High-activity short-cut nitrification rapid start and long-term stable operation technology

Abstract

The invention discloses a high-activity short-cut nitrification quick-start long-term stable operation process, which relates to the technical field of biological sewage treatment, and comprises the following steps: inoculating sludge, carrying out anaerobic fermentation pretreatment, and removing expanded sludge and sludge foam in combination with quick sludge discharge and manual removal; controlling the number of days of sludge age, reproliferating the sludge, enriching ammonia oxidizing bacteria, and inhibiting and elutriating nitrite oxidizing bacteria; long-term operation is carried out under the condition of no sludge discharge, the abundance and activity of ammonia oxidizing bacteria are maintained, and meanwhile, the abundance of nitrite oxidizing bacteria is controlled; the proliferation of nitrite oxidizing bacteria is controlled by using the predation effect of protozoa and metazoan, and the accumulation rate of nitrite in the reactor is controlled; monitoring the dissolved oxygen, the pH value and the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the reactor in real time, and regulating and controlling the influent ammonia nitrogen load and the free ammonia concentration; dissolved oxygen distribution is adjusted in an intermittent aeration or microporous aeration mode, and the operation conditions of the short-cut nitrification reactor are optimized. The method is simple to operate, economical and effective.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage biological treatment, and particularly to a process for rapidly starting up and stably operating in the long term with high-activity short-cut nitrification. Background Art

[0002] With the continuous growth of the population and the improvement of people's living standards, the per capita discharge of domestic sewage continues to increase. Urban sewage generally has insufficient carbon sources and high nitrogen and phosphorus contents. In terms of biological treatment, in the conventional biological nitrogen removal process, aerobic bacteria oxidize NH4 + -N to NO2 - -N and NO3 - -N, and then heterotrophic denitrifying bacteria use carbon sources as electron donors to reduce nitrate nitrogen and nitrite nitrogen to nitrogen gas. During this period, a large amount of aeration and internal reflux energy consumption are required, and a large amount of carbon sources are also consumed, resulting in a relatively high treatment cost.

[0003] Compared with conventional biology, the PN / A process combining short-cut nitrification and anaerobic ammonium oxidation can save aeration, requires no carbon source, and realizes sludge reduction. However, the two major bottlenecks in the actual operation of the PN / A process are, firstly, the stable source of NO2 - -N. The ammonia-oxidizing bacteria AOB and anaerobic ammonium-oxidizing bacteria AMX in the process are sensitive to the environment. It is difficult to inhibit nitrite-oxidizing bacteria NOB during operation. To achieve stable operation, multiple parameters such as dissolved oxygen concentration DO and sludge age need to be precisely controlled, and there may also be substances in the influent that are toxic to microorganisms; secondly, there is a lack of carbon separation means before entering the PN / A process. In the actual operation process, washing out nitrite-oxidizing bacteria and enriching ammonia-oxidizing bacteria to achieve stable nitrite accumulation is the research direction of many research scholars. Currently, there are many effective implementation methods; by controlling the temperature, the growth rate gap between ammonia-oxidizing bacteria and nitrite-oxidizing bacteria is expanded, and at the same time, the sludge age is controlled between the growth cycles of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria to wash out nitrite-oxidizing bacteria; dissolved oxygen concentration DO: the oxygen saturation coefficients of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria are different. By controlling DO below 0.5 mg / L and at the same time controlling the sludge age between the growth cycles of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria, nitrite-oxidizing bacteria are washed out; free ammonia FN and free nitrous nitrogen FNA pretreatment: the differential inhibition of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria by FN and FNA is used to achieve short-cut nitrification; full-load aeration and low sludge age are used to wash out nitrite-oxidizing bacteria, and anaerobic treatment combined with rapid sludge discharge is used to inhibit and wash out nitrite-oxidizing bacteria.

[0004] Currently, the above methods all have some of the following problems: (1) Continuously discharging a large amount of sludge to wash out nitrite-oxidizing bacteria may lead to a decrease in sludge concentration in an environment lacking COD, slow growth of ammonia-oxidizing bacteria genera, and limited abundance. (2) For large volumes of municipal sewage, a large amount of energy consumption will be generated to ensure the temperature. (3) Controlling low DO results in limited nitrification activity, and the system is prone to sludge bulking, causing sludge loss. (4) Using chemical addition and pre-treating with FA and FNA both have limited long-term effects, increase drug costs, and introduce additional pollutants, making it difficult to apply in actual water plants. Among them, anaerobic pretreatment can selectively inhibit nitrite-oxidizing bacteria and combine with rapid sludge discharge to economically and effectively achieve nitrite accumulation, but there are still problems such as low activity and low abundance of ammonia-oxidizing bacteria after enrichment. Summary of the Invention

[0005] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title. However, such simplifications or omissions shall not be used to limit the scope of the present invention.

