A kind of autotrophic denitrification filter material and its preparation method and application

Abstract

The present invention provides an autotrophic denitrification filter material, comprising three types of materials A, B, and C, and the weight ratio of each material is A: B: C = (10-15): (1-2): 1, wherein A is a composite denitrification ingredient, including ferrous sulfide, sulfur, sodium thiosulfate and iron powder; B is an adhesive; and C is a molecular sieve treated with a microbial culture solution. The high efficiency of the autotrophic denitrification filter material with high efficiency denitrification provided by the present invention is mainly based on the following two options: first, the filter material belongs to a multivalent composite sulfide-iron coupling denitrification scheme, and the diverse electron donors of the autotrophic denitrifying bacteria have synergistic synergy; second, the autotrophic denitrifying bacteria culture solution is pre-placed in the gap of the molecular sieve, which can be slowly released, ensuring that the autotrophic denitrifying bacteria can still maintain growth when the environment is subjected to various shocks. The autotrophic denitrification filter material provided by the present invention has a simple preparation process, is easy to operate during application, and can maintain high efficiency in denitrification capacity.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and in particular relates to an autotrophic denitrification filter material and a preparation method and application thereof. Background Art

[0002] Denitrification has always been an important topic in the field of sewage treatment. Currently, biological denitrification is the main denitrification technology. The technologies related to biological denitrification are mainly concentrated in three aspects: heterotrophic denitrification technology, autotrophic denitrification technology, and heterotrophic-autotrophic denitrification synergistic denitrification technology. These three biological denitrification technologies have their own advantages and disadvantages.

[0003] Heterotrophic denitrification technology is to remove nitrate nitrogen by converting it into nitrogen gas through heterotrophic bacteria under the appropriate carbon-nitrogen ratio. This method is relatively mature and is currently the most widely used. Under the premise that the added carbon source is relatively suitable, the microbial growth rate is faster and the denitrification effect is better; the disadvantages of this method are also obvious. It is difficult to achieve extreme denitrification. When the carbon source is insufficient, the denitrification efficiency will be reduced, and the added carbon source will increase the treatment cost and cause secondary pollution.

[0004] Autotrophic denitrification technology uses sulfur, iron and other reducing elements as substrates to cultivate autotrophic denitrifying bacteria, and then uses autotrophic denitrifying bacteria to convert nitrate nitrogen into nitrogen gas for removal. The advantages of this method are that it does not require an external carbon source and can achieve extreme denitrification. The disadvantages are that the microbial growth rate is low and the microbial adaptation to the environment is poor, which affects the treatment effect in actual projects.

[0005] Heterotrophic-autotrophic denitrification synergistic denitrification technology refers to the use of electron donors such as sulfur and iron, and then carbon sources such as sawdust, without the need for an external organic carbon source, to achieve the purpose of denitrification through the synergistic effect of heterotrophic and autotrophic bacteria. This type of technology can make up for the shortcomings of low value-added efficiency and poor impact resistance of autotrophic bacteria through the cultivation of heterotrophic denitrifying bacteria; this denitrification scheme needs to take into account two denitrification methods, which increases the difficulty of controlling the actual denitrification operation. Summary of the invention

[0006] In view of the problems existing in the above-mentioned prior art, the present invention provides an autotrophic denitrification filter material and a preparation method and application thereof. The present invention provides an autotrophic denitrification filter material.

[0007] The first aspect of the present invention provides an autotrophic denitrification filter material, comprising three types of materials A, B, and C, and the weight ratio of each material is A:B:C=(10-15):(1-2):1, wherein A is a composite denitrification ingredient, including ferrous sulfide, sulfur, sodium thiosulfate and iron powder; B is an adhesive; and C is a molecular sieve treated with a microbial culture solution.

[0008] According to some preferred embodiments of the filter material of the present invention, in the material A, the weight ratio of the components is ferrous sulfide: sulfur: sodium thiosulfate: iron powder = (10-20): (90-100): (10-20):1.

[0009] According to some preferred embodiments of the filter material of the present invention, in the material A, the weight ratio of each component is ferrous sulfide: sulfur: sodium thiosulfate: iron powder = (12-18): (94-97): (12-18): 1.

