The Environmental Impact of Ion-Exchange Water Softeners

Hard water is a common problem in most homes, making water softeners absolutely necessary. Drinking hard water isn’t harmful to your health, but it can be detrimental to your home appliances. Hard water causes scale build-up, making your appliances look unappealing and sometimes causing them to stop working. Homeowners prefer Ion-exchange softeners to water conditioners because water conditioners don’t really soften water.

Ion-exchange water softeners soften hard water and make it easier to use. But the downside is the softening process and everything that comes with it can have negative impacts on the environment

As a homeowner looking to treat your hard water with an ion-exchange water softener, you should consider the effects it can have on the environment. 

How Do Ion-Exchange Water Softeners Work and Why Do You Need One?

Unlike hard water, soft water is easy to use. With soft water, there are no issues of scale build-up in home appliances, and they last longer and work better. The only way you can enjoy soft water in your home is by getting a water softener.

Water softeners are either salt-based or salt-free. Salt-based water softeners are often referred to as ion-exchange water softeners, the salt-free systems are also called water conditioners. Homeowners prefer ion-exchange softeners to water conditioners because water conditioners don’t really soften water. They only bind to the minerals (calcium and magnesium) causing water hardness, preventing them from forming scale.

If you use well water in your home, you want to go for an ion-exchange water softener because it’s the best water softener for well water. 

Ion-exchange water softeners consist of resin beads, which are charged with sodium ions. These resin beads are negatively charged and attract positively charged ions. Calcium and magnesium, the minerals responsible for water hardness, are positively charged ions. As hard water passes through a water softener, the negatively charged resin beads attract calcium and magnesium, remove them, and release sodium ions into the water. That’s the whole secret behind water softening.

Water softeners are best used as whole-house systems. That way, you’ll have soft water at all outlets in your home and protect all your appliances. 

You may be wondering what happens to the hard water minerals after they have been attracted to a water softener’s resin beads and removed from your water. Water softeners undergo regeneration, where the hardness minerals are flushed out. Regeneration is important for your water softener. We’ll explain why it’s so important and how it affects the environment.

Why Does My Water Softener Regenerate?

Before we get to how regeneration works, it’s important to understand why it even happens. Regeneration happens while your water is being softened, and it’s necessary so that your water softener can operate effectively. As described before, the mineral ions pass through the water softener, they adhere to the resin beads.

The minerals fill up the resin beads until they become saturated, and if regeneration does not happen, your water softeners cannot continue to work.

How Do Water Softeners Regenerate?

Water softeners regenerate by removing calcium and magnesium from their resin beads, and at the same time, they get recharged with sodium ions. The whole process occurs in five stages which include:

1. The Filling Stage

Water softeners usually have a salt storage tank. For regeneration to begin, water enters this storage tank and mixes with the salt, forming a “brine solution”. This brine solution is necessary to remove the hardness minerals accumulated on the resin beads. This stage takes only about 10 minutes to complete.

2. The Brining Stage

After the brine solution is formed, it flows from the salt storage tank to the resin tank, where the resin is found. During this brining stage, a reverse ion-exchange occurs. As the brine solution passes through the softening resin, calcium and magnesium ions are removed and replaced with sodium ions present in the brine solution (hence, reverse ion exchange). The brine solution removes the accumulated hardness minerals while replenishing the resin beads with salt. This stage takes about 30 minutes to complete.

3. The Brine Rinse Stage

In this stage, the brine valve is shut close, allowing only water without brine to flow to the resin tank and through the resin beds. The water flowing into the tank is slow during this stage, allowing the ongoing exchange process to be completed. The fresh water rinses the brine, which is later discharged into nearby drains. This cycle takes about 20 minutes.

4. The Fast Rinse Stage

The fast rinse stage occurs after the slow rinse stage is complete. During this stage, water flows quickly through the resin beads, removing any remnant of brine and minerals present. The fast flow in this stage re-organizes the resin beads and prepares them for the next water softening cycle. This stage takes about 30 minutes to complete.

5. The Refill Stage

Once the fast rinse stage is completed, the whole regeneration process is almost complete. In the refill stage, water flows into the brine tank to form new brine solution, and the regen cycle can start once again.

What Do Ion-Exchange Water Softeners Do To The Environment?

For your water softener to function properly, it has to undergo regeneration, but regeneration can be bad for the environment. Some reasons for this include:

High Rate of Water Consumption

A large amount of water is used during regeneration. Water is needed to flush the hardness minerals, rinse the brine, and refill the brine tank. Most water softeners require dozens of gallons of water for regeneration to be effective, leading to significant water waste.  

Excess Salt/Sodium Discharge

During the brine rinse stage, brine which contains a high amount of salt is discharged into nearby drains. These nearby drains are usually linked to rivers and lakes with plants and animals that can only survive in fresh water. The salt discharged into these water bodies causes harm to aquatic life by making the environment unconducive for living and eventually causes death.

Soft Water Causes Alkali Soils

Soft water has no calcium and magnesium but is high in sodium. Such high amounts of sodium make it impossible to use soft water for irrigation because it causes the formation of alkali soils and makes the soil unsuitable for growing crops. 

Salt-Based Water Softening Benefits

Ion-exchange water softeners cause harm to the environment when they undergo regeneration. Still, when you have soft water in your home, you use less water for washing and bathing compared to when you have hard water. This helps strike a balance between the quantity of water used at home and the water wasted during regeneration.

Source: Nature World News

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