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Potable Water
- POTABLE WATER is another term for water that's safe to drink.
- This means it contains very LOW levels of dissolved SALTS and microbes, and is free from harmful chemical substances.
- It's not the same as PURE WATER, which ONLY contains H2O molecules, whereas potable water CAN include various dissolved substances.
Producing Potable Water from Fresh Water
There are THREE steps to obtain POTABLE WATER from FRESH WATER:
1. CHOOSING WATER SOURCES:
- The selection of water sources is crucial. In places like the UK, water providers usually collect water with low levels of dissolved substances from FRESH WATER sources such as SURFACE WATER or GROUNDWATER.
2. PASSING WATER THROUGH FILTER BEDS:
- This involves passing the water through a WIRE MESH or SAND BEDS to help remove solid particles.
3. STERILISING:
- To make water safe from harmful MICROBES, it's treated with sterilising agents like CHLORINE, OZONE, or exposed to ULTRAVIOLET LIGHT.
Dealing with Limited Fresh Water Supplies
The methods used to produce potable water depend on available supplies of water and local conditions.
For example, the UK primarily uses GROUNDWATER due to its DRIER Southeast region which leads to LESS SURFACE WATER.
Producing Potable Water from Salty Water
In places where there is LESS FRESH WATER available, alternative methods like DESALINATION of salty water or sea water are used. This involves removing SALTS from water to make them POTABLE.
DESALINATION can be done in TWO different ways:
DISTILLATION:
- This involves BOILING water to create steam and then CONDENSING it back into liquid, leaving the salts behind.
REVERSE OSMOSIS:
- A method involving a MEMBRANE which allows water particles to pass through it but NOT salt ions, meaning they can be separated.
Both desalination processes typically require a lot of ENERGY, so are EXPENSIVE processes.
Potable Water
- POTABLE WATER is another term for water that's safe to drink.
- This means it contains very LOW levels of dissolved SALTS and microbes, and is free from harmful chemical substances.
- It's not the same as PURE WATER, which ONLY contains H2O molecules, whereas potable water CAN include various dissolved substances.
Producing Potable Water from Fresh Water
There are THREE steps to obtain POTABLE WATER from FRESH WATER:
1. CHOOSING WATER SOURCES:
- The selection of water sources is crucial. In places like the UK, water providers usually collect water with low levels of dissolved substances from FRESH WATER sources such as SURFACE WATER or GROUNDWATER.
2. PASSING WATER THROUGH FILTER BEDS:
- This involves passing the water through a WIRE MESH or SAND BEDS to help remove solid particles.
3. STERILISING:
- To make water safe from harmful MICROBES, it's treated with sterilising agents like CHLORINE, OZONE, or exposed to ULTRAVIOLET LIGHT.
Dealing with Limited Fresh Water Supplies
The methods used to produce potable water depend on available supplies of water and local conditions.
For example, the UK primarily uses GROUNDWATER due to its DRIER Southeast region which leads to LESS SURFACE WATER.
Producing Potable Water from Salty Water
In places where there is LESS FRESH WATER available, alternative methods like DESALINATION of salty water or sea water are used. This involves removing SALTS from water to make them POTABLE.
DESALINATION can be done in TWO different ways:
DISTILLATION:
- This involves BOILING water to create steam and then CONDENSING it back into liquid, leaving the salts behind.
REVERSE OSMOSIS:
- A method involving a MEMBRANE which allows water particles to pass through it but NOT salt ions, meaning they can be separated.
Both desalination processes typically require a lot of ENERGY, so are EXPENSIVE processes.
