1.8 Polluted rivers Flashcards
What are the 4 causes of river pollution?
-Untreated sewage from homes, schools and factories.
-Chemical wastes from factories and mines.
-Farm chemicals such as fertilisers and pesticides.
-Waste oil and rubbish.
How is acid rain formed?
Sulphur dioxide and other gases that were from factories, power stations and motor vehicles go into the air. These gases dissolve in droplets of moisture in the atmosphere and form droplets of acid rain.
What can acid rain cause?
Acid rain kills fish and other wildlife in rivers and lakes. It also kills trees, damages crop and erodes stone buildings.
How far can acid rain fall onto the ground?
When the acid rain eventually falls onto the ground, it can sometimes fall hundreds of kilometers from where the gases were released.
What does it mean when water is covered with green algae?
This is caused because fertilizer from the farms on the riverbanks has polluted the water. When the algae die, they will sink into the river bottom and rot away. Algae also uses up most of the oxygen that is in the water, so there will be less oxygen for other water plants and animals living in the river so they will die.
What are the 5 ways to prevent river pollution?
- Having strict laws that make it illegal to pollute rivers.
- Making factories remove harmful substances from their wastewater before they let it flow into rivers.
- Making factories and mines pay to clean up rivers if they pollute them.
- Treating sewage to make it safe before the wastewater is returned to a river.
- Having laws to reduce the amount of air pollution released by factories, power stations and motor vehicles in order to reduce acid rain.
What is another important way to prevent river pollution?
We can build new sewage works where all wastewater from homes, businesses and factories will be treated instead of being put straight into the river.
How are clean rivers important?
Clean rivers are important because they show that the environment is healthy. There is another good reason why we shouldn’t pollute our rivers: the river water that we pollute today may be the water we have to drink tomorrow.
