Application of peracetic acid as short-cut nitrification inhibitor and short-cut nitrification-anaerobic ammonia oxidation sewage treatment method and device

Abstract

The invention belongs to the technical field of sewage treatment, and particularly discloses application of peracetic acid as a short-cut nitrification inhibitor and a short-cut nitrification-anaerobic ammonia oxidation sewage treatment method and device. The short-cut nitrification-anaerobic ammonia oxidation sewage treatment device comprises a short-cut nitrification reactor, a sidestream treatment reactor and an anaerobic ammonia oxidation reactor, the sidestream treatment reactor is provided with a peracetic acid storage tank, and peracetic acid is used as a short-cut nitrification inhibitor; a sludge outlet I of the short-cut nitrification reactor is communicated with a sludge inlet II of the side flow treatment reactor; a sludge outlet II of the side flow treatment reactor is communicated with a sludge inlet I of the short-cut nitrification reactor; a water outlet I of the short-cut nitrification reactor and a water outlet II of the side flow treatment reactor are independently communicated with the anaerobic ammonia oxidation reactor. According to the invention, emission reduction of N2O is realized, and the problems of secondary pollution, complex process, harsh reaction conditions and the like are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to the application of peracetic acid as a short-range nitrification inhibitor and a short-range nitrification-anaerobic ammonia oxidation sewage treatment method and device. Background Art

[0002] The synergistic efficiency of pollution reduction and carbon reduction has become an important development direction of the sewage treatment industry. In the traditional biological denitrification process of sewage, that is, full nitrification and denitrification, aeration demand and external carbon source will generate a large amount of electricity consumption and drug consumption, greatly increasing the total carbon emissions of sewage treatment plants. The anaerobic ammonia oxidation process can simultaneously convert ammonia nitrogen and nitrite nitrogen into nitrogen gas under anaerobic conditions. Compared with full nitrification and denitrification, it can save more than 60% of aeration demand and 100% of organic carbon source demand, becoming one of the most promising biological denitrification processes for sewage.

[0003] Most of the inorganic nitrogen in urban sewage exists in the form of ammonia nitrogen. Part of the ammonia nitrogen is converted into nitrite nitrogen through short-term nitrification reaction, and then the nitrite nitrogen and the remaining ammonia nitrogen are simultaneously converted into nitrogen gas through the anaerobic ammonium oxidation process. This mixed process is called short-term nitrification-anaerobic ammonium oxidation, which is a fully autotrophic nitrogen removal process and has shown significant advantages in the synergistic improvement of sewage pollution reduction and carbon reduction.

[0004] Achieving stable short-term nitrification of sewage is a key prerequisite for the application of anaerobic ammonium oxidation. At present, the method of adding inhibitors is generally used to achieve short-term nitrification. Common inhibitors include hydroxylamine, hydrazine, FNA, sulfide, etc. These inhibitors have a stronger inhibitory effect on nitrite oxidizing bacteria (NOB) than on ammonia oxidizing bacteria (AOB), thereby preventing the nitrite oxidation process, retaining some of the activity of AOB, and ultimately promoting nitrite accumulation to achieve short-term nitrification. However, the above-mentioned inhibitors still have problems such as slow start-up of short-term nitrification, unstable operation, and difficulty in precise control during application. At the same time, some inhibitors are relatively toxic and easily remain in sewage, which may affect the activity of anaerobic ammonium oxidizing bacteria and pose a potential threat to the biological denitrification system.

[0005] In addition, nitrous oxide (N2O), a strong greenhouse gas emitted during the biological nitrogen removal process of sewage, is an important part of the carbon emissions from sewage treatment plants, and its carbon emission proportion may reach more than 30%. In the short-cut nitrification-anaerobic ammonium oxidation hybrid process, N2O production usually comes from the short-cut nitrification process. Since the continuous accumulation of nitrite will stimulate the production of N2O, the N2O emission factor of the short-cut nitrification process may be higher than that of the traditional sewage biological nitrogen removal process, which is also a technical drawback faced by this hybrid process. Inhibitors such as hydroxylamine and hydrazine will significantly stimulate the production of N2O in the short-cut nitrification process, and its emissions increase by about 3 times. The warming potential of N2O is 300 times that of carbon dioxide. The stimulating effect of traditional inhibitors on the production of N2O will undoubtedly increase the carbon emissions of the short-cut nitrification-anaerobic ammonium oxidation hybrid process, which does not conform to the goal orientation of pollution reduction and carbon emission reduction. Therefore, it is of great practical significance to develop a method for realizing short-cut nitrification of sewage and reducing N2O emissions.

