Low-carbon deep denitrification treatment process for high-ammonia-nitrogen wastewater

Abstract

The invention provides a low-carbon deep denitrification treatment process for high-ammonia-nitrogen wastewater, and relates to the field of wastewater treatment. The treatment process comprises the following steps that high-ammonia-nitrogen wastewater serves as wastewater to be treated, an airlift reflux integrated sewage treatment device is selected, the device comprises an aerobic reaction chamber and an anaerobic reaction chamber, the aerobic reaction chamber is an ammonia oxidizing bacteria area, the anaerobic reaction chamber is an anaerobic ammonia oxidizing bacteria area, ammonia oxidizing bacteria and anaerobic ammonia oxidizing bacteria are subjected to partitioned culture, and the ammonia oxidizing bacteria and the anaerobic ammonia oxidizing bacteria are separated; inoculating strain sludge, and treating the anaerobic ammonia oxidation granular sludge with an external electric field, wherein the intensity of the electric field is 50-100V / m; the carbon-nitrogen ratio is controlled to be 1: (2-3); the initial hydraulic retention time is 90-120 min, the water inlet flow is 6-10 m < 3 > / h, and the reflux ratio is controlled to be 190%-210%; after one week of operation, the hydraulic retention time is adjusted to be 30-60 min, the water inlet flow is 5-8 m < 3 > / h, and the reflux ratio is controlled to be 250%-300%. The high-ammonia-nitrogen animal husbandry wastewater is treated by adopting the process disclosed by the invention, the removal rate is high, green low-carbon treatment is realized, a high-ammonia-nitrogen wastewater cooperative treatment system is constructed, and the limitation of a traditional nitrification and denitrification nitrogen removal technology is broken through.

Description

Technical Field

[0001] The invention relates to the field of wastewater treatment, and in particular to a low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater. Background Art

[0002] At present, the treatment of high ammonia nitrogen wastewater in coal chemical industry, animal husbandry, breeding, sludge treatment, landfill and other industries at home and abroad mainly adopts the traditional biological method of nitrification and denitrification and the physical and chemical method of ammonia stripping and magnesium ammonium phosphate precipitation. At present, with the rise of new denitrification processes such as short-range nitrification (PN), short-range denitrification (PD) and anaerobic ammonia oxidation (ANAMMOX), short-range nitrification-denitrification, simultaneous nitrification and denitrification (SND), PN-ANAMMOX and DN-ANAMMOX combined processes are used to treat high ammonia nitrogen wastewater in order to cope with more complex ammonia nitrogen wastewater. The coupling of PN, PD and ANAMMOX treatment processes to improve the treatment effect of ammonia nitrogen wastewater has become a hot topic of research at home and abroad.

[0003] In some areas, the treatment of high ammonia nitrogen wastewater mainly adopts physical and chemical methods and biological methods. The physical and chemical methods of ammonia stripping and chemical precipitation are inseparable from the pretreatment process with high investment and high operating costs, and may also cause secondary pollution. Ammonia stripping only transfers ammonia from the water body to the air, and the ammonia pollution problem has not been properly solved. Compared with the physical and chemical method, the traditional nitrification and denitrification biological denitrification method has the advantages of high efficiency, low cost and environmental friendliness. However, the traditional biological denitrification process mainly has the problems of long process flow, excessive energy consumption and drug consumption, and the nitrification process requires a large amount of oxygen supply, and the denitrification process requires a large amount of external carbon source, which has a high operating cost. Summary of the invention

[0004] In view of this, the present invention proposes a low-carbon deep denitrification treatment process for high ammonia nitrogen wastewater.

[0005] Ammonia nitrogen wastewater treatment has always been one of the important topics in the environmental protection industry. The new denitrification technology based on anaerobic ammonia oxidation makes up for the shortcomings of traditional biological denitrification technology. Therefore, it is of great significance to develop a new high-efficiency, low-carbon deep denitrification technology based on anaerobic ammonia oxidation, develop a denitrification system that is easier to efficiently couple microorganisms with different habits, and achieve the discharge of high-ammonia nitrogen livestock wastewater. It can not only provide key technical support for the deep treatment of high-ammonia nitrogen wastewater, but also help the construction of the "Straw to Meat" and 10 million beef cattle project, and accelerate the development of animal husbandry.

