An activated carbon-based biosynergist and its preparation method and application

Abstract

The present invention belongs to the field of sewage treatment technology, and specifically relates to an activated carbon-based biosynergist, its preparation method, and application. The fermentation extract in the biosynergist of the present invention can provide essential nutrients for microorganisms in the sewage treatment process, improve the activity of the organisms, increase the abundance of the microbial population, and strengthen the sensing mechanism of the microbial population; at the same time, the nutrient salt containing metal ions in the biosynergist can provide the elements required for the growth and reproduction of microorganisms, and the metal elements therein can enhance the flocculation performance of the activated sludge and resist the impact and load changes suffered by the microorganisms; furthermore, using soybean cake as a fermentation substrate can supplement a certain carbon source for the sewage denitrification process, avoid secondary pollution of the effluent caused by excessive addition of carbon source, and at the same time regenerate resources to a certain extent; and the activated carbon load makes storage convenient, and the adsorption capacity of the activated carbon can improve its ability to remove pollutants.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to an activated carbon-based biological enhancer and a preparation method and application thereof. Background Art

[0002] In recent years, sewage treatment effluent indicators have become increasingly higher, and local standards have become increasingly stringent. The national Class A standard (COD: 50mg / L, TN: 15mg / L) is becoming increasingly difficult to meet the increasingly stringent effluent indicators, while some sewage treatment plants are still using some old treatment methods and operating processes, making it difficult to meet local standards.

[0003] The common methods for treating wastewater include physical and chemical methods, chemical methods and biological methods, among which the biological method is the most widely used method. The biological method is divided into the activated sludge method and the biofilm method. The activated sludge method has become the mainstream method for treating wastewater in sewage treatment plants due to its good treatment effect, low treatment cost and strong applicability. The traditional activated sludge method, SBR method, MBR method and oxidation ditch method are all based on activated sludge. The most common AAO method uses aerobic tanks to degrade COD, anoxic tanks to denitrify, and anaerobic tanks to release phosphorus. If the carbon source in the anoxic tank is insufficient, it will be difficult to maintain high efficiency in the anoxic denitrification process, and the additional addition of carbon source will increase operating costs and deteriorate the effluent water quality. In addition, the capital construction cost of upgrading and renovating traditional sewage treatment plants is large. Therefore, seeking a method to enhance the denitrification effect of sewage without changing the original operating process has become a research hotspot in recent years.

[0004] The preparation of high-efficiency biological enhancers is a simple, economical and convenient method to enhance the denitrification of sewage. It can meet the discharge requirements without changing the basic facilities of the sewage treatment plant. Chinese patent CN115465958A discloses a biological nutrient for denitrification of sewage and its preparation method and device, which ferments expired and spoiled food and fruit and vegetable waste into usable microbial nutrients, especially as a carbon source in the process of sewage denitrification treatment, to achieve the purpose of resource recycling and cost reduction and efficiency improvement of sewage treatment. However, fermentation into nutrient solution only increases the carbon source. Although it will enhance the denitrification effect, if the dosage is not well controlled, it may cause secondary pollution of the effluent. It does not fundamentally enhance the activity of microorganisms and increase the abundance of populations, making it difficult to further improve the denitrification effect. Chinese patent CN107804917A discloses a biosynergist for improving the efficiency of industrial wastewater biochemical treatment systems. The biosynergist consists of Agent A and Agent B. Agent A consists of a microbial cell treatment product, a mixture of metal-containing nutrient salts, a preservative, and the remainder is water; Agent B is a solid flocculant mixture. This biosynergist can provide the necessary nutrients for microbial division and proliferation, enhancing the flocculation performance of activated sludge. However, its enhanced denitrification effect is not significant, the production and dosing methods are complex, storage is inconvenient, and environmental conditions have a significant impact on its treatment efficiency. Therefore, existing biosynergists have poor enhanced denitrification effects and are prone to secondary pollution. Summary of the Invention

[0005] The present invention aims to provide an activated carbon-based biosynergist and its preparation method and application, which can enhance the activity of denitrifying microorganisms in the sewage treatment process, improve the pollutant degradation ability, and avoid the problem of secondary pollution of the effluent.

