CN100582027C - Two-stage synchronous nitrification denitrification process for treating ammonia nitrogen wastewater - Google Patents

Abstract

The invention discloses a disposing method of ammonia nitrogen waste water in the effluent disposal technological domain, which is characterized by the following: sieving heterotrophic nitrobacteria and aerobic denitrobacteria with stronger environment adaptive ability to nitrate and denitrate simultaneously; constructing mud nitrated and denitrated system to dispose waste water with nitrogen simultaneously to satisfy different DO densities.

Description

Two-stage synchronous nitrification and denitrification method for treating ammonia nitrogen wastewater

technical field

The invention belongs to the technical field of sewage treatment and relates to a treatment method for ammonia nitrogen wastewater.

Background technique

Three different biological reactions usually occur in the biological denitrification process of urban sewage, namely aerobic oxidation of organic matter, nitrification and denitrification. Most biological denitrification processes separate the anoxic zone from the aerobic zone, forming the so-called pre-denitrification or post-denitrification process, because according to the traditional denitrification theory, nitrification and denitrification reactions cannot occur at the same time . In recent years, many tests and reports abroad have proved that nitrification and denitrification can be carried out in the same reactor under the same operating conditions, which is called simultaneous nitrification and denitrification. This method can not only overcome the existing problems of traditional biological denitrification It also has the following advantages: (1) can shorten the denitrification process; (2) save carbon source; (3) reduce power consumption; (4) improve processing capacity; (5) simplify the design and operation of the system, etc. Based on the above reasons, the phenomenon of simultaneous nitrification and denitrification has aroused widespread concern. However, due to the many and complex factors affecting simultaneous nitrification and denitrification, factors such as DO, C/N, ORP, sludge floc morphology, pH value, temperature, and sludge age all have an important impact on simultaneous nitrification and denitrification. It is difficult to realize simultaneous nitrification and denitrification in actual engineering.

Contents of the invention

The purpose of the present invention is to solve the problem of unclear source of strains in the process of synchronous nitrification and denitrification, difficult regulation, nitrification and denitrification have different requirements on DO concentration, and it is difficult to realize synchronous nitrification and denitrification in actual engineering. The invention adopts a new screening method to screen out heterotrophic nitrifying bacteria and aerobic denitrifying bacteria with strong adaptability to the environment, and uses heterotrophic nitrifying bacteria and aerobic denitrifying bacteria to construct a simultaneous nitrification and denitrification sludge system to treat nitrogen-containing wastewater , with less investment, low cost, good treatment effect, not only removes ammonia nitrogen in wastewater, but also has a high removal rate for total nitrogen. The method of the present invention is realized by following steps: one, the establishment of cultivating heterooxygenation nitrification sludge reactor: the heterotrophic nitrification bacteria of screening is expanded and cultivated, and inoculation is equivalent to the fresh activated sludge of 0.1% of whole reactor volume, empty After 3 to 7 days of aeration, the activated sludge is formed and then operated. When the ammonia nitrogen removal rate is above 50%, it indicates that a stable heterooxynitrification sludge system has been established. During the entire reactor operation, the concentration of dissolved oxygen is gradually reduced, from 4 to 5mg/L gradually reduced to 1~2mg/L;

2. Establishment of cultivating aerobic denitrification sludge reactor: expand and cultivate the screened aerobic denitrification bacteria, inoculate fresh activated sludge equivalent to 0.1% of the entire reactor volume, and form active sludge after air aeration for 3 to 7 days In this way, two reactors for cultivating aerobic denitrification sludge were established for operation; aerobic denitrification bacteria domestication culture solution 1 and aerobic denitrification bacteria domestication culture solution 2 were respectively used for the two aerobic denitrification reactions Domesticate the sludge from the tank; gradually increase the dissolved oxygen concentration during the whole domestication process, from 0.5-1 mg/L to 3-4 mg/L;

