A method and apparatus for treating high-salinity nitrogen-containing wastewater

Abstract

The application discloses a high-salt nitrogen-containing sewage treatment method, which comprises the following steps: adding filler rich in biofilm into a reactor main body; pumping high-salt nitrogen-containing sewage into the reactor main body by using a peristaltic pump; continuously monitoring the change of ammonia nitrogen and nitrate nitrogen concentration in effluent; the hydraulic retention time of the first stage is a first preset time; after the sewage treatment rate reaches a preset value, detecting complete ammonia-oxidizing bacteria in the reactor by using a real-time quantitative PCR technology, judging whether the filler successfully enriches the complete ammonia-oxidizing bacteria or not, and if the filler successfully enriches the complete ammonia-oxidizing bacteria, entering the second stage, and reducing the hydraulic retention time of each day to a second preset time. The application has the advantages of simple structure, simple operation, low cost and good treatment effect on high-salt nitrogen-containing sewage by enriching the complete ammonia-oxidizing bacteria.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of microorganism enrichment, and particularly relates to a high-salt nitrogen-containing sewage treatment method and device. BACKGROUND

[0002] Coastal areas are accelerating the use of seawater for various municipal applications to alleviate the shortage of freshwater resources, so a large amount of high-salt wastewater (Cl - >1000mg / L) is generated. In addition, the N element is an important indicator for detecting the effect of sewage treatment, so how to treat high-salt nitrogen-containing wastewater at low cost has become a hot spot in the field of water treatment in coastal areas.

[0003] Since the pioneering work of Winogradsky, nitrifying microorganisms have been generally considered as a special chemoautotroph that obtains growth energy by oxidizing NH4 + or nitrite. The known ammonia-oxidizing microorganisms (AOM) and nitrite-oxidizing bacteria (NOB) are not closely related in phylogeny and cannot simultaneously oxidize both substrates. The separation of the two nitrification steps in different organisms leads to a close cross-feeding interaction, which is often observed as the coexistence of AOM and NOB during nitrification. However, the energy produced by the functionally separated nitrification process (ΔG°' = -275 kJ mol -1 , NH4 - to NO2 - and ΔG°' = -74 kJ mol -1 , NO2 - to NO3 - ) is less than that produced by the complete ammonia oxidation process (ΔG°' = -349 kJ mol -1 NH3), so the complete ammonia oxidation bacteria (comammox) have a greater growth advantage than AOM and NOB [2] .

[0004] In 2015, Daims isolated and identified the existence of complete nitrifying bacteria, which use NH4 + as the only nitrogen source and bicarbonate as the only carbon source, and only a small amount of NO2 - is generated under the condition of 10 μM, and there is no loss of N element in the form of gas in all culture experiments, and it is further inferred that NO2 - will not be generated in actual treatment. Further experiments show that the addition of NO2 - during the comammox treatment process will not lead to further oxidation of nitrite, and in the absence of NH4 + , the metabolic activity and biosynthesis process will eventually stop.

[0005] Candidatus nitrospira, as a comammox, is found to be widely distributed in various sewage and drinking water treatment systems. Studies have found that comammox is widely present in drinking water systems in Asia and North America. In addition, Nitrispira is also found in activated sludge in sewage plants, and maintains high abundance and diversity. Based on the results of genomic sequence studies, comammox bacteria have high metabolic diversity, and their abundance is higher than that of AOB bacteria in some environments, indicating their potential in sewage treatment. At the same time, comammox is also found in saltwater (such as coastal waters, saline lake sediments), indicating that it has certain tolerance to high-salt sewage and can be used for the treatment of high-salt nitrogen-containing sewage. However, there is currently less research on comammox, so how to enrich and cultivate it in a reactor and use it to treat high-salt nitrogen-containing sewage is still a problem. At the same time, it is also very important to reduce costs while maintaining high treatment efficiency.

