Method for adding nutritional agent for promoting anaerobic ammonia oxidation granular sludge to resist heavy metal stress

Abstract

The invention discloses a method for adding a nutritional agent for promoting anaerobic ammonia oxidation granular sludge to resist heavy metal stress, and belongs to the field of biological sewage treatment. The method comprises the following steps: regularly adding a nutrient solution into an anaerobic ammonia oxidation granular sludge system which is subjected to heavy metal stress or possibly subjected to heavy metal stress subsequently, so as to improve the heavy metal stress resistance of the anaerobic ammonia oxidation granular sludge; the nutritional agent component of the nutritional agent solution is at least one of proline, arginine, glutamic acid, lysine and nicotinic acid; in the anaerobic ammonia oxidation granular sludge system after the nutritional agent solution is added, the concentration of each nutritional agent component is 5-50 [mu] M. The method is convenient to operate, a proper amount of nutrient solution is regularly added into the anaerobic ammonia oxidation granular sludge, so that the anaerobic ammonia oxidation granular sludge can keep good activity after being stressed by heavy metal, the resistance of the anaerobic ammonia oxidation granular sludge to the heavy metal is improved, and the negative influence caused by stress is relieved; and a new regulation and control means is provided for actual process operation.

Description

Technical Field

[0001] The invention belongs to the field of biological sewage treatment, and in particular relates to a method for adding a nutrient agent to promote anaerobic ammonia oxidation granular sludge to resist heavy metal stress. Background Art

[0002] The anaerobic ammonium oxidation (Anammox) process has become an upgraded technology for biological denitrification of wastewater with its advantages of low energy consumption and low carbon footprint. At present, more than 90% of the application modes of anaerobic ammonium oxidation processes are in the form of granular sludge. Granular sludge is a granular bioaggregate naturally formed by microorganisms during long-term operation due to external factors such as hydraulic shear force. The granular form can achieve the stratification of internal and external functional microorganisms and is conducive to microbial retention. The operation scenarios of anaerobic ammonium oxidation processes are currently mostly high nitrogen load environments, such as various industrial wastewaters and sludge digestion liquids. These wastewaters often contain various heavy metal ions. They remain in the discharged wastewater due to production process reasons. These heavy metal ions are toxic factors for various microorganisms in the anaerobic ammonium oxidation community. High concentrations of heavy metal ions not only directly lead to the deterioration of the denitrification effect, but also cause the disintegration of granular sludge, resulting in a large loss of functional microorganisms and increasing process costs. Based on this, the development of methods that are conducive to strengthening the heavy metal resistance and promoting recovery of anaerobic ammonium oxidation granular sludge is of great significance for the efficient, economical and stable operation of the anaerobic ammonium oxidation process.

[0003] For methods of recovery after anaerobic ammonia oxidation stress, after searching, relevant applications have been disclosed, such as the application with Chinese patent publication number CN202211402981, which discloses a method for promoting the recovery of anaerobic ammonia oxidation bacteria after being inhibited by iron ions using betaine and EDTA-2Na, and the specific steps are as follows: betaine is added to the water body containing the anaerobic ammonia oxidation bacteria in an intermittent addition manner. The intermittent addition method includes continuous addition and suspended addition that are performed alternately in sequence, wherein the continuous addition time is controlled at 8-12 days, and the suspended addition time is controlled at 3-5 days. EDTA-2Na is added before betaine is added to the water body. In addition, the application with Chinese patent publication number CN202211242932 discloses a method for rapid recovery of heavy metal inhibition of anaerobic ammonia oxidation, and the specific steps are as follows: anaerobic ammonia oxidation heavy metal inhibition is quickly restored by adding granular heavy metal ion exchange resin to the system.

[0004] The above methods reported in the patent application cases have a certain impact on the resistance of anaerobic ammonia-oxidizing bacteria to heavy metal ion inhibition. However, the added EDTA-2Na and granular adsorption resin (particle size 0.5-1mm) may cause secondary pollution of the effluent water quality, and the process steps of resin recovery are relatively complicated.

[0005] According to the changes in the content of metabolite components during the inhibition and natural recovery of anaerobic ammonium oxidizing bacteria, we can understand the types of nutrients required by anaerobic ammonium oxidizing bacteria during stress recovery. Based on this idea, we can construct a nutrient that promotes anaerobic ammonium oxidizing bacteria to resist heavy metal stress. Based on this, we can construct a nutrient using small molecules required by anaerobic ammonium oxidizing bacteria during heavy metal stress, and invent a new method for adding nutrients to promote anaerobic ammonium oxidizing granular sludge to resist heavy metal stress. Summary of the invention

[0006] The purpose of the present invention is to provide a method for adding nutrients to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress in order to solve the problem of reduced denitrification efficiency caused by various heavy metal ions in water bodies in the current anaerobic ammonium oxidation denitrification process.

