United enrichment culture device and method for autotrophic denitrifying bacteria

Abstract

The invention belongs to the field of industrial wastewater treatment, and relates to a combined enrichment culture device and method for autotrophic denitrifying bacteria. The device comprises a water inlet tank, a No.1 anaerobic reactor, a reflux tank and a No.2 anoxic reactor, the water inlet tank is provided with a water outlet pipeline of the water inlet tank, and the water outlet pipeline of the water inlet tank is connected with the No.1 anaerobic reactor; the first anaerobic reactor is provided with a first anaerobic reactor water outlet pipeline, and the first anaerobic reactor water outlet pipeline is connected with the reflux tank; a return tank water outlet pipeline is arranged at the upper part of the return tank, a return tank return pipeline is arranged at the bottom of the return tank, the return tank water outlet pipeline is connected with the second anoxic reactor, and the return tank return pipeline is connected with the first anaerobic reactor; a second anoxic reactor reflux pipeline is arranged at the bottom of the second anoxic reactor and is connected with the lower part of the reflux tank. The anaerobic ammonia oxidation reaction and the denitrification reaction promote each other, so that the anaerobic ammonia oxidation reaction can be quickly started, and the sludge leakage phenomenon is effectively avoided.

Description

Technical Field

[0001] The invention belongs to the field of industrial wastewater treatment, and in particular, relates to a device and method for combining enrichment and cultivation of autotrophic denitrifying bacteria. Background Art

[0002] The problem of nitrogen pollution in my country's water bodies is becoming increasingly serious. Excessive nitrogen discharge into receiving water bodies will lead to a series of problems such as oxygen depletion, black and smelly water, and eutrophication. The development of high-efficiency and low-consumption wastewater denitrification technology has become an urgent task in the field of pollution control.

[0003] The removal of ammonia nitrogen can be achieved through both physical and chemical methods and biochemical methods. In view of the cost and removal effect, biochemical methods are generally used to treat ammonia nitrogen in engineering. Traditional biochemical treatment mainly includes two steps: nitrification and denitrification. The nitrification process is mainly completed by ammonia bacteria, nitrite bacteria and nitrifying bacteria under aerobic conditions. The ammonia nitrogen in the water is converted into nitrate nitrogen by the action of nitrite bacteria and nitrifying bacteria. In the denitrification process, denitrifying bacteria use organic matter as electron donors to reduce nitrate nitrogen to nitrogen gas under anaerobic conditions.

[0004] The anaerobic ammonium oxidation process uses anaerobic ammonium oxidizing bacteria to convert nitrite and ammonia nitrogen into nitrogen gas. Compared with the traditional nitrification and denitrification process, the anaerobic ammonium oxidation process has the advantages of short reaction pathway, no need for additional carbon source, no need for alkalinity compensation, and low energy consumption. It has broad application prospects and has become a hot spot in the research of new biological wastewater denitrification technology. The disadvantage of this process is that the maximum total nitrogen removal rate of the anaerobic ammonium oxidation process is about 89%, and more than 11% of the total nitrogen in the influent will be converted into nitrate nitrogen in the effluent, which may cause the total nitrogen in the effluent to fail to meet the standard.

[0005] At present, there are two main approaches to achieve rapid start-up of the anaerobic ammonium oxidation process. One is to cultivate biofilm to effectively retain the anaerobic ammonium oxidizing bacteria in the biofilm to ensure a high microbial concentration in the reactor. The other is to granulate the inoculated sludge so that the enriched products with anaerobic ammonium oxidation activity are retained in the reactor, which can effectively reduce sludge loss.

[0006] In the integrated system, both reaction stages are carried out in one reactor, and two functional bacteria (AOB and AnAOB) coexist. Therefore, aeration needs to be strictly controlled. In addition, due to the coexistence of multiple microbial populations, the reactor startup time is long and it is easily affected by load shock, resulting in system instability. However, the integrated system has the advantages of low construction cost, small footprint, large volume load, and can effectively avoid the inhibitory effect caused by nitrite accumulation. Therefore, it is more widely used in engineering.

[0007] Compared with the integrated system, the reactors of the two-stage system can be adjusted and controlled independently, which is more flexible and stable. Separating the two reaction stages of autotrophic denitrification can not only optimize the enrichment of AOB and AnAOB, but also prevent toxic substances and organic matter from directly entering the subsequent anaerobic ammonium oxidation reactor by eliminating some toxic organic pollutants. However, the two-stage system has a higher investment cost and NO 2－ -N is easy to accumulate, producing free nitrite inhibition, and the system design is more complicated. Summary of the invention

[0008] In view of the shortcomings of the prior art, the present invention provides a device and method for the combined enrichment and cultivation of autotrophic denitrifying bacteria, which can achieve the rapid start-up of the anaerobic ammonium oxidation reaction, while simultaneously enriching and culturing denitrifying bacteria and reducing the problem of sludge loss in the anaerobic ammonium oxidation reactor.