[0006] In Chinese patent application (CN 109851064 A) “Batch full process nitration bacteria enrichment device based on soft filler and method thereof”, a method for enriching comammox bacteria in a soft filler batch reactor is disclosed. The reactor body is a cylindrical tank, the inside of which is filled with soft filler. A reflux port is provided at the bottom of the reactor, and the reflux pump can continuously lift the reflux liquid from the bottom to the top of the reactor, thereby realizing internal circulation of the reactor and increasing the contact between the activated sludge and the soft filler. Compared with traditional stirring by stirring tank, the disturbance to the reactor is reduced, and the environmental conditions of the reactor are ensured to be most suitable for the growth of full nitration bacteria by controlling pH and temperature. However, the construction and operation of the reactor are very complicated, which increases the cost, and the actual treatment effect is not indicated. SUMMARY

[0007] In view of this, the present application provides a high-salt nitrogen-containing sewage treatment device for treating sewage by culturing and enriching complete ammonia oxidation bacteria.

[0008] According to one aspect of the present application, a high-salt nitrogen-containing sewage treatment method is provided, comprising:

[0009] adding filler enriched with biofilm into the reactor body;

[0010] pumping high-salt nitrogen-containing sewage into the reactor body using a peristaltic pump to culture complete ammonia oxidation bacteria, and continuously monitoring the changes in ammonia nitrogen and nitrate nitrogen concentrations in the effluent; the hydraulic retention time of the first stage is a first preset time per day;

[0011] After the sewage treatment rate reaches the preset value, the full ammonia oxidation bacteria in the reactor are detected by real-time quantitative PCR technology to determine whether the filler successfully enriches full ammonia oxidation bacteria, and if the filler successfully enriches full ammonia oxidation bacteria, the hydraulic retention time is reduced to a second preset time every day.

[0012] In the high-salt nitrogen-containing sewage treatment method provided by the application, during the treatment process, the temperature in the reactor body is 20 DEG C, the dissolved oxygen concentration in the water is higher than 6 mg / L, and the pH value is 7.5-8.5.

[0013] In the high-salt nitrogen-containing sewage treatment method provided by the application, before the filler enriched with the biofilm is added into the reactor body, the filler is soaked in an aerobic tank of a sewage treatment plant, and the filler is pretreated.

[0014] In the high-salt nitrogen-containing sewage treatment method provided by the application, the specific surface area of the filler is greater than or equal to 800 m 2 / m 3 .

[0015] In the high-salt nitrogen-containing sewage treatment method provided by the application, the first preset time is 20 hours, and the second preset time is 2.85 hours.

[0016] According to another aspect of the application, another high-salt nitrogen-containing sewage treatment device comprises a reactor body, a water inlet pipe, a water outlet pipe, an air pump, an aeration device, a pH value detection module, a peristaltic pump, a dissolved oxygen detection module and a filler, one end of the water inlet pipe is connected to the reactor body, the other end is connected to the peristaltic pump, and the water inlet amount is controlled by the peristaltic pump; one end of the water outlet pipe is connected to the reactor body; the aeration device, the pH value detection module and the dissolved oxygen detection module are arranged at the bottom of the reactor body, and the air pump is connected to the aeration device; the pH value detection module is used for real-time monitoring of the pH value of the liquid in the reactor body; the dissolved oxygen detection module is used for real-time monitoring of the dissolved oxygen content of the liquid in the reactor body; the air pump is used for pumping air into the reactor, so that the dissolved oxygen content of the liquid in the reactor is greater than a first preset value; the filler is suspended in the reactor body; and the filler is used for enriching full ammonia oxidation bacteria to treat the high-salt nitrogen-containing sewage.

[0017] In the high-salt nitrogen-containing sewage treatment device provided by the application, a thermometer is further arranged at the top of the reactor body.

[0018] In the high-salt nitrogen-containing sewage treatment device provided by the application, the length:width:depth ratio of the reactor body is 1:1:2.5.

[0019] In the high-salt nitrogen-containing sewage treatment device, the PH value in the reactor body ranges from 7.5 to 8.5, and the dissolved oxygen content is greater than 6 mg / L.

[0020] In the high-salt nitrogen-containing sewage treatment device, the water inlet pipe and the water outlet pipe are arranged at the same height of the reactor body.

