Process for the treatment of waste water containing ammonia
AssigneePaques Bio Systems B.V.
InventorsHendrik Dijkman, Marc Strous
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Abstract
A process is described for the biological treatment of waste water containing ammonia, wherein the waste water is treated with sludge containing nitrifying bacteria in an aerated reactor, applying a sludge retention time in the reactor which favours nitrite-producing bacteria over nitrate-producing bacteria. The process is characterised by applying a hydraulic retention time in a continuously operated reactor, which is shorter than the sludge retention time as a result of part of the sludge being separated from the reactor effluent and being returned to the reactor. The performance of the nitrification is further improved by applying low oxygen and nitrite concentrations.
Claims14
A process for the biological treatment of water containing at least 50 mg/l of ammonia, wherein the water is treated with sludge containing nitrifying bacteria in an aerated reactor, applying a sludge retention time in the reactor which continuously favours nitrite-producing bacteria over nitrate-producing bacteria, characterised by controlling the sludge retention time by continuously separating part of the sludge from the reactor effluent and continuing the use of the separated part thus retained in the reactor, applying a sludge retention time which is shorter than the doubling time of the nitrate-producing bacteria and which is between 1 and 30 days, and applying a hydraulic retention time which is shorter than the sludge retention time.
Dependencies are inferred from the claim text.