[0006] In view of the above existing problems, the present invention is proposed.

[0007] Therefore, the present invention provides a high-activity short-cut nitrification process with rapid startup and long-term stable operation, which can solve the problems mentioned in the background technology.

[0008] To solve the above technical problems, the present invention provides the following technical solutions:

[0009] The present invention provides a high-activity short-cut nitrification process with rapid startup and long-term stable operation, which includes,

[0010] As a preferred embodiment of the high-activity short-cut nitrification process with rapid startup and long-term stable operation of the present invention, it includes: inoculating sludge and performing anaerobic fermentation pretreatment, combining rapid sludge discharge and manually removing bulking sludge and sludge foam;

[0011] Controlling the sludge age in days, performing sludge re-growth, enriching ammonia-oxidizing bacteria, and inhibiting and washing out nitrite-oxidizing bacteria;

[0012] Operating for a long time without sludge discharge, maintaining the abundance and activity of ammonia-oxidizing bacteria, and simultaneously controlling the abundance of nitrite-oxidizing bacteria;

[0013] Using the predation of protozoa and metazoa to control the proliferation of nitrite-oxidizing bacteria and controlling the nitrite accumulation rate in the reactor;

[0014] Real-time monitoring of dissolved oxygen, pH value, ammonia nitrogen, nitrite nitrogen and nitrate nitrogen concentrations in the reactor, and regulation of influent ammonia nitrogen load and free ammonia concentration;

[0015] Intermittent aeration or microporous aeration is used to adjust the dissolved oxygen distribution and optimize the operating conditions of the short-range nitrification reactor.

[0016] As a preferred solution of the high-activity short-range nitrification rapid start-up and long-term stable operation process of the present invention, wherein: the inoculated sludge is from the municipal sewage treatment plant A 2 The aerobic sludge of the O process is added with anaerobic fermentation acid sludge. Long-term natural sedimentation is used for inoculation. The dense sludge after sedimentation for 24 hours is taken and subjected to anaerobic exposure. The inoculation sludge concentration in the reactor is controlled to be 10000-8000 mg / L, the inoculation filling ratio is 100%, and the inoculation sludge concentration reaches 8-8.5 g / L after sedimentation and concentration.

[0017] As a preferred scheme for the high-activity short-range nitrification rapid start-up and long-term stable operation process of the present invention, the anaerobic fermentation pretreatment stage maintains a local anoxic environment through trace aeration, controls the dissolved oxygen concentration to 0.2 mg / L, and provides an ammonia nitrogen matrix to retain ammonia oxidizing bacteria and inhibit nitrite oxidizing bacteria.

[0018] As a preferred solution for the high-activity short-range nitrification rapid start-up and long-term stable operation process of the present invention, the rapid sludge discharge stage shortens the sedimentation time to 20-40 minutes, manually removes expanded sludge and sludge foam, and controls the sludge age to less than 7 days.

[0019] As a preferred scheme for the high-activity short-range nitrification rapid start-up and long-term stable operation process described in the present invention, the sludge regeneration stage controls the dissolved oxygen concentration within the range of 0.2-0.5 mg / L, stops sludge discharge and maintains the free ammonia concentration, selectively enriches ammonia oxidizing bacteria and inhibits nitrite oxidizing bacteria.

[0020] As a preferred solution of the high-activity short-range nitrification rapid start-up and long-term stable operation process of the present invention, the predation effect of protozoa and metazoa is enhanced by adding trace elements to the influent, and the trace elements include zinc ions, manganese ions and molybdenum ions.

[0021] As a preferred solution for the high-activity short-range nitrification rapid start-up and long-term stable operation process of the present invention, the intermittent aeration method uses a microporous aeration disk for aeration, and the aeration volume is adjusted by a gas flow meter to control the dissolved oxygen distribution gradient in the reactor.

[0022] As a preferred embodiment of the process for rapid start-up and long-term stable operation of high-activity short-cut nitrification of the present invention, wherein: the short-cut nitrification reactor is a sequencing batch SBR reactor, and the short-cut nitrification reactor operates 4-6 cycles per day, and each cycle includes a water inlet, aerobic stirring, sedimentation, drainage and idle stages.