[0021] The high-salt nitrogen-containing sewage treatment device and method have the following beneficial effects: the completely ammonia-oxidizing bacteria are enriched by the biofilm-enriched filler to treat sewage, and the change of the water inlet characteristics can be better resisted; compared with the fixed film reactor, the device has less blockage and does not need backwashing; the biomass is retained in the form of biofilm on the carrier, so that the sludge does not need to be recirculated; the device has a simple structure, the reactor is easy to operate, the cost is reduced, the completely ammonia-oxidizing bacteria are successfully enriched, and the device has good treatment effect on high-salt nitrogen-containing sewage. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings:

[0023] Figure 1 The figure is a perspective view of the high-salt nitrogen-containing sewage treatment device provided by the present application;

[0024] Figure 2 The figure is a result graph of sewage treatment by using different fillers;

[0025] Figure 3 The figure is a comparison graph of comammox relative abundance of different fillers. DETAILED DESCRIPTION

[0026] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the related drawings. The drawings show typical embodiments of the present application. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0028] The present application provides a high-salt nitrogen-containing sewage treatment method, comprising:

[0029] Step S1, soaking the filler in the aerobic tank of the sewage plant, and pretreating the filler.

[0030] Specifically, in an embodiment of the present application:

[0031] First, the filler is soaked in the aerobic tank of the sewage plant to allow comammox to adhere, and a small amount of biofilm to be enriched on the filler. When selecting the amount of filler, the required volume is different according to the specific surface area; according to the specific surface area of the filler, the required amount is calculated, and the surface area of the filler in each reactor is 4.5 square meters.

[0032] Secondly, the filler is transported to the laboratory. During transportation, the filler should be soaked in water, and during transportation, shaking and the like should be reduced to prevent the biofilm from falling off. During transportation, all carriers need to be soaked in water to maintain the activity of the biofilm. The transportation and filling procedures are completed within 24 hours to minimize the negative impact of anaerobic environments on nitrifying biofilm.

[0033] Step S2, adding the filler enriched with biofilm into the reactor body;

[0034] Specifically, in an embodiment of the present application, the obtained filler is soaked for 1-3 days to wash away the residual sludge on the filler, which is beneficial to the growth of biofilm; then, the washed filler is added to the reactor, and at the beginning, water is fed every day and the hydraulic retention time is maintained at 20 hours, wherein the reactor temperature is room temperature (20℃), the dissolved oxygen concentration in the water is detected by the dissolved oxygen detection module to be higher than 6 mg / L, and the PH is maintained at 7.5-8.5. Among them, the hydraulic retention time = reactor volume / amount of water.

[0035] Step S3, using a peristaltic pump to pump high-salt nitrogen-containing wastewater into the reactor body to cultivate complete ammonia oxidation bacteria, and continuously monitoring the changes of ammonia nitrogen and nitrate nitrogen concentrations in the effluent, and the daily hydraulic retention time is the first preset time.

[0036] Specifically, in an embodiment of the present application, the peristaltic pump stably pumps high-salt nitrogen-containing sewage into the reactor body, the water inlet pipe and the water outlet pipe have the same height, and the water outlet pipe flows out the low-ammonia nitrogen sewage treated at the same rate, so that the stable water inlet of the reactor can be ensured by detecting the water outlet flow of the water outlet pipe, and the water inlet amount of the reactor is changed every day by controlling the water inlet amount of the reactor through the peristaltic pump. The pH detection module monitors the pH in the reactor in real time, keeps the pH range at 7.5-8.5, and creates better comammox culture conditions for the reactor. The dissolved oxygen detection module can monitor the dissolved oxygen content in the water body in real time, so that the air pump can ensure that the dissolved oxygen in the reactor is greater than 6 mg / L by pumping in an appropriate amount of air. Keep the continuous flow of water and continuously monitor the changes in ammonia nitrogen and nitrate nitrogen concentrations in the effluent.

[0037] Step S4, after the sewage treatment rate reaches the preset value, the comammox bacteria in the reactor are detected by real-time quantitative PCR technology to determine whether the filler is successfully enriched with comammox bacteria, and if the filler is successfully enriched with comammox bacteria, the water inlet volume is increased to the second water inlet volume every day, and the hydraulic retention time is reduced from 20 hours when the first water inlet volume is operated to about 2.85 hours.

[0038] Specifically, in an embodiment of the present application, when the treatment rate is increased to 70%, the water inlet amount is increased until the water inlet is 140 L / d. After having a good treatment rate, comammox in the reactor is detected by real-time quantitative PCR technology to determine the proportion of comammox in the denitrifying bacteria group in the reactor. If the sequence of comammox is detected, it indicates that the reactor successfully enriches comammox. When detecting comammox bacteria specifically, the primers used are Nino_amoA_19F (5'-ATAATCAAAGCCGCCAAGTTGC-3') and Nino_amoA_252R (5'-AACGGCTGACGATAATTGACC-3'). When performing phylogenetic comparison, the comparison sequences are all from NCBI, Candidatus Nitrospira.