[0006] The present invention provides an activated carbon-based biosynergist, comprising activated carbon, a fermentation extract loaded onto the activated carbon, and a nutrient salt containing metal ions;

[0007] The preparation method of the fermentation extract comprises: mixing and ultrasonically extracting a soybean cake fermentation mixture of denitrifying bacteria, a DNA extraction phenol reagent and a protease, and performing solid-liquid separation on the obtained mixture to obtain a fermentation extract containing the fermentation extract.

[0008] Preferably, the mass ratio of the fermentation extract to the nutrient salt containing metal ions is 1-2:0.2-0.5; the mass ratio of the nutrient salt containing metal ions to the activated carbon is 10-20:45-55.

[0009] Preferably, the method for preparing the soybean cake and meal fermentation mixture of the denitrifying bacteria strain comprises: mixing and fermenting soybean cake and meal, denitrifying bacteria strain and water to obtain the soybean cake and meal fermentation mixture of the denitrifying bacteria strain;

[0010] The fermentation temperature is 30-35° C., the fermentation time is 10-15 days, the pH value is 6.5-7.2, and the oxygen content is 3000-5000 L / m 3 .

[0011] Preferably, the denitrifying bacteria include one or more of Pseudomonas, Bacillus, Paenibacillus, Saccharomyces, Acinetobacter, Aeromonas hydrophila, Moraxella osloensis and Thiobacillus denitrifying; and the effective viable count of the denitrifying bacteria is 800 million to 1.5 billion per gram.

[0012] Preferably, the mass ratio of the soybean cake, denitrifying bacteria and water is 40-50:2-6:50-80.

[0013] Preferably, the DNA extraction phenol reagent includes a DNA extraction phenol reagent with a volume percentage of 5 to 10%, and the DNA extraction phenol reagent is 5 to 15% of the volume of the soybean cake fermentation mixture of the denitrifying bacteria; the protease includes one or more of neutral protease, alkaline protease, trypsin, subtilisin and endopeptidase, and the amount of the protease is 2000 to 5000 U / g of the soybean cake fermentation mixture of the denitrifying bacteria.

[0014] Preferably, the frequency of the ultrasonic extraction is 35-60 Hz, the time is 0.5-1 h, and the temperature is 30-35°C.

[0015] Preferably, the nutrient salt containing metal ions includes ferrous sulfate heptahydrate, polyferric chloride, calcium chloride dihydrate and magnesium chloride; the mass ratio of ferrous sulfate heptahydrate, polyferric chloride, calcium chloride dihydrate and magnesium chloride is 1:1.5:5-6:8-10;

[0016] The present invention also provides a method for preparing the activated carbon-based biosynergist described in the above technical solution, comprising: loading a fermentation extract, a nutrient salt containing metal ions, and activated carbon through a liquid phase impregnation method to obtain the activated carbon-based biosynergist; the liquid phase impregnation method is carried out in an alcohol environment.

[0017] The present invention also provides the use of the activated carbon-based biosynergist described in the above technical solution or the activated carbon-based biosynergist prepared by the preparation method in sewage treatment.

[0018] Beneficial effects:

[0019] The present invention provides an activated carbon-based biosynergist, which comprises activated carbon, a fermentation extract loaded on the activated carbon, and a nutrient salt containing metal ions. The preparation method of the fermentation extract comprises: mixing a soybean cake fermentation mixture of denitrifying bacteria, a DNA extraction phenol reagent, and a protease, performing ultrasonic extraction, and performing solid-liquid separation on the obtained mixture, so as to obtain a fermentation extract containing the fermentation extract.

