Iron autotrophic denitrification coupling anaerobic ammonia oxidation combined enrichment culture device and method

Abstract

The invention belongs to the field of industrial wastewater treatment, and relates to an iron autotrophic denitrification coupling anaerobic ammonia oxidation combined enrichment culture device and method. Comprising a water inlet tank, a No.1 anoxic reactor, an intermediate tank and a No.2 anaerobic 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 anoxic reactor; the anoxic reactor I is provided with a water outlet pipeline of the anoxic reactor I, and the water outlet pipeline of the anoxic reactor I is connected with the intermediate tank; the intermediate tank is provided with an intermediate tank water outlet pipeline, and the intermediate tank water outlet pipeline is connected with the No.2 anaerobic reactor; the No.2 anaerobic reactor is provided with a No.2 anaerobic reactor water outlet pipeline; the No.2 anaerobic reactor water outlet pipeline is connected with the No.1 anoxic reactor. According to the invention, collaborative culture of autotrophic denitrification bacteria and anaerobic ammonium oxidation bacteria can be realized, an autotrophic denitrification effect provides a certain amount of nitrite and iron ions to promote anaerobic ammonium oxidation reaction, and an anaerobic ammonium oxidation effect can effectively prevent an autotrophic denitrification tank body from being mineralized.

Description

Technical Field

[0001] The present invention belongs to the field of industrial wastewater treatment, and in particular, relates to a device and method for combined enrichment and cultivation of iron autotrophic denitrification coupled with anaerobic ammonia oxidation. Background Art

[0002] Excessive nitrogen discharge into receiving water bodies can 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 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 topic in the research of new biological wastewater denitrification technologies.

[0004] Autotrophic denitrification does not require the addition of organic carbon sources. Autotrophic denitrifying bacteria use hydrogen, reduced sulfide or iron salts as electron donors and inorganic carbon as carbon sources to reduce nitrates to nitrogen. In addition, autotrophic microorganisms have a lower growth rate, which can effectively reduce sludge production and reduce the risk of secondary pollution. Autotrophic denitrification with iron as the medium can simultaneously remove nitrates and form Fe 3+ The reaction principle is that autotrophic denitrifying bacteria convert Fe 2+ Oxidized to Fe 3+ , and then through Fe 3+ Hydroxides, oxides and other metals are precipitated or adsorbed to remove pollutants, and electrons are transferred to nitrates, which are anaerobically reduced to nitrogen gas by denitrification. Most studies have shown that nitrates in iron-based autotrophic denitrification systems are completely reduced to N2 and released without the accumulation of intermediate products. Some studies have found that this process produces large amounts of nitrite and nitrous oxide. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a device and method for the combined enrichment and cultivation of anaerobic ammonia oxidation and autotrophic denitrification, which can not only simultaneously enrich and cultivate anaerobic ammonia oxidizing bacteria and autotrophic denitrifying bacteria, but also realize the rapid start of anaerobic ammonia oxidizing bacteria cultivation.

[0006] In order to achieve the above-mentioned object, the first aspect of the present invention provides an iron autotrophic denitrification coupled anaerobic ammonia oxidation combined enrichment and culture device, comprising: a water inlet tank, a No. 1 anoxic reactor, an intermediate tank and a No. 2 anaerobic reactor;

[0007] The water inlet tank is used for mixing and adjusting the water inlet components of the No. 1 anoxic reactor, and is provided with a water inlet tank outlet pipeline, and the water inlet tank outlet pipeline is connected to the No. 1 anoxic reactor;

[0008] The No. 1 anoxic reactor is used for culturing and enriching iron autotrophic denitrifying bacteria, and is provided with a No. 1 anoxic reactor outlet pipeline, and the No. 1 anoxic reactor outlet pipeline is connected to the intermediate tank;

[0009] The intermediate tank is used for mixing and adjusting the influent components of the No. 2 anaerobic reactor, and is provided with an intermediate tank outlet pipeline, which is connected to the No. 2 anaerobic reactor;

[0010] The No. 2 anaerobic reactor is used for starting, culturing and enriching anaerobic ammonia-oxidizing bacteria, and is provided with a No. 2 anaerobic reactor outlet pipeline, and the No. 2 anaerobic reactor outlet pipeline is connected to the No. 1 anoxic reactor.

