Reverse Osmosis Filters: How it Works

These days there are plenty of reasons to worry about the quality of the water that comes out of our taps. This worry is especially prevalent given the Flint Michigan water crisis has been going on for about six years.

In most cases, citizens don’t need to concern themselves with the quality of water coming out of their taps. But there are systems we can install to ensure bad contaminants like lead and silica don’t get through to the water we use.

One solution is to install reverse osmosis filters. Reverse osmosis is an effective technology that ensures water quality is up to standard for many industrial applications. These include chemical manufacturing, pharmaceutical, and food & beverage industries.

If you’re looking for a new filtration system for your building(s), keep reading.

In this article, you’ll learn more about how reverse osmosis works and the benefits of reverse osmosis filters.

What Is Osmosis?

Before we get into reverse osmosis, it’s helpful to know how osmosis works.

Osmosis is a naturally occurring process where a weak saline solution will migrate to a stronger saline solution. Basically, a solution that is less concentrated will naturally have a tendency to want to move to a solution with a higher concentration.

This process occurs when plants absorb water through their roots or when our kidneys absorb water from the blood.

A key component of reverse osmosis is there must be a semi-permeable membrane present.

Think of the semi-permeable membrane like a screen door. Air can freely pass through the screen but contaminants in the air, like bugs, cannot.

In a water system with varying saline concentrations, the water molecules will be able to pass through the membrane while the sodium chloride molecules (i.e. saline) will be left on the other side of the membrane. As more water molecules move to the higher concentration of saline, the concentration drops and becomes closer to equal with the solution on the other side.

How Does Reverse Osmosis Work?

As you might have guessed, reverse osmosis is the osmosis process going the other way. However, there’s one key difference, which is that energy must be applied to make reverse osmosis work.

You see, osmosis occurs in nature without any energy applied to the process. To get it to work in reverse, you have to “push” water back through the reverse osmosis filter or membrane. To do this, the system must apply pressure that is greater than the natural pressure present.

When water is pushed back through the membrane, most of the sodium chloride molecules (and other contaminants) are left behind. The result is desalinated water on the other side of the membrane. The membrane also blocks contaminants other than saline, leaving you with clean water.

How Do Reverse Osmosis Filters Work?

Now that you understand the reverse osmosis process, you might be wondering how we can harness that process for everyday use.

To start, you’ll need a full system that includes feed water, a pump, a reverse osmosis filter, and a collection pipe for the permeate water.

To achieve the pressure needed to force the water through the filter, you will need to use a pump. The amount of pressure you need to get the saline water to cross the membrane will depend on how concentrated the solution is.

The pump forces the water through the reverse osmosis filter, catching contaminants and salt.

If you’re wondering what happens to the saline water left behind the membrane, it’s filtered off into a reject stream which rejoins the water supply or is drained off. That’s because a reverse osmosis system will use a cross-filtration system, meaning it siphons off the contaminated water.

Why Do I Need a Reverse Osmosis System?

There are several reasons why you might want to use reverse osmosis filters.

They Remove Almost Everything But Water

Because reverse osmosis filters have a pore size of about 0.0001 microns, hardly anything can pass through them. That means they can trap most protozoa, bacteria, and viruses.

Reverse osmosis can also trap harmful chemical contaminants like metal ions, excess salt, copper, lead, arsenic, radium, and phosphorous.

You Work in a Highly Precise Industry

There are some industries that require absolute precision. Having water that you know is as close to pure as you can get is critical for the integrity of your products.

The power industry can use reverse osmosis filters to reduce the number of solids in water. They need to do this before feeding it back into boilers for power generation.

In the pharmaceutical industry, water used in the production of medicines must meet the USP grade. Reverse osmosis can help professionals meet this standard.

Reverse osmosis water is also useful in the automotive industry. It can be used for the applications of metal finishing as well as in the assembly of semiconductors.

Of course, the food & beverage industry also needs to be concerned with the quality of water they use to produce their products.

Your Business Operates in a High-Salinity Area

If your business is located in a coastal area with high salinity, it makes sense to install a reverse osmosis system.

For one thing, if your business relies on a well in a high salinity area, you can’t always rely on that well to provide clean water.

You can also see reverse osmosis as taking advantage of what you have around you.

Is Reverse Osmosis Right for You?

When constructing a new building or replacing a water system, reverse osmosis filters are a widely available option for most businesses. If pretreated and maintained correctly, a reverse osmosis system will last for years.

Of course, not every business needs a reverse osmosis system. But when you operate in an industry where the lack of precision means people get hurt or products fail, then a reverse osmosis system really should be a serious consideration.

To learn more about reverse osmosis filters, get in touch with us.