Water treatment

What is water treatment?

Water treatment is essential for a healthy life - untreated water can make you poorly

Types of sources of water:

1. Groundwater - from rocks that trap water underground (aquifers). This contains ions such as Mg2+, Ca2+, Na and K+ , these ions come from minerals in the rocks.

2. Rainwater - from rain, this contains dissolved gasses such as CO2 and O2. When CO2 dissolves in water it lowers the pH of the water

What else do water sources contain?

Water sources contain man made pollutants like pesticides, fertilisers and household and industrial waste. As well as man made pollutants, water can also contain natural pollutants like bacteria and viruses

What demands are there for sustainable water?

1. Fresh water is crucial to humans - not just for drinking but also for farming and industry

2. The global population is increasing, so there is an even greater need for water

3. Water is expected to be more scarce with water shortages being possible. Climate change also increases the risk of droughts which makes water shortages more likely

4. As the demand for water goes up so does the price, so to make our water supply more sustainable and affordable the reduction of water consumption is vital

5. We need to collect and treat water in ways that dont damage the environment

How does water become purified

1. Sedimentation - large solid particles in the water settle at the bottom of the water tank because of gravity

2. Filtration - small insoluble particles are removed by filtering through layers of sand and gravel

3. Chlorination - chlorine gas is bubbled through to kill harmful bacteria and microbes

What does natural water contain?

Ions e.g sodium, calcium, magnesium, sulfate, chloride and hydrogencarbonate. .

Gases - Oxygen, Carbon dioxide and nitrogen

microorganisms / bacteria

toxic metals salts

pollutants e.g pesticides, fertilisers