[0010] According to some preferred embodiments of the filter material of the present invention, the adhesive is selected from at least one of starch, animal hide glue, bone glue, sodium dodecylbenzene sulfonate, and sodium lignin cellulose.

[0011] According to some preferred embodiments of the filter material of the present invention, the molecular sieve is at least one of 3A molecular sieve, 4A molecular sieve, 5A molecular sieve and 13XAPG molecular sieve.

[0012] According to some preferred embodiments of the filter material of the present invention, the bacterial culture solution contains at least one of carbonate, phosphate, sulfate and chloride.

[0013] According to some preferred embodiments of the filter material of the present invention, the carbonate is selected from at least one of sodium bicarbonate, sodium carbonate, ammonium carbonate and ammonium bicarbonate.

[0014] According to some preferred embodiments of the filter material of the present invention, the phosphate is selected from at least one of potassium dihydrogen phosphate, potassium hydrogen phosphate, potassium phosphate, sodium dihydrogen phosphate, sodium hydrogen phosphate and sodium phosphate.

[0015] According to some preferred embodiments of the filter material of the present invention, the sulfate is selected from at least one of magnesium sulfate heptahydrate, copper sulfate pentahydrate, hydrated sodium sulfate, ammonium sulfate, potassium aluminum sulfate dodecahydrate and sodium thiosulfate pentahydrate.

[0016] According to some preferred embodiments of the filter material of the present invention, the chloride salt is selected from at least one of anhydrous calcium chloride, sodium chloride, potassium chloride and magnesium chloride.

[0017] According to some preferred embodiments of the filter material of the present invention, the composition of the bacterial culture solution is:

[0018]

[0019]

[0020] The rest was deionized water.

[0021] According to some preferred embodiments of the filter material of the present invention, the bacterial culture solution consists of carbonates, phosphates, sulfates and chlorides; preferably, the microbial culture solution consists of sodium bicarbonate, potassium dihydrogen phosphate, magnesium sulfate heptahydrate, anhydrous calcium chloride and sodium thiosulfate pentahydrate.

[0022] According to some preferred embodiments of the filter material of the present invention, the composition of the microbial culture solution is: 2.5 g / L sodium bicarbonate, 0.25 g / L potassium dihydrogen phosphate, 0.1 g / L magnesium sulfate heptahydrate, 0.1 g / L anhydrous calcium chloride, and 3.0 g / L sodium thiosulfate pentahydrate.

[0023] A second aspect of the present invention provides a method for preparing an autotrophic denitrification filter material, comprising:

[0024] S1. Grind each component of material A into 300-400 mesh powder;

[0025] S2, soaking the molecular sieve in a microbial culture solution and then drying it to obtain material C;

[0026] S3, mixing material A, material B and material C evenly, granulating and drying to obtain the autotrophic denitrification filter material.

[0027] According to some preferred embodiments of the preparation method of the present invention, in S3, the particle size of the granulation is 1 to 8 mm.

[0028] The third aspect of the present invention provides the application of the above autotrophic denitrification filter material or the preparation method of the above autotrophic denitrification filter material in the field of filter materials.

[0029] According to some preferred implementations of the application of the present invention, the filter material is added to a tertiary biological filter tank in a sewage treatment plant, with a filling rate of 60% to 80%.

[0030] The beneficial effects of the present invention are at least in the following aspects:

[0031] The high efficiency of the autotrophic denitrification filter material for efficient nitrogen removal provided by the present invention is mainly based on the following two options: first, the filter material belongs to a multivalent composite sulfur-iron coupling denitrification scheme, and the diverse electron donors of the autotrophic denitrifying bacteria have synergistic synergy; second, the culture solution of the autotrophic denitrifying bacteria is pre-placed in the gap of the molecular sieve, which can be slowly released to ensure that the autotrophic denitrifying bacteria can still maintain growth when the environment is subjected to various shocks. The autotrophic denitrification filter material provided by the present invention has a simple preparation process, is easy to operate during application, and can maintain efficient denitrification capacity.