[0009] In order to achieve the above-mentioned object, the first aspect of the present invention provides an autotrophic denitrifying bacteria combined enrichment and culture device, a water inlet tank, a No. 1 anaerobic reactor, a reflux tank and a No. 2 anoxic reactor;

[0010] The water inlet tank is used for mixing and adjusting the inlet components, and is provided with a water inlet tank outlet pipeline, and the water inlet tank outlet pipeline is connected to the No. 1 anaerobic reactor;

[0011] The No. 1 anaerobic reactor is used for starting, culturing and enriching anaerobic ammonia-oxidizing bacteria, and is provided with a No. 1 anaerobic reactor outlet pipeline, and the No. 1 anaerobic reactor outlet pipeline is connected to a reflux tank;

[0012] The reflux tank is used for gas discharge and collection, and a reflux tank outlet pipeline is arranged on the upper part thereof, and a reflux tank return pipeline is arranged on the bottom thereof, the reflux tank outlet pipeline is connected to the No. 2 anoxic reactor, and the reflux tank return pipeline is connected to the No. 1 anaerobic reactor;

[0013] The No. 2 anoxic reactor is used to intercept the anaerobic ammonia oxidation granular sludge carried by the effluent of the No. 1 anaerobic reactor, and cooperate with aerobic denitrification to further enrich denitrifying bacteria. A No. 2 anoxic reactor return pipeline is arranged at the bottom thereof, and the No. 2 anoxic reactor return pipeline is connected to the lower part of the reflux tank.

[0014] The second aspect of the present invention provides a method for co-enrichment and cultivation of autotrophic denitrifying bacteria, which is carried out using the autotrophic denitrifying bacteria co-enrichment and cultivation device, and comprises the following steps:

[0015] S1. Bacterial culture start-up phase:

[0016] Step 1: Add the substances required for the anaerobic ammonium oxidation reaction into the water inlet tank, inoculate the first activated sludge into the No. 1 anaerobic reactor, start the water inlet tank to empty the air in the No. 1 anaerobic reactor, start the anaerobic ammonium oxidation bacteria cultivation and domestication, and the nitrogen and water produced by the No. 1 anaerobic reactor enter the reflux tank;

[0017] Step 2: The second activated sludge is inoculated into the anoxic reactor No. 2, the effluent from the reflux tank enters the anoxic reactor No. 2, the anaerobic ammonium oxidation granular sludge carried out with the effluent from the reflux tank is intercepted, and the anoxic reactor No. 2 is placed in an anoxic state by intermittent aeration, and further denitrification and denitrification bacteria are cultivated under the anoxic state through anaerobic ammonium oxidation and denitrification;

[0018] Step 3: The sludge at the bottom of the No. 2 anoxic reactor returns to the reflux tank, settles in the reflux tank, and then returns to the No. 1 anaerobic reactor;

[0019] S2, bacterial enrichment stage:

[0020] Step 4: Monitor the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the effluent. When the total nitrogen removal rate of the effluent from anaerobic reactor No. 1 is greater than 60%, and the removal rates of nitrite nitrogen and ammonia nitrogen are greater than 65%, the anaerobic ammonia-oxidizing bacteria culture is successfully started. Then, the total nitrogen load of the influent is gradually increased. The total nitrogen amount increases by 50 to 120 mg / L, with an increasing cycle of 7 to 14 days. When the removal rates of nitrite nitrogen and ammonia nitrogen reach more than 80%, and the anaerobic reactor No. 1 turns red obviously, the enrichment of anaerobic ammonia-oxidizing bacteria is completed.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention can effectively solve the problem of large-scale sludge loss caused by sludge leakage during the startup stage of anaerobic ammonium oxidizing bacteria. First, by adding a reflux port and a reflux tank, the reactor can effectively intercept the sludge carried out with the water flow while discharging the nitrogen generated by the reaction. The sludge is returned to the reactor through a reflux pump after settling in the reflux tank. Second, an anoxic reactor No. 2 is added to intercept the anaerobic ammonium oxidizing granular sludge. In the anoxic reactor No. 2, aerobic activated sludge and anaerobic granular sludge coexist. The aerobic sludge wraps the anaerobic granular sludge and then flows back to the anaerobic reactor No. 1, which effectively avoids the sludge leakage phenomenon and can simultaneously enrich denitrifying bacteria.

[0023] (2) The present invention starts to cultivate dominant anaerobic ammonium oxidation bacteria under a low-load state, increases the total nitrogen load by gradient enhancement, quickly enriches anaerobic ammonium oxidation bacteria, and the anaerobic ammonium oxidation reaction and denitrification reaction promote each other, thereby achieving a rapid start-up of the anaerobic ammonium oxidation reaction.