[0023] As a preferred embodiment of the process for rapid start-up and long-term stable operation of high-activity short-cut nitrification of the present invention, wherein: under the stable operation conditions of the short-cut nitrification reactor, the nitrite accumulation rate is maintained above 90%, the abundance of ammonia-oxidizing bacteria exceeds 30%, and the continuous operation time of the reactor.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: the start-up of a high-activity and high-abundance short-cut nitrification reactor can be achieved by anaerobic treatment of high-concentration sludge, rapid sludge discharge and inhibition of sludge regrowth in the environment. After coupling with an anaerobic ammonia oxidation reactor, the short-cut nitrification and anaerobic ammonia oxidation process can be realized; the stable influent conditions for anaerobic ammonia oxidation are provided by high-activity short-cut nitrification, shortening the treatment cycle. During short-cut nitrification, intermittent aeration and other methods can be used to achieve the combination of more processes (intermittent aeration, partial denitrification, biofilm) to achieve the removal of total nitrogen and the degradation of COD, with simple operation, economy and effectiveness. Brief Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a running time diagram of a process for rapid start-up and long-term stable operation of high-activity short-cut nitrification provided by an embodiment of the present invention. Detailed Embodiments

[0027] In order to make the above objects, features and advantages of the present invention more comprehensible, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings of the specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0029] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that may be included in at least one implementation manner of the present invention. The "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an individual or alternative embodiment that is mutually exclusive with other embodiments.

[0030] Embodiment 1 is an embodiment of the present invention. This embodiment provides a high-activity short-cut nitrification process for rapid startup and long-term stable operation, including:

[0031] This application can effectively solve the above-mentioned problems. Next, multiple embodiments will be combined to elaborate in detail how to implement the high-activity short-cut nitrification process for rapid startup and long-term stable operation, including:

[0032] Inoculate sludge and perform anaerobic fermentation pretreatment, combined with rapid sludge discharge and manual removal of expanded sludge and sludge foam;

[0033] Control the sludge age days, perform sludge re-proliferation, enrich ammonia-oxidizing bacteria, and inhibit and elutriate nitrite-oxidizing bacteria;

[0034] Operate for a long time without sludge discharge, maintain the abundance and activity of ammonia-oxidizing bacteria, and at the same time control the abundance of nitrite-oxidizing bacteria;

[0035] Utilize the predation of protozoa and metazoa to control the proliferation of nitrite-oxidizing bacteria and control the nitrite accumulation rate in the reactor;

[0036] Real-time monitor the dissolved oxygen, pH value, ammonia nitrogen, nitrite nitrogen and nitrate nitrogen concentrations in the reactor, and regulate the influent ammonia nitrogen load and free ammonia concentration;

[0037] Adopt intermittent aeration or microporous aeration to adjust the dissolved oxygen distribution and optimize the operating conditions of the short-cut nitrification reactor.

[0038] Furthermore, the inoculated sludge is the aerobic sludge of the A 2 O process of a municipal wastewater treatment plant, and anaerobic fermentation acid-producing sludge is added. When inoculating, long-term natural precipitation is adopted, the dense sludge after 24 hours of precipitation is taken and subjected to blank aeration, the concentration of the inoculated sludge in the reactor is controlled to be 10,000 - 8,000 mg / L, the inoculation filling ratio is 100%, and the concentration of the inoculated sludge reaches 8 - 8.5 g / L after sedimentation and concentration.

[0039] Furthermore, in the anaerobic fermentation pretreatment stage, local anoxic environment is maintained by micro-aeration, the dissolved oxygen concentration is controlled to be 0.2 mg / L, and at the same time ammonia nitrogen substrate is provided to retain ammonia-oxidizing bacteria and inhibit nitrite-oxidizing bacteria.

[0040] Furthermore, during the rapid sludge discharge stage, the sedimentation time is shortened to 20 - 40 minutes, the expanded sludge and sludge foam are removed manually, and the sludge age is controlled below 7 days.

[0041] Furthermore, during the sludge re - proliferation stage, the dissolved oxygen concentration is controlled within the range of 0.2 - 0.5 mg / L, sludge discharge is stopped and the free ammonia concentration is maintained to selectively enrich ammonia - oxidizing bacteria and inhibit nitrite - oxidizing bacteria.

