Potable water

Potable water

drinking water

water resources in the UK

• rivers

• lakes

• aquifers

• reservoirs

treating ground water

• water is in then screened and pumped through to a coarse filter

• insoluble solids like leaves and soil are removed

• then put in a sedimentation tank which causes tiny particles to clump together into larger particles by adding aluminium sulphate

• fine filter removes fine particles

• chlorine is added

• stored in storage tank then transported to homes and factories

desalination

removal of salt from water

method one for desalination

distillation

method two for desalination

• pre treatment filtration

• membrane filtration → reverse osmosis

• disinfecting (e.g adding chlorine)

chlorinisation

the process of adding chlorine to water or other liquids to disinfect them

Why is chlorine added to water?

to make it safe for drinking

Advantages of chlorination

• kills harmful microorganisms

• reduces risk of waterborne illness

• removes unpleasant smells

disadvantages of chlorination

• can form harmful byproducts

• toxic gas

how is chlorine gas produced & potential long time effects?

• electrolysis

• its energy intensive → global warming

electrolysis

electricity applied sodium chloride in water which splits sodium and chloride

treating waste water

1. metal grid moves large objects

2. solid sediment sinks to the bottom → large puddle pushes sludge which is pumped into the storage tank

3. bacteria feed on organic matter through aerobic respiration → air bubbled for oxygen

4. bacteria settles to bottom and moves into sludge → water is now safe to go in rivers

5. sometimes water is sterilised with chlorine and filtered through a bed of sand

6. sludge can be fried and buried for electricity

Testing if water is pure

• evaporate water → if nothing left behind its pure

• test if it conducts electricity → shouldn’t as its simple covalent

• boil water sample → i8f boils at 100 degrees its pure