Fresh Water Pollution (T4) Flashcards Preview

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Flashcards in Fresh Water Pollution (T4) Deck (3):
1

What are the three main pollutants of fresh water?

- nitrates from fertilisers
- organic waste
- detergents

2

What is eutrophication and what can cause it?

Eutrophication is an increase in mineral ions in lakes and rivers which can occur naturally but also artificially as follows:

- farmers often add inorganic fertilisers to their crops to replace the minerals lost when crops are removed
- the nitrates in these fertilisers are very soluble and so are easily leached from the soils and can enter waterways
- the levels of nitrates and ions can rise rapidly in lakes and rivers which are affected, causing the increase in mineral ions known as eutrophication

3

Describe seven ways in which eutrophication can have disastrous and cumulative effects on waterways...

- as nitrate levels rise, algae are able to use the nitrates to produce extra proteins for growth and rapid reproduction
- the algae then form an algal bloom, preventing light from penetrating further into the water
- submerged plants cannot photosynthesise and so die
- the algae eventually die as they run out of nitrates
- bacteria decay the dead plants and algae, thus releasing more nitrates, and the cycle begins again
- the bacteria reproduce due to the large amount of dead matter, and their respiration uses up more and more oxygen
- the waterway eventually can become completely devoid of oxygen, and all like in the water will die

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