[0020] The present invention performs cell wall extraction on the fermentation mixture of denitrifying bacteria, and loads the obtained fermentation extract including DNA, protein, polysaccharide and extracellular polymer together with nutrient salts containing metal ions onto activated carbon to prepare the bio-synergist. The fermentation extract in the bio-synergist of the present invention can provide essential nutrients for microorganisms in the sewage treatment process, improve the activity of organisms, increase the abundance of microbial populations, and strengthen the sensing mechanism of microbial populations; at the same time, the nutrient salts containing metal ions in the bio-synergist can provide elements required for the growth and reproduction of microorganisms, and the metal elements therein can enhance the flocculation performance of activated sludge and resist the impact and load changes suffered by microorganisms; furthermore, using soybean cake as a fermentation substrate can supplement a certain carbon source for the sewage denitrification process, avoid secondary pollution of effluent caused by excessive addition of carbon source, and regenerate resources to a certain extent; and the activated carbon loading makes storage convenient, and the adsorption capacity of activated carbon can improve its ability to remove pollutants.

[0021] At the same time, the biosynergist of the present invention has a simple preparation process, a long storage time, is easy to use, has a significant denitrification effect, and is suitable for industrial large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below.

[0023] Figure 1 This is a diagram showing the effect of denitrification using the biosynergist in Example 1 in Application Example 1;

[0024] Figure 2 This is a diagram showing the effect of denitrification using the biosynergist in Example 2 in Application Example 1;

[0025] Figure 3 This is a diagram showing the denitrification effect in the control group in Application Example 1 where no bio-synergist was used. DETAILED DESCRIPTION

[0026] The present invention provides an activated carbon-based biosynergist, which comprises activated carbon, a fermentation extract loaded onto the activated carbon, and a nutrient salt containing metal ions;

[0027] The preparation method of the fermentation extract comprises: mixing a soybean cake fermentation mixture of denitrifying bacteria, a DNA extraction phenol reagent and a protease, performing ultrasonic extraction, and performing solid-liquid separation on the obtained mixture to obtain a fermentation extract containing the fermentation extract.

[0028] The mass ratio of the metal ion-containing nutrient salt to the activated carbon of the present invention is preferably 10-20:45-55, more preferably 12-16:50-52; the metal ion-containing nutrient salt is preferably an aqueous nutrient salt solution containing metal ions, and the concentration of the aqueous nutrient salt solution containing metal ions is preferably 3-8 ppm, more preferably 5 ppm. The metal ion-containing nutrient salt of the present invention preferably includes ferrous sulfate heptahydrate, polyferric chloride, calcium chloride dihydrate, and magnesium chloride; the mass ratio of ferrous sulfate heptahydrate, polyferric chloride, calcium chloride dihydrate, and magnesium chloride is preferably 1:1.5:5-6:8-10, more preferably 1:1.5:5:9; the metal ion-containing nutrient salt can provide the elements necessary for microbial growth and reproduction, and the metal elements therein can enhance the flocculation performance of the activated sludge and resist the shock load changes to which the microorganisms are subjected. The particle size of the activated carbon of the present invention is preferably 100-200 mesh, more preferably 120 mesh. The activated carbon of the present invention preferably comprises activated activated carbon, and the activation method preferably comprises: heating the activated carbon for activation, wherein the activation temperature is preferably 100-150°C, more preferably 100°C, and the activation time is preferably 0.8-1.2 hours, more preferably 1 hour. The activated carbon provides a carrier for the nutrient salts and the fermentation broth, and the loading method facilitates storage. The adsorption capacity of the activated carbon can improve its ability to remove pollutants.

[0029] The mass ratio of the fermentation extract of the present invention to the nutrient salt containing metal ions is preferably 1-2:0.2-0.5, more preferably 1.5:0.3. The method for preparing the fermentation extract of the present invention comprises: mixing a soybean cake fermentation mixture of a denitrifying bacterial strain, a DNA extraction phenol reagent, and a protease, performing ultrasonic extraction, and then subjecting the resulting mixture to solid-liquid separation to obtain the fermentation extract.

[0030] The present invention preferably prepares a soybean cake fermentation mixture of denitrifying bacteria. The preparation method of the soybean cake fermentation mixture of denitrifying bacteria comprises: mixing and fermenting soybean cake, denitrifying bacteria and water to obtain the soybean cake fermentation mixture of denitrifying bacteria.

