A hollow columnar sustained-release biological filler

Abstract

The invention discloses a hollow columnar sustained-release biological filler, comprising a hydrophilic outer layer and a hydrophobic inner layer, wherein the outer wall of the hydrophobic inner layer is coaxially attached to the inner wall of the hydrophilic outer layer, the Y molecular sieves of the hydrophilic outer layer and the hydrophobic inner layer both have pores, and the pores are bonded with nutrients such as starch, cellulose, glycine, phosphate, etc., which can provide carbon sources, nitrogen sources and inorganic salts for microorganisms, and most of the micropores and mesopores effectively slow down the release rate of the nutrients. The biological filler in the invention can carry more microorganisms and provide sufficient nutrients for the microorganisms. The hydrophobic molecular sieve on the inner surface of the hollow columnar biological filler is easy to adsorb organic waste gas that is difficult to dissolve in water, and the highly hydrophilic molecular sieve on the outer surface of the hollow columnar biological filler is easy to absorb water, thereby making the biofilm time faster, which is conducive to faster operation of the entire biological system, and the structure is stable, not easy to be hardened and blocked, and there is no need to frequently replace the filler.

Description

Technical Field

[0001] The invention relates to a biological filler, in particular to a hollow columnar slow-release biological filler, which is applied to a biological treatment device for organic waste gas which is insoluble in water. Background Art

[0002] After nearly 40 years of rapid economic development, environmental problems have gradually become prominent, and the atmospheric environment has become the focus of attention of the people across the country. Currently, biological fillers used for inorganic and organic waste gas treatment are divided into two categories:

[0003] (1) Inorganic fillers mainly include ceramics with different physical structures such as ceramics, rocks, ceramic Zhaxi rings and ball rings. The advantages are high mechanical strength and difficulty in compaction; the disadvantages are weak water retention capacity and the lack of nutrients required for microbial growth. Therefore, additional nutrients need to be added during operation, resulting in increased operating costs.

[0004] (2) Organic fillers mainly include aged sawdust, peat, bark, plastic tashi rings and ball rings. The advantages of aged sawdust, peat and bark are that they contain a large amount of nutrients required by microorganisms, and no additional nutrients need to be added in the short term; the disadvantage is that they have poor mechanical strength and are prone to cause compaction and clogging of the filler layer, resulting in increased pressure drop in the biofilter, increased operating energy consumption and difficulty in achieving the desired effect. Other organic fillers such as tashi rings and ball rings have the same advantages and disadvantages as inorganic fillers.

[0005] Although the national invention publication number CN110563130A (a composite filler for membrane bioreactor and its preparation method) points out that it uses 50-70 parts of acrylic acid monomer, 30-50 parts of zeolite, 1.5-6 parts of polyamide and 0.5-2.5 parts of toluene. The invention provides a composite filler for membrane bioreactor with high porosity and large specific surface area. When used as a biological filler in a contact oxidation tank, the filler volume only needs 30-40%, and the ammonia nitrogen removal rate can reach nearly 90% at a hydraulic retention time of 4-6 hours, and the load can reach 1.6kg NH 4 + -N / (m 3 ·d). However, the zeolite used in the patent is first alkali and then acid modified zeolite, which has weak hydrophilicity. Too much organic solvent, such as toluene, acrylic acid monomer and polyamide, is added during the production process, which aggravates the hydrophobicity of the modified zeolite and is not conducive to biofilm formation.

[0006] National invention publication number CN108101233A (Mixed ecological filler, composite filler ball, purification tank device and preparation process based on modified shellfish), this patent points out a mixed ecological filler, composite filler ball, purification tank device and preparation process based on modified shellfish. The mixed ecological filler is prepared by mixing calcined shellfish mixed ecological filler with tea residue activated carbon, zeolite, limestone, melon seed slices, ceramsite and soft stone. The shellfish mixed ecological filler provided by the invention has a high specific surface area, high porosity, light material and high strength, stable physical and chemical properties, and no harmful effect on the proliferation of organisms. The inner and outer two-layer structure of the filler ball not only fixes the shellfish mixed ecological filler, but also has a large specific surface area, is easy to form a film, and does not clog. The purification tank stabilization device is used, which has fixation and fluid flow, is safe and stable, and avoids scouring problems. However, it ignores the problem of internal materials blocking each other caused by multiple organic and inorganic materials together, resulting in the specific surface area of ​​the shellfish mixed ecological filler being weaker than the specific surface area of ​​the single material itself, thereby causing material waste.