[0042] Furthermore, the predation of protozoa and metazoa is enhanced by adding trace elements to the influent water, and the trace elements include zinc ions, manganese ions, and molybdenum ions.

[0043] Furthermore, the concentrations of dissolved oxygen, pH value, ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen in the reactor are monitored in real - time, and precise control is achieved by adjusting the influent ammonia - nitrogen load and the aeration volume.

[0044] Furthermore, the intermittent aeration method uses a microporous aeration disk for aeration, and the aeration volume is adjusted by a gas flow meter to control the dissolved oxygen distribution gradient in the reactor.

[0045] Furthermore, the shortcut nitrification reactor is a sequencing batch SBR reactor. The shortcut nitrification reactor operates 4 - 6 cycles per day, and each cycle includes an influent water stage, an aerobic stirring stage, a sedimentation stage, a drainage stage, and an idle stage.

[0046] Furthermore, under the stable operating conditions of the shortcut nitrification reactor, the nitrite accumulation rate is maintained above 90%, the abundance of ammonia - oxidizing bacteria exceeds 30%, and the continuous operating time of the reactor.

[0047] Example 2 is an example of the present invention. This example provides a high - activity shortcut nitrification rapid start - up and long - term stable operation process, including:

[0048] A device and method for anaerobic treatment of high - concentration sludge combined with rapid sludge discharge for sludge screening, and then no longer discharging sludge for sludge re - proliferation to rapidly achieve high - rate shortcut nitrification. The main device used is composed of a sequencing batch SBR reactor, an aeration pump, a gas rotameter, a water inlet pump, an electric stirring paddle, a microporous aeration disk, a dissolved oxygen probe, a pH probe, a DO / pH detector, a drainage pump, and a time - control device. The processes of influent water, stirring, aeration, sedimentation, and effluent water are all completed by a pre - designed time - control switch.

[0049] The artificial water - distribution water tank is connected to the SBR reactor through a first water pump;

[0050] The sequencing batch SBR reactor is equipped with an aeration pump, a gas rotameter, a microporous aeration disk, a stirrer, a pH probe, a DO probe, a pH and DO monitor;

[0051] According to claim 1, a device and method for sludge re-proliferation to rapidly obtain short-cut nitrification with high abundance of AOB and high activity by anaerobic fermentation of high-concentration sludge combined with rapid sludge discharge for sludge screening, which is characterized by the following contents:

[0052] The inoculated sludge includes: part of the inoculated sludge in the short-cut nitrification SBR reactor is the whole-process nitrification sludge of A2O in the urban sewage treatment plant. When inoculating, the sludge concentration is greatly increased by means of long-term natural precipitation. The dense sludge after 24 hours of precipitation is taken for anaerobic aeration, and the sludge after further precipitation is taken. The inoculated sludge concentration in the reactor is controlled at 10000-8000 mg / L, and the inoculated filling ratio is 100%.

[0053] The influent configuration includes: providing trace elements such as manganese and zinc and ammonia nitrogen in the influent to ensure FA inhibition in the reactor, and at the same time providing trace elements to promote the predation of bacteria by protozoa and metazoa.

[0054] The SBR reactor is operated at 30-35 °C, controlling DO = 0-0.2 mg / L, and full aeration is carried out within a 6-hour cycle, with each aeration time being 5 hours. Short-cut nitrification is started at an influent ammonia nitrogen concentration of 100-200 mg / L. After 3-7 days of anaerobic treatment with low aeration volume, the nitrification activity of the reactor is completely inhibited due to too low DO. After the sludge lysis and endogenous respiration stage ends and the effluent ammonia nitrogen is lower than the influent, the start of the short-cut nitrification process can be started.

[0055] The reactor operates 4-6 cycles per day; the reactor operation cycle includes influent for 10 minutes, aerobic stirring for 4 hours and 50 minutes or 2 hours and 50 minutes, sedimentation for 40 minutes, drainage for 10 minutes, and idling for 10 minutes. The total is 6-4 hours. During the start-up period, 6 hours are used. After the reactor starts successfully, due to high activity and the need to control the effluent ratio, the cycle time can be adjusted, such as reducing the aerobic stirring and sedimentation time, and adjusting the cycle to 4 hours.

[0056] The specific operation steps of one cycle are as follows:

[0057] Influent stage: Water is fed from the original water tank through the influent pump, and the set influent volume is 40% of the effective volume of the reactor, and the influent time is 10 minutes.

