B3.4 Flashcards
What is water pollution caused by?
~ Fertilisers from farming, which can cause plants to grow in water
~ Toxic chemicals from industrial processes
~ Sewage
What is air pollution caused by?
~ Smoke
~ Gases such as CO2 which cause global warming, and SO2 which dissolves in rain and forms acid rain
What is land pollution caused by?
~ Toxic chemicals from industrial processes
~ Pesticides and herbicides from farming
What do pesticides do?
Kill insects that eat crops
What do herbicides do?
Kill unwanted plants
What can an increase in population increase?
~ Air pollution ~ Land pollution ~ Water pollution ~ Building ~ Farming ~ Quarrying ~ Waste
How does deforestation cause an increase in CO2 levels?
~ It reduces the intake of CO2 that trees do for photosynthesis
~ When the wood burns it releases CO2
~ When the vegetation rots, microbes release CO2
What does deforestation reduce?
Biodiversity, as it’s destroys habitats so less species can live
Why is deforestation done?
~ To create land for growing food crops or crops for producing biofuels
~ For paper products
What produces methane?
~ Rice fields
~ Animals like cows
What are peat bogs?
- Partially decayed plant material
- Can be burned or used to make soil better
- Releases carbon dioxide
What may global warming cause?
- A change in climate
- Rise in sea level
- Change in species distribution
- Change in migration patterns (birds)
- reduction in biodiversity
What does it mean when carbon dioxide has been sequestered?
It’s been locked up in oceans, lakes and ponds
How can we decrease the levels of methane from the anaerobic decomposition of rice from bacteria?
Reduce use of paddy fields / eat vegetarian food
How can we decrease the levels of carbon dioxide from peat bog destruction?
Use ‘peat-free’ compost
How can we decrease the levels of carbon dioxide from deforestation?
Reduce deforestation or use carbon sequestration (e.g. Sub seafloor sequestration)
What goes into a biogas generator?
- Waste food
- Plants
- Animal waste
- Human waste
What is produced in a biogas generator?
Slurry
What are the conditions in a biogas generator?
- Anaerobic conditions
* Warmth
What would happen if there was oxygen in a biogas generator?
The anaerobic bacteria wouldn’t work and wouldn’t produce the biogases
What gases are found in biogas?
- Methane
- Carbon dioxide
- Water vapour, hydrogen, hydrogen sulfide
What is biogas used for?
Cooking, heating, generating electricity
What are benefits of biogas generators?
- Allow you to get rid of waste material
- Fertiliser is also produced which is useful
- It’s a more environmentally friendly way of producing fuel than using fossil fuels
Why, initially, is there a rise in carbon dioxide levels in a biogas generator?
Because there is oxygen in the generator at first, which is used for aerobic respiration which produces CO2. Eventually this oxygen will run out so CO2 levels will decrease.
