Reverse osmosis is a life changing process that can solve some of the world’s water problems. It can be used to treat and filter contaminated water and to treat and recycle wastewater for agricultural and landscape uses.
Traditionally, reverse osmosis has been in use in commercial plants. However, in recent times, affordable systems have been designed for residential use.
What is Osmosis?
Osmosis is a natural process in which water moves from a high concentration to a low concentration through a partially permeable membrane that allows small molecules in liquids and gases to pass through. In this situation, cells move from a low solute concentration through the membrane to a high solute concentration.
Osmosis occurs because of the pressure that is exerted on the side of the membrane that has purer water. In this phenomenon, the water moves in an effort to balance the concentration on both sides of the membrane.
In biology of the body, osmosis is important because it allows essential nutrients to be adequately distributed in the body and waste to be excreted from the body.
What is Reverse Osmosis?
Reverse osmosis is a process which reverses the naturally occurring osmosis. It uses pressure to force water through a partially permeable membrane in an effort to remove impurities from the water.
It is a slow occurring process that treats water, which is collected in a storage tank or container after treatment. Impurities and any untreated water remains completely separated from the treated water and is washed away.
Some global water issues can be solved by reverse osmosis. Many water scarce areas are faced with water issues such as low rainfall, empty water wells and depleted rivers and other natural water sources.
However, reverse osmosis can be used in countries with adequate salt water seas and oceans. Many desalination plants use and plan to use reverse osmosis to provide drinking and household water.
Reverse osmosis is highly effective in removing particles, protozoa, bacteria, viruses and chemical contaminants from water, so that it can be used for drinking and household purposes.
Cryptosporidium, Giardia, Salmonella, E.coli, Hepatitis, Norovirus, Sodium, Lead and Chromium are some of the contaminants that can be removed quite successfully. These contaminants can be removed from ground water as well as brackish water.
Reverse Osmosis Systems
The typical reverse osmosis system consists of several components:
- Filters that remove particles and bacteria;
- Cold water line that connects the system to the water source;
- A reverse osmosis partially permeable membrane to filter the water;
- Valves to control the water in the tank and block water flow;
- Faucet and drain lines or pipes carry the contaminants out of the system;
- Flow restrictor that regulates the flow of water;
- Storage tank that holds the treated water.
The filters the cold water line ; the reverse osmosis membrane filters the water; the valves are control the water in the tank and block water flow; the drain lines and pipes carry the contaminants out of the system; the flow restrictor regulates the flow of the water and the storage tank holds the treated water.
Reverse osomsys systems have been used commercially for a long time, and now they are becoming popular for residential use. The home systems can either be a point of use or point of entry.
Point of use systems usually filter the treated water to a few faucets in the home and can be installed under the sink or on the countertop.
Point of entry systems are a bit more complex, but are designed to supply treated water to the entire home via a main supply line.
There are two types of reverse osmosis systems – a one stage system and the multi stage system.
In the one stage system, the water is fed through the reverse osmosis membrane and exits the system as waste.
In a two stage system, after the water is fed through the reverse osmosis membrane, it is fed through the second stage of the system before it exists the system as waste.
How to Choose a Reverse Osmosis System
When purchasing a reverse osmosis system for the home, there are some factors to bear in mind:
- the cost of the system, the size of the system and where it will be installed;
- the amount of water that is required for your home and how much the desired system can filter;
- the effectiveness of the system;
- how much water may be lost by the system;
- system’s life expectancy.
Reverse osmosis systems can greatly improve the water quality in your home. However not all systems are created equal: homeowners have to do their homework and choose a system that is right for their individual needs.
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