[0007] The specific technical solutions adopted by the present invention are as follows:

[0008] The present invention provides a method for adding a nutrient agent to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress, which is as follows:

[0009] The nutrient solution is regularly added to the anaerobic ammonium oxidation granular sludge system that has been or may be subsequently subjected to heavy metal stress, so as to improve the ability of the anaerobic ammonium oxidation granular sludge to resist heavy metal stress;

[0010] The nutrient solution is an aqueous solution containing nutrient components, and the nutrient components are at least one of proline, arginine, glutamic acid, lysine, and nicotinic acid; in the anaerobic ammonia oxidation granular sludge system after the nutrient solution is added, the concentration of each nutrient component is 5-50 μM.

[0011] Preferably, the state of the anaerobic ammonium oxidation granular sludge system before adding the nutrient solution is under heavy metal stress.

[0012] Furthermore, the nutrient solution is added once every 12 hours in batches.

[0013] Furthermore, after the nutrient solution is added to the anaerobic ammonia oxidation granular sludge system for the first time, the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the system are continuously measured by colorimetry to determine the denitrification efficiency of the granular sludge in the system before and after the reaction; if the denitrification efficiency has not yet recovered to the preset level, it is necessary to continue to add the nutrient solution regularly.

[0014] Preferably, the state of the anaerobic ammonium oxidation granular sludge system before adding the nutrient solution is a healthy state.

[0015] Furthermore, the nutrient solution is added once every five days, and each addition lasts for one day.

[0016] Preferably, during the reaction process of adding the nutrient solution to the anaerobic ammonium oxidation granular sludge system, the pH value is 6.5-7.8 and the temperature is 20-40°C.

[0017] Preferably, in the anaerobic ammonium-oxidizing granular sludge system before adding the nutrient solution, the sludge concentration is MLSS: 500-5000 mg / L, wherein the relative abundance of anaerobic ammonium-oxidizing bacteria is 5%-50%.

[0018] Preferably, in the anaerobic ammonium oxidation granular sludge system before adding the nutrient solution, the nitrogen concentration range is 100-800 mg / L, NH4 + -N and NO2 - The molar concentration ratio of -N is maintained at 1:(1.1~1.3).

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

[0020] (1) The present invention uses a self-constructed nutrient solution for process dosing and regulation. The regular addition of nutrient solution can achieve a reduction in the denitrification efficiency of the anaerobic ammonium oxidation granular sludge system after stress by only 20%-30%, while the control group (i.e., the anaerobic ammonium oxidation granular sludge system after stress without the addition of nutrient solution) dropped by more than 50%. Long-term regular addition promotes the stability of the particle size of the granular sludge and avoids disintegration after stress.

[0021] (2) In the method of the present invention, the addition of the nutrient solution can be effectively utilized by various microorganisms of the anaerobic ammonium-oxidizing community in the anaerobic ammonium-oxidizing granular sludge system, thereby increasing the resistance of the entire community to heavy metal ions.

[0022] (3) The nutrient ingredients used in the present invention are all substances required by the human body or microorganisms. After being added and used, in addition to having a restoring effect on the granular sludge that has been stressed by heavy metals, it has no other harmful effects on the water body, is environmentally friendly, and is conducive to promotion.

[0023] (4) The nutritional supplement ingredients used in the present invention are all commercial products, relatively cheap, and easily available. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The comparison of the denitrification activity of the anaerobic ammonium oxidation particles in Example 2 when the nutrients are added during the continuous short-term heavy metal stress;

[0025] Figure 2 This is a comparison of the anti-heavy metal stress effect of the long-term anaerobic ammonium oxidation granular sludge reactor in Example 3 after regular addition of nutrients. DETAILED DESCRIPTION

[0026] The present invention is further described and illustrated below in conjunction with the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0027] The present invention provides a method for adding a nutrient agent to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress, and the method is specifically as follows:

[0028] The prepared nutrient solution is regularly added to the anaerobic ammonium oxidation granular sludge system that has been or may be subsequently subjected to heavy metal stress to improve the ability of the anaerobic ammonium oxidation granular sludge to resist heavy metal stress. The nutrient solution is an aqueous solution containing nutrient components, and the nutrient components are at least one of proline, arginine, glutamic acid, lysine, and nicotinic acid. In the anaerobic ammonium oxidation granular sludge system after the nutrient solution is added, the concentration (i.e., the final concentration) of each nutrient component is 5-50 μM.