[0032] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be achieved and satisfied by the structures particularly pointed out in the description, claims and drawings of the description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a three-stage biological filter in an embodiment of the present invention; wherein, 1-water inlet pool; 2-metering pump; 3-sieve plate; 4-filter material; 5-simulated three-stage treatment pool; 6-liftable grid; 7-sampling port valve; 8-reflux valve. DETAILED DESCRIPTION

[0034] The present invention is described in detail below by way of examples, but the protection scope of the present invention is not limited to the following description.

[0035] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or the conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be obtained through commercial channels.

[0036] [Example 1]

[0037] S1. Grind 12kg of ferrous sulfide, 94kg of sulfur, 12kg of sodium thiosulfate and 1kg of iron powder in material A into powder of 300-400 mesh;

[0038] S2. Soak 10 kg of 3A molecular sieve in microbial culture solution and then dry to obtain material C; the formula of the microbial culture solution is: 10 L of deionized water, 2.5 g / L of sodium bicarbonate, 0.25 g / L of potassium dihydrogen phosphate, 0.1 g / L of magnesium sulfate heptahydrate, 0.1 g / L of anhydrous calcium chloride, and 3.0 g / L of sodium thiosulfate pentahydrate; the soaking time is 12 h, the drying temperature is 30-35 ° C, and the drying time is 10 h.

[0039] S3. Add 7kg starch into 20kg water and stir for 10min. Then mix it with 100kg A material mixed powder and 7kg C material and put it into a rotary extrusion granulator for granulation. The drying temperature is 30-35℃ and the drying time is 10h. Screen out 2-3mm particles, which are the autotrophic denitrification filter material.

[0040] [Example 2-10]

[0041] Embodiment 2-10 is basically the same as embodiment 1, and the only difference is that the proportion of each raw material is different, see table 1-3 for details.

[0042] Among them, in Example 8, in the process step of preparing the denitrification filter material, the molecular sieve is not soaked in the bacterial culture solution, and the rest is the same as in Example 1.

[0043] Table 1 A material composition ratio and dosage in Examples 1-10

[0044]

[0045] Table 2 Dosage of each component of material B in Examples 1-10

[0046]

[0047] Table 3 C material composition ratio and dosage in Examples 1-10

[0048]

[0049]

[0050] The filter materials prepared in Examples 1-10 were evaluated. Specifically:

[0051] The experimental device is an anoxic tank simulating the tertiary treatment facilities of a sewage treatment plant, such as Figure 1 As shown, the device 5 is made of organic glass, with a total effective height of 1500mm and an inner diameter of 150mm. A sieve plate 3 is provided at the bottom and a liftable grille 6 is provided at the top for adjusting the filter material filling height. The filter material 4 is the autotrophic denitrification filter material prepared in Examples 1-10. The grille is adjusted so that the filter material filling height is 1200mm. The influent is the tail water of a sewage treatment plant to which a certain amount of potassium nitrate and activated sludge are added, which is stored in an influent pool 1. The nitrate nitrogen concentration of the influent is 35.5mg / L. The influent is pressurized by a metering pump 2 and enters the device 5. The upward flow method is adopted, the hydraulic retention time is 8h, the circulation operation is carried out, the reflux valve 8 is fully opened, and the sampling port valve 7 is closed. The biofilm is successfully formed after 2 weeks. After 3 weeks of continuous operation, the nitrate nitrogen concentration of the effluent is detected to be, and the nitrate removal rate is calculated.

[0052] Table 4

[0053] Example Nitrate nitrogen before test / ppm Nitrate nitrogen after test / ppm Denitrification efficiency / % 1 35.5ppm 0.3 99.2％ 2 35.5ppm 8.1 77.2％ 3 35.5ppm 7.5 78.9％ 4 35.5ppm 9.7 72.7％ 5 35.5ppm 8.9 75.0％ 6 35.5ppm 10.8 72.7％ 7 35.5ppm 9.7 72.7％ 8 35.5ppm 16.3 54.1％ 9 35.5ppm 22 93.8％ 10 35.5ppm 1.5 95.8％

[0054] The above experiments show that the autotrophic denitrification filter material obtained by the present invention has a certain removal effect on nitrate nitrogen in sewage in the tertiary treatment facility of the simulated sewage treatment plant. The nitrate nitrogen content of most effluents reaches below 10 mg / L, and the removal rate of nitrate nitrogen reaches more than 70%. Among them, the removal rate of nitrate nitrogen in Examples 1, 9, and 10 even reaches more than 90%. The removal rate of nitrate nitrogen in Example 8 is 54.4%, which is quite different from that in other examples, indicating that the nitrogen removal capacity of the autotrophic denitrification filter material is greatly improved after the molecular sieve is soaked in the bacterial culture solution.