[0007] In the prior art, Y molecular sieve has Al in its framework. 3+ The presence of silicon and aluminum makes it negatively charged. In order to maintain its electrical neutrality, some cations that compensate for the charge must exist in the gaps of the skeleton, and these cations become action points, which have affinity for polar molecules (such as water molecules, etc.), which is why general molecular sieves are hydrophilic. Molecular sieves with low silicon-aluminum ratios have more action points, have higher affinity for polar molecules, are easier to absorb water, and thus form membranes quickly; molecular sieves with high silicon-aluminum ratios have fewer action points, are repellent to polar molecules, and are more hydrophobic. Therefore, careful selection of Y molecular sieve raw materials with different silicon-aluminum ratios helps to produce more suitable biofillers with them. Summary of the invention

[0008] In order to solve the problems of the prior art, the purpose of the present invention is to overcome the shortcomings of the existing technology and provide a hollow cylindrical sustained-release biological filler so that it can carry more microorganisms and provide sufficient nutrients for the microorganisms. The hydrophobic molecular sieve coated on the inner surface of the hollow cylindrical biological filler adsorbs organic waste gas that is insoluble in water, which helps to purify the waste gas. At the same time, a highly hydrophilic molecular sieve is coated on the outer surface of the hollow cylindrical biological filler, which is easy to absorb water, thereby making the biofilm time faster, which is conducive to the faster operation of the entire biological system. The structure is stable and not easy to be hardened and blocked, and there is no need to frequently replace the filler.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A hollow columnar sustained-release biological filler comprises an outer hydrophilic modified Y molecular sieve and an inner hydrophobic Y molecular sieve, wherein the outer wall of the inner hydrophobic Y molecular sieve is coaxially attached to the inner wall of the outer hydrophilic modified Y molecular sieve, the outer hydrophilic modified Y molecular sieve is based on the hydrophilic modified Y molecular sieve, and the inner hydrophobic Y molecular sieve is based on the hydrophobic Y molecular sieve, and the Y molecular sieves of the outer hydrophilic modified Y molecular sieve and the inner hydrophobic Y molecular sieve both have a plurality of pores, and nutrients such as starch, cellulose, glycine, phosphate, etc., which can provide carbon sources, nitrogen sources and inorganic salts for microorganisms, are bonded in the pores.

[0011] Specifically, refer to Figure 1 The hydrophilic modified Y molecular sieve on the outside is based on the modified Y molecular sieve, which has a large number of micropores, mesopores and macropores. The pore size of the micropores is less than 2 nm, the pore size of the mesopores is between 2 nm and 50 nm, and the pore size of the macropores is greater than 50 nm; most of the pores are micropores and mesopores, and the number of macropores is small, so that the modified Y molecular sieve has a large specific surface area of ​​800 m 2 / g-950 m 2 / g, average value is 900m 2 / g, which can slow down the release of nutrients.

[0012] The modification process of the modified Y molecular sieve is as follows: adding NaY molecular sieve into a closed container, adding AlCl 3 Solution, in which AlCl 3 The liquid-to-solid ratio of the solution to the molecular sieve is 2 ml / g-100 ml / g. After stirring and mixing, the solution is subjected to ultrasonic microwave treatment at 20°C-300°C under closed conditions for 10 minutes to 24 hours. During the aluminum chloride modification process of the molecular sieve, the energy of ultrasound and microwave is used to make the surface silicon and non-framework silicon easier to separate without destroying the aluminum-oxygen tetrahedral structure. Finally, the product is separated, washed and dried.

[0013] The separation and washing are conventional operations well known to those skilled in the art. Separation can be carried out by vacuum filtration, and washing refers to washing with deionized water until the filtrate is neutral. It usually includes multiple separation and washing operations, generally 1 to 8 times. The filter cake after separation and washing is placed in a 95°C-150°C oven for drying for 4h-16h to obtain AlCl 3 Hydrophilic modified Y molecular sieve after solution modification.

[0014] The surface of the modified Y molecular sieve is irregular and not smooth, which can promote the biofilm of microorganisms. At the same time, because its skeleton contains Al metal, the whole material has a strong water absorption capacity. Starch, cellulose, glycine, phosphate and other nutrients that can provide carbon source, nitrogen source and inorganic salt for microorganisms are added to the pores of the modified water-absorbent Y molecular sieve.