[0006] In recent years, some methods have emerged to achieve short-cut nitrification of sewage or N2O reduction by constructing a side-stream treatment device or adopting certain technical means in the main nitrogen removal reactor. For example, Chinese Patent Application CN105800776A, an FNA side-stream process for reducing N2O emissions during sewage treatment, constructs a side-stream treatment tank and adds FNA to treat the concentrated sludge for a period of time and then returns it to the main reactor, significantly reducing the production of N2O during sewage treatment. However, this method does not well achieve short-cut nitrification of sewage, and its effluent contains a high concentration of nitrate nitrogen, and the additional addition of a large amount of nitrite will increase the nitrogen load of the sewage system; Chinese Patent Application CN118908416A, a side-stream enhanced biological nitrogen and phosphorus removal process with biological selection function, constructs a side-stream treatment tank and adds sodium nitrite. The added sodium nitrite generates NO in the anaerobic tank, and the high concentration of NO will inhibit the activity of NOB, ultimately achieving short-cut nitrification. This method has a complex process, harsh reaction conditions, and a risk of NO escape. Short-cut nitrification of sewage can also be achieved by controlling operating parameters such as dissolved oxygen, sludge retention time, and pH in the main nitrogen removal reactor, but it is difficult to simultaneously achieve N2O emission reduction by these methods. The above-mentioned schemes have defects such as the risk of secondary pollution, increased nitrogen load, and harsh reaction conditions. At present, there are few research reports on simultaneously achieving short-cut nitrification of sewage and N2O emission reduction. Summary of the Invention

[0007] In view of this, the present invention provides the application of peracetic acid as a short-cut nitrification inhibitor and a short-cut nitrification-anaerobic ammonium oxidation sewage treatment method and device to solve the problems that the existing short-cut nitrification methods cannot achieve N2O emission reduction, and the N2O emission reduction methods have complex processes, harsh reaction conditions, etc.

[0008] To achieve the above purpose, the present invention adopts the following technical solutions:

[0009] The application of peracetic acid as a short-cut nitrification inhibitor to achieve the reduction of N2O emissions in the short-cut nitrification process, provide an organic carbon source for in-situ utilization, and improve the reduction of nitrate nitrogen.

[0010] Another object of the present invention is to provide a short-cut nitrification-anammox sewage treatment device, which includes a short-cut nitrification reactor, a side-stream treatment reactor, and an anammox reactor;

[0011] The side-stream treatment reactor is provided with a peracetic acid storage tank, and the peracetic acid storage tank contains peracetic acid, which is used as a short-cut nitrification inhibitor;

[0012] The sludge outlet Ⅰ of the short-cut nitrification reactor is communicated with the sludge inlet Ⅱ of the side-stream treatment reactor;

[0013] The sludge outlet Ⅱ of the side-stream treatment reactor is communicated with the sludge inlet Ⅰ of the short-cut nitrification reactor;

[0014] The water outlet Ⅰ of the short-cut nitrification reactor is communicated with the anammox reactor;

[0015] The water outlet Ⅱ of the side-stream treatment reactor is communicated with the anammox reactor.

[0016] Preferably, the short-cut nitrification-anammox sewage treatment device further includes a PLC system;

[0017] The short-cut nitrification reactor is provided with a feed water pump Ⅰ, a stirrer Ⅰ, a dissolved oxygen electrode, a pH electrode, an on-line ammonia nitrogen detector, an on-line nitrite nitrogen detector, a sodium hydroxide storage tank, an alkali pump, an aeration pump, a gas flow meter, a check valve, an aeration disc, a sludge discharge valve, a sludge storage tank, a sludge outlet Ⅰ, a sludge inlet Ⅰ, a water outlet Ⅰ, and a water discharge pump Ⅰ; the dissolved oxygen electrode, the pH electrode, the on-line ammonia nitrogen detector, the on-line nitrite nitrogen detector, the aeration pump, and the alkali pump are independently electrically connected to the PLC system;