[0058] Aerobic stirring operation stage for 3 - 5h: After the water inlet is completed, it enters the aerobic operation stage. Aeration can be carried out through a sintered core aeration head. In the stable operation stage, to ensure stable effluent and achieve stable control of the ratio of nitrite nitrogen to ammonia nitrogen in the effluent, a microporous aeration disc is required to ensure stable aeration efficiency, and at the same time, a gas flow meter is used to control the aeration volume; stirring is achieved through a stirrer, controlling the stirring speed and aeration volume to ensure that the DO in the reactor is stable at 0.2mg / L; during this period, the ammonia oxidation rate, nitrite accumulation rate, nitrate, nitrite, and ammonia concentrations in the effluent of the reactor all change violently with the anaerobic treatment stage, rapid sludge discharge stage, and sludge re - proliferation stage during startup.

[0059] After aeration, it enters the sedimentation and drainage idle stage. During startup, affected by the sludge concentration and anaerobic environment, the SV30 of the sludge in the reactor is close to 60%, there is anaerobic sludge bulking and sludge foam, and sludge lysis and endogenous respiration are still ongoing, resulting in a large amount of floating sludge and flocs carried in the effluent. By reducing the sedimentation time to 20min, the sludge with poor sedimentation performance is discharged with the effluent. At the same time, manually use a fine fishing net to remove and discard the sludge foam on the water surface and the suspended flocs in the supernatant; after two rapid sludge discharges and sludge re - proliferation in the reactor, the sludge sedimentation performance is greatly improved, and the effluent becomes clear.

[0060] The system enters the next cycle and repeats the b - c stage;

[0061] It should be noted that the time - control device controls the processes of reactor water inlet, stirring, aeration, and drainage.

[0062] The present invention is a device and method for high - concentration sludge anaerobic fermentation pretreatment combined with rapid sludge discharge with a short sludge age and sludge re - proliferation to rapidly achieve shortcut nitrification and obtain shortcut nitrification sludge with a high abundance of AOB and high activity. The present invention has the following advantages:

[0063] This process uses high - concentration full - scale nitrification sludge as inoculated sludge, has no special requirements for the inoculated aerobic sludge, can use the concentrated sludge in the sedimentation tank in situ, and anaerobic treatment of it can save energy by providing a small amount of aeration and stirring. During the anaerobic treatment process, two methods can be adopted: providing substrates such as ammonia nitrogen and not providing substrates. Aeration can also be carried out by using the endogenous respiration of sludge to consume oxygen while providing a small amount of aeration and stopping aeration for only anaerobic stirring. The difference between the two is that providing a small amount of aeration can maintain a local anoxic environment during anaerobic treatment to ensure the survival of AOB, but at the same time, it is easy to cause the retention of NOB, which is difficult to completely remove through subsequent processes.

[0064] After anaerobic treatment, due to the high sludge concentration, sludge lysis and endogenous respiration occur, resulting in the proliferation of anaerobic bacteria.

[0065] The sludge concentration decreases, and the microorganisms are jointly inhibited by factors such as FA and predation. During the subsequent re-proliferation process, the abundance of AOB increases rapidly, while the abundance of NOB decreases sharply. During this period, substrate-free anaerobic treatment can be used to completely wash out NOB, and then the re-proliferation of AOB can be carried out to enrich AOB. No chemicals need to be added during the enrichment startup process, and the main operation processes can be achieved in a regulated form through stirring, aeration, sludge discharge, manual removal of floating sludge foam, and addition of trace elements. The operation is simple, economical, and effective.

[0066] To ensure the stable operation of the reactor, the aeration volume needs to be adjusted according to factors such as the actual operating temperature. Due to the high sludge activity, it is necessary to ensure the supply of DO. At the same time, to avoid the proliferation of NOB caused by the increase in DO, stable and effective aeration facilities such as microporous aeration discs need to be used. The reactor needs to maintain the DO below 0.2 mg / L. At the same time, with high sludge activity, microporous aeration discs can be used for aeration, which can stably control DO while stably supplying oxygen, save the aeration volume, achieve the differential growth of AOB and NOB, and provide stable and sufficient oxygen. Or intermittent aeration can be used to achieve the simultaneous decarbonization and ammonia oxidation of the actual wastewater, and at the same time stably control the effluent ratio to provide good influent conditions for the subsequent anaerobic ammonia oxidation.