[0011] A second aspect of the present invention provides a method for the combined enrichment and cultivation of iron autotrophic denitrification coupled with anaerobic ammonium oxidation, comprising the following steps:

[0012] S1. Start-up phase of bacterial culture

[0013] Step 1: Add the substances required for iron autotrophic denitrification into the water inlet tank, inoculate the first activated sludge into the No. 1 anoxic reactor, start the water inlet tank to empty the air in the No. 1 anoxic reactor, add 8-10g of iron powder, and start the iron autotrophic denitrification bacteria culture and domestication under anoxic conditions;

[0014] Step 2: The effluent from the No. 1 anoxic reactor enters the intermediate tank, and the substances required for the anaerobic ammonium oxidation reaction are added and mixed evenly;

[0015] Step 3: The second activated sludge is inoculated into the No. 2 anaerobic reactor, and the effluent from the intermediate tank enters the No. 2 anaerobic reactor to denitrify and enrich anaerobic ammonia bacteria under anoxic or anaerobic conditions;

[0016] S2. Bacterial enrichment stage

[0017] Step 4: monitoring the concentrations of ammonia nitrogen, nitrite nitrogen and nitric nitrogen in the effluent of the No. 1 anoxic reactor. The removal rate of nitrate in the effluent of the No. 1 anoxic reactor is greater than 70%. Ammonia and nitrite appear in the effluent. The iron autotrophic denitrification is successfully started. Then, the nitrate nitrogen load of the No. 1 anoxic reactor inlet is increased, and iron powder is supplemented. The nitrate nitrogen load is increased by 50 to 80 mg / L, and the iron powder supplement amount is 3 to 5 g / 10 days.

[0018] Step 5: Monitor the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the effluent of anaerobic reactor No. 2. The total nitrogen removal rate of the effluent of anaerobic reactor No. 2 is greater than 60%, and the removal rates of nitrite nitrogen and ammonia nitrogen are greater than 70%. The anaerobic ammonia-oxidizing bacteria culture is successfully started. Then, the total nitrogen load of the influent of anaerobic reactor No. 2 is gradually increased. The total nitrogen amount increases at a rate of 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. 2 turns red obviously, the enrichment is completed.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The present invention can realize the rapid start-up of the anaerobic ammonium oxidation reaction, start the cultivation of anaerobic ammonium oxidation dominant bacteria under a low load state, increase the total nitrogen load by gradient improvement, and quickly enrich anaerobic ammonium oxidation bacteria.

[0021] (2) The present invention can realize the coordinated cultivation of autotrophic denitrifying bacteria and anaerobic ammonium oxidizing bacteria. The autotrophic denitrification consumes the dissolved oxygen in the influent to provide anaerobic conditions for anaerobic ammonium oxidation and provides a certain amount of nitrite and iron ions to promote the anaerobic ammonium oxidation reaction. The produced water of anaerobic ammonium oxidation can be refluxed to the autotrophic denitrification tank to effectively prevent the occurrence of mineralization and promote the reaction of the autotrophic denitrification tank.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0024] Figure 1 A schematic diagram of the iron autotrophic denitrification coupled anaerobic ammonia oxidation combined enrichment culture device of the present invention is shown. DETAILED DESCRIPTION

[0025] 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.

[0026] In order to achieve the above-mentioned object, the first aspect of the present invention provides an iron autotrophic denitrification coupled anaerobic ammonia oxidation combined enrichment and culture device, comprising: a water inlet tank, a No. 1 anoxic reactor, an intermediate tank and a No. 2 anaerobic reactor;

[0027] The water inlet tank is used for mixing and adjusting the water inlet components of the No. 1 anoxic reactor, and is provided with a water inlet tank outlet pipeline, and the water inlet tank outlet pipeline is connected to the No. 1 anoxic reactor;

[0028] The No. 1 anoxic reactor is used for culturing and enriching iron autotrophic denitrifying bacteria, and is provided with a No. 1 anoxic reactor outlet pipeline, and the No. 1 anoxic reactor outlet pipeline is connected to the intermediate tank;

[0029] The intermediate tank is used for mixing and adjusting the influent components of the No. 2 anaerobic reactor, and is provided with an intermediate tank outlet pipeline, which is connected to the No. 2 anaerobic reactor;

[0030] The No. 2 anaerobic reactor is used for starting, culturing and enriching anaerobic ammonia-oxidizing bacteria, and is provided with a No. 2 anaerobic reactor outlet pipeline, and the No. 2 anaerobic reactor outlet pipeline is connected to the No. 1 anoxic reactor.

[0031] In the present invention, the feed tank and the neutralization tank are used to control the proportion of each substance in the influent, mix it, monitor the pH and dissolved oxygen and adjust it in time. The No. 1 anoxic reactor is used to cultivate and enrich iron autotrophic denitrifying bacteria, and intercept the anaerobic ammonia oxidation granular sludge carried by the No. 2 effluent to consume dissolved oxygen. The No. 2 anaerobic reactor is used to start, cultivate and enrich anaerobic ammonia oxidation bacteria. The reflux device is used to reflux the liquid of the No. 2 reactor to the No. 1 tank, and is also used for the discharge and collection of gas. The gas and liquid are discharged from the reflux port above the reactor at the same time. The water and activated sludge are returned to the No. 1 reactor through the reflux pump. The gas plays an aeration and mixing role in the No. 1 reactor and escapes to the atmosphere through the open No. 1 reactor.

