What is Reverse Osmosis and How Does it Work?

A woman holding a glass of water

You have probably heard bottled water brands like Aquafina®, Dasani®, and Nestle® Pure Life® boast that their bottled water is filtered with reverse osmosis – but do you know what reverse osmosis is or how it works? Probably not. It’s because they don’t talk about it… because they think it’s complicated. But here at Quench, we believe it’s important to explain how our state-of-the-art quenchWATER+ reverse osmosis filtration technology works so that you know exactly what’s in your water (and what’s not!) and how it will taste when you take a sip.  

What is Reverse Osmosis?

Reverse osmosis is a water purification process that uses a semi-permeable membrane (synthetic lining) to filter out unwanted molecules and large particles such as contaminants and sediments like chlorine, salt, and dirt from drinking water. In addition to removing contaminants and sediments, reverse osmosis can also remove microorganisms – which you certainly do not want to drink. It gets water clean down to a molecular level, leaving only pure H2O behind.

How Does Reverse Osmosis Work?

Before we go into the details of how reverse osmosis works, we should start by explaining how osmosis works. As you may remember from your high school chemistry class, osmosis is the process by which water passes through a semi-permeable membrane from a less concentrated solution into a more concentrated one. In other words, the pure water passes through the filter to the contaminated water in order to equalize the concentrations – which is not what we want our drinking water to do. This movement generates osmotic pressure.1

Osmosis diagram

In reverse osmosis, an applied pressure is used to overcome the osmotic pressure and push the water from high concentration of contaminants to low concentration of contaminants. This means it’s being forced in reverse and the contaminated water is trying to move into the pure water, but because it must pass through a filter first, the contaminants get trapped and only the pure water passes through; resulting in the cleanest possible drinking water – which is exactly what we want!2

Reverse Osmosis filtration diagram

Reverse osmosis typically involves four stages of filtration: a sediment filter, pre-carbon block, reverse osmosis membrane, and post-carbon filter. The sediment filter removes the largest particles, like dirt, sand, and rust to prevent clogging of the subsequent filters. The pre-carbon filter uses activated carbon to prevent anything larger than a spec of flour from passing through as well as attracting and bonding with positively charged ions to prevent chemical compounds, like chlorine and chloramines, from passing through to the third filter. The reverse osmosis membrane then removes molecules heavier than water, such as sodium, high levels of lead, dissolved minerals, and fluoride. Finally, the post-carbon filter polishes the water.

Why is Reverse Osmosis Beneficial?

Reverse osmosis differs from carbon filtration in that it can rid the water of up to 99.9% of all contaminants and sediments, or particles as small as .001 micron, whereas carbon filtration can only remove particles as small as 1 micron. Your local tap water could be award-worthy clean when it leaves the municipal plant but as it travels miles from the plant to your glass it could pick up a host of contaminants or it may have a naturally high number of total dissolved solids (TDS) in the water, so it would be best to get a reverse osmosis filtration system to safeguard that your water is contaminant-free.

Get quenchWATER+ for Reverse Osmosis Filtered Water with Mineral Additives

quenchWATER+ is our Quench branded mineral-infused water. We produce quenchWATER+ using a state-of-the-art reverse osmosis filtration technology to remove contaminants and bad tastes while adding minerals, electrolytes, and alkalinity to create amazing tasting water.

quenchWATER+ is filtered on demand through our proprietary 5-filter setup. Our filtration process produces the cleanest drinking water through our reverse osmosis system but this process also removes beneficial minerals that can be naturally occurring in the water. To create quenchWATER+, we have added the Mineral+ filter to the filtration process. The pure water passes over compressed minerals in our Mineral+ filter to add back a blend of calcium, magnesium, sodium, potassium, and other healthy minerals to create alkaline and electrolyte-enhanced water, promoting faster and longer-lasting hydration.

Quench currently offers quenchWATER+ in our Q series machines, the Quench Q7 and Q5. Both machine series provide an uninterrupted quenchWATER+ refreshment throughout the day and offer advanced sanitization technology, including LED ultraviolet light and antimicrobial surface protection, to maintain water quality. Quench Q7 and Q5 tall ergonomic “no-bend” dispensing freestanding designs allows the quenchWATER+ system to be installed directly inside the base of the machine, creating a completely closed system.

Get quenchWATER+ to drink clean, feel hydrated, and save the environment. Visit our website to learn more about quenchWATER+ and check out our Q7 and Q5 product pages to see which Quench water cooler is right for you!

1 https://www.sciencedirect.com/topics/neuroscience/osmosis
2 https://www.sciencedirect.com/topics/chemical-engineering/reverse-osmosis