Sulfur autotrophic denitrification biological carrier and its preparation method and application

Abstract

The invention relates to the technical field of sewage treatment, and proposes a sulfur autotrophic denitrification biological carrier and a preparation method and application thereof, wherein the sulfur autotrophic denitrification biological carrier comprises sulfur powder, iron ore powder, a slow-release carbon source, a binder, a denitrifying thiobacillus SZG-SAD-004 bacterial liquid and water, the slow-release carbon source is one or more combinations of dibutyl phthalate, triphenyl phosphate, dioctyl azelaic acid and chitin; the deposit number of the denitrifying thiobacillus SZG-SAD-004 is CCTCC NO:M2023992. The present invention uses sulfur powder and iron ore powder to form a composite sulfur source material, and uses a slow-release carbon source as a heterotrophic electron donor. SZG-SAD-004 is used as a biological carrier prepared by a main microorganism to improve the denitrification load of the sulfur autotrophic filler reaction. The carrier load can stably reach 3.5-5.0 kg N / t / d, and the maximum load can reach 8.0 kg N / t / d. The carrier composite denitrifying thiobacillus can be applied to high salt salinity tolerance up to 38000 ion concentration, high dissolved oxygen tolerance of 4 mg / L, and the lowest temperature tolerance of 8°C.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a sulfur autotrophic denitrification biological carrier and a preparation method and application thereof. Background Art

[0002] Sulfur autotrophic carrier technology is an innovative wastewater treatment technology. Its core lies in utilizing the biotransformation ability of sulfur autotrophic microorganisms to achieve effective removal of nitrogen pollutants in wastewater through the attachment and growth of specific microbial populations on the carrier. This technology combines the advantages of biological denitrification and sulfur autotrophic metabolism, providing a new solution for the treatment of low carbon-nitrogen ratio wastewater.

[0003] In the field of wastewater treatment, traditional biological denitrification technology mainly relies on heterotrophic microorganisms, which need to consume a large amount of organic carbon sources during the denitrification process. However, in practical applications, many wastewaters (such as urban sewage and industrial wastewater) have a low carbon-nitrogen ratio, which is difficult to meet the denitrification needs of heterotrophic microorganisms. Therefore, researchers began to explore denitrification technologies that do not require an external carbon source, among which sulfur autotrophic denitrification technology has gradually attracted attention.

[0004] In recent years, there have been many studies and patent applications on sulfur autotrophic denitrification technology at home and abroad, such as the invention patents with publication numbers CN116495893A and CN116143281A, both of which disclose biological carriers. However, the denitrification load of the sulfur autotrophic denitrification carriers is relatively low, which is difficult to meet the requirements of sulfur autotrophic denitrification technology. Therefore, it is necessary to develop a sulfur autotrophic denitrification biological carrier with a higher denitrification load. Summary of the invention

[0005] In view of this, the present invention proposes a sulfur autotrophic denitrification biological carrier with a high denitrification load, and a preparation method and application thereof.

[0006] The technical scheme of the present invention is achieved as follows: the present invention provides a sulfur autotrophic denitrification biological carrier, comprising sulfur powder, iron ore powder, a slow-release carbon source, calcium carbonate, a binder, a bacterial solution of denitrifying Thiobacillus SZG-SAD-004 and water, wherein the slow-release carbon source is one or more combinations of butylene terephthalate, dibutyl phthalate, triphenyl phosphate, dioctyl azelaic acid and chitin; the deposit number of the denitrifying Thiobacillus SZG-SAD-004 is CCTCC NO: M2023992.

[0007] The denitrifying thiobacillus SZG-SAD-004 of the present invention has a certain decomposition effect on dibutyl phthalate, triphenyl phosphate, dioctyl azelate and chitin, and can decompose them into carbon sources as heterotrophic electron donors. Sulfur powder and iron ore powder composite sulfur source materials serve as autotrophic electron donors, and nitrate in sewage serves as an electron acceptor. The combination of the three provides the denitrifying thiobacillus SZG-SAD-004 with the energy source required by the sulfur autotrophic denitrification system. At the same time, the denitrifying thiobacillus SZG-SAD-004 is also resistant to high salt, high dissolved oxygen and low temperature environments, which expands the scope of application of the biological carrier.