[0024] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0026] Figure 1 A schematic diagram of the autotrophic denitrifying bacteria co-cultivation device of the present invention is shown. DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0028] In order to achieve the above-mentioned object, the first aspect of the present invention provides an autotrophic denitrifying bacteria combined enrichment and culture device, a water inlet tank, a No. 1 anaerobic reactor, a reflux tank and a No. 2 anoxic reactor;

[0029] The water inlet tank is used for mixing and adjusting the inlet components, and is provided with a water inlet tank outlet pipeline, and the water inlet tank outlet pipeline is connected to the No. 1 anaerobic reactor;

[0030] The No. 1 anaerobic reactor is used for starting, culturing and enriching anaerobic ammonia-oxidizing bacteria, and is provided with a No. 1 anaerobic reactor outlet pipeline, and the No. 1 anaerobic reactor outlet pipeline is connected to a reflux tank;

[0031] The reflux tank is used for gas discharge and collection, and a reflux tank outlet pipeline is arranged on the upper part thereof, and a reflux tank return pipeline is arranged on the bottom thereof, the reflux tank outlet pipeline is connected to the No. 2 anoxic reactor, and the reflux tank return pipeline is connected to the No. 1 anaerobic reactor;

[0032] The No. 2 anoxic reactor is used to intercept the anaerobic ammonia oxidation granular sludge carried by the effluent of the No. 1 anaerobic reactor, and cooperate with aerobic denitrification to further enrich denitrifying bacteria. A No. 2 anoxic reactor return pipeline is arranged at the bottom thereof, and the No. 2 anoxic reactor return pipeline is connected to the lower part of the reflux tank.

[0033] In the present invention, since the operation of Reactor No. 1 is unstable at the initial start-up stage and sludge leakage occurs from time to time, Reactor No. 2 mainly plays a role in intercepting anaerobic ammonia oxidation granular sludge at this stage. Aerobic activated sludge and anaerobic granular sludge coexist in Reactor No. 2, and the aerobic sludge wraps the anaerobic granular sludge, which is precipitated in the reflux tank and then returned to Reactor No. 1, thereby effectively avoiding sludge leakage.

[0034] According to the present invention, preferably, the water inlet tank outlet pipeline, the reflux tank reflux pipeline and the No. 2 anoxic reactor reflux pipeline are all provided with pumps.

[0035] According to the present invention, preferably, the No. 1 anaerobic reactor is an upflow reactor equipped with a stirrer and a sealing cover; and the No. 2 anoxic reactor is a cone-bottom upflow reactor equipped with a stirrer.

[0036] According to the present invention, preferably, the No. 1 reactor and the No. 2 reactor are both filled with fillers.

[0037] Preferably, the filler is polyurethane sponge, and preferably, the average porosity of the polyurethane sponge is >85%.

[0038] In the present invention, the size of the polyurethane sponge used is 1 to 2 cm 3 .

[0039] The second aspect of the present invention provides a method for co-enrichment and cultivation of autotrophic denitrifying bacteria, which is carried out using the autotrophic denitrifying bacteria co-enrichment and cultivation device, and comprises the following steps:

[0040] S1. Bacterial culture start-up phase:

[0041] Step 1: Add the substances required for the anaerobic ammonium oxidation reaction into the water inlet tank, inoculate the first activated sludge into the No. 1 anaerobic reactor, start the water inlet tank to empty the air in the No. 1 anaerobic reactor, start the anaerobic ammonium oxidation bacteria cultivation and domestication, and the nitrogen and water produced by the No. 1 anaerobic reactor enter the reflux tank;

[0042] Step 2: The second activated sludge is inoculated into the anoxic reactor No. 2, the effluent from the reflux tank enters the anoxic reactor No. 2, the anaerobic ammonium oxidation granular sludge carried out with the effluent from the reflux tank is intercepted, and the anoxic reactor No. 2 is placed in an anoxic state by intermittent aeration, and further denitrification and denitrification bacteria are cultivated under the anoxic state through anaerobic ammonium oxidation and denitrification;

[0043] Step 3: The sludge at the bottom of the No. 2 anoxic reactor returns to the reflux tank, settles in the reflux tank, and then returns to the No. 1 anaerobic reactor;

[0044] S2, bacterial enrichment stage:

[0045] Step 4: Monitor the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the effluent. When the total nitrogen removal rate of the effluent from anaerobic reactor No. 1 is greater than 60%, and the removal rates of nitrite nitrogen and ammonia nitrogen are greater than 65%, the anaerobic ammonia-oxidizing bacteria culture is successfully started, and then the total nitrogen load of the influent is gradually increased. The total nitrogen amount increases by 50-120 mg / L, and the increasing cycle is 7-14 days, until the removal rates of nitrite nitrogen and ammonia nitrogen reach more than 80%, and the bacterial concentration in anaerobic reactor No. 1 increases to 0.8-1.5 g / L, when anaerobic reactor No. 1 turns obviously red, the enrichment of anaerobic ammonia-oxidizing bacteria is completed.

