using resources - potable water and waste water

Question 1

what does drinking water have to have

Answer 1

sufficiently low levels of dissolved salts such as sodium chloride and low levels of microbes

Question 2

what is water that is safe to drink called

Answer 2

potable water

Question 3

true or false
potable water is the same as pure water

Answer 3

false
pure water has no dissolved substances at all however potable water does in small amounts

Question 4

in the uk what provides most our potable water

Answer 4

rain - it collects in the ground in aquifers as well as lakes, rivers and reservoirs

Question 5

how do we produce potable water

Answer 5

• pick a suitable source e.g. river
• pass water through a filter to remove unwanted materials
• it then kets sterilized to kill microbes e.g. chlorine

Question 6

what is the process Calle dog potable water being produced from salt water

Answer 6

desalinization

Question 7

what does desalinization do

Answer 7

reduce the levels of dissolved minerals down to an acceptable level for patable water

Question 8

how can we carry out desalinization

Answer 8

distillation or reverse osmosis

Question 9

what is the problem with these methods

Answer 9

require lots of energy and so they are thereof very expensive

Question 10

where is a large amount of water used

Answer 10

personal hygiene such as baths/ showers or flushing toilets and washing clothes
as well as agriculture

Question 11

what does this waste water contain

Answer 11

a large amount of organic molecules and harmful microgansisms such as bacteria

Question 12

how is waste water treated

Answer 12

• water is screened by passing through a mesh to remove solids
• the sewage now settles in large tanks to produce an effluent and a sludge
• the sludge is taken away and is eaten by anaerobic bacteria
• in the absence of oxygen these produce biogas which is burned for electricity and the sludge can be used as fertilizer
• air is bubbled through the liquid effluent and is safely discharged

Question 13

true or false
we use cleaned sewage water as potable water in the uk

Answer 13

false

Question 14

what is the safest way to produce potable water

Answer 14

ground water from aquifers once treated with chlorine

Question 15

how can the water from aquifers be contaminated

Answer 15

by fertilizers

Question 16

how can we make sewage water into potable water

Answer 16

lots of purification