[0018] The side-stream treatment reactor is provided with a sludge pump Ⅰ, a sludge inlet Ⅱ, a stirrer Ⅱ, a peracetic acid storage tank, an electric dosing valve, a sludge outlet Ⅱ, a sludge pump Ⅱ, a water outlet Ⅱ, and a water discharge pump Ⅱ; the sludge inlet Ⅱ of the side-stream treatment reactor is connected to the sludge outlet Ⅰ of the short-cut nitrification reactor through the sludge pump Ⅰ; the sludge outlet Ⅱ of the side-stream treatment reactor is connected to the sludge inlet Ⅰ of the short-cut nitrification reactor through the sludge pump Ⅱ;

[0019] The anammox reactor is connected to the water outlet Ⅰ of the short-cut nitrification reactor through the water discharge pump Ⅰ, and the anammox reactor is connected to the water outlet Ⅱ of the side-stream treatment reactor through the water discharge pump Ⅱ.

[0020] Another object of the present invention is to provide a short-cut nitrification-anaerobic ammonium oxidation sewage treatment method, which comprises the following steps: introducing the sewage to be treated into a short-cut nitrification reactor, maintaining stirring and aeration conditions during water inlet, and carrying out nitrification reaction; after the water inlet is completed, carrying out aerobic reaction, and after the aerobic reaction is completed, carrying out a first precipitation. The supernatant obtained from the first precipitation is introduced into an anaerobic ammonium oxidation reactor to carry out anaerobic ammonium oxidation reaction, and the sewage treatment of one cycle is completed after the anaerobic ammonium oxidation reaction ends.

[0021] Wherein, according to the relative difference e between k(NH4 + ) and k(NO2 - ) of the short-cut nitrification reactor, it is judged whether to start the side-stream treatment reactor; during the aerobic reaction stage of the short-cut nitrification reactor, if e > 10%, the side-stream treatment reactor is started; if e ≤ 10%, the side-stream treatment reactor is suspended or not started.

[0022] Starting the side-stream treatment reactor: during the current cycle when e > 10% and the partial sewage of the next 1-2 cycles, independently before the first precipitation after the aerobic reaction ends, are introduced into the side-stream treatment reactor, and then peracetic acid is added for reaction; after the reaction ends, a second precipitation is carried out, and the supernatant obtained from the second precipitation is introduced into the anaerobic ammonium oxidation reactor; the sludge obtained from the second precipitation is introduced into the short-cut nitrification reactor at the beginning of the next operation cycle of the short-cut nitrification reactor.

[0023]

[0024] k(NH4 + ) is the real-time decreasing slope of the ammonia nitrogen concentration changing with time; k(NO2 - ) is the real-time increasing slope of the nitrite nitrogen concentration changing with time.

[0025] Preferably, the operation time of each cycle of the short-cut nitrification reactor is independently 4-6 h;

[0026] The introduced amount of the sewage to be treated in the short-cut nitrification reactor is 30-60% of the total capacity of the short-cut nitrification reactor, and the water inlet time in each cycle is independently 60-90 min.

[0027] Preferably, during the nitrification reaction and the aerobic reaction, the dissolved oxygen concentration in the short-cut nitrification reactor is independently 2-3 mg / L, and the pH value is independently 6.8-7.2.

[0028] Preferably, the sludge content in the short-cut nitrification reactor is 1-2 g / L.

[0029] Preferably, the partial sewage introduced into the side-stream treatment reactor in each cycle is independently 20-30% of the total capacity of the short-cut nitrification reactor.

[0030] Preferably, when reacting with peracetic acid, the mass concentration of the peracetic acid is 5-20 mg / L.

[0031] Preferably, when reacting with peracetic acid, the reaction condition is a dark and airtight condition;

[0032] The reaction time is 10-12 h.

[0033] As can be seen from the above technical solutions, compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) By constructing a side-stream treatment reactor containing peracetic acid, the activity of NOB can be selectively inhibited to achieve short-cut nitrification of sewage, providing nitrite nitrogen for the subsequent anaerobic ammonium oxidation reaction.

[0035] (2) By constructing a side-stream treatment reactor containing peracetic acid, AOB with a lower N2O production can be screened and enriched, fundamentally reducing N2O emissions during short-cut nitrification.