[0046] In the present invention, the No. 2 anoxic reactor is a denitrification reaction tank, which can utilize the front-end sludge for synchronous denitrification. The effluent from the anaerobic ammonium oxidation reaction contains a large amount of nitrate ions, which are just the nitrogen source for denitrification. The two sides will not cause a competitive relationship. In the No. 2 anoxic reactor, aerobic activated sludge and anaerobic granular sludge coexist, and the aerobic sludge wraps the anaerobic granular sludge and then flows back to the No. 1 anaerobic reactor, thereby effectively avoiding the sludge running phenomenon, and the anaerobic ammonium oxidation reaction and the denitrification reaction promote each other, which can achieve the rapid start-up of the anaerobic ammonium oxidation reaction.

[0047] According to the present invention, preferably, the total nitrogen content increases by 80 to 100 mg / L.

[0048] According to the present invention, preferably, the first activated sludge and the second activated sludge are each independently activated sludge from a secondary sedimentation tank of an industrial sewage treatment plant.

[0049] In the present invention, the activated sludge is taken from the activated sludge in the secondary sedimentation tank of an industrial sewage (sulfur-containing wastewater) treatment plant, and contains desulfurization bacteria such as anaerobic ammonia oxidizing bacteria, nitrifying bacteria and denitrifying bacteria.

[0050] Preferably, the inoculation concentration of the first activated sludge is 300-500 mg / L.

[0051] Preferably, the inoculation concentration of the second activated sludge is 100-200 mg / L.

[0052] According to the present invention, preferably, the mass ratio of ammonia nitrogen to nitrite nitrogen is 1:0.8-1, the mass ratio of total nitrogen to inorganic carbon is 1:0.5-0.8, based on the total weight of substances required for the anaerobic ammonium oxidation reaction, the content of other inorganic salts is 1-5wt%, and the content of the microliquid is 0.1-0.2wt%.

[0053] Preferably, the other inorganic salt is at least one of a calcium salt, a magnesium salt and an iron salt.

[0054] Preferably, the amount of substances required for the anaerobic ammonium oxidation reaction is added so that the total nitrogen concentration in the inlet water of the inlet tank during the startup phase does not exceed 200 mg / L, the calcium concentration is 0.1-0.2 g / L, the magnesium ion concentration is 0.1-0.2 g / L, and the iron ion concentration is 0.05-0.1 g / L.

[0055] According to the present invention, preferably, the ammonia nitrogen salt is at least one of ammonium sulfate, ammonium chloride and ammonium carbonate, preferably ammonium chloride.

[0056] Preferably, the nitrite nitrogen salt is sodium nitrite and / or potassium nitrite, preferably sodium nitrite.

[0057] Preferably, the inorganic carbon is carbonate and / or bicarbonate, preferably sodium carbonate and / or sodium bicarbonate, more preferably sodium bicarbonate.

[0058] Preferably, the calcium salt is calcium chloride.

[0059] Preferably, the magnesium salt is magnesium chloride and / or magnesium sulfate.

[0060] Preferably, the iron salt is ferrous sulfate and / or ferric sulfate.

[0061] According to the present invention, preferably, the microfluid contains cobalt chloride, manganese chloride, copper chloride, zinc chloride, boric acid, EDTA, (NH4)6Mo7O 24 ·4H2O, Na2SeO3·6H2O and NiCl2.

[0062] Preferably, the concentration of cobalt chloride is 0.1-0.2 mg / L, the concentration of manganese chloride is 0.1-0.2 mg / L, the concentration of copper chloride is 0.05-0.1 mg / L, the concentration of zinc chloride is 0.002-0.005 mg / L, the concentration of boric acid is 0.002-0.005 mg / L, the concentration of EDTA is 0.05-0.1 mg / L, and the concentration of (NH4)6Mo7O 24 The concentration of ·4H2O is 0.005~0.01mg / L, the concentration of Na2SeO3·6H2O is 0.005~0.01mg / L, and the concentration of NiCl2 is 0.002~0.005mg / L.

[0063] According to the present invention, preferably, the duration of the culture start-up phase is 10 to 30 days.

[0064] According to the present invention, preferably, the bacterial concentration in the No. 1 anaerobic reactor is increased to 0.8-1.5 g / L, and the enrichment of anaerobic ammonia-oxidizing bacteria is completed.

[0065] According to the present invention, preferably, the size of reactor No. 1 is 3-5 L, and the conditions of reactor No. 1 include: pH 7.5-8.2, dissolved oxygen concentration lower than 0.1 mg / L, and temperature 30-35°C.

[0066] According to the present invention, preferably, the No. 2 reactor is 1 to 2 L, and the conditions of the No. 2 reactor include: pH 7.0 to 8.0, dissolved oxygen concentration 0.5 to 1 mg / L, and temperature 25 to 35°C.

