25 results about "Nitrite oxidation" patented technology

The invention relates to the technical field of wastewater treatment or water quality purification, in particular to a method for synchronously culturing ammonia oxidizing bacteria and nitrite oxidizing bacteria, which comprises the following steps: selecting an inorganic material which is large in specific surface area and can quickly neutralize and release alkalinity as a nitrifying bacteria attachment carrier and an alkalinity supplement / pH regulator; the carrier is dissolved through nitration acid production, carbon dioxide and alkalinity are released, a carbon source and alkalinity required by growth are provided for nitrifying bacteria, and propagation of the nitrifying bacteria is promoted. Ammonia oxidizing bacteria and nitrite oxidizing bacteria are cultured synchronously by controlling the growth speed of the two bacteria in the culture process. By controlling the ammonia nitrogen concentration and nitrite concentration of the effluent at the end of culture to be lower than 50mg / L, sufficient time is provided for nitrite oxidizing bacteria to decompose an intermediate product nitrite, so that the purpose of simultaneously culturing AOB and NOB is achieved.

The application belongs to the technical field of electrochemical sensing, and particularly relates to an electrochemical sensing electrode with detection and anti-biofouling functions, a preparation method and application thereof. The electrochemical sensing electrode comprises a conductive substrate and a MOF-919 material loaded on the conductive substrate, and function mode switching is realized through external potential regulation. In the detection mode, a first working voltage is applied for nitrite oxidation detection; and a second working voltage is applied to release nitric oxide in situ by reducing nitrite to inhibit microbial adhesion on the electrode surface. The application does not need to additionally set an independent antibacterial layer or add an antibacterial agent, realizes the interface anti-microbial adhesion function while maintaining good electrochemical response performance of the electrode, and significantly improves the stability of long-term use in complex samples. The application provides a new technical path for anti-pollution design of an electrochemical sensing interface.

The application discloses a semi-short-cut nitrification method for middle-aged and old landfill leachate, which mainly adopts two-stage short-cut nitrification reactors to generate nitrous nitrogen, and the two-stage short-cut nitrification reactors are combined with aeration sedimentation tanks, the respective suitable process parameters and nitrite oxidation bacteria inhibition modes are controlled, and the strategy of periodically alternating the process sequence of the two-stage short-cut nitrification reactors is adopted, so that the long-term stable operation of short-cut nitrification is achieved. The method is efficient, economical, stable in operation and high in practicability.

Systems and methods for producing ammonium nitrate are disclosed herein. Exemplary systems can comprise a bioreactor positioned to receive a feed including ammonia. The bioreactor can hold a liquid solution including (i) an ammonia oxidizing bacteria (AOB) and (ii) a nitrite oxidizing bacteria (NOB). The AOB can facilitate oxidation of the ammonia to produce a nitrite at a nitritation rate and the NOB can facilitate oxidation of the nitrite at a nitratation rate. Thus, the bioreactor can produce a mixed liquor comprising a nitrate biologically. The system can further comprise a filter positioned to receive the mixed liquor and produce a permeate and a sludge. A sensor can measure the concentration of the liquid solution of the bioreactor, and a controller coupled to the sensor can regulate the mass flow of nitrogen and / or phosphorus of the bioreactor feed based on the measured concentration of the liquid solution.

To provide a water treatment method and a water treatment apparatus capable of more appropriately and stably maintaining the generation of nitrite nitrogen in a nitritation process and more efficiently performing nitrification and denitrification treatment.SOLUTION: A water treatment method for biologically treating raw water containing a nitrite component includes a nitrite-forming step of oxidizing ammoniacal nitrogen in the raw water to nitrite-nitrogen with biosludge containing ammonia-oxidizing bacteria, a nitrite treatment step of extracting a part of the biosludge in the nitrite-forming step and bringing the extracted biosludge into contact with a nitrite aqueous solution at a pH6 of less than 0 and a nitrite-nitrogen concentration of less than 250mg - N / L for 48 hours or less to suppress activity and proliferation of the nitrite-oxidizing bacteria contained in the biosludge, and a returning step of returning the biosludge after the nitrite treatment step to the nitrite-forming step.SELECTED DRAWING: Figure 1

