water pollution

Question 1

what factors affect the concentration of pollutants

Answer 1

1) effluent quantity
2) volume of water
3) residence time of water

Question 2

how does the effluent quantity affect dilution

Answer 2

volume of pollutant released will affect conc- if conc of pollutant in water is low then many pollutants are not harmful

Question 3

how does volume of water affect dilution of a pollutant

Answer 3

the larger the water body the more waste will be diluted

Question 4

how does the residence time of the water affect dilution of a pollutant

Answer 4

the shorter the residence time the more likley the pollutant will be carried away by flowing water and not accumulate

Question 5

list the factors which affect degradation

Answer 5

1) high levels of UV light
2) dissolved oxygen - increase the rate of aerobic bacteria to break down sewage
3) high temperatures - increase the rate of most reactions

Question 6

define degradation

Answer 6

the processes by which substances ae broken down- it involves both abiotic and biotitic processes

Question 7

outline how water can increase or decrease dispersal or a pollutant

Answer 7

• currents can either move pollutants away causing them to become diluted and reduce harmful effects
  or
• currents may cause pollutants to re-concentrate

Question 8

what are the causes of water pollution

Answer 8

1) industrial areas
2) areas with large human populations
3) lakes or enclosed water bodies
4) heavy shipping
5) oil terminals or ports