[0039] In the present application, by successfully enriching comammox in the reactor to treat sewage, NH4 + , only a small amount of NO2 - is generated in the product, and is basically converted into NO3 -, indicating its good treatment effect. And under the condition of 140L / d, 70mg N / L of influent, the treatment rate is more than 97%, indicating that the reactor can efficiently treat high-salt nitrogen-containing wastewater. At the same time, the fluorescence real-time quantitative PCR system is used to detect comammox in the reactor, which has high accuracy and high sensitivity, convenient detection, low cost, and can detect the relative abundance in different reactors, and more effectively study the community structure of comammox.

[0040] Figure 1 The high-salt nitrogen-containing wastewater treatment device provided by the application is shown in the figure. Figure 1 The high-salt nitrogen-containing wastewater treatment device provided by the application includes a reactor body, an influent pipe 1, an effluent pipe 4, an air pump 9, an aeration device 8, a PH value detection module 7, a thermometer 2, a peristaltic pump 5, a dissolved oxygen detection module 6 and a filler 3. One end of the influent pipe is connected to the reactor body, and the other end is connected to the peristaltic pump, which controls the influent amount. One end of the effluent pipe is connected to the reactor body. The aeration device, the PH value detection module and the dissolved oxygen detection module are arranged at the bottom of the reactor body, and the air pump is connected to the aeration device. The PH value detection module is used to monitor the PH value of the liquid in the reactor body in real time. The dissolved oxygen detection module is used to monitor the dissolved oxygen content of the liquid in the reactor body in real time. The air pump is used to pump air into the reactor, so that the dissolved oxygen content of the liquid in the reactor is greater than a first preset value. The filler is suspended in the reactor body. The filler is used to enrich complete ammonia oxidation bacteria to treat the high-salt nitrogen-containing wastewater. The thermometer 2 is arranged at the top of the reactor body.

[0041] In the application, the reactor body has an aeration device at the bottom, and the stirring device is cancelled, reducing the operating cost. A certain amount of aeration can produce appropriate shear force, ensure the relative stability of the biofilm thickness, and improve its resistance to changes in influent characteristics. In addition, no sludge is produced in the reactor, reducing the cost of sludge treatment.

[0042] When in use, the peristaltic pump 5 will pump the high-salt nitrogen-containing sewage into the reactor body stably, the inlet pipe 4 and the outlet pipe 1 have the same height, and the outlet pipe will flow out the low-ammonia nitrogen sewage treated at the same rate, so that the stable water inlet of the reactor can be ensured by detecting the outlet flow of the outlet pipe 1, and the water inlet amount of the reactor can be controlled by the peristaltic pump 5 of the reactor to change the water inlet amount of the reactor every day. The pH detection module 7 is used to monitor the pH in the reactor in real time, and the pH range is kept at 7.5-8.5, so as to create better comammox culture conditions for the reactor. The dissolved oxygen detection module can monitor the dissolved oxygen content in the water body in real time, so that the air pump 9 can ensure that the dissolved oxygen in the reactor is greater than 6 mg / L under the condition of keeping better carrier circulation. The continuous flow water inlet is kept, and the change of ammonia nitrogen and nitrate nitrogen concentration in the outlet water is continuously monitored, the water inlet amount is increased when the treatment rate is increased to 70%, and the water inlet amount is 140 L / d.

[0043] Further, in an embodiment of the present application, each reactor body comprises a cuboid reactor, and the length:width:depth ratio of the reactor body is 1:1:2.5. Specifically, in an embodiment, the reactor volume is 20 L, and the effective cross-sectional size is 200 cm in length and 200 cm in width, and the water depth inside the reactor is 500 cm.

[0044] Further, in an embodiment of the present application, the inlet pipe and the outlet pipe are arranged at the same height of the reactor body to keep better mixing efficiency.

