143 results about "Nitrite oxidation" patented technology

One kind of short range nitrifying-anaerobic aminoxidizing sequencing batch type denitrifying biomembrane mode and plant is disclosed. The limited aerating mode with real-time control of the sewage temperature inside the reactor and high frequency alternation between aeration and anaeration can inhibit the growth of nitrite oxidizing bacteria and denitrifying bacteria so that the aminoxidizing bacteria and the anaerobic aminoxidizing bacteria become the dominant bacteria in the nitrifying and denitrifying stages. In the nitrifying stage, nitrification is stopped in the nitrite step; and in the denitrifying stage, ammonia nitrogen acts as the direct electron donor to reduce nitrite. The plant is provided with fixed spherical composite stuffing with spherical shell of polypropylene and filled inside biological composite material. Sectional discrete water feeding mode is adopted to feed the sewage to be treated in four stages into the reactor.

The invention discloses a device and a method for realizing partial short-range nitrification-anaerobic ammonia oxidation by adding hydroxylamine, and belongs to the field of urban domestic sewage biological treatment. For two-stage partial short-range nitrification-anaerobic ammonia oxidation, the stable operation of the short-range nitrification is crucial to a process; the short-range nitrification is very difficult to start and maintain stably only through process parameter control; a very good nitrite accumulating effect can be achieved by adding the hydroxylamine in the patent; partial short-range nitrification reactors can be started and high nitrite accumulation can be maintained within a short time. The hydroxylamine serves as an intermediate product in a nitrifying process, is a reducing agent of ammonia monooxygenase and a stimulating agent of AOB (Ammonia Oxidizing Bacteria) and can improve the cell yield of the AOB; meanwhile, the hydroxylamine is an inhibiting agent of NOB (Nitrite Oxidizing Bacteria) and can elutriate the NOB. Compared with a conventional denitrogenation process, a partial short-range nitrification-anaerobic ammonia oxidation process can save aeration quantity and carbon source, and is particularly suitable for urban domestic sewage with low C/N.

The invention provides a method for achieving partial short-cut nitrification-Anammox/denitrification of sewage by using sludge fermentation materials, and belongs to the field of treatment of sewagesludge. A device used by the method comprises a raw water tank, an SBR reactor, a sludge fermentation material storage tank and a residual sludge fermentation tank. The method comprises mixing residual sludge fermentation materials with domestic sewage for treating, and achieving the short-cut nitrification by using the sludge fermentation materials, wherein the inhibition of the sludge fermentation materials on nitrite oxidizing bacteria is far greater than the inhibition of the sludge fermentation materials on ammonia oxidizing bacteria. The method is specifically characterized in that in ananaerobic phase, polyphosphate accumulating bacteria are used for releasing phosphorus by using the sludge fermentation materials and carbon sources in raw water, and storing the inner carbon sources, in an aerobic phase, the partial short-cut nitrification is achieved through real-time control on DO and pH, in an anoxic phase, anaerobic ammonia oxidizing bacteria are used for converting ammonianitrogen and nitrite nitrogen into nitrogen and nitric nitrogen, and heterotrophic bacteria are used for reducing residual nitrite nitrogen and the generated nitric nitrogen into nitrogen by using theinner carbon sources. Through the method, the aeration intensity is reduced; meanwhile, the deep denitrification of the domestic sewage with a low C/N ratio and the reduction of exogenous sludge areachieved.

A reactor and control method thereof for nitrogen removal in wastewater treatment achieves a measured control of maintaining high ammonia oxidizing bacteria (AOB) oxidation rates while achieving nitrite oxidizing bacteria (NOB) repression, using various control strategies, including: 1) ammonia and the use of ammonia setpoints, 2) operational DO and the proper use of DO setpoints, 3) bioaugmentation of a lighter flocculant AOB fraction, and 4) proper implementation of transient anoxia within a wide range of reactor configurations and operating conditions.

