Noun
English Wikipedia has an article on:biochemical oxygen demandWikipedia
biochemical oxygen demand (countable and uncountable, plural biochemical oxygen demands)
The amount of oxygen needed by aerobic microorganisms to decompose all the organic matter in a sample of water; it is used as a measure of pollution.
Technical Biochemical oxygen demand (BOD) is a measure of the amount of oxygen required by aerobic micro-organisms to decompose the organic matter in a sample of water. Source: Internet