[0006] The technical solution of the present invention is achieved in this way:

[0007] A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater, comprising the following steps:

[0008] Taking high ammonia nitrogen wastewater as the wastewater to be treated, a gas lift reflux integrated sewage treatment device is selected, the device includes an aerobic reaction chamber and an anaerobic reaction chamber, the aerobic reaction chamber is an ammonia oxidizing bacteria zone, the anaerobic reaction chamber is an anaerobic ammonia oxidizing bacteria zone, the ammonia oxidizing bacteria and the anaerobic ammonia oxidizing bacteria are cultured in different areas, the bacterial sludge is inoculated, and the anaerobic ammonia oxidizing granular sludge is treated with an electric field with an electric field strength of 50-100V / m; the carbon-nitrogen ratio is controlled to be 1:2-3;

[0009] The initial hydraulic retention time is 90-120 minutes, and the water flow rate is 6-10m 3 / h, control the reflux ratio to 190% to 210%;

[0010] After one week of operation, the hydraulic retention time was adjusted to 30-60 minutes and the water flow rate was 5-8m 3 / h, and control the reflux ratio to 250% ~ 300%.

[0011] Furthermore, the applied electric field strength is 75-85 V / m, the stirring speed is 100-150 r / min, and the stirring temperature is 30-35°C.

[0012] Furthermore, the volume of the sludge culture tank for the anaerobic ammonium oxidation granular sludge is 50 to 100 m 3 .

[0013] Furthermore, the dissolved oxygen concentration in the aerobic zone is controlled at 0.1-0.5 mg / L.

[0014] Furthermore, the temperature is maintained at 25°C to 30°C.

[0015] Furthermore, the pH value is controlled to be 7.0-8.0.

[0016] Furthermore, the ammonia nitrogen content of the wastewater is 800 mg / L to 1800 mg / L; the nitrate nitrogen content is 80 mg / L to 250 mg / L; the nitrite nitrogen content is 20 mg / L to 80 mg / L; and the total nitrogen content is 1000 mg / L to 2000 mg / L.

[0017] Furthermore, the effective volume of the ammonia oxidizing bacteria zone is 30 to 100 m 3 ; The effective volume of the anaerobic ammonium oxidizing bacteria zone is 20 to 100 m 3 .

[0018] Furthermore, the inoculation amount of the bacterial strain is 10% to 15% of the effective volume of the reactor.

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

[0020] (1) The process of the present invention is used to treat high-ammonia nitrogen livestock wastewater, so that the ammonia nitrogen removal rate reaches more than 90%, the total nitrogen removal rate reaches more than 85%, and the overall NRR ≥ 1.5 kg·(m 3 d) -1 , achieve green and low-carbon treatment, build a coordinated treatment system for high ammonia nitrogen wastewater, and reduce operating costs.

[0021] (2) The process of the present invention can make up for the defects existing among various processes, improve the nitrogen removal rate, shorten the biological denitrification pathway, and break the limitations of traditional nitrification and denitrification denitrification technology.

[0022] (3) The present invention treats anaerobic ammonium oxidation granular sludge, and under the action of an external electric field of a certain intensity, changes the sludge charge, promotes the sludge to quickly coagulate into granules, and maintains the uniformity of the sludge.

[0023] (4) The present invention controls a certain sludge return ratio, improves the microbial ecology, is beneficial to improving the removal efficiency, improving the effluent water quality, improving the sedimentation properties, reducing the operating cost, etc.

[0024] (5) The present invention controls the hydraulic retention time to ensure that the reaction is sufficient and the sludge is completely settled, thereby effectively improving the removal efficiency. DETAILED DESCRIPTION

[0025] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0026] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0027] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0028] The Chinese meanings of some names are as follows:

[0029] DO: dissolved oxygen;

[0030] FA: free ammonia;

[0031] FNA: free nitrite;

[0032] ANAMMOX: anaerobic ammonium oxidizing bacteria;

[0033] AOB: ammonia oxidizing bacteria;

[0034] HRT: hydraulic retention time.

[0035] The embodiment of the present invention uses a selected airlift reflux integrated sewage treatment device to prepare an airlift reflux integrated sewage treatment device by referring to Example 1 in Patent Publication No. CN101691267B and Patent Name: Airlift reflux integrated sewage treatment device.

[0036] A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater, comprising the following steps:

[0037] Livestock wastewater: ammonia nitrogen concentration is 800~1800mg / L; nitrate nitrogen content is 80mg / L~250mg / L; nitrite nitrogen content is 20mg / L~80mg / L; total nitrogen content is 1000mg / L~2000mg / L.

