The ion exchange process in water treatment

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Hard water can be an absolute nuisance in appliances - for businesses and homes alike. It causes scale and corrosion to build up, so equipment soon wears out and energy usage can increase. Not good for your bills! 

It’s not just appliances though. Hard water can often give a chalky feel or metallic taste, as well as causing product contamination in the pharmaceutical industry. 

So, how do we combat this? We turn the hard water into soft water. Water softening is a crucial process in order to eliminate the above problems. 

How ion exchange gives you soft water 

The ion exchange process in water treatment starts with cation exchange resin, or “water softening resin” as it’s more commonly referred to by manufacturers. They will fill a tank within a water softener system. 

A chemical process known as ion exchange will occur - in order to soften the water. Polymeric resin beads, specifically made for water filtration will be used here. Typically, they are of an amber/dark brown color.

It works because opposite charges attract to each other. The charge of the resin beads is negative which hold onto the sodium ions (positively charged). Note, the beads start with the sodium ions already attached to them. 

These tiny beads, within a water softener system, have their ions swapped out to harmless ones (sodium). As hard water goes over the resin, the beads attract the hard water causing minerals (calcium and magnesium). This process is what we refer to as ion exchange. 

The calcium and magnesium remain on the resin beads, meaning the water that exists the water softening system is now containing the sodium ions. You are now left with soft water that won’t accumulate into scale or interfere like hard water does. 

Regeneration phase 

Eventually, the resin will of course lose its capacity. Thanks to regeneration, the resin will be able to carry on removing ions from the water though. 

We can break this into four main steps for the regeneration phase. 

• Beginning with backwash, water is forced upwards in the resin tank to expel any dirt or sediment. 
• A concentrated saltwater (brine) solution is then flushed through to be slowly passed over the bed of resin.
• Next, fresh water will go down into the bed of resin, (same direction of brine draw). The hard minerals that are displaced get pushed out as well as the excess salt water to go out into the drain. 
• Finally. Water then will go down the resin bed in a high flow state. This flush completely pushes out the leftover salt and minerals. 

Now that the regeneration phase is finished, the beads are fully coated in sodium. They are then all set to welcome the next lot of hard water to be softened.

Why Should I consider using ion exchange resin? 

As briefly noted earlier, the problems that arise from hard water can stack up in your home over time and also on your body. Therefore, the use of using water softening ion exchange resin is recommended to eliminate these. The benefits of using water softening can really accumulate for your household and those within it.

Most noticeably, your appliances last longer. The water softening resin will remove the hard water minerals that cause scales. So, washing machines, dishwashers etc all last longer as they don’t suffer from corrosion. 

Secondly, you can expect lower energy bills because the scale no longer builds up in the heating elements (this would contribute to poor efficiency of water heating). 

You can clean more efficiently due to the soaps and detergents being able to lather better. Furthermore, the product itself will last longer so you save money on having to buy more soaps and detergents. 

Meanwhile, soft water is more gentle on your skin and hair. For dry skin conditions, it could be worth trying out to see if it eases the symptoms.

Summary 

It’s clear to see the value of the ion exchange process in water treatment. Many sectors such as pharmaceutical, beverages, windows cleaners and more all benefit from the results of ion exchange resin. Ion exchange resin price can vary - with the basic water softening resins usually being the cheapest and more speciality resin such as those that can remove arsenic for example, costing more. 

FAQ 

1. What is Ion Exchange Resin?
    They are tiny polymer beads designed to swap out the undesired ions for other ions that are less harmful such as sodium. 
   
   
2. Is it expensive to use ion exchange resin to soften water?
   No - this is because ion exchange resin lasts a very long time (10-15 years). The main cost thereafter comes from buying the salt for regeneration, but this is a small monthly maintenance fee only. 
   
   
3. What does hard water mean?
   Simply put, it is water high in dissolved minerals – mainly calcium and magnesium. 
   
   
4. What does soft water mean?
   This is water that has a low concentration of dissolved minerals (calcium and magnesium). 
   
   
5. Is softened water safe to drink?
   It is not suitable for infants or those on low sodium diets as softened water has an increased sodium content. It is okay for most adults to drink on occasion, but not recommended to drink regularly. Hard water is recommended for drinking purposes. 
   
   
6. Where can I get ion exchange resin in Delhi?
   You can purchase ion exchange resin from Pure Resin Products. On their website, it is located at the top of their Product category. Pure Resin Products is located in Dwarka, Delhi.