[0067] The present invention will be further described below in conjunction with embodiments, but the scope of the present invention is not limited to these embodiments.

[0068] In the following examples, the activated sludge comes from the activated sludge in the secondary sedimentation tank of an industrial sewage (sulfur-containing wastewater) treatment plant, and contains desulfurization bacteria such as anaerobic ammonia-oxidizing bacteria, nitrifying bacteria and denitrifying bacteria.

[0069] Example 1

[0070] In this embodiment, the Figure 1 The autotrophic denitrifying bacteria combined enrichment culture device shown in the figure is carried out, and the device includes: a water inlet tank, a No. 1 anaerobic reactor, a reflux tank and a No. 2 anoxic reactor; wherein the No. 1 anaerobic reactor is an upflow reactor equipped with a stirrer and a sealing cover; the No. 2 anoxic reactor is a cone-bottom upflow reactor equipped with a stirrer, and the No. 1 anaerobic reactor and the No. 2 anoxic reactor are both filled with polyurethane sponges, and the size of the polyurethane sponges is 1 to 2 cm 3 , the average void ratio is 90%.

[0071] The water inlet tank is used for mixing and adjusting the inlet components, and is provided with an inlet tank outlet pipeline, and the inlet tank outlet pipeline is connected to the No. 1 anaerobic reactor; the No. 1 anaerobic reactor is used for starting, culturing and enriching anaerobic ammonia-oxidizing bacteria, and is provided with an anaerobic reactor outlet pipeline, and the No. 1 anaerobic reactor outlet pipeline is connected to the reflux tank; the reflux tank is used for discharging and collecting gases, and is provided with a reflux tank outlet pipeline at the top and a reflux tank return pipeline at the bottom, the reflux tank outlet pipeline is connected to the No. 2 anoxic reactor, and the reflux tank return pipeline is connected to the No. 1 anaerobic reactor; the No. 2 anoxic reactor is used to intercept the anaerobic ammonia-oxidizing granular sludge carried by the effluent of the No. 1 anaerobic reactor, and to further enrich the denitrifying bacteria in coordination with aerobic denitrification, and is provided with a No. 2 anoxic reactor return pipeline at the bottom, and the No. 2 anoxic reactor return pipeline is connected to the lower part of the reflux tank. Pumps are provided on the water inlet tank outlet pipeline, the reflux tank reflux pipeline and the No. 2 anoxic reactor reflux pipeline.

[0072] The combined enrichment culture method of autotrophic denitrifying bacteria comprises the following steps:

[0073] S1. Bacterial culture start-up phase:

[0074] Step 1: Add the substances required for anaerobic ammonium oxidation reaction into the water inlet tank, inoculate 500 mg / L of activated sludge into the No. 1 reactor, start the water inlet tank to empty the air in the No. 1 reactor, start the anaerobic ammonium oxidation bacteria cultivation and domestication, and the nitrogen and water produced by the No. 1 reactor enter the reflux tank;

[0075] Step 2: 200 mg / L activated sludge is inoculated into the No. 2 reactor, the effluent from the reflux tank enters the No. 2 reactor, the anaerobic ammonium oxidation granular sludge carried out with the effluent from the reflux tank is intercepted, and the reactor is placed in an anoxic state by intermittent aeration. Under the anoxic state, further denitrification and denitrification bacteria are cultivated through anaerobic ammonium oxidation and denitrification;

[0076] Step 3: The sludge at the bottom of the No. 2 reactor returns to the reflux tank, settles in the reflux tank and returns to the No. 1 reactor;

[0077] In the startup phase, the concentration of ammonia nitrogen in the influent is 50 mg / L, the concentration of nitrite nitrogen is 40 mg / L, the concentration of inorganic carbon is 45 mg / L, the concentration of calcium ion is 0.1 mg / L, the concentration of magnesium ion is 0.1 mg / L, and the concentration of iron ion is 0.07 mg / L. Among them, the substance providing ammonia nitrogen is ammonium chloride, the substance providing nitrite nitrogen is sodium nitrite, and the substance providing inorganic carbon is sodium bicarbonate. The composition of the influent micro-liquid is cobalt chloride 0.1 mg / L, manganese chloride 0.1 mg / L, copper chloride 0.05 mg / L, zinc chloride 0.005 mg / L, boric acid 0.005 mg / L, EDTA 0.05 mg / L, (NH4)6Mo7O 24 ·4H2O 0.005mg / L, Na2SeO3·6H2O0.005mg / L, NiCl2 0.005mg / L. Start water inflow, flow rate is 2L / day, effective volume of No. 1 anaerobic reactor is 5L, hydraulic retention time is 2.5 days, dissolved oxygen concentration is 0.05mg / L, temperature is controlled at 35℃, pH is 7.6, stirring rate is 35rpm. Effective volume of No. 2 anoxic reactor is 3L, dissolved oxygen concentration is 0.6mg / L, temperature is controlled at 35℃, pH is 7.5.

