4.4 water pollution

Question 1

types of pollutants

Answer 1

• Chemical pollutants e.g. toxic metals.
• Physical pollutants e.g. noise and thermal pollution.
• Biological pollutants e.g. invasive species.

Question 2

organic pollution

Answer 2

aerobic breakdown of organic materials produces nitrates, phosphates, sulfates, and carbon dioxide.

Question 3

problems with eutrophication

Answer 3

• unsuitable for drinking unless expensive treatment used
• reduced recreational use of the water due to plants
• reduced commercial value (fish)
• increase in water-related diseases

Question 4

metals

Answer 4

Minamata, Japan 1950
- people were affected from eating seafood contaminated with mercury compounds
- mercury compounds discovered to bioaccumulate within the organisms and levels were biomagnified through the food chain
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Question 5

oil

Answer 5

• covers the water forming a surface film preventing gaseous exchange –> can result in oxygen depletion in water.
• oil film blocks out light and prevents photosynthesis

Question 6

how to measure physical and chemical parameters

Answer 6

• pH: calibrated pH probe
• temp: thermometer
• suspended solids: filter and filter paper
• oxygen: oxygen meter