[0038] A gas lift reflux integrated sewage treatment device was selected, the device included an aerobic reaction chamber and an anaerobic reaction chamber, AOB bacteria and ANAMMOX bacteria were cultured in different areas, the aerobic reaction chamber was the AOB area (effective volume was 30m 3 ), the anaerobic reaction chamber is the ANAMMOX zone (effective volume is 20m 3 ), the inoculation amount of the bacteria is 10% to 15% of the effective volume of the reactor, and the bacteria sludge is inoculated;

[0039] Among them, the volume of the anaerobic ammonium oxidation granular sludge culture tank (made of stainless steel) is 50-100m 3 , anaerobic ammonium oxidation granular sludge external electric field treatment, the electric field strength is 75-85V / m, the stirring speed is 100-150r / min, and the stirring temperature is 30-35℃;

[0040] Control the following process parameters:

[0041] Control the carbon-nitrogen ratio to 1:2-3;

[0042] The dissolved oxygen concentration in the aerobic zone is controlled at 0.1-0.5 mg / L;

[0043] Keep the temperature between 25℃ and 30℃;

[0044] Control pH value to 7.0-8.0;

[0045] The initial hydraulic retention time is 90-120 minutes, and the water flow rate is 6-10m 3 / h, control the reflux ratio to 190% to 210%;

[0046] After one week of operation, the hydraulic retention time was adjusted to 30-60 minutes and the water flow rate was 5-8m 3 / h, and control the reflux ratio to 250% ~ 300%.

[0047] Example 1

[0048] A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater, comprising the following steps:

[0049] Livestock wastewater: ammonia nitrogen concentration is 800~1800mg / L; nitrate nitrogen content is 80mg / L~250mg / L; nitrite nitrogen content is 20mg / L~80mg / L; total nitrogen content is 1000mg / L~2000mg / L.

[0050] A gas lift reflux integrated sewage treatment device was selected, the device included an aerobic reaction chamber and an anaerobic reaction chamber, AOB bacteria and ANAMMOX bacteria were cultured in different areas, the aerobic reaction chamber was the AOB area (effective volume was 30m 3 ), the anaerobic reaction chamber is the ANAMMOX zone (effective volume is 20m 3 ), the inoculation amount of the bacteria is 13% of the effective volume of the reactor, and the inoculated bacteria sludge,

[0051] Among them, the volume of the anaerobic ammonium oxidation granular sludge culture tank (made of stainless steel) is 100m 3 , anaerobic ammonium oxidation granular sludge external electric field treatment, the electric field strength is 80V / m, the stirring speed is 120r / min, and the stirring temperature is 32℃±2℃;

[0052] Control the following process parameters:

[0053] Control the carbon-nitrogen ratio to 1:2.5;

[0054] The dissolved oxygen concentration was controlled at 0.3±0.1mg / L;

[0055] Maintain the temperature at 28℃±2℃;

[0056] The pH value was controlled at 7.5 ± 0.2;

[0057] The initial hydraulic retention time is 100 min and the inlet flow rate is 8 m 3 / h, control the reflux ratio to 200%;

[0058] After one week of operation, the hydraulic retention time was adjusted to 50 minutes and the water flow rate was 7m 3 / h, and the reflux ratio is controlled at 280%.

[0059] Example 2

[0060] A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater, comprising the following steps:

[0061] Livestock wastewater: ammonia nitrogen concentration is 800~1800mg / L; nitrate nitrogen content is 80mg / L~250mg / L; nitrite nitrogen content is 20mg / L~80mg / L; total nitrogen content is 1000mg / L~2000mg / L.

[0062] A gas lift reflux integrated sewage treatment device was selected, the device included an aerobic reaction chamber and an anaerobic reaction chamber, AOB bacteria and ANAMMOX bacteria were cultured in different areas, the aerobic reaction chamber was the AOB area (effective volume was 30m 3 ), the anaerobic reaction chamber is the ANAMMOX zone (effective volume is 20m 3 ), the inoculation amount of the bacteria is 13% of the effective volume of the reactor, and the bacteria sludge is inoculated;

[0063] Among them, the volume of the anaerobic ammonium oxidation granular sludge culture tank (made of stainless steel) is 100m 3 The anaerobic ammonium oxidation granular sludge was treated with an external electric field, the electric field strength was 50V / m, the stirring speed was 150r / min, and the stirring temperature was 32℃±2℃.

[0064] Control the following process parameters:

[0065] Control the carbon-nitrogen ratio to 1:2;

[0066] The dissolved oxygen concentration was controlled at 0.3±0.1mg / L;

[0067] Maintain the temperature at 28℃±2℃;

[0068] The pH value was controlled at 7.5 ± 0.2;

[0069] The initial hydraulic retention time is 90 minutes and the water flow rate is 6m 3 / h, the reflux ratio is controlled to be 210%;

[0070] After one week of operation, the hydraulic retention time was adjusted to 30 minutes and the water flow rate was 5m 3 / h, and the reflux ratio is controlled at 300%.

