Everybody needs potable, or drinkable, water but some may live in areas where the public water supply isn’t clean enough to drink straight from the tap. In these common cases, a reverse osmosis (RO) system may be used to purify the home’s water supply.
Reverse osmosis occurs when water pressure is used to push water through an extremely fine (semipermeable) membrane, which cleans the water and traps contaminates on the other side of the membrane. This membrane is much like certain kinds of fabric which contain pores so small that they prevent water droplets from coming in, yet still allow smaller water vapor to pass through.
For example, if a tube of salty water with a semipermeable membrane attached to one end is submerged in a body of fresh water, both the fresh water and the salty water will pass through, only more fresh water will pass through than salty water because the membrane will not allow the salt molecules to pass through. In this way, particles in a home’s water supply can be filtered out. If the water coming through your RO system doesn’t seem clean, it may be because the membrane needs to be replaced.
Reverse osmosis generally requires a great amount of pressure and time. The remaining contaminated water also has to be flushed. This is why RO systems are installed, to take care of these two requirements in the process. Because the process is natural however, the RO system does not require electricity and purifies more water per day than distillers.