[0055] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. An autotrophic denitrification filter material, comprising three types of materials A, B, and C, wherein the weight ratio of each material is A:B:C=(10-15):(1-2):1, wherein: A is a composite denitrification ingredient, including ferrous sulfide, sulfur, sodium thiosulfate and iron powder, and the weight ratio of each component is ferrous sulfide: sulfur: sodium thiosulfate: iron powder = (12-18): (94-97): (12-18): 1; B is an adhesive; C is a molecular sieve treated with a microbial culture solution; The composition of the microbial culture solution is: Carbonate 2g / L~3g / L; Phosphate 0.2g / L~0.3g / L; Sulfate 0.05g / L~4.0g / L; Chloride 0.05g / L~0.2g / L; The rest is deionized water; The carbonate is selected from at least one of sodium bicarbonate, sodium carbonate, ammonium carbonate and ammonium bicarbonate; The phosphate is selected from at least one of potassium dihydrogen phosphate, potassium hydrogen phosphate, potassium phosphate, sodium dihydrogen phosphate, sodium hydrogen phosphate and sodium phosphate; The sulfate is selected from at least one of magnesium sulfate heptahydrate, copper sulfate pentahydrate, hydrated sodium sulfate, ammonium sulfate, potassium aluminum sulfate dodecahydrate and sodium thiosulfate pentahydrate; The chloride salt is selected from at least one of anhydrous calcium chloride, sodium chloride, potassium chloride and magnesium chloride.

2. The filter material according to claim 1, characterized in that The adhesive is selected from at least one of starch, animal hide glue, bone glue, sodium dodecylbenzene sulfonate and sodium lignin cellulose.

3. The filter material according to claim 1, characterized in that The molecular sieve is at least one of 3A molecular sieve, 4A molecular sieve, 5A molecular sieve and 13XAPG molecular sieve.

4. The filter material according to any one of claims 1 to 3, characterized in that The concentration of carbonate in the microbial culture solution is 2.2 g / L to 2.8 g / L.

5. The filter material according to any one of claims 1 to 3, characterized in that: The concentration of sulfate in the microbial culture solution is 0.08 g / L to 3.5 g / L.

6. The filter material according to any one of claims 1 to 3, characterized in that: The concentration of chloride in the microbial culture solution is 0.08 g / L to 0.15 g / L.

7. The filter material according to any one of claims 1 to 3, characterized in that: The microbial culture solution consists of sodium bicarbonate, potassium dihydrogen phosphate, magnesium sulfate heptahydrate, anhydrous calcium chloride and sodium thiosulfate pentahydrate.

8. The filter material according to claim 7, characterized in that The composition of the microbial culture solution is: 2.5 g / L sodium bicarbonate, 0.25 g / L potassium dihydrogen phosphate, 0.1 g / L magnesium sulfate heptahydrate, 0.1 g / L anhydrous calcium chloride, and 3.0 g / L sodium thiosulfate pentahydrate.

9. The method for preparing the autotrophic denitrification filter material according to any one of claims 1 to 8, comprising: S1. Grind each component of material A into 300-400 mesh powder; S2, soaking the molecular sieve in a microbial culture solution and then drying it to obtain material C; S3, mixing material A, material B and material C in proportion and stirring evenly, granulating and drying to obtain the autotrophic denitrification filter material, the granulated particle size is 1-8 mm.

10. Use of the autotrophic denitrification filter material according to any one of claims 1 to 8 or the method for preparing the autotrophic denitrification filter material according to claim 9 in the field of filter materials.

11. The use according to claim 10, characterized in that: The filter material is added to the tertiary biological filter of the sewage treatment plant, and the filling rate is 60% to 80%.

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