Topic 7 Decay Flashcards
What is compost
Decomposed organic matter that is used as natural fertiliser for crops and garden plants
What is the rate of decay affected by
Temperature
oxygen availability
water availability
number of decay micro organisms
What are responsible for decomposition
Micro organisms such as bacteria and fungi as well as detritus feeders
How does temperature affect the rate of decay
Warmer temperatures make things decompose quicker because they increase the rate the enzymes involved in decomposition work
if too hot decomposition slows down or stops because the enzymes are destroyed and organisms die
really cold temperatures The rate of decomposition slows right down
How does oxygen availability affect the rate of decay
Many organisms need oxygen to respire which they need to survive
the micro organisms involved in Arabic Decay do not need oxygen
How does water availability affect the rate of decay
Decay takes place fast in moist environment because the Organisms involved in decay need water to carry out biological processes
How does the number of decay organisms affect the rate of decay
The more Micro organisms and detritus feeders there a faster decomposition happens
What is biogas made by
The anaerobic decay of waste material
What is biogas mainly made up of
Methane which can be burned as a fuel
What do microorganisms decay plant and animal waste anaerobically into
Methane gas
What is used to make biogas on a large scale
Sewage waste from sewage works or sugar factories
How is biogas made
In a simple fermenter called a digester or generator
Why do biogas generators need to kept at constant temperature
To keep the micro organisms respiring away
Why can’t biogas be stored as a liquid
It needs to high-pressure
What happens to biogas if it can’t be stored
Used straight away from heating, cooking , lighting or to power a turbine to generate electricity