[0008] The slow-release carbon source is used as a heterotrophic electron donor, and Thiobacillus denitrificans SZG-SAD-004 is used as the main microorganism. The microbial carrier is obtained by extrusion granulation under the action of a binder.

[0009] On the basis of the above technical scheme, preferably, calculated by weight, it includes 20-60 parts of sulfur powder, 5-20 parts of iron ore powder, 10-30 parts of slow-release carbon source, 30-55 parts of calcium carbonate, 5-15 parts of binder, 3-8 parts of denitrifying Thiobacillus SZG-SAD-004 bacterial solution and 8-12 parts of water.

[0010] On the basis of the above technical solution, preferably, the iron ore powder is ground from one or more of siderite, pyrite, orpyrite and marcasite.

[0011] On the basis of the above technical solution, preferably, the particle size of the sulfur powder is greater than 200 meshes, and the particle size of the iron ore powder is 70-120 meshes.

[0012] On the basis of the above technical solution, preferably, the binder is one or more combinations of diatomaceous earth, gypsum, silicate cement, aluminum phosphate, calcium carbonate and polyvinyl alcohol.

[0013] On the basis of the above technical solution, preferably, the number of viable bacteria in the denitrifying Thiobacillus SZG-SAD-004 bacterial solution is greater than or equal to 10 8 CFU / g.

[0014] The present invention also provides a method for preparing a sulfur autotrophic denitrification biological carrier, which is characterized by comprising the following steps:

[0015] S1, inoculating Thiobacillus denitrificans SZG-SAD-004 into a culture medium for activation to obtain a bacterial solution;

[0016] S2, sulfur powder, iron ore powder, slow-release carbon source, calcium carbonate, binder and water are mixed and stirred evenly, extruded and granulated to obtain a carrier, and then the denitrifying Thiobacillus SZG-SAD-004 bacterial liquid is sprayed on the surface of the carrier to obtain a sulfur autotrophic denitrification biological carrier.

[0017] On the basis of the above technical solution, preferably, the amount of water used is 8%-12% of the total weight of sulfur powder, iron ore powder, slow-release carbon source and binder.

[0018] The invention also provides an application of a sulfur autotrophic denitrifying biological carrier in sewage treatment.

[0019] The sulfur autotrophic denitrification biological carrier and its preparation method and application of the present invention have the following beneficial effects compared with the prior art:

[0020] (1) The denitrifying Thiobacillus SZG-SAD-004 of the present invention can degrade dibutyl phthalate, triphenyl phosphate, and dioctyl azelate, and use them as carbon sources and energy sources for growth and reproduction, thereby improving the denitrification capacity and load of the denitrifying Thiobacillus SZG-SAD-004.

[0021] (2) Traditional denitrification technology requires the addition of an organic carbon source. The present invention utilizes sulfur powder and iron ore powder as electron donors and a slow-release carbon source as a heterotrophic electron donor to participate in sulfur autotrophic denitrification technology, achieving denitrification under anaerobic or anoxic conditions without the need for an external carbon source, thereby reducing the generation of heterotrophic bacteria and reducing the production of sludge and operating costs.

[0022] (3) The sulfur autotrophic denitrification filler of the present invention can not only provide a suitable biofilm growth environment and promote the activity of sulfur autotrophic denitrifying bacteria, but also couple iron autotrophic and heterotrophic denitrification to fundamentally improve the denitrification efficiency.

[0023] (4) The filler of the present invention has strong adaptability. Combined with the self-developed denitrifying Thiobacillus, it can adapt to different water qualities and environmental conditions, especially high-salt, high-dissolved oxygen, and low-temperature environments, thereby improving the scalability of the technology.

