Samuel Chiltern answered
The decomposition rates of biodegradable materials can vary wildly. Primarily, the rate depends upon the type of material in question, its size and thickness, and the environment that it is in.
Biological Processes That Break Down Materials
The process of materials being broken down by bacteria (or by other biological processes) is called biodegradation.
To work effectively, this process requires light, water and oxygen, although certain types of materials can also break down without oxygen.
Measuring the Rate of Biodegradation
Scientists often measure the rate of biodegradation using what are called respirometry tests - and you could almost think of the biodegradation process as breathing, or respiring.
This process releases carbon dioxide, which, in a controlled environment, scientists can measure in order to establish the rate of decomposition.
Decomposition Rate of Biodegradable Materials
You haven't specified which materials you are interested in, so I will list a selection of them. However, the figures below are very approximate, given that we haven't been able to establish any of the key variables mentioned previously.
Biological Processes That Break Down Materials
The process of materials being broken down by bacteria (or by other biological processes) is called biodegradation.
To work effectively, this process requires light, water and oxygen, although certain types of materials can also break down without oxygen.
Measuring the Rate of Biodegradation
Scientists often measure the rate of biodegradation using what are called respirometry tests - and you could almost think of the biodegradation process as breathing, or respiring.
This process releases carbon dioxide, which, in a controlled environment, scientists can measure in order to establish the rate of decomposition.
Decomposition Rate of Biodegradable Materials
You haven't specified which materials you are interested in, so I will list a selection of them. However, the figures below are very approximate, given that we haven't been able to establish any of the key variables mentioned previously.
- Aluminium can - 200-500 years
- Apple core - between one and two months
- Cardboard - between one and two months
- Cotton cloth - five months
- Batteries - 100 years (and these contain dangerous materials too)
- Glass bottles - one million years (although we can't be sure about that!)
- Leather Shoes - between 40 and 50 years
- Nylon (commonly used in clothes) - between 30 and 40 years
- Paper Towel - two to four weeks
- Plastic bags - between 10 and 20 years
- Plastic bottles - 450 years
- Styrofoam - one million years (but we're not sure - perhaps never!)
- Wool sock - one year