[0036] (3) By constructing a side-stream treatment reactor containing peracetic acid, acetic acid, the hydrolysis product of peracetic acid, can be used in situ as an organic carbon source to promote the reduction process of nitrate nitrogen, solve the problem of excessive nitrate nitrogen concentration in the effluent, and improve the total nitrogen removal rate of sewage;

[0037] (4) Peracetic acid is easy to hydrolyze, and its hydrolysis products are acetic acid and hydrogen peroxide, which are non-toxic and harmless, and will not cause residue and secondary pollution problems;

[0038] (5) This method is easy to implement and can be in-situ modified on the existing denitrification process in the sewage treatment plant without affecting the overall sewage denitrification efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0040] Figure 1 It is a schematic structural diagram of the short-cut nitrification-anaerobic ammonium oxidation sewage treatment device described in the present invention;

[0041] Among them, 1 - short - cut nitrification reactor; 1.1 - inlet pump Ⅰ; 1.2 - agitator Ⅰ; 1.3 - dissolved oxygen electrode; 1.4 - pH electrode; 1.5 - on - line ammonia nitrogen detector; 1.6 - on - line nitrite nitrogen detector; 1.7 - sodium hydroxide storage tank; 1.8 - alkali pump; 1.9 - aeration pump; 1.10 - gas flow meter; 1.11 - check valve; 1.12 - aeration disc; 1.13 - sludge discharge valve; 1.14 - sludge storage tank; 1.15 - sludge outlet Ⅰ; 1.16 - sludge inlet Ⅰ; 1.17 - water outlet Ⅰ; 1.18 - outlet pump Ⅰ; 2 - side - stream treatment reactor; 2.1 - sludge pump Ⅰ; 2.2 - sludge inlet Ⅱ; 2.3 - agitator Ⅱ; 2.4 - peracetic acid storage tank; 2.5 - electric dosing valve; 2.6 - sludge outlet Ⅱ; 2.7 - sludge pump Ⅱ; 2.8 - water outlet Ⅱ; 2.9 - outlet pump Ⅱ; 3 - anaerobic ammonium oxidation reactor; 3.1 - inlet pump of anaerobic ammonium oxidation reactor; 4 - PLC system. Detailed implementation mode

[0042] The present invention provides an application of peracetic acid as a short - cut nitrification inhibitor to achieve the reduction of N2O emissions during the short - cut nitrification process, and provide an organic carbon source for in - situ utilization to improve the reduction of nitrate nitrogen.

[0043] The present invention also provides a short - cut nitrification - anaerobic ammonium oxidation sewage treatment device, and the short - cut nitrification - anaerobic ammonium oxidation sewage treatment device includes a short - cut nitrification reactor 1, a side - stream treatment reactor 2 and an anaerobic ammonium oxidation reactor 3.

[0044] In the present invention, the side - stream treatment reactor 2 is provided with a peracetic acid storage tank 2.4, and the peracetic acid storage tank 2.4 contains peracetic acid, and peracetic acid is used as a short - cut nitrification inhibitor;

[0045] In the present invention, the sludge outlet Ⅰ 1.15 of the short - cut nitrification reactor 1 is communicated with the sludge inlet Ⅱ 2.2 of the side - stream treatment reactor 2; the sludge outlet Ⅱ 2.6 of the side - stream treatment reactor 2 is communicated with the sludge inlet Ⅰ 1.16 of the short - cut nitrification reactor 1; the water outlet Ⅰ 1.17 of the short - cut nitrification reactor 1 is communicated with the anaerobic ammonium oxidation reactor 3; the water outlet Ⅱ 2.8 of the side - stream treatment reactor 2 is communicated with the anaerobic ammonium oxidation reactor 3.

[0046] In the present invention, the short - cut nitrification - anaerobic ammonium oxidation sewage treatment device further includes a PLC system 4;

[0047] In the present invention, the shortcut nitrification reactor 1 is provided with a feed water pump I 1.1, a stirrer I 1.2, a dissolved oxygen electrode 1.3, a pH electrode 1.4, an on-line ammonia nitrogen detector 1.5, an on-line nitrite nitrogen detector 1.6, a sodium hydroxide storage tank 1.7, an alkali pump 1.8, an aeration pump 1.9, a gas flowmeter 1.10, a check valve 1.11, an aeration disc 1.12, a sludge discharge valve 1.13, a sludge storage tank 1.14, a sludge outlet I 1.15, a sludge inlet I 1.16, a water outlet I 1.17, and a water discharge pump I 1.18; the dissolved oxygen electrode 1.3, the pH electrode 1.4, the on-line ammonia nitrogen detector 1.5, the on-line nitrite nitrogen detector 1.6, the aeration pump 1.9, and the alkali pump 1.8 are independently electrically connected to the PLC system 4.

