Glossary beginning with B

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non-polluting alternative fuel extracted from renewable, freely available resources such as vegetable oils. Biodiesel does not contain petroleum, but can be mixed with diesel in various proportions. It can be used in place of gasoline in suitably adapted engines.


all life forms on Earth. It comprises every biological variation of genetic inheritance (breeds or varieties of species, both wild and cultivated), species (animals, plants, fungi, microorganisms), and ecosystems (natural habitats such as aquatic, forest or alpine environments).


gas produced by the biological decomposition of organic material in the absence of oxygen, subsequently refined to achieve a methane concentration of 95%. Used as a biofuel for motor vehicles in the same way as natural gas (or fossil methane).

BOD (Biochemical Oxygen Demand)

total mass of oxygen used by microorganisms, over a specific time period at 20°C, to decompose (oxidize) the organic material present in a liter of water (normally expressed in mg/l). The standard test period for BOD is 5 days (BOD5).