[0031] The denitrifying bacteria described herein preferably include one or more of Pseudomonas, Bacillus, Paenibacillus, Saccharomyces, Acinetobacter, Aeromonas hydrophila, Moraxella osloensis, and Denitrifying Thiobacillus, with Pseudomonas, Bacillus, Paenibacillus, Saccharomyces, Acinetobacter, and Denitrifying Thiobacillus being more preferred. The effective viable cell counts of Pseudomonas, Bacillus, Paenibacillus, Saccharomyces, Acinetobacter, and Denitrifying Thiobacillus are preferably in a ratio of 2:1:1:1:1:2. The present invention does not specifically limit the strain type of the denitrifying bacteria; any strain of the corresponding species can achieve the technical effects of the present invention. The effective viable cell count of the denitrifying bacteria described herein is preferably 800-1.5 billion cells / g, more preferably 1 billion cells / g. The present invention does not specifically limit the source of the soybean cake and meal; conventional commercially available products in the art can be used. The present invention does not specifically limit the ratio of soybean cake to soybean meal in the soybean cake and meal; any ratio can be used. The present invention uses soybean meal as a fermentation substrate for denitrifying bacteria, which can provide nutrients required by microorganisms after fermentation and can also supplement part of the carbon source for microorganisms in the sewage treatment process, thereby regenerating resources to a certain extent.

[0032] The mass proportion of the soybean meal of the present invention is preferably 40 to 50 parts, more preferably 42 to 46 parts, and more preferably 45 parts; the mass proportion of the denitrifying bacteria is preferably 2 to 6 parts, more preferably 3 to 5 parts, and more preferably 4 parts; the mass proportion of water is preferably 50 to 80 parts, more preferably 60 to 70 parts, and more preferably 60 parts, that is, the mass ratio of the soybean meal, denitrifying bacteria and water of the present invention is preferably 40 to 50:2 to 6:50 to 80, and more preferably 45:4:60.

[0033] The fermentation of the present invention is preferably aerobic fermentation; the fermentation temperature is preferably 30-35°C, more preferably 33°C; the fermentation time is preferably 10-15 days, more preferably 13 days; the pH value is preferably 6.5-7.2, more preferably 7.2; the oxygen content is preferably 3000-5000 L / m 3 , more preferably 4200L / m 3 The fermentation conditions of the present invention can promote the rapid growth and reproduction of denitrifying bacteria.

[0034] After obtaining the soybean cake fermentation mixture of the denitrifying bacteria, the soybean cake fermentation mixture of the denitrifying bacteria, a DNA extraction phenolic reagent, and a protease are mixed and ultrasonically extracted. The DNA extraction phenolic reagent of the present invention preferably includes a DNA extraction phenolic reagent with a volume percentage of 5-10%, more preferably 6%; the volume of the DNA extraction phenolic reagent is preferably 5-15% of the volume of the soybean cake fermentation mixture of the denitrifying bacteria, more preferably 10%. The protease of the present invention preferably includes one or more of neutral protease, alkaline protease, trypsin, subtilisin, and endopeptidase, and multiple proteases are preferably used in equal amounts; the enzymatic activity of each protease is preferably 2500-5500U, more preferably 4200U; the amount of the protease is preferably 3000-5000U / g of the soybean cake fermentation mixture of the denitrifying bacteria, more preferably 3800g / U of the soybean cake fermentation mixture of the denitrifying bacteria.

[0035] The present invention preferably uses a vortex mixer for the mixing to achieve the purpose of uniformly mixing the soybean cake fermentation mixture of the denitrifying bacteria, the DNA extraction phenol reagent and the protease; the mixing time is preferably 3 to 5 minutes, more preferably 4 minutes.

[0036] The ultrasonic extraction frequency of the present invention is preferably 35-60 Hz, more preferably 45 Hz; the extraction time is preferably 0.5-1 hour, more preferably 0.8 hour; and the temperature is preferably 30-35°C, more preferably 32°C. The ultrasonic extraction of the present invention can achieve the effect of cell wall-breaking and extracting DNA, proteins, polysaccharides, and extracellular polymers. The extracted substances can increase microbial abundance and enhance microbial activity, thereby enhancing the denitrification capacity of sludge during sewage treatment.

