Water and Wastewater Terms Beginning R
A B C D E F G H I J K L M N O P Q R S T U V W Y Z
rising sludge
Rising sludge occurs in the secondary clarifiers of activated sludge systems when the sludge settles to the bottom of the clarifier, is compacted, and then starts to rise to the surface, usually as a result of denitrification, or anaerobic biological activity that produces carbon dioxide or methane.