The invention provides a system and a method for municipal wastewater treatment through continuous flow step-feed water partial nitrification/anaerobic ammonia oxidation, and belongs to the field of biological sewage treatment. The system comprises a raw water tank, a continuous flow step-feed water partial nitrification/anaerobic ammonia oxidation reactor, an on-line monitoring and feedback system and a vertical-flow type precipitation tank; activated sludge and a biological membrane are combined, partial nitrification is realized in activated sludge, and anaerobic ammonia oxidation is realized in the biological membrane, so that the sludge age ratio contradiction between partial nitrification and anaerobic ammonia oxidation is solved, the stability is enhanced and the efficiency is improved; the on-line monitoring and the feedback system is used for dissolved oxygen control in an aerobic stage, and hydraulic retention time real-time control is combined, so that problems that stabilization maintenance in a continuous flow partial nitrification process is difficult and half partial nitrification cannot be realized are solved; an alternate aerobic or anoxic operation is applied to a continuous flow system to inhibit nitrite-oxidizing bacteria; raw water is fed into all of anoxic stages in a segmental manner, and a silicon source in the raw water is utilized to realize denitrification, so that a problem of nitrate nitrogen is solved.

The invention relates to an An/O type composite artificial wetland system for the enhanced treatment of low-C/N ratio wastewater. The invention relates to a wastewater treatment apparatus, which is a land treatment apparatus suitable for treating low-C/N ratio wastewater and recycling treated water. According to the An/O type composite artificial wetland system, wastewater sequentially flows through a horizontal subsurface flow wetland and a vertical subsurface flow wetland, effluent water part then flows back into the horizontal subsurface flow wetland, and a dissolved oxygen (DO) gradient is utilized to couple aerobic ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB) and anammox in the vertical subsurface flow wetland by means of effluent water level regulation in order to enhance the low-C/N ratio wastewater denitrification efficiency of the An/O type composite artificial wetland system. Broken bricks, oyster shells and other packing with large specific surface area, high porosity and good adsorbability are filled in the composite artificial wetland system, consequently, the amount of organisms held by the system is greatly increased, and high phosphorus-and-nitrogen-removing efficiency is guaranteed. The An/O type composite artificial wetland system has the advantages of simple structure, multiple functions, high efficiency, low cost and the like, is easy to operate and manage, can stably operate, and can synchronously remove carbon, nitrogen and phosphorus, the treated effluent water can be directly recycled, landscape plants can be planted on the ground surface, and the An/O type composite artificial wetland system can be combined with ecological construction and city and town greening functions.

The invention discloses a device and a method for strengthening sludge fermentation by FNA and realizing short-distance nitrogen and phosphorus removal of wastewater, and belongs to the field of wastewater and sludge treatment. The device comprises a raw water tank, an SBR reactor, an intermediate water tank, a UASB reactor, a sludge treatment reactor, and a sludge fermentation tank. According tothe method, FNA is used for inhibiting nitrite oxidizing bacteria to achieve short-cut nitrification and taken as sludge fermentation pretreatment step to promote the combination of hydrolysis and acidification, a part of sludge discharged by a short-range nitrification reactor is returned after being treated by FNA, and the other part of the sludge enters into the sludge fermentation tank. The SBR reactor firstly performs anoxic denitrification to remove excessive nitrite in the upper cycle, then anaerobic phosphorus release, aerobic phosphorus absorption and partial short-range nitrification, effluent enters UASB together with sludge fermentation broth, a part of ammonia nitrogen and nitrite are subjected to autotrophic nitrogen removal through anaerobic ammonia oxidizing bacteria, and residual nitrite and produced nitrate nitrogen are removed by denitrification of organic matters in the sludge fermentation broth. According to the invention, FNA is used for promoting the developmentof an internal carbon sources and realizing nitrogen and phosphorus removal of municipal wastewater, and the amount of the sludge is reduced, and the energy consumption of wastewater treatment is reduced.