[0067] After the enrichment of high-abundance AOB sludge, the short-cut nitrification activity reaches 100 mgN / gMLVSS·h, which puts forward higher requirements for the aeration efficiency. At the same time, its reaction rate increases significantly, and the volumetric activity can reach 128 gN / m3·h, reducing the demand for HRT in actual operation. And due to the good enrichment effect, no sludge discharge is required, which helps to reduce the capital investment and provide sufficient space for the subsequent in-depth treatment of anaerobic ammonia oxidation, and also provides sufficient potential to resist low-temperature operation.

[0068] After the reactor is anaerobically started with highly concentrated aerobic sludge, sludge lysis, sludge bulking, and sludge endogenous respiration occur, generating a large amount of sludge flocs, which provide food for protozoa and metazoa. After the startup process, the remaining protozoa and micro-metazoa are strengthened by trace elements for predation and tend to prey on NOB during the long-term sludge discharge-free operation of the reactor. And the AOB community abundance exceeds 30% and grows rapidly and stably in a suitable operating environment.

[0069] When NOB proliferation occurs after the reactor has been operating for a long time or the influent introduces NOB bacteria, resulting in an increase in nitrate nitrogen in the effluent, the predation of protozoa and metazoa can play a role in continuously washing out NOB bacteria. When a large amount of NOB proliferation occurs, a similar startup method can be used to re-start the sludge, or anaerobic treatment, introduction of protozoa and micro-metazoa, etc. can be used to kill NOB, and the AOB bacteria enter the proliferation stage again after treatment.

[0070] Example 3, referring to Figure 1, which is an embodiment of the present invention. This embodiment provides a process for rapid start-up and long-term stable operation of high-activity short-cut nitrification. To verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0071] The reactor used in this method is an SBR, which is cylindrical in shape, with an effective volume of 5L and is made of glass. The outer layer is a circulating water bath layer to control the temperature at 22 - 33°C. A microporous aeration disk is installed at the bottom of the reactor, and the required dissolved oxygen can be controlled by adjusting the flow meter. The stirrer ensures the mixing of mud and water during the reaction, and the inlet and outlet pumps are controlled by a time-controlled switch set. The influent contains ammonia nitrogen and trace elements.

[0072] The specific situation of the influent water quality during the experiment is as follows in the table:

[0073] Table 1 Influent Water Quality Table

[0074]

[0075]

[0076] Table 2 Composition Table of Trace Elements

[0077]

[0078] During the operation of the system, the sewage treatment process is as follows: The artificial water distribution in the inlet water tank is pumped into the short-cut nitrification reactor by the inlet pump, and the whole process is aerated by the aeration pump through the microporous aeration disk. At the same time, the aeration volume is controlled for anoxic stirring, and the DO is controlled within the range of 0.1 - 0.2. The anaerobic environment of the reactor is maintained by the rapid consumption of dissolved oxygen by the high-activity sludge and the adjustment of the aeration volume. After the anaerobic treatment, rapid sludge discharge, and sludge re-proliferation stages during the start-up period, stable short-cut nitrification can be achieved by adjusting the effluent ammonia nitrogen concentration and operating conditions such as intermittent aeration.

[0079] The device and method for anaerobic fermentation of high-concentration sludge combined with rapid sludge discharge and sludge re-proliferation are characterized by the following contents:

[0080] Start-up of short-cut nitrification:

[0081] First, high-concentration full-scale nitrification sludge is inoculated in the reactor: The inoculated nitrification sludge is the aerobic sludge of the A2 / O treatment process of a certain urban sewage treatment plant. After precipitation and concentration, the sludge concentration in the inoculated reactor is 8 - 8.5 g / L;

[0082] The working volume of the sequencing batch reactor is 5L;

[0083] The influent is artificially prepared and includes ammonia nitrogen, sodium bicarbonate and trace elements. The influent NH4+-N is 150-200 mg / L. It operates for 4-6 cycles per day, and the influent-to-effluent ratio is 2 / 5.

[0084] Short-cut nitrification is started under the normal temperature condition of 32°C. The artificially prepared influent is pumped from the influent tank into the reactor by an influent pump for 10 minutes.

[0085] The reactor starts aeration and agitation to control the aeration volume to achieve a DO lower than 0.2 mg / L. During the operation cycle, ensure that the effluent ammonia nitrogen concentration maintains an FA inhibition environment. During the precipitation stage of startup, it is necessary to control the precipitation time to eliminate the sludge with poor precipitation performance. After drainage, it enters the next cycle after the idle stage.

