Back to results
US 6,183,642 B2Granted
Biological treatment of wastewater
AssigneeGrontmij Advies & Techniek B.V.
InventorsJoseph Johannes Heijnen, Marinus Cornelius Maria van Loosdrecht
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeGrontmij Advies & Techniek B.V.
InventorsJoseph Johannes Heijnen, Marinus Cornelius Maria van Loosdrecht
Estimating the term…
A method is described for the biological treatment of ammonium-rich wastewater in at least one reactor which has a temperature of at least 25° C., which involves the wastewater being passed through the said reactor(s) with a population, obtained by natural selection in the absence of sludge retention, in the suspended state of nitrifying and denitrifying bacteria to form, in a first stage with the infeed of oxygen, a nitrite-rich wastewater and by the nitrite-rich wastewater thus obtained being subjected, in a second stage without the infeed of oxygen, to denitrification in the presence of an electon donor of inorganic or organic nature, in such a way that the contact time between the ammonium-rich wastewater and the nitrifying bacteria is at most about two days, and the pH of the medium is controlled between 6.0 and 8.5 and the excess, formed by growth, of nitrifying and denitrifying bacteria and the effluent formed by the denitrification are extracted. In addition the growth rate of the nitrifying and denitrifying bacteria is expediently controlled by means of the retention time, in the reactor, of the wastewater to be treated which is fed in.
A method for the biological treatment of ammonium-rich wastewater in at least one reactor which has a temperature of at least 25° C., by the wastewater being passed through the said reactor(s) with a population, obtained by natural selection in the absence of sludge retention, in the suspended state of nitrifying and denitrifying bacteria to form, in a first stage with the infeed of oxygen, a nitrite-rich wastewater and by the nitrite-rich wastewater thus obtained being subjected, in a second stage without the infeed of oxygen, to denitrification in the presence of an electron donor of inorganic or organic nature, in such a way that the contact time between the ammonium-rich wastewater and the nitrifying bacteria is at most about two days, and the pH of the medium is controlled between 6.0 and 8.5 and the excess, formed by growth, of nitrifying and denitrifying bacteria and the effluent formed by the denitrification are extracted, the demand for said electron donor during the treatment being controlled as a function of the amount of heat produced in the reactor.
A method for the biological treatment of ammonium-rich wastewater in at least one reactor which has a temperature of at least 25° C., by the wastewater being passed through the said reactor(s) with a population of nitrifying and denitrifying bacteria to form, in a first stage with the infeed of oxygen, a nitrite-rich wastewater and by the nitrite-rich wastewater thus obtained being subjected, in a second stage without the infeed of oxygen, and with sludge retention, to denitrification in the presence of an electron donor of inorganic or organic nature, in such a way that the contact time between the ammonium-rich wastewater and the nitrifying bacteria is at most about two days, and the pH of the medium is controlled between 6.0 and 8.5 and the excess, formed by growth, of nitrifying and denitrifying bacteria and the effluent formed by the denitrification are extracted, the demand for said electron donor during the treatment being controlled as a function of the amount of heat produced in the reactor.
Dependencies are inferred from the claim text.