According to the present invention, based on the integrated shortcut nitrification-anaerobic ammonium oxidation combination process effect deterioration phenomenon caused by large breeding of nitrite oxidizing bacteria (NOB), the measure of combination of hydroxylamine or hydrazine pouring and sludge age control is used so as to quickly and efficiently achieve the in-situ recovery; and the recovery process is divided into two stages, wherein in the first stage, hydroxylamine or hydrazine and the like are poured to improve the activity and the abundance of ammonia oxidizing bacteria (AOB) and anammox while inhibit the NOB activity so as to rapidly reduce the NO3<->-N concentration in the combination process effluent, and in the second stage, the sludge age control is combined to gradually eliminate the NOB being in the inhibiting state out from the system so as to synchronically improve the NO2<->-N accumulation rate, the Anammox activity and the denitrification load in the combination process, and after running for a certain time, even if the pouring of the hydroxylamine or hydrazine and the like is stopped, the system can still maintain a stable denitrification effect, such that it is indicated that the successful recovery is achieved.

The invention relates to an urban sewage treatment device and method for quick realization of partial nitrification based on free nitrous acid inhibition and belongs to the field of sewage treatment. The method comprises the steps that an FNA treatment unit is arranged in parallel in the sludge backflow process of a traditional A2/O technology secondary sedimentation tank, the growth activity of nitrite oxidizing bacteria (NOB) is partially inhibited by using the selective bacterium inhibiting effect of FNA on ammonia oxidizing bacteria (AOB) and NOB under the anoxic condition, sludge then flows back to a main flow A2/O reactor, NOB in active sludge are gradually elutriated under the effect of sludge age control, and thus partial nitrification of the urban sewage is quickly achieved in the main flow A2/O reactor. The method is simple, heating or real-time control is not needed, and a good sedimentation effect is achieved; in addition, phosphate removal and nitrogen removal are carried out simultaneously, the phosphate removal effect is not affected by addition of the FNA treatment unit, the efficient and simultaneous phosphate removal and nitrogen removal effect of the low-carbon source urban sewage is achieved, and the urban sewage treatment device and method for quick realization of partial nitrification based on free nitrous acid inhibition are suitable for upgrading transformation of existing urban sewage plants.

The invention discloses a method for treating kitchen anaerobic waste water through short-cut nitrification and denitrification and belongs to the technical field of environmental engineering sewage biological treatment. The method aims at high-ammonia-nitrogen and low-C/N characteristics of the waste water, and the deep denitrification effect is realized through an efficient biological denitrification reactor, a short-cut nitrification reactor and an endogenous denitrification tank under proper condition control. In view of the problem of unbalance of C/N of the kitchen waste water, biodegradable COD is fully used for denitrification at a front anoxic stage, and meanwhile, NH4<+>-N is oxidized to an NO2<->-N stage in the short-cut nitrification reactor, so that carbon sources required at a denitrification stage are saved. Only an ammoxidation reaction instead of a nitrite oxidation reaction exists in the short-cut nitrification process, so that the required aeration quantity is fewer, and the energy consumption is lower. NH4<+>-N, TN and COD can be better removed in the whole process, and the treated effluent completely reaches local connecting pipe emission standards.

The invention discloses a rapid start-up and stable maintenance short-cut nitrification/anaerobic ammonia oxidation-integrated device and method based on hydroxylamine, and belongs to the field of biological treatment of urban domestic wastewater. Stable operation of short-cut nitrification and activity of anaerobic ammonium oxidation bacteria matched with the short-cut nitrification are very important to a short-cut nitrification/anaerobic ammonia oxidation-integrated process, rapid start-up and stable maintenance of operation of the short-cut nitrification/anaerobic ammonia oxidation of theurban wastewater are very difficult to realize only by controlling of process parameters. The effect of inhibiting of the activity of nitrite-oxidizing bacteria and increasing of the activity of anaerobic ammonia oxidation can be achieved by adding of the hydroxylamine (HA), and a short-cut nitrification/anaerobic ammonia oxidation-integrated reactor can be started in a short time, and better treatment results can be maintained. Compared with a traditional nitrification-denitrification nitrogen removal process, the short-cut nitrification/anaerobic ammonia oxidation-integrated process saves aeration rate, reduces sludge production, saves carbon sources, and is especially suitable for low-C/N urban domestic wastewater.