[0032] At present, the difficulty of anaerobic ammonium oxidation is that the startup is slow and unstable, and there is mud running. Iron autotrophic denitrification is prone to mineralization. Iron compounds wrap the sludge, resulting in slow mass transfer. A certain amount of anaerobic sludge can effectively solve the sludge mineralization problem. The culture environment of anaerobic ammonium oxidizing bacteria needs to be strictly anaerobic. The influent will carry a certain amount of dissolved oxygen, which leads to slow startup. Autotrophic denitrification is an anoxic reaction that can effectively consume the dissolved oxygen in the influent, and a certain amount of iron ions can promote the anaerobic ammonium oxidation reaction. In addition, the byproduct nitrite produced in the autotrophic denitrification system can be further removed by anaerobic ammonium oxidation. Therefore, the two have a good synergistic effect. By coupling autotrophic denitrification with anaerobic ammonium oxidation, it is possible to achieve the simultaneous enrichment of autotrophic denitrifying bacteria and anaerobic ammonium oxidizing bacteria, and at the same time achieve the rapid start of the anaerobic ammonium oxidation test.

[0033] According to the present invention, preferably, a No. 1 anoxic reactor bottom return pipeline is provided at the bottom of the No. 1 anoxic reactor, and a No. 2 anaerobic reactor bottom return pipeline is provided at the No. 2 anaerobic reactor.

[0034] Preferably, the water outlet pipeline of the water inlet tank, the bottom return pipeline of the No. 1 anoxic reactor, the water outlet pipeline of the intermediate tank, the water outlet pipeline of the No. 2 anaerobic reactor and the bottom return pipeline of the No. 2 anaerobic reactor are all provided with pumps.

[0035] According to the present invention, preferably, the No. 1 anoxic reactor is an upflow reactor equipped with a three-phase separation device and a stirrer.

[0036] According to the present invention, preferably, the No. 2 anaerobic reactor is an upflow reactor equipped with a stirrer and a sealing cover.

[0037] According to the present invention, preferably, the No. 1 reactor and the No. 2 reactor are both filled with fillers.

[0038] Preferably, the filler is polyurethane sponge, and preferably, the average porosity of the polyurethane sponge is 80% to 95%.

[0039] In the present invention, the size of the polyurethane sponge used is 1 to 2 cm 3 .

[0040] A second aspect of the present invention provides a method for the combined enrichment and cultivation of iron autotrophic denitrification coupled with anaerobic ammonium oxidation, comprising the following steps:

[0041] S1. Start-up phase of bacterial culture

[0042] Step 1: Add the substances required for iron autotrophic denitrification into the water inlet tank, inoculate the first activated sludge into the No. 1 anoxic reactor, start the water inlet tank to empty the air in the No. 1 anoxic reactor, add iron powder, and start the iron autotrophic denitrification bacteria culture and domestication under anoxic conditions;

[0043] Step 2: The effluent from the No. 1 anoxic reactor enters the intermediate tank, and the substances required for the anaerobic ammonium oxidation reaction are added and mixed evenly;

[0044] Step 3: The second activated sludge is inoculated into the No. 2 anaerobic reactor, and the effluent from the intermediate tank enters the No. 2 anaerobic reactor to denitrify and enrich anaerobic ammonia bacteria under anoxic or anaerobic conditions;

[0045] S2. Bacterial enrichment stage

[0046] Step 4: Monitor the concentrations of ammonia nitrogen, nitrite nitrogen and nitric nitrogen in the effluent of the No. 1 anoxic reactor. The removal rate of nitrate in the effluent of the No. 1 anoxic reactor is greater than 70%. Ammonia and nitrite appear in the effluent. The iron autotrophic denitrification is successfully started. Then, the nitrate nitrogen load in the influent of the No. 1 anoxic reactor is increased and iron powder is added.

[0047] Step 5: Monitor the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the effluent of anaerobic reactor No. 2. The total nitrogen removal rate of the effluent of anaerobic reactor No. 2 is greater than 60%, and the removal rates of nitrite nitrogen and ammonia nitrogen are greater than 70%. The anaerobic ammonia-oxidizing bacteria culture is successfully started. Then, the total nitrogen load of the influent of anaerobic reactor No. 2 is gradually increased. The total nitrogen amount increases at a rate of 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. 2 turns red obviously, the enrichment is completed.

[0048] According to the present invention, preferably, the total nitrogen content increases in a ratio of 80 to 100 mg / L.

[0049] According to the present invention, preferably, the dosage of the iron powder is 8-10 g, and the particle size of the iron powder is preferably 150-200 meshes.

[0050] Preferably, the nitrate nitrogen load increases according to 60-80 mg / L, and the iron powder supplement amount is 3-5 g / 10 days.

[0051] In the present invention, in order to ensure that the start-up of the No. 1 anoxic reactor is carried out smoothly, it is necessary to ensure that the iron powder is excessive, 8 to 10 g is added at the start-up, and then 3 to 5 g is added every ten days according to the iron powder surplus in the reactor. After the iron powder is added, it sinks to the bottom. Divalent iron is generated by stirring contact, and then trivalent iron is generated by oxidation. The trivalent iron gathers in the upper part of the reactor, and the divalent iron mainly gathers in the middle part of the reactor, which is also the place where the reaction mainly takes place. The upflow speed is controlled to be 3 to 4 m / h.