The invention provides a method for rapidly stabilizing and improving the denitrification efficiency of a shortcut nitrification coupled anaerobic ammonia oxidation (PN / A) system, and aims to stabilize a continuous packed fixed bed PN / A reactor in a mainstream state and improve the denitrification performance of the continuous packed fixed bed PN / A reactor at the same time. 2.0 mg N / L of free nitrous acid (FNA) and 30.0 mg N / L of free ammonia (FA) are used for treating and inhibiting nitrite oxidizing bacteria (NOB) in the system so as to reduce the concentration of nitrate nitrogen (NO3 <->-N) in effluent, and 3.0 mg N / L of FNA needs to be used for further inhibiting the nitrate nitrogen (NO3 <->-N) when the high aeration flow speed (30 mL / min) is adopted. Experiments show that by means of the method, nitrate nitrogen in effluent is reduced from 15.64 mg N / L to 3.10 mg N / L, and the total nitrogen removal rate is increased from 143.43 mg N / L / d to 589.25 mg N / L / d and is increased by 4.11 times. Besides, the reactor used in the invention is a continuous filler fixed bed reactor, so that the sewage treatment load is improved, the sludge biomass retention capability is good, the operation is simple, and the method is environment-friendly. The overall efficiency of the sewage treatment system is greatly improved, the stability of the continuous PN / A system is also improved, and the continuous PN / A system is suitable for sewage treatment scenes with efficient denitrification requirements.

The invention discloses a method for promoting growth of nitrite oxidizing bacteria, and belongs to the technical field of culture of nitrifying microorganisms in the field of environmental microorganisms. According to the method, an adsorption medium can be provided for growth of bacteria, the growth speed of the nitrite oxidizing bacteria is increased, under the condition that cationic polyacrylamide and closed cell perlite are used as culture medium additives, the growth speed of the nitrite oxidizing bacteria is remarkably increased compared with that under the condition of an original culture medium, and the production period is shortened. The method is simple to operate, low in cost and capable of theoretically reducing cost and increasing benefits, on one hand, the culture time is shortened, on the other hand, the cell density of unit volume in the culture medium is averaged due to the fact that the closed-cell perlite is low in density, thalli are adsorbed on holes of the closed-cell perlite and are easily dispersed along with flowing of culture medium liquid, and then the competitive pressure between the thalli is reduced; the thallus culture density and the thallus obtaining amount of the system are improved, and the production cost is greatly reduced compared with that of a conventional large-scale aeration stirring culture method.

The application relates to a short-range nitrification continuous flow control method and system based on free ammonia concentration analysis, wherein the free ammonia concentration of influent of an n# short-range nitrification reactor at a first reference moment is denoted as FA1; the free ammonia concentration of influent of the n# short-range nitrification reactor at a second reference moment is denoted as FA0; the FA of the n# short-range nitrification reactor meeting [FA0, FA1] is a normal standard; if the FA of the n# short-range nitrification reactor is lower than the normal standard, the system aeration amount is gradually reduced until the FA of the n# short-range nitrification reactor meets the normal standard; if the FA of the n# short-range nitrification reactor is higher than the normal standard, the system aeration amount is gradually increased. The application can maintain a high conversion rate of ammonia nitrogen in treated wastewater, significantly improve the operation stability of a short-range nitrification denitrification continuous flow reactor, gradually eliminate nitrite oxidizing bacteria in microorganisms from the bacterial population, and obtain a high nitrite accumulation rate.

The present application relates to the field of microbial engineering and environmental biotechnology, and proposes a preservation method of nitrite oxidoreducing bacteria, comprising the following steps: S1, adding a nickel-containing solution into the nitrite oxidoreducing bacteria liquid, the nickel ions combine with the oxidoreductase in NOB and inhibit the enzyme activity, and the strain enters a low metabolic state; S2, preserving the bacteria liquid treated in step S1 in a 25-28 DEG C light-proof environment; S3, after the preservation is completed, removing the nickel ions in the bacteria liquid by using a chelating agent, and restoring the activity of the bacteria body. The method of the present application controls the reversible combination between the metal ions and the enzyme activity center, temporarily inhibits the metabolism of the NOB bacteria body, prolongs the preservation time of the bacteria liquid under the premise of avoiding refrigeration conditions and high-cost additives, and restores the activity of the bacteria body by removing the nickel ions before use.

The application discloses a kind of urban sewage short path nitrification effect prediction device and its using method.The urban sewage short path nitrification effect prediction device includes activated sludge detection system and control adjustment system.The application detects the activity of some bacterial flora in activated sludge by maintaining an optimal environment for the growth of nitrite oxidizing bacteria, with a simple process flow, flexible control operation and high accuracy.The short path prediction device of the application has the advantages of simple structure, reasonable design, flexible and convenient operation, high processing efficiency, easy to carry, stable operation, safety and reliability, etc.