[0048] In the present invention, the PLC system 4 detects the dissolved oxygen concentration in the shortcut nitrification reactor 1 through the dissolved oxygen electrode 1.3. When the dissolved oxygen concentration is too low, the PLC system 4 controls the aeration pump 1.9 to increase aeration through the aeration disc 1.12.

[0049] In the present invention, the PLC system 4 detects the pH value in the shortcut nitrification reactor 1 through the pH electrode 1.4. When the pH value is too low, the PLC system 4 controls the alkali pump 1.8 to add sodium hydroxide in the sodium hydroxide storage tank 1.7 to the shortcut nitrification reactor 1 to adjust the pH value.

[0050] In the present invention, the sidestream treatment reactor 2 is provided with a sludge pump I 2.1, a sludge inlet II 2.2, a stirrer II 2.3, a peracetic acid storage tank 2.4, an electric dosing valve 2.5, a sludge outlet II 2.6, a sludge pump II 2.7, a water outlet II 2.8, and a water discharge pump II 2.9; the sludge inlet II 2.2 of the sidestream treatment reactor 2 is connected to the sludge outlet I 1.15 of the shortcut nitrification reactor 1 through the sludge pump I 2.1; the sludge outlet II 2.6 of the sidestream treatment reactor 2 is connected to the sludge inlet I 1.16 of the shortcut nitrification reactor 1 through the sludge pump II 2.7.

[0051] In the present invention, the anaerobic ammonium oxidation reactor 3 is connected to the water outlet I 1.17 of the shortcut nitrification reactor 1 through the water discharge pump I 1.18, and the anaerobic ammonium oxidation reactor 3 is connected to the water outlet II 2.8 of the sidestream treatment reactor 2 through the water discharge pump II 2.9.

[0052] In the present invention, the anaerobic ammonium oxidation reactor 3 is further provided with an anaerobic ammonium oxidation reactor feed water pump 3.1 for introducing the sewage to be treated that does not undergo shortcut nitrification treatment.

[0053] In the present invention, the check valve 1.11 can prevent the backflow of mud and water.

[0054] In the present invention, the structural schematic diagram of the shortcut nitrification-anaerobic ammonium oxidation sewage treatment device is asFigure 1 as shown

[0055] The present invention also provides a short-cut nitrification-anaerobic ammonium oxidation sewage treatment method, which includes the following steps: introducing the sewage to be treated into a short-cut nitrification reactor, maintaining stirring and aeration conditions during water inlet, and performing nitrification reaction; after the water inlet ends, performing aerobic reaction, and after the aerobic reaction ends, performing a first precipitation. The supernatant obtained from the first precipitation is introduced into an anaerobic ammonium oxidation reactor for anaerobic ammonium oxidation reaction, and the sewage treatment for one cycle is completed after the anaerobic ammonium oxidation reaction ends.

[0056] Among them, whether to start the side-stream treatment reactor is judged according to the relative difference e between k(NH4 + ) and k(NO2 - ) of the short-cut nitrification reactor; during the aerobic reaction stage of the short-cut nitrification reactor, if e > 10%, the side-stream treatment reactor is started; if e ≤ 10%, the side-stream treatment reactor is suspended or not started.

[0057] In the present invention, the side-stream treatment reactor is default opened in the first operation cycle.

[0058] Starting the side-stream treatment reactor: Part of the sewage in the current cycle and part of the sewage in the next 1-2 cycles when e > 10% are independently introduced into the side-stream treatment reactor before the aerobic reaction ends and before the first precipitation, and then peracetic acid is added for reaction; after the reaction ends, a second precipitation is performed, and the supernatant obtained from the second precipitation is introduced into the anaerobic ammonium oxidation reactor; the sludge obtained from the second precipitation is introduced into the short-cut nitrification reactor at the beginning of the next operation cycle of the short-cut nitrification reactor.

[0059]

[0060] k(NH4 + ) is the real-time decline slope of the ammonia nitrogen concentration changing with time; k(NO2 - ) is the real-time growth slope of the nitrite nitrogen concentration changing with time.

[0061] In the present invention, the reaction types of the nitrification reaction and the aerobic reaction are the same, and the only difference is whether water is inlet during the reaction process.

[0062] In the present invention, the next 1-2 cycles refer to 1-2 adjacent cycles when e > 10%.