[0037] After the ultrasonic extraction, the present invention preferably performs solid-liquid separation on the resulting mixture, and collects the supernatant to obtain a fermentation extract. The solid-liquid separation method of the present invention is preferably centrifugation, and the centrifugation speed is preferably 6000-7000 rpm, more preferably 6800 rpm; the time is preferably 25-28 minutes, more preferably 26 minutes.

[0038] The present invention also provides a method for preparing the activated carbon-based biosynergist described in the above technical solution, comprising: loading the fermentation extract, nutrient salts containing metal ions and activated carbon through a liquid phase impregnation method to obtain the activated carbon-based biosynergist; the liquid phase impregnation method is carried out in an alcohol environment.

[0039] The loading method described herein preferably comprises mixing and stirring a fermentation extract, a nutrient salt containing metal ions, an alcohol, and activated carbon to produce an activated carbon-based bio-enhancer. The alcohol described herein preferably comprises anhydrous ethanol, methanol, or propanol, more preferably anhydrous ethanol. The mass ratio of the alcohol to the nutrient salt containing metal ions is preferably 1:0.2-0.5, more preferably 1:0.3-0.4. The anhydrous ethanol described herein has the effect of coagulating proteins, providing a stabilizing effect on wastewater treatment or the preparation of bio-enhancers. The stirring time described herein is preferably 1 hour. The stirring method described herein is not particularly limited; conventional stirring methods in the art may be employed.

[0040] After obtaining the activated carbon-based biosynergist, the present invention preferably further comprises vacuum drying the activated carbon-based biosynergist. The vacuum drying temperature of the present invention is preferably 10-15°C, more preferably 12-15°C, and the drying time is preferably 16-24 hours, more preferably 20-24 hours. The particle size of the activated carbon-based biosynergist of the present invention is preferably 0.05-0.2 mm, more preferably 0.1-0.15 mm.

[0041] The present invention performs cell wall extraction on the fermentation mixture of denitrifying bacteria, and loads the obtained fermentation extract including DNA, protein, polysaccharide and extracellular polymers together with nutrient salts containing metal ions onto activated carbon to prepare the activated carbon-based bio-synergist. The fermentation extract in the bio-synergist of the present invention can provide necessary nutrients for microorganisms in the sewage treatment process, improve the activity of organisms, increase the abundance of microbial populations, and strengthen the sensing mechanism of microbial populations; at the same time, the nutrient salts containing metal ions in the bio-synergist can provide elements required for the growth and reproduction of microorganisms, and the metal elements therein can enhance the flocculation performance of activated sludge and resist the impact and load changes suffered by microorganisms; furthermore, using soybean cake as a fermentation substrate can supplement a certain carbon source for the sewage denitrification process, avoid secondary pollution of effluent caused by excessive addition of carbon source, and regenerate resources to a certain extent; and the activated carbon loading makes storage convenient, and the adsorption capacity of activated carbon can improve its ability to remove pollutants.

[0042] Based on the above advantages, the present invention further provides the use of the activated carbon-based biosynergist described in the above technical solution or the activated carbon-based biosynergist prepared by the preparation method in sewage treatment, preferably biological sewage treatment, and more preferably biological sewage denitrification. In the present invention, the specific method for performing the sewage denitrification treatment preferably includes: mixing the activated carbon-based biosynergist with sludge and then adding the mixed sludge, wherein the amount of the activated carbon-based biosynergist used is preferably 0.5% of the dry solid weight of the sludge.

[0043] In order to further illustrate the present invention, the technical solution provided by the present invention is described in detail below with reference to the accompanying drawings and embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0044] The sources and parameters of the components in the following examples

[0045] Soybean meal; from a feed factory in Jiangsu;

[0046] Highly efficient denitrifying commercially available bacteria from the Shanghai Collection Biotechnology Center, including Pseudomonas, Bacillus, Paenibacillus, Saccharomyces, Acinetobacter, and Denitrifying Thiobacillus in a ratio of 2:1:1:1:1:2, with a total effective viable count of 960 million cells / g;

