Topic 10

Answer 1

water that has been treated,safe for humans to drink
not pure otherwise only contain h20 molecules.
potable water contains lots of dissolved salts ,can’t be too high ,PH (6.5-8.5P)arent any bacteria except from microbes

Answer 2

rain water is a type of fresh water (doesn’t have much dissolved in it )
when it rains collects as surface water or groundwater
most of water id groundwater bc it dries up to quickly ?
freshwater goes through to processes -Filtration and sterilization

Answer 3

desalination -dry countries (not enough groundwater so seawater must be desalinated to provide potable water )
vey expenisve ,not practical for large quantities of water
reverse osmosis

Question 4

Whats the first step ?
What’s the second step?
What happens third step ?
What happens fourth ?

Answer 4

1)screening and grit removal (removing twigs and plastic bags )
2)Sedimantation -Scum(top)sludge (bottom)used as great feartlisers .
effluent inbetween cleaner water
3)effluent is removed and treated by biological aerobic respiration
4)sludge from the bottom is removed and transferred into large tanks ,broken down by anaerobic respiration
breaks down organic matter in sludge releasing methane gas
6)might have to add chemicals

Question 5

distillation for desalination

Answer 5

1)test ph of water using a PH meter ,if too high or too low use titration to neutralise it
test water for presence of sodium chloride by doing -sodium flame test ,flame will turn yellow if they are present