[0024] (5) The calcium and sulfur contained in the gypsum in the binder are nutrients required for the growth of microorganisms. The addition of these nutrients can effectively promote the growth of sulfur-oxidizing bacteria such as denitrifying Thiobacillus. Moreover, under anaerobic conditions, sulfate-reducing bacteria can reduce sulfates (such as sulfate ions in gypsum) to sulfides. At the same time, the energy released in this process can be used to simultaneously realize the circulation of sulfur elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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 or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 The figures are the physical pictures of the biological carriers of different colors of the present invention;

[0027] Figure 2 This is a diagram showing changes in carrier load of the biological carrier of the present invention under different salt concentration environments;

[0028] Figure 3 This is a diagram showing the change in carrier load of the biological carrier of the present invention under different dissolved oxygen environments;

[0029] Figure 4 This is a diagram showing the change in carrier load of different batches of biological carriers in different temperature environments of the present invention;

[0030] Figure 5 This is a diagram showing changes in carrier load of the biological carrier of the present invention under a long-term low-temperature environment;

[0031] Figure 6 This is a graph showing changes in nitrate nitrogen and denitrification load in factory wastewater. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The denitrifying Thiobacillus SZG-SAD-004 used in the present invention was deposited in the China Center for Type Culture Collection (CCTCC) (Address: Wuhan University, Wuhan, China, Postal Code: 430072) on June 12, 2023, with a deposit number of CCTCC NO: M2023992, and the protection center identified the strain Thiobacillus denitrificans SZG-SAD-004 as active on June 19, 2023. In the present invention, the strain is referred to as SZG-SAD-004.

[0034] Preparation of SZG-SAD-004 bacterial solution: SZG-SAD-004 was inoculated into the culture medium at an inoculation amount of 10% v / v, the pH of the culture medium was adjusted to 7.0-7.2, sterilized at 121°C for 30 min, controlled at 30°C, and cultured for 24 h to obtain SZG-SAD-004 fermentation liquid with a viable count of greater than or equal to 10 8 CFU / g.

[0035] Culture medium: sodium thiosulfate pentahydrate 0.6 g / L, potassium nitrate 0.3 g / L, sodium bicarbonate 0.2 g / L, potassium dihydrogen phosphate 0.2 g / L, magnesium chloride hexahydrate 0.1 g / L, ferrous sulfate heptahydrate 0.02 g / L.

[0036] Example 1

[0037] The preparation method of the sulfur autotrophic denitrification biological carrier of this embodiment comprises the following steps:

[0038] S1, take 300g of sulfur powder above 200 mesh, 150g of siderite powder of 100 mesh, 30g of triphenyl phosphate, 70g of butylene terephthalate, 25g of diatomaceous earth, 25g of silicate cement, 100g of gypsum and 300g of 200 mesh calcium carbonate and mix them evenly, atomize the mixed materials with water in an amount of 100g, stir them evenly at room temperature, granulate them with a double-roll extrusion granulator after the materials are fully mixed, and obtain oval particles with a particle size of 5mm. The powder is sieved and heated in an oven at 180°C for 30min, and cooled at room temperature for 2h to obtain a carrier product.

[0039] S2, take 50g of the activated SZG-SAD-004 fermentation liquid, dilute it 10 times with pure water, and spray it evenly on the surface of the carrier to obtain the sulfur autotrophic denitrification biological carrier material.

[0040] Example 2

[0041] The preparation method of the sulfur autotrophic denitrification biological carrier of this embodiment comprises the following steps:

[0042] S1, take 600g of sulfur powder above 200 mesh, 50g of 100 mesh pyrite powder, 80g of dioctyl azelate, 70g of chitin, 10g of diatomaceous earth, 10g of aluminum phosphate, 5g of polyvinyl alcohol, 25g of cement, 50g of gypsum, and 400g of 200 mesh calcium carbonate and mix them evenly, atomize the mixed materials with water, the water dosage is 156g, stir them evenly at room temperature, granulate them with a double-roll extrusion granulator after the materials are fully mixed, and obtain oval particles with a particle size of 5mm. Sieve the powder clean, heat it in an oven at 180℃ for 30min, and cool it at room temperature for 2h to obtain the carrier product.

[0043] S2, take 80g of the activated SZG-SAD-004 fermentation liquid, dilute it 10 times with pure water, and spray it evenly on the surface of the carrier to obtain the sulfur autotrophic denitrification biological carrier material.