[0047] Water; deionized water; nutrient salt; ferrous sulfate heptahydrate, polyferric chloride, calcium chloride dihydrate and magnesium chloride (all from Aladdin reagent); the weight ratio of ferrous sulfate heptahydrate, polyferric chloride, calcium chloride dihydrate and magnesium chloride is 1:1.5:5:9; DNA extraction phenol reagent: volume fraction: 6%, from Aladdin reagent; protease: from Aladdin reagent, specifically neutral protease, alkaline protease, trypsin, subtilisin and endopeptidase, the mass ratio of the neutral protease, alkaline protease, trypsin, subtilisin and endopeptidase is 1:1:1:1:1, and the enzymatic activity of each protease is 4200U; ethanol: anhydrous ethanol; activated carbon: particle size is 100 mesh.

[0048] Example 1

[0049] A method for preparing a biosynergist comprises the following steps:

[0050] Weigh the soybean meal, high-efficiency denitrification bacteria and water in the ratio of 45:4:60 and mix them evenly at a temperature of 33°C, a pH of 7.2 and an oxygen content of 4200 L / m 3 The mixture was placed in a fermentation tank and fermented for 13 days under the conditions of 10% phenol reagent for DNA extraction and 3800 U / g of protease. After the fermentation was completed, 10% DNA extraction phenol reagent and 3800 U / g of protease were added to the fermentation mixture and mixed evenly in a vortex mixer for 4 minutes. After mixing evenly, the mixture was ultrasonically broken at a frequency of 45 Hz for 0.8 hours, and then centrifuged at a speed of 6800 rpm for 27 minutes to obtain a centrifuged fermentation liquid.

[0051] Activated carbon was activated at 100°C for 1 hour to obtain activated carbon. 52 parts by mass of activated carbon and 15 parts by mass of nutrient solution were weighed. A certain amount of centrifuged fermentation broth was mixed with ethanol and nutrient solution (5 ppm concentration) in a mass ratio of 1:1.5:0.35. Subsequently, activated carbon was added to the mixture of centrifuged fermentation broth and nutrient solution and the mixture was stirred for 1 hour. Finally, the mixture was vacuum-dried at 12°C for 20 hours to obtain the bio-enhancer.

[0052] Example 2

[0053] The biosynergist was prepared by the preparation method in Example 1, except that the weight fraction of activated carbon was 45 parts and the weight fraction of nutrient salt solution was 15 parts.

[0054] Application Example 1

[0055] The biological enhancer prepared in Examples 1 to 2 was used in a 3L biological denitrification filter reactor in the laboratory at a dosage of 50 mg / L per day. The heterotrophic denitrification sludge was inoculated. The activated sludge came from a sewage treatment plant in Jiangsu Province and had good denitrification capacity after 60 days of simulated wastewater cultivation in the laboratory. The three reactors were respectively designated R1 and R2. In addition, a denitrification biological filter R0 using a commercially available biological enhancer (brand: [Microbial Enhancer] Industrial and Municipal Aquaculture Wastewater Treatment Agent Bacteria Promoter from Suzhou Ruisen Environmental Technology Co., Ltd., purchased online) was set as a control group.

[0056] The three reactors were fed with simulated wastewater from the laboratory. The simulated water was prepared with laboratory tap water. Initially, potassium nitrate (KNO3) was added to each reactor as the only source of nitrogen. NO3 - -N concentration was about 80 mg / L, and sodium acetate was added as a carbon source, CODZ was controlled at 100 mg / L, the initial pH value of each reactor was about 7.2, and the room temperature was 25 ° C. In the experiment, the laboratory simulated wastewater, and the total nitrogen (TN) content was approximately the internal NO3 - -N, NO2 - -N and NH4 + The reactor was operated for a total of 60 days, which was divided into two stages. The first stage, 0 to 30 days, was the efficiency adaptation stage, with an HRT (hydraulic retention time) of 8 hours. The second stage, 30 to 60 days, was the load increase stage, with the HRT increased to 4 hours. The experimental results are shown in Figure 2. Figures 1 to 3 As shown:

[0057] The first stage after the R1 reactor is inoculated with activated sludge is the efficiency adaptation period. Figure 1 As shown in the figure, it can be seen that the TN removal rate is above 50% when the reactor starts to operate. Then the bio-synergist is added and after about 10 days of operation, the bio-synergist begins to play a role and the activity of activated sludge increases significantly. - The removal rate was 80.52% and the TN removal rate was 75.32%. - The removal rate was 89.47%, the TN removal rate was 77.63%, and the TN reached 17 mg / L, almost meeting the national Class A standard. At the end of the first stage, NO3 -The removal rate was 93.98%, the TN removal rate was 92.77%, and TN dropped to 6 mg / L, meeting the TN emission standards of various places. As the water retention time was reduced from 8h to 4h, the nitrogen removal rate increased slightly at the beginning of the second stage. As the reactor was running, at 49 days, NO3 - The removal rate was 88.75%, and the TN removal rate was 86.13%. At the end of the second stage for 60 days, NO3 - The removal rate was 97.2% and the TN removal rate was 96.53%.

[0058] In summary, the biosynergist prepared by this method has a good denitrification effect. The reactor has been running continuously for 60 days, and the TN removal rate has been stable at more than 95%, dropping to 5 mg / L. In order to meet the needs of the project, the hydraulic retention time is shortened, and the denitrification efficiency is still maintained at a very high level without affecting the denitrification effect. It far meets the TN emission standards of various places and is an economical and efficient method to improve the denitrification efficiency.

[0059] The R2 reactor is a low-carbon bio-synergist. The first stage after inoculation of activated sludge is the synergistic adaptation period. Figure 2 As shown in the figure, it can be seen that the TN removal rate was not good at the beginning of the operation of the reactor. Then the bio-synergist was added. After about 10 days of operation, the bio-synergist began to play a role, the activity of the activated sludge increased significantly, and NO3 - The removal rate was 75.29% and the TN removal rate was 67.06%. - The removal rate was 90.21%, the TN removal rate was 88.05%, and TN reached 9.8 mg / L, meeting the national Class A standard. At the end of the first stage, NO3 - The removal rate was 92%, the TN removal rate was 88.13%, and TN dropped to 8.9 mg / L, meeting the TN emission standards of various places. As the water retention time was reduced from 8h to 4h, the nitrogen removal rate increased slightly at the beginning of the second stage. As the reactor was running, at 49 days, NO3 - The removal rate was 82.93%, and the TN removal rate was 78.66%. At the end of the second stage for 60 days, NO3 - The removal rate was 95.12%, the TN removal rate was 91.22%, and the COD in both stages was below 50 mg / L, meeting the emission standards.

[0060] In summary, the biosynergist modified activated carbon produced by R2 has fewer components, and the TN is below 8 mg / L during 60 days of stable operation, but the denitrification effect is lower than that of the R1 reactor. The TN removal rate is also very fast, but the TN is always above 5 mg / L and cannot achieve the purpose of deep denitrification. This shows that the modified activated carbon has a higher pollutant removal effect and is an important component of this biosynergist.

[0061] The R0 reactor is the control group using common bio-enhancers. The first stage after inoculation of activated sludge is the synergistic adaptation period. Figure 3 As shown in the figure, it can be seen that in the first stage, after 17 days of operation, TN dropped below 20 mg / L. At the end of the first stage, NO3 - The removal rate was 86.67%, the TN removal rate was 82%, and the TN was 13.5 mg / L, reaching the national Class A standard. In the second stage, as the water retention time decreased from 8h to 4h, the nitrogen removal rate began to rise with the operation of the reactor. At the end of the second stage for 60 days, NO3 - The removal rate was 83.53%, the TN removal rate was 79.41%, and the TN was 17.5 mg / L, which was a slight increase in nitrogen removal efficiency compared to the end of the first stage.

[0062] In summary, the denitrification effect and denitrification rate of the R0 reactor are much lower than those of the R1 and R2 reactors using bio-boosting agents. The TN in the first stage can reach below 15 mg / L, but the operation effect is not stable. After shortening the hydraulic retention time, after 30 days of stable operation, the TN is still above 15 mg / L, and the denitrification effect is difficult to further improve.