[0052] 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.

[0053] Preferably, the inoculation concentration of the first activated sludge is 500-800 mg / L.

[0054] Preferably, the inoculation concentration of the second activated sludge is 300-500 mg / L.

[0055] According to the present invention, preferably, the culture start-up phase of the No. 1 anoxic reactor lasts for 20-40 days.

[0056] According to the present invention, preferably, the culture start-up phase of the No. 2 anaerobic reactor lasts for 30-40 days.

[0057] According to the present invention, preferably, the substances required for the iron autotrophic denitrification are nitrate nitrogen salt, first inorganic carbon and first microliquid, wherein the mass ratio of nitrate nitrogen to the first inorganic carbon is 1:1-2, and based on the total weight of the substances required for the iron autotrophic denitrification, the content of the first microliquid is 0.1-0.2wt.

[0058] Preferably, the nitrate nitrogen salt is sodium nitrate; the first inorganic carbon is sodium bicarbonate; and the first microliquid contains potassium dihydrogen phosphate, dipotassium hydrogen phosphate, calcium chloride and magnesium chloride.

[0059] More preferably, the concentration of potassium dihydrogen phosphate is 0.5-1 g / L, the concentration of dipotassium hydrogen phosphate is 1-2 g / L, the concentration of calcium chloride is 0.3-0.5 g / L, and the concentration of magnesium chloride is 0.5-0.8 g / L.

[0060] According to the present invention, preferably, the substances required for the anaerobic ammonium oxidation reaction are ammonia nitrogen salt, nitrite nitrogen salt, a second inorganic carbon, other inorganic salts and a second microliquid, wherein the mass ratio of ammonia nitrogen and nitrite nitrogen is 1:0.8-1, the mass ratio of total nitrogen to the second inorganic carbon is 1:0.5-0.8, the content of the other inorganic salts is 1-5wt%, and the content of the microliquid is 0.1-0.2wt%.

[0061] Preferably, the other inorganic salt is at least one of a calcium salt, a magnesium salt and an iron salt.

[0062] More preferably, the amount of substances required for the anaerobic ammonia oxidation reaction is such that in the water in the water inlet tank during the startup phase, the total nitrogen concentration does not exceed 200 mg / L, the calcium ion 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.

[0063] 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.

[0064] Preferably, the nitrite nitrogen salt is sodium nitrite and / or potassium nitrite, preferably sodium nitrite.

[0065] Preferably, the second inorganic carbon is carbonate and / or bicarbonate, preferably sodium carbonate and / or sodium bicarbonate, more preferably sodium bicarbonate.

[0066] Preferably, the calcium salt is calcium chloride.

[0067] Preferably, the magnesium salt is magnesium chloride and / or magnesium sulfate.

[0068] Preferably, the iron salt is ferrous sulfate and / or ferric sulfate.

[0069] According to the present invention, preferably, the second microfluid comprises potassium dihydrogen phosphate, cobalt chloride, manganese chloride, copper chloride, zinc chloride, boric acid, EDTA, (NH4)6Mo7O 24 ·4H2O, Na2SeO3·6H2O and NiCl2.

[0070] Preferably, the concentration of potassium dihydrogen phosphate is 25-35 mg / L, 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.

[0071] According to the present invention, preferably, the bacterial concentration in the No. 2 anaerobic reactor is increased to 0.8-1.5 g / L, and the enrichment of anaerobic ammonia-oxidizing bacteria is completed.

[0072] According to the present invention, preferably, the volume of the No. 1 anoxic reactor is 3-5 L, and the control conditions of the No. 1 reactor include: pH 6.5-7.2, dissolved oxygen concentration 0.2-0.4 mg / L, and temperature 30-35°C.

[0073] According to the present invention, preferably, the volume of the No. 2 anaerobic reactor is 3-5 L, and the control conditions of the No. 2 reactor include: pH 7.0-8.2, dissolved oxygen concentration lower than 0.1 mg / L, and temperature 30-35°C.

[0074] 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.

[0075] 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.

[0076] Example 1

[0077] In this embodiment, the Figure 1 The iron autotrophic denitrification coupled anaerobic ammonia oxidation combined enrichment culture device shown is carried out, and the device includes: a water inlet tank, anoxic reactor No. 1, an intermediate tank and anaerobic reactor No. 2; wherein, the anoxic reactor No. 1 is an upflow reactor equipped with a three-phase separation device and an agitator; the anaerobic reactor No. 2 is an upflow reactor equipped with an agitator and a sealing cover, and the anoxic reactor No. 1 and the anaerobic reactor No. 2 are both filled with polyurethane sponges, and the average porosity of the polyurethane sponges is 90%.