[0044] Example 3

[0045] The preparation method of the sulfur autotrophic denitrification biological carrier of this embodiment comprises the following steps:

[0046] S1, take 200g of sulfur powder above 200 mesh, 200g of orpiment iron powder, 25g of butylene terephthalate, 25g of triphenyl phosphate, 25g of diatomaceous earth, 25g of gypsum, and 350g of 200 mesh calcium carbonate and mix them evenly, atomize the mixed materials with water, the water dosage is 85g, stir them evenly at room temperature, granulate them with a double-roll extrusion granulator after the materials are fully mixed, and obtain oval particles with a particle size of 5mm. The powder is sieved and heated in an oven at 180°C for 30min, and cooled at room temperature for 2h to obtain the finished product.

[0047] S2, take 30g of the activated SZG-SAD-004 fermentation liquid, dilute it 10 times with pure water, and spray it evenly on the surface of the carrier to obtain the sulfur autotrophic denitrification biological carrier material.

[0048] Example 4

[0049] The preparation method of the sulfur autotrophic denitrification biological carrier of this embodiment comprises the following steps:

[0050] S1, take 500g of sulfur powder above 200 mesh, 100g of white iron ore powder, 100g of dibutyl phthalate, 100g of chitin, 20g of silicate cement, 80g of gypsum, 20g of polyvinyl alcohol, and 550g of 200 mesh calcium carbonate and mix them evenly, atomize the mixed materials with water in an amount of 160g, stir them evenly at room temperature, granulate them with a double-roll extrusion granulator after the materials are fully mixed, and obtain oval particles with a particle size of 5mm. The powder is sieved and heated in an oven at 180°C for 30min, and cooled at room temperature for 2h to obtain the finished product.

[0051] S2, take 60g of the activated SZG-SAD-004 fermentation liquid, dilute it 10 times with pure water, and spray it evenly on the surface of the carrier to obtain the sulfur autotrophic denitrification biological carrier material.

[0052] Comparative Example 1

[0053] The difference between Comparative Example 1 and Example 1 is that the slow-release carbon sources triphenyl phosphate and butylene terephthalate are missing, and the rest of the contents are the same as Example 1.

[0054] Comparative Example 2

[0055] The difference between Comparative Example 2 and Example 1 is that the iron source siderite powder is missing, and the rest of the contents are the same as Example 1.

[0056] Comparative Example 3

[0057] The difference between Comparative Example 3 and Example 1 is that the slow-release carbon source triphenyl phosphate, butylene terephthalate and iron source siderite powder are missing, and the rest of the contents are the same as Example 1.

[0058] 1. Mechanical properties test of biological carrier

[0059] The performance tests were performed on the carriers prepared in the examples and comparative examples. The results are shown in Table 1.

[0060] Table 1 Bio-carrier properties

[0061]

[0062]

[0063] Figure 1 The biological carrier prepared in the example is shown in Table 1. Compared with the comparative example, the biological carrier prepared in the present invention has higher comprehensive mechanical properties. Now, its chemical properties are tested.

[0064] 2. Biological carrier load test

[0065] Take the carrier fillers prepared in Examples 1-7 respectively, according to the volume of 2L sulfur autotrophic denitrification device, add 1 / 3 device volume of pebbles, 500g carrier, 0.5v% BP116 (Sulfur autotrophic bacteria agent of Water Country), 0.02v% BP110 (Compound denitrification bacteria of Water Country), add 1L culture solution (containing 100mg / L nitrate nitrogen and 2mg / L phosphorus), and let it stand for 24h before starting the water inlet experiment (the first round of water inlet contains 100mg / L nitrate nitrogen and 2mg / L phosphorus), and speed up by staying for two days at each hydraulic retention time of 8h-4h-2h-1h-0.5h. After speeding up to 0.5h, the inlet nitrate nitrogen concentration is increased according to 100-150-200-300-400-600mg / L.

[0066] Sampling time: Sampling and measuring device data every 24 hours, measuring index: measuring NO 3- —N, NO 2- —N, NH 4+ —N, PH, TP, TN indicators, calculate the stable load of the carrier device, the results are shown in the table below.

[0067] Table 2 Biological carrier performance test

[0068]

[0069]

[0070] As shown in Table 2, the biological carrier prepared in the embodiment of the present invention can stably tolerate nitrate concentrations up to 250-400 mg / L and a stable load of 4.2-5 kg ​​N / m 3 / d, the maximum load can reach 10kg N / m 3 / d, which is much higher than that of comparative examples 1-3. It can be seen that adding iron source and slow-release carbon source has a positive effect on the compliance of the biological carrier.

