Showing papers on "Enhanced biological phosphorus removal published in 1982"

Method of removing phosphorus from organic waste liquids

Abstract: Phosphorus, nitrogen and BOD are removed from organic waste liquid containing the same by mixing the organic waste liquid with activated sludge which is substantially free of oxygen, nitric acid and nitrous acid and subjecting the mixture to the action of the activated sludge under anaerobic conditions which forms a mixture of a liquid rich in soluble phosphorus and an activated sludge low in phosphorus. The sludge and liquid are separated. A portion of the liquid is subjected to solid-liquid separation to form a liquid high in phosphorus and a sludge low in phosphorus. This latter sludge is, along with the other portion of the liquid and the sludge from which the liquid has been initially separated are mixed with oxygen, in the presence of nitric acid or nitrous acid and subjected to aerobic biological oxidation. This results in the formation of a liquid low in phosphorus and an activated sludge. The activated sludge is used as the activated sludge free of oxygen, nitric acid and nitrous acid in the first stage of the process. The liquid high in phosphorus from the portion subjected to solid-liquid separation of the separated liquid is subjected to chemical removal of the soluble phosphorus therein.