[0078] The water inlet tank is used for mixing and adjusting the inlet components of the No. 1 anoxic reactor, and is provided with an inlet tank outlet pipeline, and the inlet tank outlet pipeline is connected to the No. 1 anoxic reactor; the No. 1 anoxic reactor is used for culturing and enriching iron autotrophic denitrifying bacteria, and is provided with an anoxic reactor outlet pipeline, and the No. 1 anoxic reactor outlet pipeline is connected to the intermediate tank; the intermediate tank is used for mixing and adjusting the inlet components of the No. 2 anaerobic reactor, and is provided with an intermediate tank outlet pipeline, and the intermediate tank outlet pipeline is connected to the No. 2 anaerobic reactor; the No. 2 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. 2 anaerobic reactor outlet pipeline is connected to the No. 1 anoxic reactor. The bottom of the No. 1 anoxic reactor is provided with a No. 1 anoxic reactor bottom reflux pipeline, and the No. 2 anaerobic reactor is provided with a No. 2 anaerobic reactor bottom reflux pipeline. Preferably, the water inlet tank outlet pipeline, the No. 1 anoxic reactor bottom reflux pipeline, the intermediate tank outlet pipeline, the No. 2 anaerobic reactor outlet pipeline and the No. 2 anaerobic reactor bottom reflux pipeline are all provided with pumps.

[0079] The iron autotrophic denitrification coupled with anaerobic ammonium oxidation combined enrichment culture includes the following steps:

[0080] S1. Start-up phase of bacterial culture

[0081] Step 1: Add the substances required for iron autotrophic denitrification into the water inlet tank, inoculate 800 mg / L of activated sludge into the No. 1 anoxic reactor, start the water inlet tank to empty the air in the No. 1 anoxic reactor, add 8-10g of iron powder, and start the iron autotrophic denitrification bacteria culture and domestication under anoxic conditions;

[0082] Step 2: The effluent from the No. 1 anoxic reactor enters the intermediate tank, and the substances required for the anaerobic ammonium oxidation reaction are added and mixed evenly;

[0083] Step 3: 500 mg / L activated sludge is inoculated into the No. 2 anaerobic reactor, and the effluent from the intermediate tank enters the No. 2 anaerobic reactor to denitrify and enrich anaerobic ammonia bacteria under anoxic or anaerobic conditions;

[0084] During the startup phase, the nitrate nitrogen concentration in the inlet tank is 50 mg / L, and the inorganic carbon concentration is 100 mg / L. The substance providing nitrate nitrogen is sodium nitrate, and the substance providing inorganic carbon is sodium bicarbonate. The inlet micro-liquid is 1 g / L potassium dihydrogen phosphate, 2 g / L potassium hydrogen phosphate, 1 g / L calcium chloride, and 2 g / L magnesium chloride. The influent ammonia nitrogen concentration of the intermediate tank is 50mg / L, nitrite nitrogen concentration is 40mg / L, inorganic carbon concentration is 45mg / L, calcium ion concentration is 0.1mg / L, magnesium ion concentration is 0.1mg / L, total phosphorus concentration is 0.2mg / L, and iron ion concentration is 0.07mg / L. 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 micro-liquid is 0.1mg / L of cobalt chloride, 0.1mg / L of manganese chloride, 0.05mg / L of copper chloride, 0.005mg / L of zinc chloride, 0.005mg / L of boric acid, 0.05mg / L of EDTA, (NH4)6Mo7O 24 ·4H2O 0.005mg / L, Na2SeO3·6H2O0.005mg / L, NiCl2 0.005mg / L.

[0085] Start water inlet, the flow rate of No. 1 anoxic reactor is 2L / day, add 10g of iron powder, and add iron powder at any time according to the reactor later. The effective volume of the reactor is 5L, the hydraulic retention time is 2.5 days, the dissolved oxygen is controlled at 0.3mg / L, the temperature is controlled at 30 degrees, the pH is 6.9, the stirring rate is 35rpm, and the upflow speed is 3.5m / h. The concentrations of ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen in the effluent are tested daily.

[0086] The inlet flow rate of anaerobic reactor No. 2 is 2L / day, the effective volume of the reactor is 5L, the hydraulic retention time is 2.5 days, the dissolved oxygen is controlled at 0.1mg / L, the temperature is controlled at 35 degrees, the pH is 7.3, and the stirring rate is 100rpm.

[0087] The concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the effluent were tested daily. Eight days after the device was started, the nitrate nitrogen in the effluent of the No. 1 anoxic reactor was less than 20 mg / L, the ammonia nitrogen in the effluent of the No. 2 anaerobic reactor was less than 1 mg / L, and the nitrite nitrogen concentration was less than 1 mg / L. The inlet flow rate was gradually increased to reduce the hydraulic retention time.

[0088] On the 20th day after startup, the inlet flow rate of the No. 1 anoxic reactor was 5L / day, the hydraulic retention time was 24h, the effluent nitrate nitrogen of the No. 1 anoxic reactor was less than 15mg / L, and the effluent ammonia nitrogen and nitrite nitrogen were both less than 1mg / L. The effluent ammonia nitrogen of the No. 2 anaerobic reactor was less than 1mg / L, the nitrite nitrogen concentration was less than 1mg / L, and the total nitrogen removal rate was greater than 80%, and the startup was completed.

