What is a Membrane
Membrane filters act as a barrier to separate contaminants from water, or they remove the particles contaminating the water. Reverse osmosis, ultrafiltration, and nanofiltration all use a membrane in their different filtration processes. Our Master Water Specialist, John Woodard, explains what a membrane filter is and how it works inside different water filtration systems.
How does a membrane filter work?
Reverse osmosis applies pressure to a semipermeable membrane that allows the water molecules to pass through while flushing the dissolved inorganic compounds to the drain. So it separates the water into two pathways.
What’s the difference between a reverse osmosis and an ultrafiltration membrane?
Reverse osmosis and ultrafiltration differ quite a bit. Reverse osmosis is able to reject dissolved minerals from the water, whereas UF only filters solids or particulate. Reverse osmosis is able to get out dissolved inorganic minerals that will pass through the UF membrane.
What are membrane filters made of?
Membranes are made of different types of materials. With reverse osmosis, they’re often referred to as thin-film composite membranes. Previously, the reverse osmosis membrane was made of cellulose triacetate or CTA. CTA membranes are no longer sold. They were the first version of the RO membrane and had a low pH tolerance. They didn’t make a lot of water per square inch. Thin-film enables an RO system to make a lot of water in less space, which makes it possible to get larger membranes in smaller housings. This revolutionized the style of reverse osmosis membranes. UF uses the same kind of material with a slightly different formula.
What does a reverse osmosis system remove?
A reverse osmosis system removes dissolved solids like arsenic and fluoride through the RO membrane. An RO system also includes sediment and carbon filtration for a broad spectrum of reduction. The carbon filters in an RO system remove chlorine and bad taste and odors, and the sediment filter removes dirt and debris
Does a reverse osmosis system remove…
- Fluoride? Yes.
- Salt? Yes.
- Sediment? Yes.
- Chlorine? Yes.
- Arsenic? Yes.
- VOCs? Yes.
- Herbicides and pesticides? Yes.
- Many other contaminants? Yes. The contaminants listed are some of the most popular ones treated with an RO system, but the system also removes a slew of other contaminants.
What are the benefits of owning a reverse osmosis system?
A reverse osmosis system is one of the most extensive methods of filtration. It removes 98% of dissolved solids, which makes it healthier to drink. A water distiller is the only other drinking water system that also reduces TDS, but it’s less efficient than an RO system.
- Harmful dissolved contaminants reduced
- Sodium reduced
- Bad tastes and odors reduced
- More environmentally friendly than bottled water
- Easy to install and maintain
- Fits under the kitchen sink
Is consuming reverse osmosis water good for you?
A reverse osmosis water system removes dissolved contaminants that you can’t see but that could make you sick. Reverse osmosis does work for your kidneys by filtering water before it enters your body. It also removes beneficial minerals like calcium and magnesium from water, but that does not make reverse osmosis water bad for you.
How long does it take before you must change?
Reverse osmosis membranes usually last 6 months to 1 a year, sometimes longer. This is all depending on your raw water quality.