3. Simultaneous nitrification and denitrification treatment of ammonia nitrogen wastewater: Add the sludge domesticated with aerobic denitrification bacteria domestication culture solution 1 to the stable heterooxynitrification sludge system in 3 times, and measure the concentration of ammonia nitrogen and nitrite in the reactor every day When the removal rate of ammonia nitrogen and nitrite in the reactor reaches more than 50%, the sludge domesticated with aerobic denitrification bacteria acclimation culture solution 2 is added to the reactor in 3 times, and the ammonia nitrogen and nitrite in the reactor are measured every day. The change of nitrate and nitrate concentration, when the removal rate of ammonia nitrogen, nitrite and nitrate in the reactor reaches more than 50%, it proves that a stable synchronous nitrification and denitrification sludge has been cultivated.

The result of the method of the present invention shows that the heterooxynitrifying bacteria with a higher growth and reproduction rate and a high removal rate of ammonia nitrogen are screened out by the present invention, and still have a higher denitrification effect when the dissolved oxygen concentration is higher than 2 mg/L. Aerobic denitrifying bacteria, using the screened nitrifying bacteria to construct a two-stage synchronous nitrification and denitrification reactor to treat ammonia nitrogen wastewater and achieved good treatment results. The two-stage synchronous nitrification and denitrification solved the traditional synchronous nitrification and denitrification. Dissolved oxygen concentration is sensitive, and it is difficult to realize real synchronous nitrification and denitrification, so it has great application potential in the treatment of ammonia nitrogen-containing wastewater.

Detailed ways

Specific implementation mode 1: Taking the reactor to treat ammonia nitrogen sewage as an example, the method described in this implementation mode is realized through the following steps:

1. Prepare the following medium and acclimatization medium:

1. Different oxygen nitrification separation medium: NH ₄ Cl 0.382g, sodium acetate 2g, MgSO ₄ 7H ₂ O 0.05g, K ₂ HPO ₄ 0.2g, NaCl 0.12g, MnSO ₄ 4H ₂ O 0.01g, FeSO ₄ 0.01g, H ₂ O 1000ml, pH=7~7.5, sterilized at 121°C for 20min.

2. Aerobic denitrification separation medium: sodium succinate 4.7g, KNO ₃ 1.5g, NaNO ₂ 0.5g, KH ₂ PO ₄ 0.5g, MgSO ₄ 7H ₂ O 0.1g, trace element solution 2ml, H ₂ O 1000ml, sterilized at 121°C for 20min. The composition of the trace element solution is: EDTA 50g/l, ZnSO ₄ 2.2g/l, CaCl ₂ 5.5g/l, MnCl ₂ 4H ₂ O 5.06g/l, FeSO4 7H2O 5.0g/l, (NH4) ₆ Mo ₇ O ₂ .4H ₂ O 1.1 g/l, CuSO ₄ .5H ₂ O 1.57 g/l, CoCl ₂ .6H ₂ O 1.61 g/l.

3. Aerobic denitrifying bacteria acclimation culture solution 1: 1g sodium succinate, 0.2g NaNO ₂ , 0.1g KH2PO ₄ , 0.02g MgSO ₄ ·7H ₂ O, 1ml trace element solution, 1000ml H ₂ O. The composition of the trace element solution is: EDTA 50g/l, ZnSO ₄ 2.2g/l, CaCl ₂ 5.5g/l, MnCl ₂ 4H ₂ O 5.06g/l, FeSO ₄ 7H ₂ O 5.0g/l, ( NH ₄ ) ₆ Mo ₇ O ₂ ·4H ₂ O 1.1 g/l, CuSO ₄ ·5H ₂ O 1.57 g/l, CoCl ₂ ·6H ₂ O 1.61 g/l.

4. Aerobic denitrifying bacteria acclimation culture solution 2: 1g sodium succinate, 0.4g KNO ₃ , 0.1g KH ₂ PO ₄ , 0.02g MgSO ₄ ·7H ₂ O, 1ml trace element solution, 1000ml H ₂ O. The composition of the trace element solution is: EDTA 50g/l, ZnSO ₄ 2.2g/l, CaCl ₂ 5.5gg/l, MnCl ₂ 4H ₂ O 5.06g/l, FeSO ₄ 7H ₂ O 5.0g/l, (NH ₄ ) ₆ Mo ₇ O ₂ ·4H ₂ O 1.1 g/l, CuSO ₄ ·5H ₂ O 1.57 g/l, CoCl ₂ ·6H ₂ O 1.61 g/l.