[0089] S2. Bacterial enrichment stage

[0090] Step 4: enrichment culture was carried out by increasing the total nitrogen concentration gradient, and the concentrations of nitrate nitrogen, ammonia nitrogen, nitrite nitrogen and inorganic carbon in the influent of reactors 1 and 2 were gradually increased, while other concentrations remained unchanged. The ratio of nitrate nitrogen to inorganic carbon in the influent of anoxic reactor 1 was controlled at 1:1.5, and the ratio of ammonia nitrogen, nitrite nitrogen and inorganic carbon in the influent of anaerobic reactor 2 was controlled at 1:0.8:0.5. The nitrate nitrogen load of reactor 1 increased by 60 mg / L / 7 days, and the total nitrogen load of reactor 2 increased by The concentration of nitrogen increased by 100 mg / L / 7 days. On the 55th day, the inlet nitrate nitrogen of the anoxic reactor No. 1 was 300 mg / L, the effluent nitrate nitrogen was 85 mg / L, the nitrite nitrogen and ammonia nitrogen were both less than 10 mg / L. The inlet ammonia nitrogen of the anaerobic reactor No. 2 was 300 mg / L, the nitrite nitrogen was 240 mg / L, the total nitrogen concentration was 540 mg / L, the effluent total nitrogen was 53.6 mg / L, the removal rate reached 90.07%, the sludge in the reactor turned obviously red, and the enrichment was completed.

[0091] Example 2

[0092] In this embodiment, the iron autotrophic denitrification coupled anaerobic ammonia oxidation combined enrichment culture device and the iron autotrophic denitrification coupled anaerobic ammonia oxidation combined enrichment culture method are the same as those in Example 1, except that the nitrate nitrogen concentration of the water inlet tank in the startup phase is 100 mg / L, the inorganic carbon concentration is 150 mg / L, the substance providing nitrate nitrogen is sodium nitrate, the substance providing inorganic carbon is sodium bicarbonate, and the inlet microliquid 2 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. The inlet water ammonia nitrogen concentration of the intermediate tank is 100mg / L, nitrite nitrogen 80mg / L, inorganic carbon concentration 90mg / L, calcium ion concentration 0.2mg / L, magnesium ion concentration 0.2mg / L, total phosphorus concentration 0.4mg / L, iron ion concentration 0.14mg / L, among which 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 micro-liquid is the same as the inlet water tank.

[0093] Start water inlet, flow rate is 1L / day, add 8g iron powder, and add iron powder at any time according to the reactor later. The effective volume of the reactor is 5L, the hydraulic retention time is 5 days, the dissolved oxygen is controlled at 0.2mg / L, the temperature is controlled at 30 degrees, the pH is 7, the stirring rate is 80rpm, and the upflow speed is 3m / h. The concentrations of ammonia nitrogen, nitrite nitrogen, and nitric nitrogen in the effluent are tested daily.

[0094] The influent flow rate of the No. 2 anaerobic reactor is 1L / day, the effective volume of the reactor is 5L, the hydraulic retention time is 5 days, the dissolved oxygen is controlled at 0.1mg / L, the temperature is controlled at 35 degrees, the pH is 7, and the stirring rate is 30rpm. The concentrations of ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen in the effluent are tested daily.

[0095] Three days after the device was started, the nitrate nitrogen in the No. 1 effluent was less than 20 mg / L, the ammonia nitrogen in the No. 2 anaerobic reactor effluent 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 the start-up, the inlet flow rate of the two reactors was 5L / day, the hydraulic retention time was 24h, the nitrate nitrogen in the No. 1 anoxic reactor effluent was less than 30 mg / L, the ammonia nitrogen and nitrite nitrogen in the effluent were both less than 1 mg / L, the ammonia nitrogen in the No. 2 anaerobic reactor effluent was less than 10 mg / L, the nitrite nitrogen concentration was less than 10 mg / L, the total nitrogen removal rate was greater than 80%, and the start-up was completed.

[0096] The total nitrogen concentration gradient was used for enrichment culture, and the concentrations of nitrate nitrogen, ammonia nitrogen, nitrite nitrogen and inorganic carbon in the influent of reactors 1 and 2 were gradually increased. The concentration gradient was the same as that in Example 1, and other concentrations remained unchanged. The ratio of nitrate nitrogen to inorganic carbon in the influent of the anoxic reactor No. 1 was controlled at 1:1.5, and the ratio of ammonia nitrogen, nitrite nitrogen and inorganic carbon in the influent of the anaerobic reactor No. 2 was controlled at 1:0.8:0.5. By the 58th day, the nitrate nitrogen in the influent of the anoxic reactor No. 1 was 300 mg / L, the nitrate nitrogen in the effluent was 80 mg / L, and the nitrite nitrogen and ammonia nitrogen were both less than 10 mg / L. The ammonia nitrogen in the influent of the anaerobic reactor No. 2 was 300 mg / L, the nitrite nitrogen was 240 mg / L, the total nitrogen concentration was 540 mg / L, and the total nitrogen in the effluent was 48.2 mg / L. The removal rate reached 91%, and the sludge in the reactor turned red significantly, and the enrichment was completed.