The invention relates to a device and method of enhancing sludge stability and sludge digestion liquid treatment, belonging to the field of treating sludge and sludge digestion liquid. The ammonia concentration (300-500mg/L) of the sludge digestion liquid is higher, and in a nitrifying process, the ammonia oxidizing bacteria are enriched due to the inhibition effect of free ammonia and free nitrous acid to nitrite oxidizing bacteria, so that short nitrification can be easily realized, the nitrite concentration of nitrified effluent water is 200-450mg/L. The nitrite firstly contacts with biological ball fillers inside a suspending filler column after entering a reactor, anaerobic ammonium oxidation bacterial conducts anaerobic ammonia oxidation reaction by utilizing ammonia nitrogen produced in a sludge digestion process, so that the ammonia nitrogen and the nitrite are converted into nitrogen and nitrate. The nitrogen overflows from the reactor, the denitrifying bacteria reduce the nitrite for an electronic donor by utilizing organic matters released during the sludge digestion, thereby finally achieving the purposes of eliminating ammonia nitrogen released during the sludge digestion and treating the short-nitrified effluent water of the sludge digestion liquid.

The invention provides a method and a device for culturing oxidizing bacteria capable of quickly enriching nitrite. According to the invention, a sequencing batch activated sludge process is mainly adopted, and the enrichment is realized by gradually increasing the nitrite concentration in nutrient solution and controlling a dissolved oxygen process, wherein the main ingredient of the adopted enrichment nutrient solution is inorganic salt and the enrichment nutrient solution comprises trace element nutrient solution, buffer solution and sodium nitrite; and by adopting the device, the concentration of the dissolved oxygen is kept to be above 5mg/L, pH is kept at 7.2-7.9, and temperature is kept at 22-25 DEG C. By adopting the method provided by the invention, the growth of heterotrophic bacteria and ammonia oxidizing bacteria in sludge can be obviously inhibited, and finally, the nitrite-enriching oxidizing bacteria account for 85-90% of the total amount of the microorganism bacteria in the activated sludge and can bear higher and higher nitrite concentration; and finally, the oxidizing bacteria can treat nitrite waste water of which the concentration is up to 1000mg/L is obtained,and reduce the high-concentration nitrite in the waste water to be below 0.2mg/L.

The invention discloses a method for screening and enrichment culture of nitrifying bacterium floras with alternation of intermittent ammonia nitrogen flow and intermittent operation, and belongs to the technical field of water treatment. According to the method, activated sludge containing nitrifying bacteria is used as inoculation sludge, and the screening and enrichment culture of the nitrifying bacterium floras are achieved by using a bacterial fermentation tank by virtue of a method for alternation of intermittent ammonia nitrogen flow and intermittent operation. The initial ammonia nitrogen load is gradually increased by using intermittent operation so as to improve the ammonia-nitrogen oxidation rate, and the ammonia nitrogen flow and intermittent operation maintain the ammonia-nitrogen oxidation rate and achieve a low nitrite accumulation rate. By adopting the method, the screening and enrichment culture of the nitrifying bacterium floras can be achieved in a short time. The nitrifying bacterium floras obtained by the method disclosed by the invention have an advantage in numbers in total bacterial count, and a high ammonia-nitrogen oxidation rate and a high nitrite oxidation rate can be achieved.

