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- The term biodegradable is used for any item
- capable of being broken down by living
- organisms, principally bacteria and fungi.
- In biodegradable substances, such as food and
- sewage, the natural processes of decay lead
- to compaction and liquefaction, and to the
- release of nutrients that are then recycled
- by the ecosystem. This process can have some
- disadvantageous side effects, such as the
- release of methane, an explosive greenhouse
- gas. However, the technology now exists for
- waste tips to collect methane in underground
- pipes, drawing it off and using it as a cheap
- source of energy. Nonbiodegradable
- substances, such as glass, heavy metals, and
- most types of plastic, present serious
- problems, now and in the future of disposal
- techniques.
-
- Subject by: John Denver
-