[0097] Example 3

[0098] The difference between this embodiment and embodiment 1 is that, in the bacterial enrichment stage, nitric nitrogen increases at a rate of 50 mg / L / 10 days and total nitrogen increases at a rate of 100 mg / L / 10 days.

[0099] On the 70th day after startup, the inlet nitrate nitrogen of the No. 1 anoxic reactor was 300 mg / L, the effluent nitrate nitrogen was 76 mg / L, the nitrite nitrogen and ammonia nitrogen were both less than 10 mg / L, the inlet ammonia nitrogen of the No. 2 anaerobic reactor was 300 mg / L, the nitrite nitrogen was 250 mg / L, the total nitrogen concentration was 550 mg / L, the effluent total nitrogen was 40.3 mg / L, the removal rate reached 92.6%, the sludge in the reactor turned obviously red, and the enrichment was completed.

[0100] Example 4

[0101] The difference between this embodiment and embodiment 1 is that during the bacterial enrichment stage, the total nitrogen content increases at a rate of 150 mg / L / 7 days.

[0102] On the 50th day after start-up, the inlet nitrate nitrogen of the No. 1 anoxic reactor was 300 mg / L, the effluent nitrate nitrogen was 85 mg / L, the nitrite nitrogen and ammonia nitrogen were both less than 10 mg / L, the inlet ammonia nitrogen of the No. 2 anaerobic reactor was 300 mg / L, the nitrite nitrogen was 240 mg / L, the total nitrogen concentration was 540 mg / L, the effluent total nitrogen was 88.9 mg / L, and the removal rate was 83.5%. The excessive total nitrogen content produced an inhibitory effect and failed to reach the predetermined removal rate.

[0103] 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.

[0104] 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 iron autotrophic denitrification coupled with anaerobic ammonium oxidation, characterized in that: include: Inlet tank, anoxic reactor No. 1, intermediate tank and anaerobic reactor No. 2; The water inlet tank is used for mixing and adjusting the water inlet components of the No. 1 anoxic reactor, and is provided with a water inlet tank outlet pipeline, and the water inlet tank outlet pipeline is connected to the No. 1 anoxic reactor; The No. 1 anoxic reactor is used for culturing and enriching iron autotrophic denitrifying bacteria, and is provided with a No. 1 anoxic reactor outlet pipeline, and the No. 1 anoxic reactor outlet pipeline is connected to the intermediate tank; The intermediate tank is used for mixing and adjusting the influent components of the No. 2 anaerobic reactor, and is provided with an intermediate tank outlet pipeline, which is connected to the No. 2 anaerobic reactor; The No. 2 anaerobic reactor is used for starting, culturing and enriching anaerobic ammonia-oxidizing bacteria, and is provided with a No. 2 anaerobic reactor outlet pipeline, and the No. 2 anaerobic reactor outlet pipeline is connected to the No. 1 anoxic reactor.

2. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture device according to claim 1, wherein: The bottom of the No. 1 anoxic reactor is provided with a No. 1 anoxic reactor bottom reflux pipeline, and the No. 2 anaerobic reactor is provided with a No. 2 anaerobic reactor bottom reflux pipeline; Preferably, the water inlet tank outlet pipeline, the No. 1 anoxic reactor bottom return pipeline, the intermediate tank outlet pipeline, the No. 2 anaerobic reactor outlet pipeline and the No. 2 anaerobic reactor bottom return pipeline are all provided with pumps.

3. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture device according to claim 1, wherein: The anoxic reactor No. 1 is an upflow reactor equipped with a three-phase separation device and a stirrer; The No. 2 anaerobic reactor is an upflow reactor equipped with a stirrer and a sealing cover.

4. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture device according to claim 1, wherein: Reactor No. 1 and Reactor No. 2 are both filled with fillers; The filler is preferably polyurethane sponge, and preferably, the average porosity of the polyurethane sponge is 80% to 95%.