[0086] The initially inoculated high-concentration sludge needs to be anaerobically treated through the anaerobic fermentation stage. Since the inoculated sludge concentration reaches 8 g / L, due to the influence of the actual precipitation performance, a large amount of sludge loss is likely to occur during this period, resulting in a gradual decrease in the sludge concentration. At the same time, in this stage, micro-aeration without ammonia nitrogen substrate and micro-aeration with ammonia nitrogen substrate can be used to deplete the dissolved oxygen by the endogenous respiration of the sludge for anaerobic treatment. The complete killing of NOB can be achieved without ammonia nitrogen, while the effective retention of AOB can be achieved with ammonia nitrogen substrate, but there is a disadvantage of NOB residue. At the same time, due to the continuous supply of DO in the reactor, aerobic microorganisms continuously utilize the internal carbon source, resulting in aerobic starvation and then lysis and death. The dead microorganisms provide organic matter and polysaccharides in the reactor, which are utilized by anaerobic microorganisms for anaerobic fermentation, and heterotrophic anaerobic bacteria are retained. After treatment, it enters the rapid sludge discharge stage;

[0087] In the rapid sludge discharge stage, manual sludge discharge is carried out daily to ensure that the SRT is lower than 10 d. At the same time, due to the reactor being in a low dissolved oxygen environment, sludge bulking occurs, generating sludge foam. Manually clean the sludge foam on the surface of the reactor, shorten the precipitation time, and discharge the expanded sludge that is difficult to precipitate, so that the sludge concentration rapidly decreases and the SRT is lower than 7 d. The effluent ammonia nitrogen gradually rises, the nitrate nitrogen rapidly rises and then rapidly decreases due to sludge loss, and the NAR rapidly rises to 90% (rapid accumulation of nitrite nitrogen occurs, resulting in a decrease in pH. At this point, sufficient sodium bicarbonate is added to the influent to provide alkalinity). Wait until the effluent nitrate nitrogen is extremely low or disappears (during this period, anaerobic treatment and other methods can be used to completely kill NOB), and then enter the sludge re-proliferation stage.

[0088] During the sludge regrowth stage, since the sludge concentration is lower than 1 g / L, it is necessary to further control the aeration volume to control the effluent ammonia nitrogen concentration to maintain the inhibitory environment of the reactor, and stop sludge discharge to achieve selective AOB growth. The abundance of NOB itself is extremely low and it is difficult to effectively grow due to inhibition. When the nitrite nitrogen in the effluent gradually rises after the growth of AOB, and the abundance of AOB exceeds 40% after regrowth, this process can be re-performed for secondary regrowth to achieve sludge washing, optimize sedimentation performance, and improve activity. After the regrowth is completed, due to good sedimentation performance, there is no longer sludge loss in the reactor, and at the same time, manual sludge discharge is no longer carried out. The reactor operates stably. During the stable operation of the reactor, NAR is stable at 90%. After stable operation, the short-cut nitrification activity of the sludge can reach 100 - 200 mgN / g(VSS)·h, while the nitrite oxidation activity is difficult to detect and is still lower than 0.5 mgN / g(VSS)·h after long-term operation;

[0089] The reactor is successfully started within 40 - 60 days. After the reactor operates stably and the sludge concentration rises, stable effluent at different temperatures can be achieved by simultaneously regulating the temperature and aeration volume to provide an effective influent environment for AMX. At the same time, there are protozoa and micro-metazoans in the reactor for predation. Despite potential NOB ingestion, preferential predation can still be carried out to achieve control of the NOB genus.

[0090] Since the obtained sludge has a very high AOB abundance and a large AOB activity potential, the reactor has a strong resistance to adverse environments such as FA inhibition, FNA inhibition, low DO environment, low temperature, and low alkalinity. After operating in a harmful environment, it can still ensure the treatment effect and can be effectively restored by operating without sludge discharge.

[0091] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limitations. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

[0092] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript.

[0093] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing device produce a means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0094] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including an instruction means that implements the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0095] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0096] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0097] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and modifications.