[0078] S2, bacterial enrichment stage:

[0079] Step 4: Detect the concentrations of effluent ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen daily. Five days after the device was started, the effluent ammonia nitrogen was less than 1 mg / L, and the nitrite nitrogen concentration was less than 1 mg / L. The inlet flow rate was gradually increased and the hydraulic retention time was reduced. On the 25th day after startup, the inlet flow rate was 5L / day, the hydraulic retention time was 24h, the effluent ammonia nitrogen was less than 1mg / L, the nitrite nitrogen concentration was less than 1mg / L, the total nitrogen removal rate was greater than 80%, and the nitrite nitrogen and ammonia nitrogen concentrations were both less than 1mg / L, and the startup was completed.

[0080] The total nitrogen concentration was increased by gradient enrichment culture, and the total nitrogen content increased by 100 mg / L / 7 days. The concentrations of ammonia nitrogen, nitrite nitrogen and inorganic carbon in the influent were gradually increased, and other concentrations remained unchanged. The ratio of ammonia nitrogen, nitrite nitrogen and inorganic carbon was controlled at 1:0.8:0.5. By the 55th day, the influent ammonia nitrogen was 290 mg / L, the nitrite nitrogen was 200 mg / L, the total nitrogen concentration was 490 mg / L, the effluent total nitrogen was 47.1 mg / L, and the total nitrogen removal rate reached 90.38%. The bacterial concentration in the No. 1 anaerobic reactor increased to 1 g / L, the sludge turned red significantly, and the enrichment was completed.

[0081] Example 2

[0082] In this embodiment, the autotrophic denitrifying bacteria co-culture device and the autotrophic denitrifying bacteria co-culture method are the same as those in Example 1, except that, in the startup phase, the concentration of influent ammonia nitrogen is 100 mg / L, the concentration of nitrite nitrogen is 80 mg / L, the concentration of inorganic carbon is 94 mg / L, the concentration of calcium ions is 0.2 mg / L, the concentration of magnesium ions is 0.2 mg / L, and the concentration of iron ions is 0.1 mg / L, wherein the substance providing ammonia nitrogen is ammonium chloride, the substance providing nitrite nitrogen is sodium nitrite, the substance providing inorganic carbon is sodium bicarbonate, and the influent microliquid is 0.1 mg / L of cobalt chloride, 0.1 mg / L of manganese chloride, 0.05 mg / L of copper chloride, 0.005 mg / L of zinc chloride, 0.005 mg / L of boric acid, 0.05 mg / L of EDTA, (NH4)6Mo7O 24 ·4H2O 0.005mg / L, Na2SeO3·6H2O 0.005mg / L, NiCl2 0.005mg / L.

[0083] Start water inflow, flow rate is 1L / day, reactor effective volume is 5L, hydraulic retention time is 5 days, dissolved oxygen is 0.05mg / L, temperature is controlled at 30℃, pH is 8.0, stirring rate is 50rpm. The effective volume of anoxic reactor No. 2 is 3L, dissolved oxygen concentration is 0.5mg / L, temperature is controlled at 28℃, pH is 7.0.

[0084] The concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the effluent were tested daily. Three days after the device was started, the ammonia nitrogen in the effluent was less than 1 mg / L, and the nitrite nitrogen concentration was less than 1 mg / L. The influent flow rate was gradually increased and the hydraulic retention time was reduced. On the 28th day after the start-up, the influent flow rate was 5L / day, the hydraulic retention time was 24h, the ammonia nitrogen in the effluent was less than 1 mg / L, the nitrite nitrogen concentration was less than 1 mg / L, and the total nitrogen removal rate was greater than 80%, and the start-up was completed.

[0085] The total nitrogen concentration was increased by gradient enrichment culture, and the concentrations of ammonia nitrogen, nitrite nitrogen and inorganic carbon in the influent were gradually increased. The total nitrogen concentration gradient was the same as in Example 1, 100 mg / L / 7 days, and other concentrations remained unchanged, wherein the ratio of ammonia nitrogen, nitrite nitrogen and inorganic carbon was controlled to be 1:0.8:0.5. By the 60th day, the influent ammonia nitrogen was 290 mg / L, the nitrite nitrogen was 200 mg / L, the total nitrogen concentration was 490 mg / L, the effluent total nitrogen was 40.67 mg / L, the removal rate reached 91.7%, the bacterial concentration in the No. 1 anaerobic reactor increased to 1.3 g / L, the sludge turned red significantly, and the enrichment was completed.

[0086] Example 3

[0087] The difference between this embodiment and embodiment 1 is that during the bacterial enrichment stage, the total nitrogen content increases by 100 mg / L / 10 days.