2. Treatment of ammonia nitrogen sewage:

1. Screening of heterotrophic nitrifying bacteria: put the water sample aside and discard the supernatant, take the activated sludge and inoculate it in the heterooxygen nitrification liquid separation medium, the inoculation amount is 5-10%, at 30-35°C, 120 Cultivate with constant temperature shaking at ~140rpm. When there is obvious growth (increased turbidity of the culture medium by visual inspection), transplant it into a fresh medium for shaking culture, and use a sterile pipette to draw 10 mL of the culture medium that has been enriched and acclimatized. Put it into a conical flask containing 90mL of sterilized water, add several glass beads, and shake fully; prepare a series of dilutions, take one drop of each 10 ^-5 to 10 ^-8 dilution, and use them on the different oxygen nitrification solid separation medium plate Sterilized spatula coating, two parallel samples were made for each dilution, and the coated plates were left to stand at room temperature for 2 hours, and then incubated in an inverted incubator for 2 to 3 days. Pick the colony and inoculate it into the nitrification solid separation medium, and repeat the above operation until the separation is pure. The nitrification performance was determined by conventional methods.

2. Screening of good denitrifying bacteria: put the water sample aside and discard the supernatant, take the activated sludge and inoculate it into the aerobic denitrification liquid separation medium, the inoculation amount is 5-10%, at 30-35°C , 120-140rpm under the condition of constant temperature shaking culture, when there is obvious growth (increased turbidity of the culture medium by visual inspection), transplant it into a fresh medium for shaking culture, and use a sterilized pipette to absorb the culture medium that has been enriched and acclimated Add 10mL to a Erlenmeyer flask containing 90mL sterilized water, add a few glass beads, and shake fully; prepare a series of dilutions, take one drop of each 10 ^-5 to 10 ^-8 dilution, and place them in the "Aerobic Denitrification Solid Separation and Cultivation Use a sterilized spatula to coat on the "base" plate, and make two parallel samples for each dilution. After standing at room temperature for 2 hours, the coated plate is incubated in an inverted incubator for 2 to 3 days. Pick the colony and inoculate it into the aerobic denitrification solid separation medium, and repeat the above operation until the separation is pure. The denitrification performance was determined by conventional methods.

3. The establishment of the reactor: expand the culture of the screened heterotrophic nitrifying bacteria, inoculate fresh activated sludge equivalent to 0.1% of the entire reactor volume, and operate after 3 to 7 days of air aeration to form activated sludge. When the removal rate of ammonia nitrogen is above 50%, it indicates that a stable heterooxynitration sludge system has been established, and the concentration of dissolved oxygen is gradually reduced during the operation of the reactor, from 4 to 5 mg/L to 1 to 2 mg/L. The screened aerobic denitrification bacteria were expanded and cultivated, inoculated with fresh activated sludge equivalent to 0.1% of the entire reactor volume, and activated sludge was formed after air aeration for 3 to 7 days. In this way, two cultured aerobic denitrification sewage The sludge reactor was operated, and the sludge from the two aerobic denitrification reactors was domesticated by using aerobic denitrification bacteria domestication culture solution 1 and aerobic denitrification bacteria domestication culture solution 2 respectively, and the dissolved oxygen was gradually increased during the whole domestication process. Concentration, gradually increased from 0.5 ~ 1mg/L to 3 ~ 4mg/L.