The application discloses a high-activity short-cut nitrification fast-starting long-term stable operation process and relates to the technical field of sewage biological treatment, which comprises the following steps: inoculating sludge and performing anaerobic fermentation pretreatment, combining with rapid sludge discharge and manual removal of expanded sludge and sludge foam; controlling sludge age in days, performing sludge repropagation, enriching ammonia-oxidizing bacteria, inhibiting and eluting nitrite-oxidizing bacteria; long-term operation under the condition of no sludge discharge, maintaining the abundance and activity of ammonia-oxidizing bacteria, and simultaneously controlling the abundance of nitrite-oxidizing bacteria; controlling the proliferation of nitrite-oxidizing bacteria by using the predation of protozoa and metazoan, and controlling the nitrite accumulation rate in the reactor; monitoring the concentrations of dissolved oxygen, pH value, ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the reactor in real time, adjusting the ammonia nitrogen load and free ammonia concentration of influent, and adopting intermittent aeration or microporous aeration to adjust the distribution of dissolved oxygen and optimize the operation conditions of the short-cut nitrification reactor. The application is simple, economical and effective.

The present application relates to sewage biological treatment technology field, disclose a kind of short-cut nitrification long-term no sludge stable control nitrite oxidation bacteria operation strategy.This strategy uses high concentration inoculation sludge by anaerobic fermentation, fast sludge discharge, sludge is repopulated to realize short-cut nitrification start, obtain high activity AOB sludge;By retaining / inoculating predatory microorganism, combined with anaerobic hydrolysis to destroy biofilm, trace element strengthens predatory effect, realize long-term accurate control to NOB under no sludge condition;While regulating and controlling DO, FA and other environmental factors, maintain the dominant position of AOB.The present application can realize short-cut nitrification reactor 400d above no sludge stable operation, AOB abundance is stably above 30%, nitrite accumulation rate maintains above 90%, NOB abundance is controlled below 0.01% and activity is difficult to detect;With the characteristics of simple operation, economic and efficient, strong impact resistance, adapt to low carbon nitrogen ratio municipal sewage denitrification, can be coupled with anaerobic ammonia oxidation process to realize efficient denitrification, suitable for existing water plant original transformation.

To provide a water treatment method capable of efficiently and stably biologically treating ammoniacal nitrogen in organic wastewater containing night soil or septic tank sludge using nitrite type nitrification and denitrification treatment, a water treatment apparatus, and a method for starting up the water treatment apparatus.SOLUTION: A water treatment method includes a nitrifying step of oxidizing ammonium nitrogen in organic wastewater containing human waste or septic tank sludge into nitrite nitrogen using organism-attaching carriers in which ammonium-oxidizing bacteria are attached to carriers, an extracting step of extracting some of the organism-attaching carriers in the nitrifying step, a nitrite treatment step of suppressing activity and growth of the nitrite-oxidizing bacteria attached to the organism-attaching carriers by bringing the extracted organism-attaching carriers into contact with a nitrite aqueous solution, and a returning step of returning the organism-attaching carriers obtained in the nitrite treatment step to the nitrifying step.SELECTED DRAWING: Figure 3

The invention belongs to the technical field of wastewater treatment, and discloses a method for realizing stable nitrosation of low-concentration ammonia-nitrogen wastewater by enriching free nitrous acid in situ. Comprising the following steps that anion exchange resin is placed in a solution containing nitrite nitrogen to be adsorbed to be in a saturated state, then the anion exchange resin is added into a pre-reactor containing activated sludge, and microorganisms in the activated sludge grow on the surface of the resin in an attached mode and form a biological membrane. The concentration of free nitrous acid (FNA) on the surface of the resin reaches 1.5-2.3 mg / L, and selective inhibition on nitrite oxidizing bacteria (NOB) is realized. And adding the resin after biofilm formation into a sequencing batch bioreactor, feeding low-concentration ammonia nitrogen wastewater, and continuously operating for a period of time, so that the nitrite nitrogen accumulation rate (NAR) is stably greater than 90%. The method has the advantages of high nitrosation efficiency, stable operation, energy conservation, consumption reduction and the like, and provides a new way for low-concentration ammonia-nitrogen wastewater treatment.

The utility model relates to a biochemical pond for sewage treatment, including the pond body, the top of pond body is equipped with the support, the support is equipped with oxford cloth, the oxford cloth bottom surface fixed mounting is with one side is the collection box of opening, the support is equipped with the movement component for pulling oxford cloth and moving along the length direction of pond body. Purpose at in a kind of biochemical pond for sewage treatment, to solve the scum in sewage in prior art can stay in the formation of scum layer under the adsorption of algae in aerobic zone, make oxygen diffusion resistance increase, lead to the biological available oxygen concentration of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria habitat area reduces, make the problem of denitrification efficiency reduction.