[0088] On the 80th day after startup, the influent ammonia nitrogen was 290 mg / L, nitrite nitrogen was 200 mg / L, total nitrogen concentration was 490 mg / L, effluent total nitrogen was 46.8 mg / L, and the removal rate reached 90.4%. The bacterial concentration in anaerobic reactor No. 1 increased to 1.2 g / L, the sludge turned obviously red, and the enrichment was completed.

[0089] Example 4

[0090] The difference between this embodiment and embodiment 1 is that during the bacterial enrichment stage, the total nitrogen content increases by 150 mg / L / 7 days.

[0091] On the 48th day after start-up, the inlet ammonia nitrogen was 290 mg / L, nitrite nitrogen was 200 mg / L, total nitrogen concentration was 490 mg / L, effluent total nitrogen was 82 mg / L, and the removal rate was 83.2%. On the 55th day after start-up, the inlet ammonia nitrogen was 290 mg / L, nitrite nitrogen was 200 mg / L, total nitrogen concentration was 490 mg / L, effluent total nitrogen was 73 mg / L, and the removal rate was 85.1%. The high total nitrogen content produced an inhibitory effect and failed to reach the predetermined removal rate.

[0092] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0093] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

Claims

1. A combined enrichment and cultivation device for autotrophic denitrifying bacteria, characterized in that: The device includes: a water inlet tank, a No. 1 anaerobic reactor, a reflux tank and a No. 2 anoxic reactor; The water inlet tank is used for mixing and adjusting the inlet components, and is provided with a water inlet tank outlet pipeline, and the water inlet tank outlet pipeline is connected to the No. 1 anaerobic reactor; The No. 1 anaerobic reactor is used for starting, culturing and enriching anaerobic ammonia-oxidizing bacteria, and is provided with a No. 1 anaerobic reactor outlet pipeline, and the No. 1 anaerobic reactor outlet pipeline is connected to a reflux tank; The reflux tank is used for gas discharge and collection, and a reflux tank outlet pipeline is arranged on the upper part thereof, and a reflux tank return pipeline is arranged on the bottom thereof, the reflux tank outlet pipeline is connected to the No. 2 anoxic reactor, and the reflux tank return pipeline is connected to the No. 1 anaerobic reactor; The No. 2 anoxic reactor is used to intercept the anaerobic ammonia oxidation granular sludge carried by the effluent of the No. 1 anaerobic reactor, and cooperate with aerobic denitrification to further enrich denitrifying bacteria. A No. 2 anoxic reactor return pipeline is arranged at the bottom thereof, and the No. 2 anoxic reactor return pipeline is connected to the lower part of the reflux tank.

2. The autotrophic denitrifying bacteria combined enrichment and culture device according to claim 1, wherein: Pumps are provided on the water inlet tank outlet pipeline, the reflux tank reflux pipeline and the No. 2 anoxic reactor reflux pipeline.

3. The autotrophic denitrifying bacteria combined enrichment and culture device according to claim 1, wherein: The No. 1 anaerobic reactor is a flat-bottomed upflow reactor equipped with a stirrer and a sealing cover; The anoxic reactor No. 2 is a cone-bottom upflow reactor equipped with a stirrer.

4. The autotrophic denitrifying bacteria combined enrichment and culture device according to claim 1, wherein: The No. 1 anaerobic reactor and the No. 2 anoxic reactor are both filled with fillers; The filler is preferably a polyurethane sponge, and preferably, the average porosity of the polyurethane sponge is >85%.

5. A method for combined enrichment and cultivation of autotrophic denitrifying bacteria, characterized in that: The method is carried out using the autotrophic denitrifying bacteria co-cultivation device according to any one of claims 1 to 4, and comprises the following steps: S1. Bacterial culture start-up phase: Step 1: Add the substances required for the anaerobic ammonium oxidation reaction into the water inlet tank, inoculate the first activated sludge into the No. 1 anaerobic reactor, start the water inlet tank to empty the air in the No. 1 anaerobic reactor, start the anaerobic ammonium oxidation bacteria cultivation and domestication, and the nitrogen and water produced by the No. 1 anaerobic reactor enter the reflux tank; Step 2: The second activated sludge is inoculated into the anoxic reactor No. 2, the effluent from the reflux tank enters the anoxic reactor No. 2, the anaerobic ammonium oxidation granular sludge carried out with the effluent from the reflux tank is intercepted, and the anoxic reactor No. 2 is placed in an anoxic state by intermittent aeration, and further denitrification and denitrification bacteria are cultivated under the anoxic state through anaerobic ammonium oxidation and denitrification; Step 3: The sludge at the bottom of the No. 2 anoxic reactor returns to the reflux tank, settles in the reflux tank, and then returns to the No. 1 anaerobic reactor; S2, bacterial enrichment stage: Step 4: Monitor the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the effluent. When the total nitrogen removal rate of the effluent from anaerobic reactor No. 1 is greater than 70%, and the removal rates of nitrite nitrogen and ammonia nitrogen are greater than 75%, the anaerobic ammonia-oxidizing bacteria culture is successfully started. Then, the total nitrogen load of the influent is gradually increased. The total nitrogen amount increases by 50 to 120 mg / L, with an increasing cycle of 7 to 14 days. When the removal rates of nitrite nitrogen and ammonia nitrogen reach more than 90%, and the anaerobic reactor No. 1 turns red obviously, the enrichment of anaerobic ammonia-oxidizing bacteria is completed.

