How does a Reverse Osmosis System work?

Now that we know how Reverse Osmosis as a process works, let's take that and apply it to a real, working TWRO or BWRO System. If it only needed the membranes and a pump, it certainly wouldn't be so big, right?

A) Pre-Chlorination Dosing System

If the feed water contains traces of heavy metals or contaminated, it is high recommended to dose some chlorine to change the dissolved heavy metals to physical form, the media filter will be able to filter most of it.

B) Raw Water Storage Tank

Although some RO Systems can draw water right out of a well or pipe feed, most systems start with a large tank that stores the contaminated water. Not having enough feed water can damage a pump, so having a large storage tank for your intake water is an easy way to make sure your pump lasts for as long as possible.

C) Feed Water Pump

commercial or industrial pump provides the initial pressure for the Treatment System. This motor usually provides enough water pressure to get through any pretreatment as well as the RO membranes, but if it doesn't a booster pump may be necessary farther down the line.

D) Multi-Layer or Media Filter

As much as we hate to admit it, there are some things that membranes can't purify. Nitrates, a common contaminant found in fertilizers and animal waste, are a good example of particles that dissolve too well in water for reverse osmosis to catch them. Things like foul odor and taste usually aren't prevented by reverse osmosis, either. A Multi-Layer filter can be filled with media that specifically targets the things your RO System can't catch. If you need to eliminate these contaminants, a Multi-Layer Filter is a must. An example of MMF or multi media filters is our MF-1000 Series.

E) Activated Carbon Filter

Activated carbon filters are good solution to reduce organic, bad taste, smell and chlorine from the water.

F) Automatic Water Softener

Automatic water softeners are designed to remove water hardness, calcium and magnesium ions, for small RO systems, we usually recommend water softeners instead of the antiscalant chemical dosing. 


G) Antiscalant Chemical Dosing System

For larger RO systems, we use antiscalant dosing systems to dose our PA0100 antiscalant RO chemical, which helps in preventing membranes fouling. Please refer to our chemical dosing pumps series for more information CDS-Series.

H) Reverse Osmosis System

We finally have our Reverse Osmosis System. If a booster pump is necessary, it will typically be just before this step. The Reverse Osmosis System can produce up to one million gallons of product water a day from a steady intake, as well as a sizable amount of waste. Usually the waste water can be dumped down the drain, but check with your local water authorities in case it needs to be handled with care.

I) Product Water Storage Tank

The permeate from the RO purification system will usually go to a large tank, where it is held for use. If it didn't, the system would need to be running in order to have access to fresh water, which can be inconvenient. Sometimes, an RO treatment System pumps water directly into a well or aquifer for recharging instead of being used in many of the normal industries or applications it is used in.

J) Post-Chlorination Dosing System

If the permeate water is intended to be stored for more than one day, it is highly recommended to dose some chlorine to maintain clean and non contaminated water.

K) Product Water Pump (Re-pressurization)

This pump repressurizes the permeate water to the point of use ends. This is selected based on the overall travelling distance and required head. This pump must be selected in stainless steel to prevent any contamination to the permeate water.

L) Product Water UV Sterilizer

The UV sterilizer is placed after the storage tank, and as a final disinfection device. Most of the time, we either use post chlorination as a disinfectant agent, or ultraviolet sterilization.