We describe a method of determining a food-to-biomass ratio in an aqueous fluid the method comprising: providing an aqueous fluid comprising viable biomass and food for said biomass, and wherein there is insufficient available food to sustain all said viable biomass; using a sensor (for example a respirometer or a sensor for sensing an amount of ammonia, ammonium, nitrates or nitrites) to determine an amount of food in said aqueous fluid available to said biomass; determining a measure of viable biomass in said aqueous fluid by measuring polarisability of viable biomass cells in an AC electric field; and determining a food-to-biomass ratio from said amount of food and said measure of viable biomass.

A system and method of treating wastewater. In one embodiment, the system comprises a biological reactor fluidly connected to a source of wastewater and having a treated wastewater outlet, a fixed film biological reactor connected to the source of wastewater and having a fixed film effluent outlet, and a ballasted system fluidly connected to the fixed film effluent outlet. The ballasted system may comprise a ballast reactor tank configured to provide a ballasted effluent, and a source of ballast material fluidly connected to an inlet of the ballast reactor tank. The system may further comprise a bypass line having an inlet fluidly connected to the source of wastewater, a first outlet fluidly connected to the ballasted system, and a second outlet fluidly connected to the fixed film biological reactor, the bypass line configured to bypass the fixed film biological reactor.

A system and method for automatically controlling aeration and mixing processes are disclosed.

A biological nitrogen removal method based on multistage feeding and anoxic/aerobic chambers for adopting a constant flow operation mode, enabling wastewater subjected to primary treatment to enter a first-stage and a second-stage A/O reaction units from two position points; lifting and refluxing an effluent to an influent end of the first-stage units; lifting and refluxing an effluent to an influent end of the second-stage units; and clarifying, separating and discharging an effluent from an outlet end of a third-stage A/O reaction unit. The wastewater treatment mode combines a process based on two-stage wastewater feeding and three-stage anoxic/aerobic chambers with biofilms in different reaction zones, =optimizing and controlling a reflux ratio of each segment according to an amount of organic matters available for denitrification in influent, reducing the impact of hydraulic loading at the cross section in the reactors while removing organic matters and nitrogen-containing pollutants at a low temperature.

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 method for optimizing filtration in an aquaculture system. The method for optimizing filtration includes, taking at least one sample of matter from an aquaculture system, defining at least one predetermined characteristic to test the sample of matter for, testing the at least one sample of matter, determining if the at least one predetermined characteristic is present within the sample, modifying resource distribution within the aquaculture system, taking at least two samples of matter within the aquaculture system, re-defining at least one predetermined characteristic to test the at least two samples of matter for, testing the at least two samples of matter, determining if the re-defined at least one predetermined characteristic is present within the at least two samples of matter and ensuring the filtration system will retain a state of optimization.

Systems and method for treating wastewater including a vessel having an inlet and an outlet, a pump in fluid communication with the outlet of the vessel, the pump configured to pump wastewater out of the vessel, a separator in fluid communication with the pump, the separator configured to separate grit from the wastewater, the separator having a first outlet for discharging a grit stream and a second outlet for discharging a wastewater stream, a grit washing system in fluid communication with a source of washing fluid and the first outlet of the separator, the grit washing system configured to wash and dewater grit from the grit stream, the grit washing system having an outlet for discharging a wash wastewater stream, and a return conduit configured to recycle the wastewater stream discharged from the separator to one of the inlet of the vessel and an inlet to the pump.

An intelligent detection system of effluent total nitrogen (TN) based on fuzzy transfer learning algorithm belongs to the field of intelligent detection technology. To detect the TN concentration, the artificial neural network can be used to model wastewater treatment process due to the nonlinear approximation ability and learning ability. However, wastewater treatment process has the characteristic of time-varying dynamics and external disturbance, artificial neural network prediction method cannot acquire sufficient data to ensure the accuracy of TN prediction, and data loss and data deficiency will make the prediction model invalid. The invention proposed an intelligent detection system of effluent total nitrogen based on fuzzy transfer learning algorithm; the proposed system contains several functional modules, including detection instrument, data acquisition, data storage and TN prediction. For the TN prediction module, the fuzzy transfer learning algorithm build the fuzzy neural network based intelligent prediction model, which the parameters are adjusted by the transfer learning method.

Process for treating effluents containing nitrogen in ammonium form, using a sequential biological reactor (1), according to which: a volume of effluents to be treated in one complete cycle is introduced into the biological reactor in one or more successive fractions by volume, each fraction by volume being treated during a subcycle; each subcycle comprises a phase of feeding with a fraction by volume, and at least a first aerated step, during which total or partial oxidation of the ammonium to nitrites takes place by injection of air or of oxygen into the effluent, a settling out and emptying step taking place after the end of the complete cycle; the weight of N—NH.sub.4 to be treated is determined from the volume of effluents in the reactor at the end of the feeding phase, and from the difference between the initial N—NH.sub.4 concentration in the reactor and a concentration desired at the end of the aerated step, a maximum aeration time TM is dedicated to the aerated step, and an initial air flow rate Qairinit, for the beginning of the aerated step, is determined by taking into account the weight of N—NH.sub.4 to be treated and the maximum aeration time TM.

A process for reducing the production of sludge by municipal or industrial wastewater purification plants, comprising a step of mesophilic or thermophilic anaerobic digestion (20), or anaerobic digestion combining these two operating modes, of a stream of sludge to be treated (1), and at least one biological solubilization anaerobic treatment step (30); the process comprises, upstream of the anaerobic digestion step, a step of dehydration (10) of the sludge to be treated, followed by a step of mixing (15) the dehydrated sludge with a recirculated fraction of sludge that is more liquid, originating from recycling of the digestion (20), and/or from the anaerobic treatment step (30), and/or centrates originating from a final dehydration (50) of the treated sludge, wherein the recirculation rate is chosen such that the mixture has a dryness suitable for digestion, this mixture then being directed towards the digestion.