4. Add the sludge domesticated with aerobic denitrification bacteria domestication culture solution 1 to the stable heterooxynitrification sludge system in 3 times, and measure the changes in the concentration of ammonia nitrogen and nitrite in the reactor every day. When the reactor responds to ammonia nitrogen and When the removal rate of nitrite reaches more than 50%, add the sludge domesticated with aerobic denitrification bacteria acclimation culture solution 2 to the reactor in 3 times, and measure the changes in the concentration of ammonia nitrogen, nitrite and nitrate in the reactor every day , when the removal rate of ammonia nitrogen, nitrite and nitrate in the reactor reaches more than 50%, it proves that a stable synchronous nitrification and denitrification sludge can be cultivated.

Specific implementation mode two: In this implementation mode, the reactor treatment of ammonia nitrogen sewage is taken as an example:

1. For the screening of heterotrophic nitrifying bacteria, put the water sample aside and discard the supernatant, take the activated sludge and inoculate it in the heterooxygenation nitrification liquid separation medium, the inoculum size is 5%, 30 ℃, 120rpm constant temperature oscillation cultivation, see When there is obvious growth (increased turbidity of the culture medium by visual inspection), transfer to fresh medium for shaking culture, use a sterilized pipette to absorb 10 mL of the culture medium that has been enriched and acclimatized, and add it to a Erlenmeyer flask containing 90 mL of sterilized water , add a few glass beads, shake fully; prepare a series of dilutions, take one drop of 10 ^-5 to 10 ^-8 dilutions, and spread them on the iso-nitration solid separation medium plate with a sterilized spatula, each dilution Two parallel samples were made, and the coated plates were allowed to stand at room temperature for 2 hours, and then incubated in an inverted incubator for 2 to 3 days. Pick the colony and inoculate it into the nitrification solid separation medium, and repeat the above operation until the separation is pure. The nitrification performance was determined by conventional methods.

2. For the screening of good denitrifying bacteria, put the water sample aside and discard the supernatant, take the activated sludge and inoculate it into the aerobic denitrification liquid separation medium, the inoculum amount is 5%, and cultivate at 30°C and 120rpm constant temperature oscillation , when there is obvious growth (increased turbidity of the culture medium by visual inspection), transplant it into a fresh medium for shaking culture, use a sterilized pipette to absorb 10 mL of the culture medium that has been enriched and acclimatized, and add 90 mL of sterilized water to the triangle Add a few glass beads into the bottle and shake it fully; prepare a series of dilutions, take one drop of 10 ^-5 to 10 ^-8 dilutions, and spread them on the aerobic denitrification solid separation medium plate with a sterilized spatula. Two parallel samples were made for one dilution, and the coated plate was left to stand at room temperature for 2 hours, and then incubated in an inverted incubator for 2 to 3 days. Pick the colony and inoculate it into the aerobic denitrification solid separation medium, and repeat the above operation until the separation is pure. The denitrification performance was determined by conventional methods.

3. For the establishment of the reactor, the screened heterotrophic nitrifying bacteria are expanded and cultivated, inoculated with fresh activated sludge equivalent to 0.1% of the entire reactor volume, and the activated sludge is formed after air aeration for 3-7 days before operation. When the ammonia nitrogen removal rate is above 50%, it indicates that a stable heterooxynitration sludge system has been established, and the concentration of dissolved oxygen is gradually reduced during the operation of the reactor, from 4-5mg/L to 1-2mg/L. The screened aerobic denitrification bacteria are expanded and cultivated, inoculated with fresh activated sludge equivalent to 0.1% of the entire reactor volume, and activated sludge is formed after air aeration for 3-7 days. In this way, two cultured aerobic denitrification sewage Sludge reactor for operation. The sludge from the two aerobic denitrification reactors was acclimatized by aerobic denitrification bacteria domestication culture solution 1 and aerobic denitrification bacteria domestication culture solution 2 respectively, and the dissolved oxygen concentration was gradually increased throughout the domestication process, from 0.5-1mg/ L gradually increased to 3-4mg/L.

