnesium and no sodium, and at this point they stop softening the water. It is then time to regenerate the beads or zeolite."

Welcome to my Water Softening blog. Here we provide all information about water softening.


What is water softening ?

Water softening is a technique that serves the removal of the ions that cause the water to be hard, in most cases calcium and magnesium.

Hard water simply means that it contains more minerals than ordinary water. These are especially the minerals calcium and magnesium. The degree of hardness of the water increases, when more calcium and magnesium dissolves. Hard water causes two problems :

  • It can cause "scale" to form on the inside of pipes, tea kettles, water heater and so on. The calcium and magnesium precipitate out of the water and stick to things. The scale doesn't conduct heat well and it also reduces the flow through pipes. Eventually, pipes can become completely clogged.
  • It reacts with soap to form a sticky scum, and also reduces the soap's ability to lather. Since most of us like to wash with soap, hard water makes a bath or shower less productive.

The solution to hard water is either to filter the water by distillation or reverse osmosis to remove the calcium and magnesium, or to use a water softener. Filtration would be extremely expensive to use for all the water in a house, so a water softener is usually a less costly solution.

Water softeners are specific ion exchangers that are designed to remove ions, which are positively charged.
Softeners mainly remove calcium (Ca2+) and magnesium (Mg2+) ions. Calcium and magnesium are often referred to as 'hardness minerals'.
Softeners are sometimes even applied to remove iron. The softening devices are able to remove up to five milligrams per litre (5 mg/L) of dissolved iron.
Softeners can operate automatic, semi-automatic, or manual. Each type is rated on the amount of hardness it can remove before regeneration is necessary.

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).
All that process is called water softening.