The invention discloses a short-cut nitrification and denitrification nitrogen removal treatment method for high-ammonia-nitrogen wastewater, belongs to the technical field of wastewater biological treatment, and prepares a poly (glycidyl methacrylate-co-acrylic acid) grafted Fe / Mn co-doped mesoporous charcoal functional carrier; through covalent immobilization of epoxy groups on ammonia oxidizing bacteria and targeted inhibition of iron and manganese ions on enzyme activity of nitrite oxidizing bacteria, stable short-cut nitrification, coupled anaerobic hydrolytic acidification in-situ carbon production and anoxic denitrification are realized, the total nitrogen removal rate reaches 92% or above, and aeration energy consumption is saved by 45% or above.

In this method for producing ammonium nitrate, ammonia is supplied to a reaction liquid including water, ammonia-oxidizing bacteria, and nitrite-oxidizing bacteria that include at least bacteria belonging to the family Xanthobacteraceae, the ammonia is converted into nitric acid by the metabolic action of the ammonia-oxidizing bacteria and the nitrite-oxidizing bacteria, ammonium nitrate is further generated by a neutralization reaction of the ammonia and the nitric acid, and the ammonium nitrate is accumulated in the reaction liquid.

The application discloses a kind of stable and efficient short-range nitrification membrane aeration biofilm construction method, belong to wastewater treatment technical field.The method is as follows: the ammonia nitrogen-containing wastewater is continuously introduced into the membrane aeration biofilm reactor (MABR) inoculated with nitrification sludge, and first forms nitrification biofilm.Further by adding alkali pump to the reactor intermittent injection containing sulfide lye, maintain the pH value of reactor between 8.0~8.5, sulfide ion concentration is not less than 15mg S / L.At the same time, adjust the gas supply pressure, so that the reactor dissolved oxygen is less than 0.1mg / L.Utilize sulfide ion (HS ‑ ), pH and low dissolved oxygen combination, efficiently inhibit nitrite oxidizing bacteria in biofilm, construct stable short-range nitrification membrane aeration biofilm.The biofilm can be used for low-concentration ammonia nitrogen wastewater treatment, and energy consumption is low, easy to control.

This invention discloses a method for promoting the growth of nitrite-oxidizing bacteria, belonging to the field of nitrifying microorganism cultivation technology within the field of environmental microbiology. The method provides an adsorption medium for bacterial growth, accelerating the growth rate of nitrite-oxidizing bacteria. Under conditions where cationic polyacrylamide and closed-cell perlite are used as culture medium additives, the growth rate of nitrite-oxidizing bacteria is significantly faster and the production cycle is shortened compared to the original culture medium conditions. This method is simple to operate and low in cost, theoretically reducing costs and increasing efficiency: on the one hand, the cultivation time is shortened; on the other hand, due to the low density of closed-cell perlite, the bacteria are adsorbed onto its pores and easily dispersed with the flow of the culture medium liquid, averaging the cell density per unit volume in the culture medium, thereby reducing the competitive pressure between bacteria, increasing the bacterial culture density and the amount of bacteria obtained, and significantly reducing production costs compared to previous methods involving large-scale aeration and stirring.

The invention discloses a device and a method for realizing quick start and stable operation of shortcut nitrification by accurately controlling sludge retention time, and belongs to the field of urban sewage biological treatment. The method comprises the following specific steps: (1) by taking secondary precipitation return sludge of an urban sewage treatment plant as seed sludge and taking inlet water as simulated urban sewage, elutriating nitrite oxidizing bacteria by controlling extremely low sludge retention time in an oxygen-limited operation mode; (2) keeping the oxygen-limited operation mode and prolonging the sludge retention time to quickly enrich ammonia oxidizing bacteria, thereby realizing the quick start of the short-cut nitrification system; and (3) controlling the dissolved oxygen to be 0.1-0.5 mg / L in combination with a dissolved oxygen concentration on-line monitoring device, so that the long-term stable maintenance of the short-cut nitrification process can be realized. The method has the advantages that the control operation in the starting process is simple, and the long-term stable operation method is convenient. And long-term stable maintenance of the short-cut nitrification system can be realized under the condition of regulating and controlling fewer operating parameters.

This invention discloses an early warning method for the proliferation of nitrite-oxidizing bacteria (NOB) in simultaneous short-cut nitrification and denitrification (SMD) processes. It utilizes an online water quality analyzer to detect ammonia nitrogen (ANON) and COD in the influent and effluent of a continuous-flow SMD process. The water quality data is processed using a programming platform, and a trained XGBoost model is employed to provide early warning of rapid NOB proliferation in the reaction system, thereby preventing the collapse of the short-cut nitrification system due to excessive NOB growth. This invention enables accurate early warning during the initial stage of rapid NOB proliferation in SMD systems, maintaining stable operation of short-cut nitrification while reducing NOB detection costs. It facilitates online monitoring of NOB in the reaction system and promotes long-term stable and efficient operation of the SMD process.