[0063] In the present invention, the purpose of taking the current cycle and the next 1 - 2 cycles when e > 10% is that only 20 - 30% of the total capacity of the shortcut nitrification reactor is discharged each time. If the discharge amount is too high at one time, it will cause excessive instantaneous sludge loss and excessive load in the shortcut nitrification reactor, and the treatment efficiency cannot meet the requirements. If sludge is discharged once in the current cycle when e > 10% and the sidestream treatment is started, the efficiency is too low and it takes too long to completely inhibit NOB and achieve shortcut nitrification (because the time for each sidestream treatment is relatively long, 10 - 12 h), so sludge is discharged in multiple times with small amounts.

[0064] In the present invention, the sewage to be treated is preferably sewage in which inorganic nitrogen mainly exists in the form of ammonia nitrogen, and more preferably municipal sewage.

[0065] In the present invention, the operating time of each cycle of the shortcut nitrification reactor is independently 4 - 6 h, and specifically can be 4.5 h, 5 h, 5.5 h.

[0066] In the present invention, the inflow amount of the sewage to be treated in the shortcut nitrification reactor is 30 - 60% of the total capacity of the shortcut nitrification reactor, and specifically can be 35%, 40%, 45%, 50%, 55%; the water inlet time in each cycle is independently 60 - 90 min, and specifically can be 65 min, 70 min, 75 min, 80 min, 85 min.

[0067] In the present invention, during the nitrification reaction and aerobic reaction, the dissolved oxygen concentration in the shortcut nitrification reactor is independently 2 - 3 mg / L, and specifically can be 2.2 mg / L, 2.4 mg / L, 2.5 mg / L, 2.6 mg / L, 2.8 mg / L; the pH value is independently 6.8 - 7.2, and specifically can be 6.9, 7, 7.1.

[0068] In the present invention, the sludge content in the shortcut nitrification reactor is 1 - 2 g / L, and specifically can be 1.2 g / L, 1.4 g / L, 1.5 g / L, 1.6 g / L, 1.8 g / L.

[0069] In the present invention, when there is excessive sludge, part of the sludge is discharged.

[0070] In the present invention, the part of the sewage introduced into the sidestream treatment reactor in each cycle is independently 20 - 30% of the total capacity of the shortcut nitrification reactor, and specifically can be 22%, 24%, 25%, 26%, 28%.

[0071] In the present invention, when reacting with peracetic acid, the mass concentration of the peracetic acid is 5 - 20 mg / L, and specifically can be 8 mg / L, 10 mg / L, 12 mg / L, 14 mg / L, 15 mg / L, 16 mg / L, 18 mg / L.

[0072] In the present invention, when reacting with peracetic acid, the reaction conditions are dark and airtight conditions; the reaction time is 10 to 12 hours, specifically it can be 10.5 hours, 11 hours, or 11.5 hours.

[0073] In the present invention, the supernatant obtained from the first precipitation and the supernatant obtained from the second precipitation are the sewage to be treated after short-cut nitrification treatment. Untreated sewage that has not undergone short-cut nitrification treatment is additionally introduced into the anaerobic ammonium oxidation reactor for anaerobic ammonium oxidation reaction.

[0074] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0075] Example 1

[0076] In this example, artificially prepared sewage was used to simulate the influent of the short-cut nitrification reactor, with an ammonia nitrogen content of 50 mgN / L and no additional organic carbon source added. The structural schematic diagram of the short-cut nitrification-anaerobic ammonium oxidation sewage treatment device used is as Figure 1 shown.

