AQA GCSE FOUNDATION Chemistry: Potable Water and Treatment

AQA GCSE Foundation Chemistry: Potable Water and Treatment

What is Potable Water?

Potable water is water that is safe to drink. It must be free from harmful microorganisms, dissolved chemicals, and suspended solids.

Sources of Water

• Surface water: Rivers, lakes, and reservoirs.
• Groundwater: Water found beneath the Earth's surface.

Contamination of Water

Water sources can be contaminated by:

• Human waste: Sewage, fertilizers, and industrial waste.
• Agricultural runoff: Pesticides, herbicides, and animal waste.
• Industrial waste: Chemicals, heavy metals, and oil spills.

Water Treatment Processes

1. Screening: Removes large debris like twigs and leaves.

2. Sedimentation: Allows heavier particles to settle at the bottom.

3. Coagulation and Flocculation: Chemicals are added to cause small particles to clump together, making them easier to remove.

4. Filtration: Water is passed through sand and gravel filters to remove remaining particles.

5. Disinfection: Chlorine or UV light is used to kill harmful bacteria and viruses.

Key Chemical Processes

• Chlorination: Chlorine gas is added to the water to disinfect it.
• UV disinfection: Ultraviolet light is used to kill bacteria and viruses.

Importance of Water Treatment

• Health: Prevents the spread of waterborne diseases.
• Environment: Protects water sources from pollution.

Summary

Water treatment is essential for providing safe drinking water. By understanding the processes involved, we can appreciate the importance of this critical infrastructure.

Further Exploration

• Research the different types of water treatment plants and their specific processes.
• Investigate the role of water conservation in protecting our water resources.
• Explore the impact of climate change on water availability and quality.