What is potable water

Question 1

What is potable water

Answer 1

Potable water is water that has been processed and is safe for human consumption and daily use

Question 2

The difference between pure water and potable water is that

Answer 2

pure water is solely made up of H2O molecules, whereas potable water may contain different substances, usually dissolved minerals and salts

Question 3

Potable water should have the following characteristics:

Answer 3

Have a pH between 6.5 and 8.5.

The dissolved substances (e.g. salts) will be present is very small regulated quantities

Be free of bacteria or potentially harmful microbes

Question 4

Water is considered fresh when it is relatively free from dissolves substances e.g. rainwater
Water can collect in reservoirs, lakes and rivers and is known as

Answer 4

surface water

Question 5

In addition, it can collect in aquifers which are porous rocks that store water underground
This water is called ?

Answer 5

groundwater

Question 6

despite being relatively low in dissolved substances, there is still a process in place to ensure the fresh water is safe and suitable for use.
Two important steps in this process are:

filtration

Answer 6

Debris such as pieces of soil and dirt, small pebbles, twigs, etc. are removed by a wire mesh screen

After this, other debris is filtered through sand beds and gravel

Question 7

Sterilisation

Answer 7

Ultraviolet light or ozone can be used to sterilise water or alternatively chlorine gas is bubbled through the water

This removes any dangerous bacteria or microbes

Question 8

Where aquifers are not present and/or the collection of surface water is limited, the process of desalination must be used to provide potable water to the population
Desalination involves the treatment of seawater to remove the salt by

Answer 8

distillation or reverse osmosis

Question 9

What is salinization

Answer 9

a process that involves the use of membranes
When salt water is put through a semi-permeable membrane, only water molecules can pass through it. This happens as the membrane stops larger molecules and ions passing through

Desalination is an expensive process as it consumes large amounts of energy and is not ideal when producing large quantities of fresh water