[0029] As a preferred embodiment of the present invention, the nutrient composition includes five components: proline, arginine, glutamic acid, lysine, and niacin, and the final concentration of each component is 5-50 μM.

[0030] As a preferred embodiment of the present invention, the state of the anaerobic ammonium oxidation granular sludge system before adding the nutrient solution is under heavy metal stress. At this time, the nutrient solution is added once every 12 hours and added in batches. Regularly adding the nutrient solution to the anaerobic ammonium oxidation granular sludge system under heavy metal stress can avoid a significant decrease in the activity of the granular sludge in the system, and promote activity recovery and maintenance of particle size.

[0031] In actual use, after the nutrient solution is added to the anaerobic ammonium oxidation granular sludge system for the first time, the activity state of the anaerobic ammonium oxidation granular sludge can be checked regularly until the activity of the anaerobic ammonium oxidation granular sludge in the system is restored to the target state. It should be noted that the target state refers to the desired state, that is, the activity state of the anaerobic ammonium oxidation granular sludge artificially stipulated or required before treatment, which can be adjusted according to actual conditions and is not limited here. In other words, after the nutrient solution is added to the anaerobic ammonium oxidation granular sludge system for the first time, the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the system can be continuously determined by colorimetry to determine the denitrification efficiency of the granular sludge in the system before and after the reaction, and then the activity recovery state of the granular sludge microorganisms in the system can be obtained; if the denitrification efficiency has not yet recovered to the preset level, it is necessary to continue to add the nutrient solution regularly.

[0032] As a preferred embodiment of the present invention, the state of the anaerobic ammonium oxidation granular sludge system before adding the nutrient solution is in a healthy state. At this time, the nutrient solution is added once every five days, and each time is added for one day. Regularly adding the nutrient solution to the anaerobic ammonium oxidation granular sludge system in a healthy state can promote the stability of the particle size of the granular sludge in the system and avoid the disintegration after stress.

[0033] As a preferred embodiment of the present invention, during the reaction process of adding the nutrient solution into the anaerobic ammonium oxidation granular sludge system, the pH value of the system should be maintained at 6.5-7.8 and the temperature should be maintained at 20-40°C.

[0034] As a preferred embodiment of the present invention, in the anaerobic ammonium oxidizing granular sludge system before adding the nutrient solution, the sludge concentration is MLSS: 500-5000 mg / L, wherein the relative abundance of anaerobic ammonium oxidizing bacteria is 5%-50%.

[0035] As a preferred embodiment of the present invention, in the anaerobic ammonium oxidation granular sludge system before adding the nutrient solution, the nitrogen concentration range is 100-800 mg / L, NH4 + -N and NO2 - The molar concentration ratio of -N is maintained at 1:(1.1~1.3).

[0036] The method and effects of the present invention will be specifically described below through examples.

[0037] Example 1

[0038] This example compares the activity decay rate of anaerobic ammonium oxidation sludge after short-term heavy metal stress with different nutrient components at different addition doses to test the effectiveness of different components to determine the final nutrient component ratio, including the following steps:

[0039] Step 1) Take the anaerobic ammonium oxidation granular sludge from an actual wastewater biochemical treatment section to conduct a reactor operation test (the experimental reaction system is a 100mL serum bottle, the pH is maintained at 7.3-7.7, the temperature is 37°C, and the initial NH4 + -N, NO2 - -N concentration is 30mg N / L, 40mg N / L, NH4 + -N and NO2 - -N molar concentration ratio is about 1:1.3, sludge concentration is MLSS:800mg / L). The same temperature and uniform water inlet conditions were maintained in each comparative experiment. The same concentration of copper, zinc, and nickel heavy metals (all at 3mg / L) were added to each test serum bottle.

[0040] Step 2) adding different doses of nutrient components (such as proline, glutamic acid, etc.) to the experimental group, and then starting the shake flask reaction.

[0041] Step 3), after 12 hours of reaction, the specific activity of the granular sludge in the stressed anaerobic ammonium oxidation granular sludge system is detected, and the anaerobic ammonium oxidation activity decay rate is calculated (100% - specific activity at the end of the test / specific activity at the beginning of the test * 100%).