[0071] Example 3

[0072] A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater, comprising the following steps:

[0073] Livestock wastewater: ammonia nitrogen concentration is 800~1800mg / L; nitrate nitrogen content is 80mg / L~250mg / L; nitrite nitrogen content is 20mg / L~80mg / L; total nitrogen content is 1000mg / L~2000mg / L.

[0074] A gas lift reflux integrated sewage treatment device was selected, the device included an aerobic reaction chamber and an anaerobic reaction chamber, AOB bacteria and ANAMMOX bacteria were cultured in different areas, the aerobic reaction chamber was the AOB area (effective volume was 30m 3 ), the anaerobic reaction chamber is the ANAMMOX zone (effective volume is 20m 3 ), the inoculation amount of the bacteria is 13% of the effective volume of the reactor, and the bacteria sludge is inoculated;

[0075] Among them, the volume of the anaerobic ammonium oxidation granular sludge culture tank (made of stainless steel) is 100m 3 The anaerobic ammonium oxidation granular sludge was treated with an external electric field, the electric field strength was 100V / m, the stirring speed was 100r / min, and the stirring temperature was 32℃±2℃.

[0076] Control the following process parameters:

[0077] Control the carbon-nitrogen ratio to 1:3;

[0078] The dissolved oxygen concentration was controlled at 0.3±0.1mg / L;

[0079] Maintain the temperature at 28℃±2℃;

[0080] The pH value was controlled at 7.5 ± 0.2;

[0081] The initial hydraulic retention time is 120 min and the inlet flow rate is 10 m 3 / h, control the reflux ratio to 190%;

[0082] After one week of operation, the hydraulic retention time was adjusted to 60 minutes and the water flow rate was 8m 3 / h, and the reflux ratio is controlled at 250%.

[0083] Test example

[0084] High ammonia nitrogen wastewater from cattle farms was selected, with an average ammonia nitrogen concentration of 1200 mg / L; an average nitrate nitrogen content of 150 mg / L; an average nitrite nitrogen content of 50 mg / L; and an average total nitrogen content of 1500 mg / L. The operation was carried out according to Examples 1-3 for 14 consecutive days, and the wastewater treatment results are shown in Table 1:

[0085] Table 1 Wastewater treatment

[0086] Ammonia nitrogen removal rate Total nitrogen removal rate Overall NRR Example 1 95.3％ 90.3％ <![CDATA[≥1.5kg·(m 3 ·d) -1 ]]> Example 2 90.7％ 85.7％ <![CDATA[≥1.5kg·(m 3 ·d) -1 ]]> Example 3 92.1％ 87.3％ <![CDATA[≥1.5kg·(m 3 ·d) -1 ]]>

[0087] As shown in Table 1, the livestock wastewater was run by the methods of Examples 1-3 of the present invention, so that the ammonia nitrogen removal rate reached more than 90%, the total nitrogen removal rate reached more than 85%, and the overall NRR ≥ 1.5 kg·(m 3 d) -1, achieve green and low-carbon treatment, build a coordinated treatment system for high ammonia nitrogen wastewater, and effectively reduce operating costs.

[0088] Comparative Example 1

[0089] The main difference between this comparative example and Example 1 is that the electric field strength is 30 V / m. Specifically, the volume of the anaerobic ammonium oxidation granular sludge culture tank (made of stainless steel) is 100 m 3 , the anaerobic ammonium oxidation granular sludge was treated with an external electric field, the electric field strength was 30V / m, the stirring speed was 150r / min, and the stirring temperature was 32°C±2°C. Other treatments were consistent with Example 1. It was found that the sludge formed particles slowly and could not quickly condense to form particles.

[0090] Comparative Example 2

[0091] The main difference between this comparative example and Example 1 is that the electric field strength is 120 V / m. Specifically, the volume of the anaerobic ammonium oxidation granular sludge culture tank (made of stainless steel) is 100 m 3 The anaerobic ammonium oxidation granular sludge was treated with an external electric field, the electric field strength was 120V / m, the stirring speed was 150r / min, and the stirring temperature was 32°C±2°C. Other treatments were consistent with Example 1. The results showed that although the sludge formed granules quickly, the sludge uniformity was poor.