[0077] The working volume of the shortcut nitrification reactor is 4 L, the single-cycle operation time is 240 min, and it operates 6 cycles per day. First, 2 L of water is continuously fed into the shortcut nitrification reactor within 60 min. While feeding water, the stirrer and aeration pump are turned on. The dissolved oxygen concentration in the shortcut nitrification reactor is controlled between 2 and 3 mg / L, and the pH value is controlled between 6.8 and 7.2 through the PLC system. After the water feeding is completed, the aerobic reaction continues for 120 min, and 0.8 L of the mud-water mixture is discharged to the sidestream treatment reactor. Subsequently, the stirring device and aeration pump are turned off (the sidestream treatment reactor is default open in the first cycle). After the mud and water settle for 40 min, 1.2 L of the supernatant is discharged to the anaerobic ammonium oxidation reactor (the single-cycle 240 min includes: a total reaction of 180 min (where the first 60 min is the reaction while feeding water), sedimentation for 40 min, water discharge for 10 min, and idling for 10 min). After continuously operating for 3 cycles according to the above mode, the shortcut nitrification reactor no longer discharges the mud-water mixture to the sidestream treatment reactor at the end of the aerobic reaction stage, and other operating conditions are the same as the above mode. At the same time, the sidestream treatment reactor has received a total of 2.4 L of the mud-water mixture. Then, the electric dosing valve is opened to add a certain amount of peracetic acid, and its initial concentration is controlled at 20 mg / L. It reacts continuously for 12 h under dark and airtight conditions. Then, the stirrer is turned off. After the sludge in the sidestream treatment reactor settles by gravity for 4 h, the supernatant is discharged to the anaerobic ammonium oxidation reactor, and the sludge settled at the bottom is all refluxed to the shortcut nitrification reactor. After that, the shortcut nitrification reactor starts to discharge the mud-water mixture to the sidestream treatment reactor again at the end of the aerobic reaction stage for another 3 consecutive cycles, and the whole set of devices operates in a cycle according to the above mode. After operating stably for a period of time, the PLC system shows that during the aerobic reaction stage in the shortcut nitrification reactor, the relative difference e between k(NH4 + ) and k(NO2 - ) is ≤ 10%. Then, the operation of the sidestream treatment reactor is suspended. At this time, the average nitrite accumulation rate in the shortcut nitrification reactor reaches more than 92%, and the N2O emission factor within a single cycle is 1.1%. In the traditional autotrophic nitrogen removal reactor operating as a control group, there is no accumulation of nitrite nitrogen, that is, all the ammonia nitrogen in the influent is converted into nitrate nitrogen, and the N2O emission factor within a single cycle is 4.5%. Compared with the traditional autotrophic nitrogen removal process, the method adopted in the present invention can not only effectively achieve shortcut nitrification of sewage, but also reduce the N2O emission by 76%.

[0078] Example 2

[0079] In this embodiment, actual municipal sewage is used as the influent of the shortcut nitrification reactor. Among them, the ammonia nitrogen content is 43 mgN / L, the chemical oxygen demand is 183 mg / L, and other implementation conditions are the same as those of the device and method described in Embodiment 1. After stable operation, no nitrite nitrogen accumulation occurred in the traditional autotrophic nitrogen removal process, and the N2O emission factor in a single cycle was 5.8%; through the operation device and operation method adopted in the present invention, the average nitrite accumulation rate in the shortcut nitrification reactor was 90%, and the N2O emission factor in a single cycle was 1.6%. In comparison, the method adopted in the present invention not only realizes the shortcut nitrification of sewage, but also reduces the N2O emission by 72%.

[0080] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same and similar parts among the various embodiments, reference may be made to each other.

[0081] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The use of peracetic acid as a short-range nitrification inhibitor is characterized in that: It can achieve the reduction of N2O emission in the short-term nitrification process, provide an organic carbon source, realize in-situ utilization, and improve the reduction of nitrate nitrogen.

2. A short-cut nitrification-anaerobic ammonium oxidation sewage treatment device, characterized in that: The short-cut nitrification-anaerobic ammonium oxidation sewage treatment device comprises a short-cut nitrification reactor, a side stream treatment reactor and an anaerobic ammonium oxidation reactor; The side stream treatment reactor is provided with a peracetic acid reserve tank, wherein the peracetic acid reserve tank contains peracetic acid, and the peracetic acid serves as a short-range nitrification inhibitor; The mud outlet I of the short-range nitrification reactor is connected to the mud inlet II of the side stream treatment reactor; The mud outlet II of the side stream treatment reactor is connected to the mud inlet I of the short-range nitrification reactor; The water outlet I of the short-cut nitrification reactor is connected to the anaerobic ammonium oxidation reactor; The water outlet II of the side stream treatment reactor is connected to the anaerobic ammonium oxidation reactor.