[0042] The experimental results are as follows:

[0043] According to the results shown in Table 1, various amino acids and niacin at an addition dose of 5-50 μM have the effect of reducing the activity decay rate of anaerobic ammonium oxidation granular sludge after being subjected to the combined stress of three heavy metals: copper, zinc and nickel.

[0044] Table 1 Activity decay rate of anaerobic ammonium-oxygen oxidation granular sludge under different nutrient component dosages (%)

[0045]

[0046] Example 2

[0047] This example demonstrates the effectiveness of the nutrient in the present invention in resisting heavy metal stress of anaerobic ammonium oxidation granular sludge by comparing the sludge activity during short-term heavy metal stress, and includes the following steps:

[0048] Step 1) The anaerobic ammonium oxidation granular sludge involved in this experiment is the anaerobic ammonium oxidation granular sludge (AMX1) obtained from the actual project site and the anaerobic ammonium oxidation granular sludge (AMX2) cultured in the laboratory for a long time (the reaction system of this experiment is a 100mL serum bottle, the pH is maintained at 7.3-7.7, the temperature is 37℃, and the initial NH4 + -N, NO2 - -N concentration is 30mg N / L, 40mg N / L, NH4 + -N and NO2 - -N molar concentration ratio is about 1:1.3, sludge concentration is MLSS:800mg / L). The same temperature and uniform water inlet conditions were maintained in each comparative experiment. The same concentration of copper, zinc, and nickel heavy metals (all at 3mg / L) were added to each test serum bottle.

[0049] Step 2) Add a nutrient solution (an aqueous solution containing five nutrient components, namely proline, arginine, glutamic acid, lysine and niacin, and the concentration of these five components is 10 μM) to the experimental group (i.e., the nutrient group). Then start the shake flask reaction. After 12 hours of reaction, wash the sludge and add the heavy metals and the corresponding nutrient solution again and react for another 12 hours, and repeat this cycle 3 times.

[0050] Step 3), detecting the specific activity of the granular sludge in the stressed anaerobic ammonium oxidation granular sludge system, and calculating the anaerobic ammonium oxidation activity decay rate, the calculation formula is 100% - specific activity at the end of the test / specific activity at the beginning of the test * 100%.

[0051] In this embodiment, the experimental results are as follows:

[0052] according to Figure 1 As shown, after the anaerobic ammonium oxidation granular sludge in the control group (i.e., normal operation without the addition of any nutrients) was subjected to the combined stress of three heavy metals, copper, zinc, and nickel, the specific activity of the actual engineering site anaerobic ammonium oxidation granular sludge (AMX1) and the laboratory anaerobic ammonium oxidation sludge (AMX2) were attenuated by 29.83% and 39.49%, respectively. In contrast, the specific activity of the anaerobic ammonium oxidation granular sludge with the auxiliary addition of nutrients in the experimental group of this embodiment was only attenuated by 20.24% and 23.42%, respectively. This shows that the resistance of anaerobic ammonium oxidation granular sludge to heavy metals can be significantly improved with the auxiliary addition of nutrient solution.

[0053] Example 3

[0054] This example reflects the effectiveness of the nutrient solution in the present invention in resisting heavy metal stress of anaerobic ammonium oxidation granular sludge by comparing the operating status during long-term operation, and includes the following steps:

[0055] Step 1) Take the anaerobic ammonium oxidation granular sludge from an actual wastewater biochemical treatment section to conduct a reactor operation test. The reaction system is a 500mL UASB reactor, the pH is maintained at 7.3-7.7, the temperature is 37°C, and the initial NH4 + -N, NO2 - -N concentration is 100mg N / L, 130mg N / L, NH4 + -N and NO2 - The molar concentration ratio of -N is about 1:1.3, and the initial sludge concentration is MLSS:3000mg / L. The same temperature and uniform water inlet conditions were maintained in each comparative experiment. The experimental group was supplemented with nutrient solution (reactor No. 1), and reactor No. 2 was the control group.

[0056] Step 2), add a nutrient solution (an aqueous solution comprising five nutrients, namely proline, arginine, glutamic acid, lysine and niacin, and the concentration of these five components is 5 μM) to the reactor once every 5 days for 1 day, and the nutrient solution is added by a flow-feed pump.

[0057] Step 3), on the 68th day of the operation of the reactor, 3 mg / L of heavy metal ions of copper, zinc and nickel were introduced into the influent for stress, and the stress time was 24 hours.

[0058] Step 4), then regularly sample and continuously monitor the water quality operation, calculate the specific activity of the granular sludge, and determine the size of the granular sludge.