5. A method for the combined enrichment and cultivation of iron autotrophic denitrification coupled with anaerobic ammonium oxidation, characterized in that: The method is carried out using the iron autotrophic denitrification coupled anaerobic ammonia oxidation combined enrichment culture device according to any one of claims 1 to 4, and comprises the following steps: S1. Start-up phase of bacterial culture Step 1: Add the substances required for iron autotrophic denitrification into the water inlet tank, inoculate the first activated sludge into the No. 1 anoxic reactor, start the water inlet tank to empty the air in the No. 1 anoxic reactor, add iron powder, and start the iron autotrophic denitrification bacteria culture and domestication under anoxic conditions; Step 2: The effluent from the No. 1 anoxic reactor enters the intermediate tank, and the substances required for the anaerobic ammonium oxidation reaction are added and mixed evenly; Step 3: The second activated sludge is inoculated into the No. 2 anaerobic reactor, and the effluent from the intermediate tank enters the No. 2 anaerobic reactor to denitrify and enrich anaerobic ammonia bacteria under anoxic or anaerobic conditions; S2. Bacterial enrichment stage Step 4: Monitor the concentrations of ammonia nitrogen, nitrite nitrogen and nitric nitrogen in the effluent of the No. 1 anoxic reactor. The removal rate of nitrate in the effluent of the No. 1 anoxic reactor is greater than 70%. Ammonia and nitrite appear in the effluent. The iron autotrophic denitrification is successfully started. Then, the nitrate nitrogen load in the influent of the No. 1 anoxic reactor is increased and iron powder is added. Step 5: Monitor the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the effluent of anaerobic reactor No.

2. The total nitrogen removal rate of the effluent of anaerobic reactor No. 2 is greater than 60%, and the removal rates of nitrite nitrogen and ammonia nitrogen are greater than 70%. The anaerobic ammonia-oxidizing bacteria culture is successfully started. Then, the total nitrogen load of the influent of anaerobic reactor No. 2 is gradually increased. The total nitrogen amount increases by 50 to 120 mg / L, and the increasing cycle is 7 to 14 days. When the removal rates of nitrite nitrogen and ammonia nitrogen reach more than 90%, and the anaerobic reactor No. 2 turns red obviously, the enrichment is completed.

6. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture method according to claim 5, wherein: The total nitrogen content increases from 80 to 100 mg / L.

7. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture method according to claim 5, wherein: The dosage of the iron powder is 8-10 g, and the particle size of the iron powder is preferably 150-200 mesh; The nitrate nitrogen load is increased by 50-80 mg / L, and the iron powder supplement amount is 3-5 g / 10 days.

8. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture method 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 500-800 mg / L; The inoculation concentration of the second activated sludge is 300-500 mg / L.

9. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture method according to claim 5, wherein: The time of the culture start-up phase of the No. 1 anoxic reactor is 20-40 days; The culture start-up phase of the No. 2 anaerobic reactor lasts for 30-40 days.

10. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture method according to claim 5, wherein: The substances required for the iron autotrophic denitrification are nitrate nitrogen salt, first inorganic carbon and first micro-liquid, wherein the mass ratio of nitrate nitrogen to the first inorganic carbon is 1:1-2, and the content of the first micro-liquid is 0.1-0.2wt% based on the total weight of the substances required for the iron autotrophic denitrification; Preferably, the nitrate nitrogen salt is sodium nitrate; the first inorganic carbon is sodium bicarbonate; the first microliquid contains potassium dihydrogen phosphate, dipotassium hydrogen phosphate, calcium chloride and magnesium chloride; More preferably, the concentration of potassium dihydrogen phosphate is 0.5-1 g / L, the concentration of dipotassium hydrogen phosphate is 1-2 g / L, the concentration of calcium chloride is 0.3-0.5 g / L, and the concentration of magnesium chloride is 0.5-0.8 g / L.

11. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture method according to claim 5, wherein: The substances required for the anaerobic ammonium oxidation reaction are ammonia nitrogen salt, nitrite nitrogen salt, second inorganic carbon, other inorganic salts and second micro-liquid, wherein the mass ratio of ammonia nitrogen to nitrite nitrogen is 1:0.8-1, the mass ratio of total nitrogen to the second inorganic carbon is 1:0.5-0.8, the content of 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 ion 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.

12. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture method according to claim 11, 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 second 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.

13. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture method according to claim 11, wherein: The second microfluid contains potassium dihydrogen phosphate, cobalt chloride, manganese chloride, copper chloride, zinc chloride, boric acid, EDTA, (NH4)6Mo7O 24 4H2O, Na2SeO3·6H2O and NiCl2; Preferably, the concentration of potassium dihydrogen phosphate is 25-35 mg / L, 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.

14. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture method according to claim 5, wherein: The bacterial concentration in the No. 2 anaerobic reactor increases to 0.8-1.5 g / L, and the enrichment of anaerobic ammonia-oxidizing bacteria is completed.

15. The iron autotrophic denitrification coupled anaerobic ammonium oxidation combined enrichment culture method according to claim 5, wherein: The volume of the anoxic reactor No. 1 is 3-5 L, and the control conditions of the reactor No. 1 include: pH 6.5-7.2, dissolved oxygen concentration 0.2-0.4 mg / L, and temperature 30-35° C.; The volume of the No. 2 anaerobic reactor is 3-5 L, and the control conditions of the No. 2 reactor include: pH 7.0-8.2, dissolved oxygen concentration lower than 0.1 mg / L, and temperature 30-35°C.

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