Last edited 16 Jan 2020

Biodegradable

[edit] Introduction

A material that is biodegradable is one that can be broken down by living organisms, such as bacteria and fungi, without leaving any contaminating substances behind. A natural decay process, biodegradability results in compaction and liquefaction of materials. The nutrients released are eventually recycled into the environment by natural processes. Typical examples of biodegradable materials include leaves, food and sewage. Increasingly, biodegradable packaging materials are also available.

One side effect of this process can be the release into the atmosphere of the gas methane, which as a greenhouse gas can trap 100 times more heat than CO2.

[edit] Construction

The essence of biodegradability is not that these products break down – many other non-biodegradable products can also share this characteristic – but that the breakdown occurs without releasing toxins into the environment. This is of great significance to the demolition of buildings, which typically comprise a mix of potentially toxic materials.

The traditional building site or demolition site, is likely to produce an abundance of waste materials that are non-biodegradable and will end up in landfill (even if they are first reused or recycled). This includes most industrial materials such as plastics, glass and heavy metals, the disposal of which presents long-term problems for society. A study by Cardiff University found that 70–105 million tonnes of waste is created in the UK from demolishing buildings every year; only 20% of that is biodegradable.

Recent years have seen an increase in the availability of biodegradable materials and packaging, which may eventually help avoid accumulating mountains of potentially polluting waste.

Materials which are biodegradable include:

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