1. Topic 4.4: Water Pollution
Starter:
1) List as many sources of water pollution as you can think off.
2) Suggest how we could reduce each of these.

2. Types of Water Pollution
Anthropogenic or natural
Anthropogenic pollution
thegreatimmensity.org
Red Tide Caused by algae bloom

3. Types of Water Pollution
Point and Non “Point

4. Types of Water Pollution
Organic or Inorganic
Human and animal waste
Gulf of Mexico
animalradio.com

5. Types of Water Pollution
Direct or Indirect
Dumping toxins into waterways
blogs.ntu.edu.sg
Excess nitrates entering waterways

6. Possible Sources of Water Pollution
Sewage (human & animal)
Pesticides
Industry
Pathogens
Nitrates (fertilizers)
Phosphates (detergents)
Heavy metals (industry)
Oil spills
Heat (thermal pollution from electrical stations)
Radioactive waste
Solid domestic waste (trash debris)
Suspended particles (from erosion)
Invasive species

7. Possible Effects of Water Pollution
Eutrophication
Loss of biodiversity (species & habitat)
Increase in disease from pathogens
Bioaccumulation and biomagnification
Disruption of breeding grounds, nesting sites
Damage to coral reefs
Damage to organisms (ingesting plastics)

8. Measuring Water Pollution Direct MethodpH
Nitrates or ammonia
Dissolved oxygen
Conductivity (may indicate dissolved pollutants or heavy metals)
Turbidity
Fecal coliform test

9. Measuring Water Pollution Indirect Method
Biochemical Oxygen Demand (BOD)
Amount of dissolved oxygen required for decomposers to aerobically break down organic matter into a given volume of water

10. Measuring Water Pollution Indirect Method
Biochemical Oxygen Demand (BOD)
If enough oxygen is present, aerobic decomposers will continue unit all waste is consumed

11. Measuring Water Pollution Indirect Method
Biodegradation of organic material utilizes oxygen.
There is a finite source of oxygen, and once it is used the water becomes anoxic.
This leads to anaerobic decomposition which leads to the formation of methane, hydrogen sulphide and ammonia (toxic).

12. Measuring Water Pollution Indirect Method
Biochemical Oxygen Demand (BOD)
DO should be measured the initial amount of oxygen in the sample
Sample should be sealed and in the dark
After 5 days a second DO reading should be recorded
Calculate the change in oxygen levels
Unpolluted, natural water has a BOD less that 5mg/L

13. Measuring Water Pollution Indicator Species
Organisms that show something about their environment by their abundance or scarcity
These species are sensitive to changes in an environmental factor

14. Measuring Water Pollution Indicator Species
In Freshwater Ecosystems the following are often indicators of the water quality
Frogs and Toads have permeable skin so are affected by water pollutants
Mayfly larva indicate clean water
Water louse indicate polluted water
Sludgeworms indicate very polluted water

15. Measuring Water Pollution
Image from biology portfolio

16. Indicator species and biotic index
Indicator species indicate whether there is pollution present or not.
Biotic index is an indirect measure of pollution.
Assessing the relative abundance of different organisms.

17. Measuring Water Pollution
Biotic Indices (ex Trent Biotic Index)
Indirect measure of pollution
Often used in conjunction with BOD as invertebrates are sensitive to decreases in oxygen demand
Often used to compare 2 ecosystems or point source pollutants using Simpson’s diversity index
Measures the effect of pollutants on biodiversity

18. Eutrophication Occurs when excess nutrients enter an aquatic ecosystem
Drastic increase in algae growth
May happen in freshwater or oceans (red tide)
Natural or anthropogenic
Human influence by using fertilizers or detergents

19. Dead Zones

20. Red tides Algal bloom Phytoplankton Red species
Produce toxins that kill fish and accumulate in shell fish – can make humans seriously ill

21. Dealing With Pollution

22. Dealing with pollution
Research methods aimed at mitigating the effects of eutrophication and place them in one of the above categories.
Then evaluate 3 of your methods.
E.g.
Ban or limit detergents with phosphate (phosphate are only needed in hard water areas).
This could be difficult as you would have to get companies to agree to making two products, and would people accept their washing powder being not as effective .