To provide a water treatment method and a water treatment apparatus capable of efficiently adjusting sludge used for nitrification and denitrification treatment to a state suitable for nitrite type nitrification and denitrification treatment by a simple method.SOLUTION: A water treatment method for biologically treating raw water containing a nitrite component includes a nitrite formation step of oxidizing ammoniacal nitrogen in the raw water to nitrite nitrogen by sludge containing ammonia-oxidizing bacteria, a nitrite treatment step of extracting a part of the sludge in the nitrite formation step and bringing the extracted sludge into contact with a nitrite aqueous solution containing nitrite to suppress activity and growth of the nitrite-oxidizing bacteria contained in the sludge, and a return step of returning the sludge after the nitrite treatment step to the nitrite formation step. In the water treatment method, the water quality in the nitrous acid treatment tank 10 is controlled based on the water quality measurement result by the water quality measuring means 21.SELECTED DRAWING: Figure 1

This invention relates to the field of water treatment technology for recirculating aquaculture systems (RAS), and discloses a method for rapidly cultivating stable nitrifying bacteria in a land-based recirculating aquaculture system. The method includes the following steps: Step S1, system preparation and enrichment of ammonia-oxidizing bacteria; Step S2, oxygen deprivation and regulation to inhibit ammonia-oxidizing bacteria and create a growth window for nitrite-oxidizing bacteria; Step S3, restarting oxygenation to promote the establishment of nitrite-oxidizing bacteria dominance; Step S4, stable system operation. This method for rapidly cultivating stable nitrifying bacteria in a land-based recirculating aquaculture system achieves rapid startup of the biofilter and synchronization with aquaculture production, greatly improving facility utilization. This invention completely changes the traditional two-stage model of "cultivating bacteria first, then releasing fish." By simultaneously releasing low-density aquaculture organisms after system water injection, the bacteria cultivation process is fully integrated into the early stage of aquaculture. This allows the biofilter to reach a stable operating state within 25-30 days after the start of aquaculture, significantly shortening the system idle period.

This invention relates to an apparatus and method for rapidly inhibiting nitrite-oxidizing bacteria to achieve deep nitrogen and phosphorus removal in urban wastewater, belonging to the field of biological wastewater treatment. The apparatus includes an influent reactor unit, an influent unit, an aeration unit, and an effluent unit. The method operates a short-cut nitrification / anaerobic ammonium oxidation system with low nitrogen and phosphorus removal efficiency due to the proliferation of nitrite-oxidizing bacteria in an anaerobic-aerobic-anoxic mode. By controlling the aerobic and anoxic time distributions, the nitrite accumulation rate in the aerobic section of the system is rapidly increased, reducing the total nitrogen and phosphate content in the effluent. This invention, by changing the operating mode, rapidly inhibits nitrite-oxidizing bacteria, improves the nitrogen and phosphorus removal efficiency of the short-cut nitrification / anaerobic ammonium oxidation system operating in an anaerobic-aerobic-anoxic mode, achieves deep nitrogen and phosphorus removal in urban wastewater with a low C / N ratio, and ensures stable operation. The operation and control are simple, requiring no external energy, thus saving energy and reducing consumption.

The invention discloses a high ammonia nitrogen photovoltaic wastewater nitrosation strategy based on HRT control and a machine learning prediction method. According to the method, ammonia oxidizing bacteria are enriched, nitrite oxidizing bacteria are inhibited and stable accumulation of nitrite is realized by increasing hydraulic retention time in a gradient manner in a continuous flow reactor, and the method specifically comprises the following steps: adjusting the high-ammonia-nitrogen photovoltaic wastewater to be alkaline, and pumping the high-ammonia-nitrogen photovoltaic wastewater into the continuous flow reactor inoculated with aerobic activated sludge; controlling the concentration of dissolved oxygen in the continuous flow reactor; the operation stages of the hydraulic retention time HRT are increased in a gradient mode, and at least two operation stages are included; and when the system is stable, the concentration ratio of nitrite nitrogen to ammonia nitrogen in effluent reaches 1.0-1.3. The method is developed based on the continuous flow reactor and actual photovoltaic wastewater, control parameters are easy to monitor and adjust on line, input characteristics of the constructed machine learning model are conventional monitoring indexes, and the method has good engineering application prospects.