Assertion: hydrogen sulfide | /r/HasSubevent | total absence of oxygen
Facets:
value: generally
type: MANNER
Source sentences:
text: Hydrogen sulfide (sulfate reduction) generally results from the bacterial breakdown of organic matter in the total absence of oxygen, where as de-nitirifcation (nitrate reduction) that lowers nitrates while producing free nitrogen generally happens in an environment that is mostly devoid of oxygen but not completely devoid as in hydrogen sulfide production.