[0045] Embodiment one

[0046] The specific surface area of the filler A used for sewage treatment is 800 m 2 / m 3 The reactor water inlet is increased from 20 L / d to 140 L / d, Figure 2 It is shown that after the water inlet is increased to 140 L / d and the ammonia nitrogen concentration is 70 mg N / L, the reactor finally reaches stability, the ammonia nitrogen removal rate is more than 97%, and there is basically no nitrite accumulation. Through Figure 3 It can be found that the comammox has been successfully enriched in the reactor, and the removal effect is positively correlated with the abundance of comammox. From Figure 2 It can be seen that the comammox is enriched by the device of the present application to treat high-salt nitrogen-containing sewage, and a stable treatment effect can be achieved.

[0047] Embodiment two

[0048] The specific surface area of the filler B used for sewage treatment is 650 m 2 / m 3 The reactor water inlet is increased from 20 L / d to 140 L / d, Figure 2It is shown that after the influent is increased to 140 L / d and the ammonia nitrogen concentration is 70 mg N / L, the reactor eventually reaches stability, the ammonia nitrogen removal rate reaches 90%, and there is a small amount of nitrite accumulation. Figure 3 It can be found that comammox has been successfully enriched in the reactor, and the abundance is lower than that of the filler A, indicating that the removal effect is positively correlated with the abundance of comammox, and the accumulation amount of nitrite is negatively correlated with the abundance of comammox.

[0049] The embodiments of the application are described above in combination with the drawings, but the application is not limited to the specific embodiments described above, and the specific embodiments described above are only illustrative but not limiting, and those skilled in the art can make many forms under the inspiration of the application without departing from the purpose of the application and the scope protected by the claims, which are all within the protection of the application.

Claims

1. A process for the treatment of high-salinity nitrogen-containing wastewater, characterized in that, The application comprises the following steps: The packing enriched with biofilm is added into the reactor main body, wherein the temperature in the reactor main body is 20℃, the dissolved oxygen concentration in water is higher than 6 mg / L, the PH value is 7.5-8.5, the specific surface area of the packing is ≥800 m 2 / m 3 ; The high-salt nitrogen-containing sewage is pumped into the reactor body by using a peristaltic pump to cultivate complete ammonia-oxidizing bacteria, and the changes of ammonia nitrogen and nitrate nitrogen concentrations in the effluent are continuously monitored, the hydraulic retention time of the first stage is the first preset time, and the first preset time is 20 hours; After the sewage treatment rate reaches the preset value, the complete ammonia-oxidizing bacteria in the reactor are detected by using a real-time quantitative PCR technique to determine whether the filler is successfully enriched with complete ammonia-oxidizing bacteria, and if the filler is successfully enriched with complete ammonia-oxidizing bacteria, the hydraulic retention time of each day is reduced to the second preset time, and the second preset time is 2.85 hours.

2. The high-salinity nitrogen-containing wastewater treatment method according to claim 1, characterized by, Before the filler with a biofilm is added into the reactor body, the filler is soaked in an aerobic tank of a sewage plant to pretreat the filler.

3. A high-salinity nitrogen-containing wastewater treatment apparatus characterized by comprising: The reactor body, the water inlet pipe, the water outlet pipe, the air pump, the aeration device, the PH value detection module, the peristaltic pump, the dissolved oxygen detection module and the filler are comprised, one end of the water inlet pipe is connected to the reactor body, the other end of the water inlet pipe is connected to the peristaltic pump, and the water inlet amount is controlled by the peristaltic pump; one end of the water outlet pipe is connected to the reactor body; the aeration device, the PH value detection module and the dissolved oxygen detection module are arranged at the bottom of the reactor body, the air pump is connected to the aeration device; the PH value detection module is used for real-time monitoring of the PH value of the liquid in the reactor body; the dissolved oxygen detection module is used for real-time monitoring of the dissolved oxygen content of the liquid in the reactor body; the air pump is used for pumping air into the reactor, so that the dissolved oxygen content of the liquid in the reactor is greater than a first preset value; the filler is suspended in the reactor body; the filler is used for enriching complete ammonia-oxidizing bacteria to treat the high-salt nitrogen-containing sewage; a thermometer is arranged at the top of the reactor body; the PH value in the reactor body ranges from 7.5 to 8.5, and the dissolved oxygen content is greater than 6 mg / L.

4. The high salt nitrogen-containing wastewater treatment device of claim 3, wherein, The length:width:depth ratio of the reactor body is 1:1:2.

5.

5. The high salt nitrogen-containing wastewater treatment device of claim 3, wherein, The water inlet pipe and the water outlet pipe are arranged at the same height of the reactor body.

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