Raw water containing ammonium-nitrogen is introduced into a nitrification tank and nitrification of nitrite-nitrogen by nitrite oxidizing bacteria is inhibited according to inhibition of the ammonium-nitrogen, thereby conducting stable nitrification of nitrous acid type at a high load by the action of ammonium oxidizing bacteria. Carbonate and/or bicarbonate are added into the nitrification tank 1. The inorganic carbon concentration in the nitrification tank 1 is maintained at 35 mg-C/L or more. The nitrified liquid thus obtained is introduced into a denitrification tank and denitrification reaction is conducted by the action of denitrifying bacteria with the remaining ammonium-nitrogen as an electron donor and the nitrite-nitrogen as an electron acceptor.

The invention discloses a method for quickly starting a shortcut nitrification reactor. The method comprises the following steps: after performing inoculation on the reactor, firstly performing overaeration, and applying an aeration impact so as to accelerate the elimination of anaerobic bacteria in sludge; quickly enriching nitrifying bacteria, and then applying a combined load impact comprising a substrate concentration impact and a hydraulic retention time impact so as to quickly restrain and eliminate nitrite oxidizing bacteria; finally, under the condition that an appropriate substrate concentration and an appropriate hydraulic retention time are maintained, increasing the concentration of an inorganic carbon source so as to enrich ammonia oxidizing bacteria and accelerate the accumulation of nitrite. According to the invention, the various continuous impacts are combined, the enrichment of the ammonia oxidizing bacteria in the sludge is accelerated within a shorter time, and the quick start of the shortcut nitrification reactor is realized.

A process for converting ammonium (NH₄⁺) of a mainstream of a wastewater plant to dinitrogen gas (N₂), including the consecutive steps of i.) removing biodegradable carbon compounds in the mainstream, ii.) converting ammonium (NH₄⁺) in the mainstream to nitrite (NO₂⁻) in an aerated biological process containing ammonium oxidizing bacteria (AOB) in a nitration vessel (133a-133d); and iii.) denitrifying the resulting stream from step ii.) to dinitrogen gas in an anammox vessel (200). Growth of nitrite oxidizing bacteria (NOB) in step ii.) is prevented by periodically subjecting the bacteria in said nitration vessel (133a-133d) to water suppressing growth of nitrite oxidizing bacteria (NOB).

The invention discloses a device and method for realizing short-cut nitrification-anaerobic ammonia oxidation based on lateral inhibition of hydroxylamine and belongs to the field of urban sewage treatment. Short-cut nitrification is realized in a treatment way that nitrite-oxidizing bacteria (NOB) is inhibited by using hydroxylamine, so that stable nitrite is provided for subsequent anaerobic ammonia oxidation. Hydroxylamine serving as a key intermediate product of a nitrification reaction plays a connecting role for the balance of the whole nitrification process, so that the aims of increasing the cell yield of ammonia oxidizing bacteria (AOB) and inhibiting the activity of NOB can be achieved by appropriately adding hydroxylamine, and furthermore, stable short-cut nitrification is realized. However, hydroxylamine has toxicity, and therefore, AOB and NOB can simultaneously lose activity if hydroxylamine is excessively added. Therefore, the excess problem can be controlled by lateralsludge treatment of hydroxylamine in the patent, meanwhile, short-cut nitrification can be relatively rapidly started, and relatively high nitrite accumulation can be maintained. The method is simplein operation and solves the problem that nitrite is difficult to stably maintain if urban sewage is treated by using a short-cut nitrification-anaerobic ammonia oxidation process.

The invention relates to a short-range denitrification/dephosphorization device and method based on sludge side pretreatment, belonging to the field of sewage treatment. The device comprises a municipal sewage raw water tank, a denitrification/dephosphorization reactor, an intermediate water tank, a short-range nitration reactor, a first sludge pretreatment reactor and a second sludge pretreatment reactor. The method comprises the following steps: municipal sewage enters the denitrification/dephosphorization reactor, sludge subjected to FNA pretreatment is added, and microbes convert organic matters in raw water and pretreated sludge into PHAs; the sewage enters the short-range nitration reactor to perform short-range nitration; and on the basis of sludge side pretreatment, part of surplus sludge is subjected to FNA treatment and flows back into the reactor to inhibit the propagation of nitrite oxidizing bacteria, thereby implementing and maintaining the short-range nitration of the system stable. The sewage subjected to short-range nitration is synchronously denitrified and dephosphorized. The method quickly and stably implements the short-range denitrification/dephosphorization, saves the carbon sources, reduces the sludge amount, and lowers the sewage treatment energy consumption.