4. Add the sludge domesticated with aerobic denitrification bacteria domestication culture solution 1 to the stable heterooxynitrification sludge system in 3 times, and measure the changes in the concentration of ammonia nitrogen and nitrite in the reactor every day. When the reactor responds to ammonia nitrogen and When the removal rate of nitrite reaches more than 50%, add the sludge domesticated with aerobic denitrification bacteria acclimation culture solution 2 to the reactor in 3 times, and measure the changes in the concentration of ammonia nitrogen, nitrite and nitrate in the reactor every day , when the removal rate of ammonia nitrogen, nitrite and nitrate in the reactor reaches more than 50%, it proves that a stable synchronous nitrification and denitrification sludge can be cultivated.

Claims (4)

1. A two-stage synchronous nitrification and denitrification method for treating ammonia nitrogen wastewater, characterized in that the method is: 1. Establishment of the reactor for cultivating heterooxygen nitrification sludge: Expand the culture of the screened heterooxynitrification bacteria, inoculate fresh activated sludge equivalent to 0.1% of the entire reactor volume, and form activated sludge after air aeration for 3 to 7 days When the ammonia nitrogen removal rate is above 50%, it indicates that a stable heterooxygen nitrification sludge system has been established, and the concentration of dissolved oxygen is gradually reduced during the operation of the reactor, from 4 to 5 mg/L to 1 to 2 mg/L ; 2. Establishment of cultivating aerobic denitrification sludge reactor: expand and cultivate the screened aerobic denitrification bacteria, inoculate fresh activated sludge equivalent to 0.1% of the entire reactor volume, and form active sludge after air aeration for 3 to 7 days In this way, two reactors for cultivating aerobic denitrification sludge were established for operation; aerobic denitrification bacteria domestication culture solution 1 and aerobic denitrification bacteria domestication culture solution 2 were respectively used for the two aerobic denitrification reactions Domesticate the sludge from the tank; gradually increase the dissolved oxygen concentration during the whole domestication process, from 0.5-1 mg/L to 3-4 mg/L; 3. Simultaneous nitrification and denitrification treatment of ammonia nitrogen wastewater: Add the sludge domesticated with aerobic denitrification bacteria domestication culture solution 1 to the stable heterooxynitrification sludge system in 3 times, and measure the concentration of ammonia nitrogen and nitrite in the reactor every day When the removal rate of ammonia nitrogen and nitrite in the reactor reaches more than 50%, the sludge domesticated with aerobic denitrification bacteria acclimation culture solution 2 is added to the reactor in 3 times, and the ammonia nitrogen and nitrite in the reactor are measured every day. Changes in nitrate and nitrate concentration, when the removal rate of ammonia nitrogen, nitrite and nitrate in the reactor reaches more than 50%, it proves that a stable synchronous nitrification and denitrification sludge has been cultivated; The screening method of nitrifying bacteria is as follows: put the water sample aside and discard the supernatant, take the activated sludge and inoculate it in the different oxygen nitrification liquid separation medium, the inoculum amount is 5-10%, at 30-35°C, 120-140rpm When the turbidity of the culture medium increases visually, transplant it into a fresh medium for shaking culture, use a sterilized pipette to absorb 10mL of the enriched culture and domesticated culture medium, and add 90mL of sterile water to the triangle Add a few glass beads into the bottle and shake it fully; prepare a series of dilutions, take one drop of each of the ^10-5 to ^10-8 dilutions, and spread them on the different