The solution to the problem of hard water is to
get rid of the calcium and magnesium. There are chemical treatments that do get
rid of these minerals the most popular answer is a water softener.
The typical water softener is a mechanical appliance that's installed into your home's water supply system. All water softeners use the same operating principle: they trade the minerals for something else in most cases sodium. The process is called ion exchange.
In the middle of a water softener is a mineral tank. It's filled with small polystyrene beads (also known as resin or zeolite) that carry a negatively charged ion.
Calcium and magnesium in water both carry positive charges. This means that these minerals will cling to the beads as the hard water passes through the mineral tank. Sodium ions also have positive charges although not as strong as the charge on the calcium and magnesium. When a very strong salt water solution is flushed through a tank that has beads already saturated with calcium and magnesium the volume of the sodium ions is enough to drive the calcium and magnesium ions off the beads. Water softeners have a separate salt water tank that uses common salt to create this brine solution.
Hard water moves into the mineral tank and the calcium and magnesium ions move to the beads that replace sodium ions. Then the sodium ions go into the water. Once the beads are saturated with calcium and magnesium the unit enters a three part regenerating cycle. First the backwash phase reverses water flow to flush dirt out of the tank. In the recharge (second) phase the strong sodium-rich salt solution is carried from the brine tank through the mineral tank. The sodium collects on the beads, replacing the calcium and magnesium, which go down the drain. Once this phase is over, the mineral tank is flushed of excess brine and the brine tank is refilled as the last phase in the cycle.
The typical water softener is a mechanical appliance that's installed into your home's water supply system. All water softeners use the same operating principle: they trade the minerals for something else in most cases sodium. The process is called ion exchange.
In the middle of a water softener is a mineral tank. It's filled with small polystyrene beads (also known as resin or zeolite) that carry a negatively charged ion.
Calcium and magnesium in water both carry positive charges. This means that these minerals will cling to the beads as the hard water passes through the mineral tank. Sodium ions also have positive charges although not as strong as the charge on the calcium and magnesium. When a very strong salt water solution is flushed through a tank that has beads already saturated with calcium and magnesium the volume of the sodium ions is enough to drive the calcium and magnesium ions off the beads. Water softeners have a separate salt water tank that uses common salt to create this brine solution.
Hard water moves into the mineral tank and the calcium and magnesium ions move to the beads that replace sodium ions. Then the sodium ions go into the water. Once the beads are saturated with calcium and magnesium the unit enters a three part regenerating cycle. First the backwash phase reverses water flow to flush dirt out of the tank. In the recharge (second) phase the strong sodium-rich salt solution is carried from the brine tank through the mineral tank. The sodium collects on the beads, replacing the calcium and magnesium, which go down the drain. Once this phase is over, the mineral tank is flushed of excess brine and the brine tank is refilled as the last phase in the cycle.
No comments:
Post a Comment