[0071] The application of the test biological carrier in high salt, high dissolved oxygen and low temperature environment, the specific test method and test results are as follows:

[0072] 3. Biological carrier salt tolerance test (0-4%)

[0073] The carrier filler was prepared according to Example 1. According to the volume of the sulfur autotrophic denitrification device of 2L, 1 / 3 of the device volume of pebbles, 500g of carriers, 0.5% BP116 (sulfur autotrophic agent of Water Country), 0.02% BP110 (composite denitrifying bacteria of Water Country) were added to each device. 1L of culture solution (containing 100mg / L nitrate nitrogen and 2mg / L phosphorus) was added and the bacteria were cultured for 24h. Then, the water inlet experiment was started (the first round of water inlet contained 100mg / L nitrate nitrogen and 2mg / L phosphorus). The speed was increased by staying for two days at each hydraulic retention time of 8h-4h-2h-1h-0.5h. The water inlet nitrate nitrogen concentration was always 150mg / L. The inlet NaCl concentration was set to 0wt%, 2wt%, 3wt%, and 4wt%, respectively. The results are shown in FIG. Figure 2 .

[0074] Figure 2 As shown in the figure, under the condition of 0-wt3% NaCl, there was no significant difference in the 0-10 h interval, but there was a large fluctuation in the 10-20 h interval, and it tended to be 2.8-3.0 kg N / m at 21 h. 3 / d. Under 4wt% NaCl conditions, the carrier load showed an up-down-up trend and tended to 2.5kg N / m at 21h. 3 / d, thus it can be seen that the carrier of the present invention can be applied to the environment of 0-4wt% NaCl.

[0075] 4. Biological carrier dissolved oxygen resistance test (0.4~2.5mg / L)

[0076] Prepare the carrier filler according to Example 1, prepare the carrier filler according to Example 1, according to the volume of 2L sulfur autotrophic denitrification device, add 1 / 3 device volume of pebbles to each device, 500g carrier, add 0.5v% BP116 (Sulfur autotrophic bacteria agent of Water Country), 0.02v% BP110 (Compound denitrification bacteria of Water Country), add 1L culture solution (containing 100mg / L nitrate nitrogen and 2mg / L phosphorus), let it stand for 24h, then start the water inlet experiment (the first round of water inlet contains 100mg / L nitrate nitrogen and 2mg / L phosphorus), and speed up by staying for two days at each hydraulic retention time of 8h-4h-2h-1h-0.5h. Always feed water at a nitrate nitrogen concentration of 150mg / L, set different dissolved oxygen concentrations of 0.4, 1.2, and 2.5mg / L for water inlet experiment, and continuously collect data for analysis. The results are shown in the figure. Figure 3 .

[0077] Figure 3 As shown in the figure, under the environment of dissolved oxygen 0.4-2.5 mg / L, the carrier load showed an overall upward trend, reached equilibrium in 20 hours, and reached 3-6 kgN / m 3 / d range, reaching 4.5~5.5kg N / m in 52h 3 / d, which shows that the carrier of the present invention can be used in a dissolved oxygen environment of 0.4-2.5 mg / L.

[0078] 5. Biological carrier temperature resistance test

[0079] The carrier filler was prepared according to Example 1. According to the volume of the 2L sulfur autotrophic denitrification device, 1 / 3 of the device volume of pebbles, 500g of carrier, 0.5v% BP116 (Sulfur autotrophic bacteria of Water Country), 0.02v% BP110 (Compound denitrifying bacteria of Water Country) and 1L of culture solution (containing 100mg / L nitrate nitrogen and 2mg / L phosphorus) were added to each device. After standing and cultivating the bacteria for 24h, the water inlet experiment was started (the first round of water inlet contained 100mg / L nitrate nitrogen and 2m g / L phosphorus), and the speed was increased by two days of retention time at each hydraulic retention time of 8h-4h-2h-1h-0.5h. The influent nitrate nitrogen concentration was always 150mg / L. The first round of high temperature experiments was increased from 37℃ to 45℃ every 2-3d, and then low temperature experiments were carried out; the second round of low temperature experiments was carried out from 20℃ to 10℃ every 2℃ to verify the treatment effect. Each temperature condition was operated for 2-3d, and data was continuously collected for analysis. The results are shown in Figure 4-5 .

