Liquid removed from settled sludge. Supernatant commonly refers to the liquid between the sludge on the bottom and the water surface of a basin or container.
SUPERNATANT (SUE-PER-NAY-TENT)
Meaning of SUPERNATANT (SUE-PER-NAY-TENT) in English
Environmental engineering English vocabulary. Английский словарь экологического инжиниринга. 2012