Methods and systems for controlling nitrous oxide production in a wastewater treatment facility in which wastewater is treated with microbes in a biological reactor. Nitrous oxide production can be controlled by determining an amount of two or more nutrients in the biological reactor, calculating a value that represents a comparison of the values, comparing the calculated value to a threshold value, and optionally taking a corrective action to reduce nitrous oxide production based on the comparison. In one aspect, nitrous oxide production can be controlled by determining an amount of ammonium in the biological reactor, determining an amount of a nitrogen compound that can include nitrite, nitrate, and/or hydroxylamine, calculating a value that compares the amount of ammonium to the amount of the nitrogen compound, and taking a corrective action that changes a system parameter to reduce the nitrous oxide production if the calculated value surpasses a threshold limit.

A method for treating effluents containing nitrogen in the form of ammonium, implementing chemical reactions for oxidizing and reducing the nitrogen in a sequencing batch reactor, the method including: introducing a volume of effluents to be treated into the reactor, injecting oxygen or air into the reactor for partial oxidation of the ammonium into nitrites and/or nitrates, interrupting the injection of oxygen or air, thus producing gaseous nitrogen, depositing the sludge at the bottom of the reactor and clarifying the content of the reactor close to the surface of same, discharging a clarified fraction of the content of the reactor. The draining and feeding steps occur simultaneously. During the feeding step, the volume of effluents is introduced close to the bottom of the reactor. During the draining step, the clarified fraction of the content of the reactor is discharged close to the surface of the content of the reactor.

The present invention provides a method of controlling a wastewater treatment plant. The plant comprises at least one process tank and an aeration structure configured for aeration of the at least one process tank. The method comprises alternating steps of increasing aeration to the at least one process tank when a first event occurs, wherein the first event is one of when a first threshold value of a first tank parameter is reached and when a first predetermined time period has expired, and decreasing aeration to the at least one process tank when a second event occurs, wherein the second event is one of when a second threshold value of a second tank parameter is reached and when a second predetermined time period has expired. The first and second tank parameters are selected from a group consisting of nitrate concentration, nitrite concentration, and ammonium concentration determined in the water in the at least one process tank, and the steps of increasing aeration and decreasing aeration are carried out to reduce N2O emissions from the plant.

A water neutralization system that includes a first source of water that is acidic and a second source of water that is basic. A storage reservoir communicates with each of the first source and the second source, and includes a pH sensor that is configured to transmit a signal indicative of a pH of the water stored in the storage reservoir. At least one valve controls fluid communication between the storage reservoir and at least one of the first source and the second source, and a controller communicates with each of the pH sensor and the valve. Based on the signal indicative of the pH of the water stored in the storage reservoir, the controller instructs the valve to adjust an amount of water received from at least one of the first source and the second source to neutralize a pH of the water stored in the storage reservoir.

A water neutralization system that includes a first source of water that is acidic and a second source of water that is basic. A storage reservoir communicates with each of the first source and the second source, and includes a pH sensor that is configured to transmit a signal indicative of a pH of the water stored in the storage reservoir. At least one valve controls fluid communication between the storage reservoir and at least one of the first source and the second source, and a controller communicates with each of the pH sensor and the valve. Based on the signal indicative of the pH of the water stored in the storage reservoir, the controller instructs the valve to adjust an amount of water received from at least one of the first source and the second source to neutralize a pH of the water stored in the storage reservoir.

The present invention provides a method and apparatus for controlling gas flow rate to the membrane of a membrane aerated biofilm reactor (MABR) in order to effect one or more process outcomes, in particular to reduce or minimize N.sub.2O emissions in the exhaust gas from the MABR while managing gas delivery to mixing apparatus of the MABR and maintaining NH.sub.4 and NO.sub.3 targets in the treated effluent, the method comprising monitoring one or more parameters of the wastewater and the exhaust gas and modulating the supply of feed gas to the membrane based on the one or more parameters in order to control the composition of the exhaust gas.

A method for treating effluents containing nitrogen in the form of ammonium, implementing chemical reactions for oxidizing and reducing the nitrogen in a sequencing batch reactor, the method including: introducing a volume of effluents to be treated into the reactor, injecting oxygen or air into the reactor for partial oxidation of the ammonium into nitrites and/or nitrates, interrupting the injection of oxygen or air, thus producing gaseous nitrogen, depositing the sludge at the bottom of the reactor and clarifying the content of the reactor close to the surface of same, discharging a clarified fraction of the content of the reactor. The draining and feeding steps occur simultaneously. During the feeding step, the volume of effluents is introduced close to the bottom of the reactor. During the draining step, the clarified fraction of the content of the reactor is discharged close to the surface of the content of the reactor.

A central controller is used in a treatment method and system for removing at least one of nitrogen or phosphorus from wastewater. Based on data received from a plurality of sensors, each of which is coupled to a component of a wastewater treatment system, a control signal is sent from the central controller to at least one chemical delivery system, which dispenses at least one chemical compound into the wastewater in an amount effective to reduce the level of nitrogen or phosphorus in the wastewater.

A process is provided, comprising: (a) supplying ammonium-containing wastewater to a reactor containing granular sludge comprising granules having a core of anammox bacteria and an outer rim of ammonia oxidizing bacteria; (b) subjecting the wastewater to ammonium oxidation at a temperature between 5 to 25? C., a dissolved oxygen concentration between 0.4 mg/L to 4.0 mg/L, and a hydraulic retention time between 0.5 hours to 1.5 days, obtaining a nitrogen gaseous stream and a dispersion of granular and non-sludge in treated wastewater; and (c) separating the dispersion into a granular sludge stream and a stream of treated wastewater and non-granular sludge, and (d) recycling the granular sludge to the reactor while discharging the non-granular sludge, wherein the granular sludge has a reactor retention time at least ten times the hydraulic retention time, and wherein the retention time of non-granular sludge is no more than three times the hydraulic retention time.

A wastewater treatment system comprising a basin, an N2O sensor, and an organic carbon source. The basin is configured to subject wastewater to an activated sludge-based biological treatment wherein nitrogen is removed from the wastewater. The N2O sensor is positioned in the basin and configured to produce an N2O detection in the biological treatment. The organic carbon source is fluidly connected to the basin. The wastewater treatment system is configured to dose organic carbon from the organic carbon source to the biological treatment based on the N2O detection so that the wastewater treatment system controls an N2O level of the biological treatment via the organic carbon.