Home
Fact-checked

At WiseGEEK, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is a Reverse Osmosis System?

E. Hill
E. Hill

A reverse osmosis system is a water purification process for homes that utilizes a semi-permeable filter and water pressure to extract inorganic contaminants from household water. Unlike traditional water filters, this process is of great benefit if the water is slightly salty or brackish, as it rids the water of its salty taste. It also removes small-sized particles that other distillation methods aren't able to eliminate.

Reverse osmosis as a system was propounded in the mid-1900's as one of President J.F. Kennedy's goals for his presidential term. An adequate filter was scientifically tested in 1959 by Samuel Yuster, Sidney Loeb and Srinivasa Sourirajan, a carbon acetate polymer that allowed the system to be functionally effective by limiting energy needed to allow water to move through the filter while eliminating the chemicals.

A reverse osmosis system uses a semi-permeable filter and water pressure to purify water.
A reverse osmosis system uses a semi-permeable filter and water pressure to purify water.

Water filtration by reverse osmosis proceeds in this way: water enters the tanks, moved along by the water pressure naturally in the water lines. The ensuing pressure forces the contaminated water against the filters, at which juncture the chemicals will either bind or get stuck in the filter, while the uncontaminated water is pushed through the filter to the clean or permeate side, to be used as drinking, cooking or aquarium water.

The main disadvantage of a reverse osmosis system is the amount of wastewater that is produced in the process. For every gallon (3.78 L) of clean water produced, there are between 3 and 9 gallons (11.35 to 34.09 L) of wastewater containing the concentrate of inorganic chemicals remaining. A permeate pump can be added to the system, which will lower the wastewater output by over 80%.

There are many advantages to reverse osmosis (RO) water filtration systems. Though slower than distillation and most other water purification processes, this system is capable of a greater per day output of water than that of the other systems. Desalination was the original function of RO filters, though these systems also eliminate such dissolved minerals as arsenic and lead, as well as viruses other contaminants. One main advantage to using reverse osmosis is that the process requires no electricity, thus allowing clean and good-tasting water with very little energy consumption.

Discuss this Article

Post your comments
Login:
Forgot password?
Register:
    • A reverse osmosis system uses a semi-permeable filter and water pressure to purify water.
      By: Dreamy Girl
      A reverse osmosis system uses a semi-permeable filter and water pressure to purify water.