Topic 10: Monitoring Water Pollution

Question 1

What factors determine the method selected to monitor water pollution?

Answer 1

Speed of data collection, level of expertise required, degree of accuracy,indication of long term historical pollution levels,measurement of the effects of the pollutant

Question 2

How is organic pollution measured?

Answer 2

By the level of deoxygenation caused
Biochemical oxygen deman BOD

Question 3

How is BOD standardised?

Answer 3

1 litre of water
20oC temperature
5 day period
In the dark to prevent oxygen replacement by photosynthesis by algae

Question 4

Chemical Oxygen Demand (COD)

Answer 4

Similar to BOD
It measures the amount of oxygen needed to chemically oxidise all the organic and inorganic substances in a water sample

Question 5

Coliform count

Answer 5

E.coli is present in water contaminated with faecal matter
Health risk can be determined by measuring the number of coliform bacteria

Question 6

What is a biotic index?

Answer 6

A scale for showing the quality of an environment by indicating the types of organism present

Question 7

Characteristics of species used in biotic indices
D

Answer 7

Different sensitivities to pollution
Easy to identify/find
Normally common
Generally distributed

Question 8

Advantages of biotic indices

Answer 8

A rapid assessment of current and recent pollution can be made
Expensive equipment isnt required

Question 9

Disadvantages of biotic indicies

Answer 9

Sorting samples is time consuming
Skill required to identify taxa
Further testing is required to detect specific pollutants present

Question 10

2 examples of commonly used biotic indicies

Answer 10

Lichens to monitor atmospheric acidic pollution
Aquatic invertebrates to monitor water pollution