[0063] The R1, R2, and R0 reactors were compared. Soybean meal was mixed and fermented with sludge inoculated with a highly efficient denitrifying bacterial strain. The fermentation mixture was then ultrasonically disrupted, and the supernatant was extracted for protein, polysaccharides, and extracellular polymers (ECPs) for solid-liquid separation. Finally, the mixture and nutrients were loaded onto activated carbon powder via liquid-phase impregnation. The resulting bioaugmenter significantly enhanced activated sludge activity, increased microbial population abundance, and supplemented a carbon source. This bioaugmenter demonstrated high nitrogen removal efficiency. After 60 days of operation, at a HRT of 6 hours, TN remained below 5 mg / L, with a removal rate above 95%, and COD remained below 50 mg / L. This activated carbon-based bioaugmenter for wastewater denitrification represents a new approach and a novel solution for addressing denitrification challenges in sewage treatment plant upgrading, industrial wastewater tailwater treatment, and secondary effluent treatment at municipal wastewater treatment plants. It holds significant implications for practical engineering applications.

[0064] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. An activated carbon-based biosynergist, characterized in that: The invention comprises activated carbon and a fermentation extract and a nutrient salt containing metal ions loaded on the activated carbon, wherein the fermentation extract and the nutrient salt containing metal ions are loaded on the activated carbon; The preparation method of the fermentation extract comprises: mixing a soybean cake fermentation mixture of denitrifying bacteria, a DNA extraction phenol reagent and a protease, performing ultrasonic extraction, and performing solid-liquid separation on the obtained mixture to obtain a fermentation extract containing the fermentation extract; The nutrient salt containing metal ions includes ferrous sulfate heptahydrate, polyferric chloride, calcium chloride dihydrate and magnesium chloride; the mass ratio of the ferrous sulfate heptahydrate, polyferric chloride, calcium chloride dihydrate and magnesium chloride is 1:1.5:5~6:8~10.

2. The activated carbon-based biosynergist according to claim 1, characterized in that The mass ratio of the fermentation extract to the nutrient salt containing metal ions is 1-2:0.2-0.5; the mass ratio of the nutrient salt containing metal ions to the activated carbon is 10-20:45-55.

3. The activated carbon-based biosynergist according to claim 1, characterized in that The method for preparing the soybean cake and meal fermentation mixture of the denitrifying bacteria comprises: mixing and fermenting soybean cake and meal, denitrifying bacteria and water to obtain the soybean cake and meal fermentation mixture of the denitrifying bacteria; The fermentation temperature is 30-35°C, the fermentation time is 10-15 days, the pH value is 6.5-7.2, and the oxygen content is 3000-5000 L / m 3 .

4. The activated carbon-based biosynergist according to claim 1 or 3, characterized in that The effective viable bacteria count of the denitrifying bacteria is 800-1.5 billion / g.

5. The activated carbon-based biosynergist according to claim 3, characterized in that The mass ratio of the soybean cake, denitrifying bacteria and water is 40-50:2-6:50-80.

6. The activated carbon-based biosynergist according to claim 1, characterized in that The DNA extraction phenol reagent comprises a DNA extraction phenol reagent with a volume percentage of 5-10%, and the DNA extraction phenol reagent is 5-15% of the volume of the soybean cake fermentation mixture of the denitrifying bacteria; the dosage of the protease is 2000-5000U / g of the soybean cake fermentation mixture of the denitrifying bacteria.

7. The activated carbon-based biosynergist according to claim 1 or 6, characterized in that The frequency of the ultrasonic extraction is 35-60 Hz, the time is 0.5-1 h, and the temperature is 30-35°C.

8. The method for preparing the activated carbon-based biosynergist according to any one of claims 1 to 7, characterized in that: include: The fermentation extract, nutrient salt containing metal ions and activated carbon are loaded by a liquid phase impregnation method to obtain the activated carbon-based biosynergist; the liquid phase impregnation method is carried out in an alcohol environment.

9. Use of the activated carbon-based biosynergist according to any one of claims 1 to 7 or the activated carbon-based biosynergist prepared by the preparation method according to claim 8 in sewage treatment.

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