oxygen nitrification solid separation medium plate with a sterilized spatula, each Two parallel samples were made for the dilution, and the coated plates were left to stand at room temperature for 2 hours, and then incubated in an inverted incubator for 2 to 3 days; the colonies were picked and inoculated into the nitrification solid separation medium, and the above operations were repeated until the separation was pure; The preparation method of the different oxygen nitrification liquid separation medium is as follows: NH ₄ Cl 0.382g, sodium acetate 2g, MgSO ₄ 7H ₂ O 0.05g, K ₂ HPO ₄ 0.2g, NaCl 0.12g, MnSO ₄ 4H ₂ O 0.01 g, FeSO ₄ 0.01g, H ₂ O 1000ml, PH = 7-7.5, sterilized at 121°C for 20 minutes; the screening method for aerobic denitrifying bacteria described in step 2 is: put the water sample aside and discard the supernatant, and take The activated sludge is inoculated in the aerobic denitrification liquid separation medium, the inoculation amount is 5-10%, and it is incubated at a constant temperature under the conditions of 30-35°C and 120-140rpm. When the turbidity of the culture medium increases visually, transplant it to Shake the fresh medium for culture, use a sterilized pipette to absorb 10mL of the enriched culture and domesticated culture solution, add it to a conical flask containing 90mL sterilized water, add several glass beads, and oscillate fully; prepare a series of dilutions, take One drop each of the 10 ^-5 to 10 ^-8 dilutions, respectively spread on the aerobic denitrification solid separation medium plate with a sterilized spatula, make two parallel samples for each dilution, and put the coated plates at room temperature After 2 hours, incubate in an inverted incubator for 2 to 3 days; pick colonies and inoculate them into the aerobic denitrification solid separation medium, repeat the above operation until the separation is pure; the preparation method of the aerobic denitrification liquid separation medium is as follows: Sodium succinate 4.7g, KNO ₃ 1.5g, NaNO ₂ 0.5g, KH ₂ PO ₄ 0.5g, MgSO ₄ ·7H ₂ O 0.1g, trace element solution 2ml, H ₂ O 1000ml, sterilized at 121°C for 20min; the composition of aerobic denitrifying bacteria acclimation culture solution 1 in step 2 is as follows: succinic acid Sodium 1g, NaNO ₂ 0.2g, KH ₂ PO ₄ 0.1g, MgSO ₄ 7H ₂ O 0.02g, trace element solution 1ml, H ₂ O 1000ml; the composition of aerobic denitrifying bacteria acclimation culture solution 2 in step 2 is as follows : Sodium succinate 1g, KNO ₃ 0.4g, KH ₂ PO ₄ 0.1g, MgSO ₄ ·7H ₂ O 0.02g, trace element solution 1ml, H ₂ O 1000ml. 2. The two-stage synchronous nitrification and denitrification method for treating ammonia nitrogen wastewater according to claim 1, characterized in that the trace element solution in the aerobic denitrification liquid separation medium consists of: EDTA 50g/l, ZnSO ₄ 2.2 g/l, CaCl ₂ 5.5g/l, MnCl ₂ 4H ₂ O 5.06g/l, FeSO ₄ 7H ₂ O 5.0g/l, (NH ₄ ) ₆ Mo ₇ O ₂ 4H ₂ O 1.1g/l , CuSO ₄ ·5H ₂ O 1.57 g/l, CoCl ₂ ·6H ₂ O 1.61 g/l. 3. The two-stage synchronous nitrification and denitrification method for treating ammonia nitrogen wastewater according to claim 1, characterized in that the trace element solution in the aerobic denitrification bacteria domestication culture solution 1 is composed of: EDTA50g/l, ZnSO ₄ 2.2 g/l, CaCl ₂ 5.5g/l, MnCl ₂ 4H ₂ O 5.06g/l, FeSO ₄ 7H ₂ O 5.0g/l, (NH ₄ ) ₆ Mo ₇ O ₂ 4H ₂ O 1.1g/l , CuSO ₄ ·5H ₂ O 1.57 g/l, CoCl ₂ ·6H ₂ O 1.61 g/l. 4. The two-stage synchronous nitrification and denitrification method for treating ammonia nitrogen wastewater according to claim 1, characterized in that the trace element solution in the aerobic denitrification bacteria domestication culture solution 2 is composed of: EDTA50g/l, ZnSO ₄ 2.2 g/l, CaCl ₂ 5.5g/l, MnCl ₂ 4H ₂ O 5.06g/l, FeSO ₄ 7H ₂ O 5.0g/l, (NH ₄ ) ₆ Mo ₇ O ₂ 4H ₂ O 1.1g/l , CuSO ₄ ·5H ₂ O 1.57 g/l, CoCl ₂ ·6H ₂ O 1.61 g/l.