[0059] Table 2 Granular sludge size

[0060]

[0061] like Figure 2 As shown in the figure, after the addition of heavy metal stress on the 68th day, the nitrogen removal efficiency of reactors 1 and 2 decreased significantly. The removal efficiency of the nutrient group (reactor 1) decreased by about 30%, while the removal efficiency of the control group (reactor 2, i.e., normal operation without the addition of any nutrient solution) decreased by more than 50%. After the stress, the nitrogen removal efficiency of the nutrient group was able to quickly recover to 90% of the original level within 2 days, while the control group needed a longer time.

[0062] Activity and particle size of granular sludge As shown in the results of Table 2 above, the size of granular sludge in reactor No. 1 was significantly larger than that in reactor No. 2 (1403.5μm vs 1308.3μm on the 32nd day) under continuous addition of nutrient solution. After heavy metal stress, the size of granular sludge did not decrease significantly (1289.8μm vs 1116.0μm on the 70th day). At the same time, the change trend of granular sludge activity was similar to the overall nitrogen removal efficiency of the reactor. After heavy metal stress (the 70th day), the specific activity of granular sludge in reactor No. 1 was significantly higher than that in reactor No. 2 (85.7 vs 55.0 mg N / g vss / d).

[0063] The above results show that regular auxiliary addition of nutrient solution has a good anti-heavy metal stress effect on long-term anaerobic ammonium oxidation granular sludge reactor. The specific function is reflected in the improvement of higher anaerobic ammonium oxidation activity in a healthy state and after stress. At the same time, the addition of nutrient solution is conducive to the maintenance of the morphology of anaerobic ammonium oxidation granular sludge.

[0064] The method of the present invention is easy to operate. By regularly adding nutrient solution to the anaerobic ammonium oxidation granular sludge reactor, it can effectively achieve rapid recovery of anaerobic ammonium oxidation activity and formation of sludge particles, alleviate the negative impact of stress, and provide a new control method for actual process operation.

[0065] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A method for adding nutrients to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress, characterized in that: The details are as follows: The nutrient solution is regularly added to the anaerobic ammonium oxidation granular sludge system that has been or may be subsequently subjected to heavy metal stress, so as to improve the ability of the anaerobic ammonium oxidation granular sludge to resist heavy metal stress; The nutrient solution is an aqueous solution containing nutrient components, and the nutrient components are at least one of proline, arginine, glutamic acid, lysine, and nicotinic acid; in the anaerobic ammonia oxidation granular sludge system after the nutrient solution is added, the concentration of each nutrient component is 5-50 μM.

2. The method for adding nutrients to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress according to claim 1, characterized in that: The state of the anaerobic ammonium oxidation granular sludge system before adding the nutrient solution is under heavy metal stress.

3. The method for adding nutrients to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress according to claim 2, characterized in that: The nutrient solution is added once every 12 hours in batches.

4. The method for adding nutrients to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress according to claim 1, characterized in that: The state of the anaerobic ammonium oxidation granular sludge system before adding the nutrient solution is a healthy state.

5. The method for adding nutrients to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress according to claim 4, characterized in that: The nutrient solution is added once every five days, and each time is added for one day.

6. The method for adding nutrients to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress according to claim 1, characterized in that: During the reaction process of adding the nutrient solution to the anaerobic ammonium oxidation granular sludge system, the pH value is 6.5-7.8 and the temperature is 20-40°C.

7. The method for adding nutrients to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress according to claim 1, characterized in that: In the anaerobic ammonium-oxidizing granular sludge system before adding the nutrient solution, the sludge concentration is MLSS: 500-5000 mg / L, wherein the relative abundance of anaerobic ammonium-oxidizing bacteria is 5%-50%.

8. The method for adding nutrients to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress according to claim 1, characterized in that: In the anaerobic ammonium oxidation granular sludge system before adding the nutrient solution, the nitrogen concentration range is 100-800 mg / L, NH4 + -N and NO2 - The molar concentration ratio of -N is maintained at 1:(1.1~1.3).

9. The method for adding nutrients to promote anaerobic ammonium oxidation granular sludge to resist heavy metal stress according to claim 2, characterized in that: After the nutrient solution is first added to the anaerobic ammonium oxidation granular sludge system, the concentrations of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the system are continuously measured by colorimetry to determine the denitrification efficiency of the granular sludge in the system before and after the reaction; If the denitrification efficiency has not yet recovered to the preset level, it is necessary to continue to add nutrient solution regularly.

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