Chapter 5 - Water Treatment Processes Flashcards
What does screening do
- removed large or floating solids
What does sedimentation do
In static water settling removes suspended solids
What does flocculation do
- alum or poly electrolytes neutralise electrical charges
- removes clay/ colloidal material
What does aeration do
Reactions with oxygen removes odours, some metals and organic matter
What do activated carbon filters do
Some organic compounds and pesticides are removed as they are absorbed
How does pH control work
Acids are neutralised by adding lime
How does sterilisation work
Addition of chlorine, ozone or exposure to UV light is used to sterilise the water and kill pathogens
What is fluoridation
Fluorides are added to water to improve the dental health of people that drink the water
How does distillation work
Water is boiled by heating and/or reducing the pressure. The steam that is produced is condensed and collected
What is reverse osmosis
Saline water is filtered at very high pressure through the partially permeable membranes of very small polyamide tubes.
