In the art world, it is fostered by an incessant rain of numbers in the media whenever an art star comes to its attention. Graffiti Artists Turn on Banksy: The Rise of Art Hate Anthony Haden-Guest August 6, 2014
For the music genre, see Sludge metal. Sludge. Sludge is a semi-solid slurry and can be produced as sewage sludge from wastewater treatment processes or as a settled suspension obtained from conventional drinking water treatment and numerous other industrial processes.
In the wastewater linguistic usage the following terms are used for sludge. Raw sludge is untreated non-stabilized sludge, which can be taken from wastewater treatment plants. It tends to acidify digestion and produces odour. Primary sludge is produced through the mechanical wastewater treatment process.