6. The method for combined enrichment and cultivation of autotrophic denitrifying bacteria according to claim 5, wherein: The total nitrogen content increases from 80 to 100 mg / L.

7. The method for combined enrichment and cultivation of autotrophic denitrifying bacteria according to claim 5, wherein: The first activated sludge and the second activated sludge are each independently activated sludge from the secondary sedimentation tank of an industrial sewage treatment plant; The inoculation concentration of the first activated sludge is 300-500 mg / L; The inoculation concentration of the second activated sludge is 100-200 mg / L.

8. The method for combined enrichment and cultivation of autotrophic denitrifying bacteria according to claim 5, wherein: The substances required for the anaerobic ammonium oxidation reaction are ammonia nitrogen salts, nitrite nitrogen salts, inorganic carbon, other inorganic salts and micro-liquids, wherein the mass ratio of ammonia nitrogen to nitrite nitrogen is 1:0.8-1, the mass ratio of total nitrogen to inorganic carbon is 1:0.5-0.8, based on the total weight of the substances required for the anaerobic ammonium oxidation reaction, the content of the other inorganic salts is 1-5wt%, and the content of the micro-liquid is 0.1-0.2wt%; Preferably, the other inorganic salt is at least one of a calcium salt, a magnesium salt and an iron salt; More preferably, the amount of substances required for the anaerobic ammonium oxidation reaction is such that in the water inlet tank during the startup phase: the total nitrogen concentration does not exceed 200 mg / L, the calcium concentration is 0.1-0.2 g / L, the magnesium ion concentration is 0.1-0.2 g / L, and the iron ion concentration is 0.05-0.1 g / L.

9. The method for combined enrichment and cultivation of autotrophic denitrifying bacteria according to claim 8, wherein: The ammonia nitrogen salt is at least one of ammonium sulfate, ammonium chloride and ammonium carbonate, preferably ammonium chloride; The nitrite nitrogen salt is sodium nitrite and / or potassium nitrite, preferably sodium nitrite; The inorganic carbon is carbonate and / or bicarbonate, preferably sodium carbonate and / or sodium bicarbonate, more preferably sodium bicarbonate; The calcium salt is calcium chloride; The magnesium salt is magnesium chloride and / or magnesium sulfate; The iron salt is ferrous sulfate and / or ferric sulfate.

10. The method for combined enrichment and cultivation of autotrophic denitrifying bacteria according to claim 8, wherein: The microfluid contains cobalt chloride, manganese chloride, copper chloride, zinc chloride, boric acid, EDTA, (NH4)6Mo7O 24 4H2O, Na2SeO3·6H2O and NiCl2; Preferably, the concentration of cobalt chloride is 0.1-0.2 mg / L, the concentration of manganese chloride is 0.1-0.2 mg / L, the concentration of copper chloride is 0.05-0.1 mg / L, the concentration of zinc chloride is 0.002-0.005 mg / L, the concentration of boric acid is 0.002-0.005 mg / L, the concentration of EDTA is 0.05-0.1 mg / L, and the concentration of (NH4)6Mo7O 24 The concentration of ·4H2O is 0.005~0.01mg / L, the concentration of Na2SeO3·6H2O is 0.005~0.01mg / L, and the concentration of NiCl2 is 0.002~0.005mg / L.

11. The method for combined enrichment and cultivation of autotrophic denitrifying bacteria according to claim 5, wherein: The duration of the culture start-up phase is 10 to 30 days.

12. The method for combined enrichment and cultivation of autotrophic denitrifying bacteria according to claim 5, wherein: When the bacterial concentration in the No. 1 anaerobic reactor increases to 0.8-1.5 g / L, the enrichment of anaerobic ammonia-oxidizing bacteria is completed.

13. The method for co-culturing autotrophic denitrifying bacteria according to claim 5, wherein: The volume of the No. 1 anaerobic reactor is 3-5 L, and the control conditions of the No. 1 anaerobic reactor include: pH 7.5-8.2, dissolved oxygen concentration less than 0.1 mg / L, and temperature 30-35° C.; The volume of the No. 2 anoxic reactor is 1-2L, and the control conditions of the No. 2 anoxic reactor include: pH 7.0-8.0, dissolved oxygen concentration 0.5-1 mg / L, and temperature 25-35°C.

Images