[0092] Comparative Example 3

[0093] The main difference between this comparative example and Example 1 is that the reflux ratio is adjusted. Specifically, the initial hydraulic retention time is 120 min, the inlet flow rate is 10 m 3 / h, and the reflux ratio was controlled to 150%; after one week of operation, the hydraulic retention time was adjusted to 60min, and the water flow rate was 8m 3 / h, and the reflux ratio was controlled to be 200%. Other treatments were consistent with Example 1. The results showed that the removal efficiency was low and the sludge settling property was deteriorated.

[0094] Comparative Example 4

[0095] The main difference from Example 1 is that the reflux ratio is adjusted. Specifically, the initial hydraulic retention time is 120 min, the inlet flow rate is 10 m 3 / h, and the reflux ratio was controlled to 250%; after one week of operation, the hydraulic retention time was adjusted to 60min, and the water flow rate was 8m 3 / h, and the reflux ratio was controlled to be 400%. Other treatments were consistent with Example 1. As a result, it was found that there were problems such as poor sludge settling performance and sludge bulking.

[0096] Comparative Example 5

[0097] The main difference between this comparative example and Example 1 is that the carbon-nitrogen ratio is controlled to be 1:4. Other treatments are consistent with Example 1. The results show that the removal efficiency decreases and the effluent water quality decreases significantly.

[0098] Comparative Example 6

[0099] The main difference between this comparative example and Example 1 is that the initial hydraulic retention time is 60 min. Specifically, the initial hydraulic retention time is 60 min, and the water flow rate is 8 m 3 / h, and the reflux ratio was controlled to 200%; after one week of operation, the hydraulic retention time was adjusted to 50min, and the water flow rate was 7m 3 / h, and the reflux ratio was controlled to be 280%. Other treatments were consistent with Example 1. The results showed that the sludge sedimentation was incomplete, the reaction was insufficient, and the removal rate was significantly reduced.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-carbon deep denitrification process for high-ammonia nitrogen wastewater, characterized in that: The following steps are involved: Taking high ammonia nitrogen wastewater as the wastewater to be treated, a gas lift reflux integrated sewage treatment device is selected, the device includes an aerobic reaction chamber and an anaerobic reaction chamber, the aerobic reaction chamber is an ammonia oxidizing bacteria zone, the anaerobic reaction chamber is an anaerobic ammonia oxidizing bacteria zone, the ammonia oxidizing bacteria and the anaerobic ammonia oxidizing bacteria are cultured in different zones, the bacterial sludge is inoculated, and the anaerobic ammonia oxidizing granular sludge is treated by applying an electric field, and the electric field strength is 50-100V / m; Control the carbon-nitrogen ratio to 1:2-3; The initial hydraulic retention time is 90-120 minutes, and the water flow rate is 6-10m 3 / h, control the reflux ratio to 190% to 210%; After one week of operation, the hydraulic retention time was adjusted to 30-60 minutes, and the water flow rate was 5-8m 3 / h, and control the reflux ratio to 250% ~ 300%.

2. A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater according to claim 1, characterized in that: The applied electric field strength is 75-85 V / m, the stirring speed is 100-150 r / min, and the stirring temperature is 30-35° C.

3. A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater according to claim 1, characterized in that: The volume of the sludge culture tank for the anaerobic ammonium oxidation granular sludge is 50 to 100 m 3 .

4. A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater according to claim 1, characterized in that: The dissolved oxygen concentration is controlled at 0.1-0.5 mg / L.

5. A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater according to claim 1, characterized in that: Maintain the temperature at 25℃~30℃ and control the pH value at 7.0~8.

0.

6. A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater according to claim 1, characterized in that: The wastewater has an ammonia nitrogen content of 800 mg / L to 1800 mg / L; a nitrate nitrogen content of 80 mg / L to 250 mg / L; a nitrite nitrogen content of 20 mg / L to 80 mg / L; and a total nitrogen content of 1000 mg / L to 2000 mg / L.

7. A low-carbon deep denitrification treatment process for high-ammonia nitrogen wastewater according to claim 1, characterized in that: The effective volume of the ammonia oxidizing bacteria zone is 30 to 100 m 3 The effective volume of the anaerobic ammonium oxidizing bacteria zone is 20 to 100 m 3 .

8. A low-carbon deep denitrification process for high-ammonia nitrogen wastewater according to claim 7, characterized in that: The inoculation amount of the bacterial strain is 10% to 15% of the effective volume of the reactor.

9. The low-carbon deep denitrification treatment process for high ammonia nitrogen wastewater according to any one of claims 1 to 8, characterized in that: The wastewater is animal husbandry wastewater.