[0080] Figure 4 As shown in the figure, in the high temperature experiment (37-45°C), as the operation time increases and the temperature rises, the carrier load shows a slow upward trend. When the operation time is 2-36 days, the carrier load is less than 1kg N / m 3 / d, 40d and 44d showed an increasing trend, reaching 3kgN / m at 45℃44d 3 / d and 5.5kgN / m 3 / d, which is the highest load of the two batches of carriers. The carrier loads in low temperature experiments (20-10℃) are all higher than 1kgN / m 3 / d, and with the extension of running time and the decrease of temperature, the carrier load shows a slow downward trend (same Figure 5 ), indicating that low temperature has a certain effect on the carrier loading.

[0081] 6. Actual application of a chemical wastewater

[0082] On December 27, 2023, the conventional physical and chemical indicators of a chemical wastewater were measured. The results are shown in Table 3, and the inhibition conditions and corresponding treatment measures were determined.

[0083] Table 3 Conventional physical and chemical indicators of chemical wastewater

[0084]

[0085] (1) Add the corresponding amount of sodium carbonate precipitant according to the calcium and magnesium ion concentration in the raw water. If the calcium and magnesium ion concentration of the raw water is 100mmol / L=0.1mol / L, the amount of sodium carbonate required to precipitate all the calcium and magnesium ions per liter of raw water is 0.1×10 6 =10.6g.

[0086] (2) After adding the precipitant and adjusting the pH to about 8, 0.1 wt% of trace elements were added, and 2 mg / L of phosphorus was supplemented in the influent.

[0087] (3) According to the device volume of 2L, add 1 / 3 device volume of pebbles, 500g carrier, 10v% BP116, 0.2v‰ BP110, and 1L culture solution (containing 100mg / L nitrate nitrogen and 2mg / L phosphorus) to each device. After standing and cultivating the bacteria for 24h, start the water inlet experiment.

[0088] (4) The water inlet at one end of the device is used as the raw water inlet, and the water inlet at the other end is used as the return water inlet. At the beginning of startup, the raw water inlet retention time is set to 24h, the return ratio is 600%, and the return water retention time is 4h; when the denitrification effect is stable for at least 2d under this condition, the speed is increased according to the raw water retention time of 12h and the return ratio of 300%.

[0089] (5) Take samples at regular intervals every day to measure the total nitrogen, nitrate nitrogen, nitrite nitrogen and pH of the water entering and leaving the device. The results are shown in the table below. Figure 6 .

[0090] From the results of this round of experiments, it can be seen that the current SZG carrier sulfur autotrophic pilot device can degrade 2000mg / L 600% reflux to 30mg / L, and the maximum carrier load is 8.21kgN / t / d (see Figure 6 ). The specific operation requires the removal of calcium and magnesium ions in the influent water and the addition of appropriate trace elements to properly treat a certain chemical wastewater.

[0091] 7. Actual application of a chemical wastewater

[0092] The nitrate and nitrite wastewater of this enterprise is mainly generated during the production process of cleaning the surface of plated parts. Due to the instability of rainwater and production output in the factory area, the water quality and quantity of the wastewater will fluctuate greatly. First, the conventional physical and chemical indicators of the wastewater are measured (see Table 4). The blue barrel and the white barrel are the water quality of two different sampling points, and the inhibition conditions and corresponding treatment measures are determined.

[0093] Table 4 Water quality indicators of electroplating surface cleaning wastewater

[0094]

[0095] From the analysis of the production sources of nitrate and nitrite wastewater of the enterprise, it can be seen that the water quality of the wastewater has the following main characteristics:

[0096] The wastewater has a low carbon-nitrogen ratio, a low COD, and a nitrite nitrogen content of nearly 75%. The carbon-nitrogen ratio is about 1:1, which is a low carbon-nitrogen ratio wastewater. The pH value of the wastewater is high. When performing biological denitrification, the pH generally needs to be controlled between 6-9, so the pH of the wastewater needs to be strictly controlled. The calcium and magnesium ion content is high. High calcium and magnesium ions are prone to scaling. When alkaline substances are used to adjust the pH, there will be a lot of precipitation. Therefore, when performing biological denitrification, pretreatment needs to be added at the front end to remove the precipitation.