3. A short-cut nitrification-anaerobic ammonium oxidation sewage treatment device according to claim 2, characterized in that: The short-cut nitrification-anaerobic ammonium oxidation sewage treatment device also includes a PLC system; The short-range nitrification reactor is provided with a water inlet pump I, an agitator I, a dissolved oxygen electrode, a pH electrode, an online ammonia nitrogen detector, an online nitrite nitrogen detector, a sodium hydroxide storage tank, an alkali pump, an aeration pump, a gas flow meter, a check valve, an aeration plate, a mud discharge valve, a mud storage tank, a mud outlet I, a mud inlet I, a water outlet I, and a water outlet pump I; the dissolved oxygen electrode, the pH electrode, the online ammonia nitrogen detector, the online nitrite nitrogen detector, the aeration pump, and the alkali pump are independently electrically connected to the PLC system; The side stream treatment reactor is provided with a sludge pump I, a sludge inlet II, a stirrer II, a peracetic acid storage tank, an electric dosing valve, a sludge outlet II, a sludge pump II, a water outlet II, and a water outlet pump II; the sludge inlet II of the side stream treatment reactor is connected to the sludge outlet I of the short-range nitrification reactor through the sludge pump I; the sludge outlet II of the side stream treatment reactor is connected to the sludge inlet I of the short-range nitrification reactor through the sludge pump II; The anaerobic ammonium oxidation reactor is connected to the water outlet I of the short-range nitrification reactor through a water outlet pump I, and the anaerobic ammonium oxidation reactor is connected to the water outlet II of the side stream treatment reactor through a water outlet pump II.

4. A short-cut nitrification-anaerobic ammonium oxidation wastewater treatment method, characterized in that: The method comprises the following steps: passing the sewage to be treated into a short-range nitrification reactor, maintaining stirring and aeration conditions during water inflow, and performing a nitrification reaction; after the water inflow is completed, performing an aerobic reaction, performing a first precipitation after the aerobic reaction is completed, and passing the supernatant obtained by the first precipitation into an anaerobic ammonium oxidation reactor for an anaerobic ammonium oxidation reaction, and completing the anaerobic ammonium oxidation reaction to complete a cycle of sewage treatment; Among them, according to the k(NH4 + ) and k(NO2 - ) to determine whether to start the side stream treatment reactor; in the aerobic reaction stage of the short-range nitrification reactor, if e>10%, the side stream treatment reactor is started; if e≤10%, the side stream treatment reactor is suspended or does not need to be started; Starting the side stream treatment reactor: when e>10%, part of the sewage in the current cycle and part of the sewage in the next 1-2 cycles are independently introduced into the side stream treatment reactor after the aerobic reaction is completed and before the first precipitation, and then peracetic acid is added to react; after the reaction is completed, the second precipitation is carried out, and the supernatant obtained by the second precipitation is introduced into the anaerobic ammonia oxidation reactor; the sludge obtained by the second precipitation is introduced into the short-cut nitrification reactor at the beginning of the next operation cycle of the short-cut nitrification reactor; k(NH4 + ) is the real-time decreasing slope of ammonia nitrogen concentration over time; k(NO2 - ) is the real-time growth slope of nitrite nitrogen concentration over time.

5. A short-cut nitrification-anaerobic ammonium oxidation wastewater treatment method according to claim 4, characterized in that: The operation time of each cycle of the short-range nitrification reactor is independently 4 to 6 hours; The amount of sewage to be treated introduced into the short-cut nitrification reactor is 30-60% of the total capacity of the short-cut nitrification reactor, and the water inlet time in each cycle is independently 60-90 minutes.

6. A short-cut nitrification-anaerobic ammonium oxidation wastewater treatment method according to claim 5, characterized in that: During the nitrification reaction and the aerobic reaction, the dissolved oxygen concentration in the short-range nitrification reactor is independently 2-3 mg / L, and the pH value is independently 6.8-7.

2.

7. A short-cut nitrification-anaerobic ammonium oxidation wastewater treatment method according to claim 6, characterized in that: The sludge content in the short-range nitrification reactor is 1-2 g / L.

8. A method for treating wastewater by short-cut nitrification-anaerobic ammonium oxidation according to any one of claims 4 to 7, characterized in that: The portion of sewage introduced into the side stream treatment reactor in each cycle is independently 20-30% of the total capacity of the short-range nitrification reactor.

9. A short-cut nitrification-anaerobic ammonium oxidation wastewater treatment method according to claim 8, characterized in that: When reacting with peracetic acid, the mass concentration of the peracetic acid is 5 to 20 mg / L.

10. A short-cut nitrification-anaerobic ammonium oxidation wastewater treatment method according to claim 9, characterized in that: When reacting with peracetic acid, the reaction conditions are dark and closed conditions; The reaction time is 10 to 12 hours.

Images