Claims

1. A process for rapid start-up and long-term stable operation of high-activity short-range nitrification, characterized in that: Including, Inoculating sludge and performing anaerobic fermentation pretreatment, combined with rapid sludge discharge and manual removal of bulking sludge and sludge foam; Controlling the sludge age days, performing sludge re-proliferation, enriching ammonia-oxidizing bacteria, and inhibiting and elutriating nitrite-oxidizing bacteria; Operating for a long time without sludge discharge, maintaining the abundance and activity of ammonia-oxidizing bacteria, and at the same time controlling the abundance of nitrite-oxidizing bacteria; Using the predation of protozoa and metazoa to control the proliferation of nitrite-oxidizing bacteria and controlling the nitrite accumulation rate in the reactor; Real-time monitoring of the dissolved oxygen, pH value, ammonia nitrogen, nitrite nitrogen and nitrate nitrogen concentrations in the reactor, and regulating the influent ammonia nitrogen load and free ammonia concentration; Adopting intermittent aeration or microporous aeration methods to adjust the dissolved oxygen distribution and optimizing the operating conditions of the shortcut nitrification reactor.

2. The high-activity short-cut nitrification rapid start-up and long-term stable operation process according to claim 1, characterized in that: The inoculated sludge is the aerobic sludge of the A / O process in a municipal wastewater treatment plant, and anaerobic fermentation acid-producing sludge is added. During inoculation, long-term natural sedimentation is adopted, and the dense sludge after 24 hours of sedimentation is taken and subjected to blank aeration. The concentration of the inoculated sludge in the reactor is controlled to be 10,000 - 8,000 mg / L, and the inoculation filling ratio is 100%. The concentration of the inoculated sludge reaches 8 - 8.5 g / L after sedimentation and concentration. 2 O process aerobic sludge, and anaerobic fermentation acid-producing sludge is added. When inoculating, long-term natural sedimentation is used, and the dense sludge after 24 hours of sedimentation is taken and subjected to blank aeration. The concentration of the inoculated sludge in the reactor is controlled to be 10,000 - 8,000 mg / L, and the inoculation filling ratio is 100%. The concentration of the inoculated sludge reaches 8 - 8.5 g / L after sedimentation and concentration.

3. The high-activity short-range nitrification rapid start-up and long-term stable operation process according to claim 2, characterized in that: In the anaerobic fermentation pretreatment stage, a local anoxic environment is maintained through micro-aeration, the dissolved oxygen concentration is controlled at 0.2 mg / L, and at the same time an ammonia nitrogen substrate is provided to retain ammonia-oxidizing bacteria and inhibit nitrite-oxidizing bacteria.

4. The high-activity short-range nitrification rapid start-up and long-term stable operation process according to claim 3, characterized in that: In the rapid sludge discharge stage, the sedimentation time is shortened to 20 - 40 minutes, the bulking sludge and sludge foam are manually removed, and the sludge age is controlled below 7 days.

5. The process for rapid start-up and long-term stable operation of highly active short-cut nitrification according to claim 4, characterized in that: In the sludge re-proliferation stage, the dissolved oxygen concentration is controlled within the range of 0.2 - 0.5 mg / L, sludge discharge is stopped and the free ammonia concentration is maintained, selectively enriching ammonia-oxidizing bacteria and inhibiting nitrite-oxidizing bacteria.

6. The high-activity short-range nitrification rapid start-up and long-term stable operation process according to claim 5, characterized in that: The predation of protozoa and metazoa is strengthened by adding trace elements to the influent, and the trace elements include zinc ions, manganese ions and molybdenum ions.

7. The high-activity short-cut nitrification rapid start-up and long-term stable operation process according to claim 6, characterized in that: The real-time monitoring of the dissolved oxygen, pH value, ammonia nitrogen, nitrite nitrogen and nitrate nitrogen concentrations in the reactor is precisely controlled by adjusting the influent ammonia nitrogen load and the aeration volume.

8. The high-activity short-cut nitrification rapid start-up and long-term stable operation process according to claim 7, characterized in that: The intermittent aeration method uses a microporous aeration disk for aeration, and the aeration volume is adjusted through a gas flow meter to control the dissolved oxygen distribution gradient in the reactor.

9. The high-activity short-range nitrification rapid start-up and long-term stable operation process according to claim 8, characterized in that: The shortcut nitrification reactor is a sequencing batch SBR reactor, and the shortcut nitrification reactor operates 4 - 6 cycles per day, and each cycle includes an influent stage, an aerobic stirring stage, a sedimentation stage, a drainage stage and an idle stage.

10. The high-activity short-cut nitrification rapid start-up and long-term stable operation process according to claim 9, characterized in that: Under the stable operating conditions of the shortcut nitrification reactor, the nitrite accumulation rate is maintained above 90%, the abundance of ammonia-oxidizing bacteria exceeds 30%, and the continuous operating time of the reactor.

Images