[0097] At the beginning, the inlet TN was set at 270mg / L, and the operation was tried for 4h. The total nitrogen removal efficiency was limited, and the sulfur autotrophic bacteria had not yet fully adapted to the wastewater. Therefore, it was adjusted to 8h operation, and after 3 days of continuous operation. The effluent total nitrogen continued to decrease, and on the 4th day TN had dropped to about 13, so starting from the 5th day, it was adjusted to 6h operation, and the inlet TN was maintained at about 180-200mg / L. The continuous effluent TN data were maintained within 10mg / L, and the highest removal rate could reach 98.57%.

[0098] According to the expected target, the water intake is 0.96m 3 / d is 0.04m 3 / h, the carrier load that can make the effluent stable and meet the standard is 2.16kgN / m 3 / d; the maximum carrier load so far is 5.86kg N / m 3 / d, and can basically stabilize the carrier load at 4-6kg N / m 3 / d, which is far beyond expectations. Based on this data, the maximum daily water intake of the existing device is 3.3m 3 Under the condition of high pressure, the total nitrogen in the effluent can reach the discharge standard.

[0099] The total nitrogen in the water of this sulfur autotrophic pilot equipment is 200-270mg / L, and the total nitrogen in the effluent can be stably maintained below 10mg / L, which is far below the emission standard. The carrier load is greater than 2kg N / m 3 / d, up to 5.86kg N / m 3 / d, this result shows that the denitrification of wastewater using sulfur autotrophic denitrification technology is completely stable and reliable.

[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 spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sulfur autotrophic denitrification biological carrier, characterized in that: It includes sulfur powder, iron ore powder, slow-release carbon source, calcium carbonate, binder, and denitrifying Thiobacillus SZG-SAD-004 bacterial solution, wherein the slow-release carbon source is one or more combinations of dibutyl phthalate, triphenyl phosphate and dioctyl azelate; The accession number of the denitrifying Thiobacillus SZG-SAD-004 is CCTCC NO: M2023992; Calculated by weight, the invention comprises 20-60 parts of sulfur powder, 5-20 parts of iron ore powder, 10-30 parts of slow-release carbon source, 30-55 parts of calcium carbonate, 5-15 parts of binder and 3-8 parts of denitrifying Thiobacillus SZG-SAD-004 bacterial liquid.

2. A sulfur autotrophic denitrifying biological carrier according to claim 1, characterized in that: The iron ore powder is obtained by grinding one or more of siderite, pyrite, pyrite and marcasite.

3. A sulfur autotrophic denitrifying biological carrier according to claim 2, characterized in that: The particle size of the sulfur powder is greater than 200 meshes, and the particle size of the iron ore powder is 70-120 meshes.

4. A sulfur autotrophic denitrifying biological carrier according to claim 1, characterized in that: The binder is one or more combinations of diatomaceous earth, gypsum, silicate cement, aluminum phosphate and polyvinyl alcohol.

5. A sulfur autotrophic denitrifying biological carrier according to claim 1, characterized in that: The number of live bacteria in the denitrifying Thiobacillus SZG-SAD-004 bacterial solution is greater than or equal to 10 8 CFU / g.

6. A method for preparing a sulfur autotrophic denitrifying biological carrier according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, inoculating Thiobacillus denitrificans SZG-SAD-004 into a culture medium for activation to obtain a bacterial solution; S2, sulfur powder, iron ore powder, slow-release carbon source, calcium carbonate, binder and water are mixed and stirred evenly, extruded and granulated to obtain a carrier, and then the denitrifying Thiobacillus SZG-SAD-004 bacterial liquid is sprayed on the surface of the carrier to obtain a sulfur autotrophic denitrification biological carrier.

7. The method for preparing a sulfur autotrophic denitrifying biological carrier according to claim 6, characterized in that: The amount of water used in step S2 is 8%-12% of the total weight of sulfur powder, iron ore powder, slow-release carbon source, calcium carbonate and binder.

8. Use of a sulfur autotrophic denitrifying biological carrier as described in any one of claims 1 to 7 in sewage treatment.

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