A determination of a quality of a reducing agent solution containing ammonia used to reduce nitrogen oxides involves actuating a metering unit that delivers metered quantities of reducing agent solution into an engine's discharged exhaust gas and determining an efficiency value that is at least correlated with the efficiency of the SCR catalytic converter and comparing the efficiency value to a predefinable limit value. If an efficiency value not corresponding to proper functioning of the SCR exhaust emission control system is identified by the comparison, a switch is made to a diagnostic mode in a second method step. If a predefinable deviation of the efficiency value from a limit value is identified after expiration of the second method step time period, a third method step is performed for conditioning the SCR catalytic converter. A fourth step involves an adaptation mode in which a deviation from the efficiency value is determined.

A method for producing a nitrite type nitrification-reactive sludge includes the step of subjecting an activated sludge to alkali treatment so that the pH of the activated sludge containing at least the ammonium oxidizing bacteria and nitrite oxidizing bacteria can be 10 or higher, in order to accumulate ammonium oxidizing bacteria with higher priority in the activated sludge.

The invention discloses a method for quickly starting shortcut nitrification of urban domestic sewage through hydroxylamine hydrochloride intervention, and belongs to the field of sewage treatment. Main devices involved include a raw water tank, a sequencing batch reactor (SBR) and an automatic control system. By utilizing the strong inhibition effect of hydroxylamine hydrochloride on nitrite-oxidizing bacteria (NOB), an ammoxidation reaction is limited at the stage of producing nitrite, and thus shortcut nitrification is realized. The method comprises the steps that the hydroxylamine hydrochloride is added in the stably-operating complete nitrification SBR at the initial stage of aeration, other conditions remain unchanged, and shortcut nitrification can be stably and rapidly realized. The method is suitable for realization of shortcut denitrification of the urban domestic sewage, and has the simple and feasible characteristics, nitrite nitrogen can be provided for anaerobic ammonia oxidation and denitrification, and the purposes of energy saving and consumption reduction can further be achieved.

The invention relates to a biological multiplication sewage treatment plant lowering denitrification carbon source demand and a treatment method thereof. The method comprises the following steps of allowing to-be-treated sewage to enter a circulation area from a sewage inlet tube, allowing the sewage to enter a lifting area from a bottom water inlet groove of the circulation area, uniformly distributing the to-be-treated sewage and pushing the to-be-treated sewage to an aeration area by the lifting area, performing combined bio-technology-based treatment on the sewage in the aeration area through a biological contact oxidation process, finally, separating sludge from clear water of sludge-water mixture flowing from the aeration area in a sludge-water separation area, thereby outputting andobtaining clear water, allowing at least a part of settled sludge to flow back to the circulation area, introducing air into water in the circulation area, oxidizing a part of ammonia and nitrogen insewage into nitrite, and oxidizing ammonia and nitrogen in sewage by the nitrite.

The invention discloses a method for flue gas denitration through partial oxidation, absorption and recycle. Flue gas passes through a liquid phase oxidizing agent in an oxidation tower, the flue gas residence time and the concentration of the oxidizing agent are controlled, about 45-50% of NO in the flue gas is oxidized into NO2, then the gas flue is sprayed and absorbed by an alkali liquor in a denitrating tower for generating nitrite, and finally air is pumped into the bottom of the denitrating tower for oxidizing nitrite into nitrate, thereby realizing flue gas denitration through partial oxidation, absorption and recycle. The invention employs traditional absorption process with mild operation condition, and the process is carried out at normal temperature and under normal pressure with a high denitration rate and low operation cost, thereby realizing NOx recycling.