[0015] In actual production, nutrients account for 10%-50% of the total mass of the filler, and a small amount of aluminum phosphate aqueous solution is mixed to act as a glue to fix various nutrients in the hydrophilic Y molecular sieve. The mass of aluminum phosphate accounts for 0.05%-0.1% of the overall hollow columnar sustained-release biological filler. The dilution water used for aluminum phosphate is tap water or pure water. After mixing with the aluminum phosphate aqueous solution, the biological filler is semi-wet stirred and then filled into a mold to shape into a hollow column.

[0016] After the hollow columnar hydrophilic layer is manufactured, a high silicon-aluminum ratio hydrophobic Y molecular sieve with a silicon-aluminum ratio of 70-150 is added to the inner side of the hollow column, and finally the hollow column is extruded and dried to obtain the finished product.

[0017] Preferably, the Y molecular sieve raw material used for modification is preferably NaY molecular sieve with a silicon-aluminum ratio of 1-2.

[0018] Preferably, AlCl 3 The liquid-to-solid ratio of the solution to the molecular sieve is 10 ml / g-30 ml / g.

[0019] Preferably, the ultrasonic microwave treatment conditions during the modification of the Y molecular sieve are: ultrasonic microwave treatment at 20° C.-100° C. under closed conditions for 10 min-1 h.

[0020] Preferably, the outer hydrophilic modified Y molecular sieve has a unit cell constant of 2.33 nm-2.5 nm, a relative crystallinity of 98%-99.5%, and a SiO 2 / Al 2 O 3 The molar ratio is 0.1-0.9.

[0021] Preferably, in the modification process of the Y molecular sieve, the drying temperature of the hollow columnar biological filler filled with the filter cake after separation and washing into the shaping mold is between 100°C and 105°C, and a gradient heating method is required, with the temperature increasing by 1°C to 10°C every minute. When the temperature is increased to 75°C, it is necessary to maintain the temperature of 75°C for 2-4 hours; when the temperature is increased to 105°C, it is necessary to maintain the temperature of 105°C for 4-8 hours.

[0022] Preferably, the composition ratio of the nutrients such as starch, cellulose, glycine, phosphate, etc. that can provide carbon source, nitrogen source and inorganic salt for microorganisms is starch: cellulose: glycine: phosphate = (1-3): (0.5-2): (2-4): (0-2).

[0023] Preferably, the specific surface area of ​​the hydrophobic Y molecular sieve is 700 m 2 / g-1000 m 2 / g.

[0024] Preferably, the hydrophobic molecular sieve with a high silicon-to-aluminum ratio has a silicon-to-aluminum ratio of 70-150.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The hollow columnar sustained-release biological filler of the present invention has a hydrophilic outer layer and a hydrophobic inner layer, and can store nutrients, thereby reducing the problem of the biological filler being easy to harden, clog or lack of nutrients.

[0027] 2. The surface of the hydrophilic modified Y molecular sieve in the hollow columnar sustained-release biological filler provided by the present invention is irregular, which is conducive to rapid biofilm formation and rapid reproduction of microorganisms, laying a solid foundation for the efficient treatment of waste gas; the surface of the hydrophobic Y molecular sieve is hydrophobic, which is conducive to the adsorption of organic waste gas that is insoluble in water, thereby increasing the area of ​​the reaction between the waste gas that is insoluble in water and the microorganisms, and helping to improve the treatment efficiency of the organic waste gas that is insoluble in water. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of the hollow columnar sustained-release biological filler.

[0029] In the figure: 1. Hydrophilic modified Y molecular sieve on the outside; 2. Hydrophobic Y molecular sieve on the inside. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] Embodiment 1:

[0032] A hollow columnar sustained-release biological filler comprises an outer hydrophilic modified Y molecular sieve 1 and an inner hydrophobic Y molecular sieve 2, wherein the outer wall of the inner hydrophobic Y molecular sieve 2 is coaxially attached to the inner wall of the outer hydrophilic modified Y molecular sieve 1, the outer hydrophilic modified Y molecular sieve 1 is based on the hydrophilic modified Y molecular sieve, and the inner hydrophobic Y molecular sieve 2 is based on the hydrophobic Y molecular sieve, and the Y molecular sieves of the outer hydrophilic modified Y molecular sieve 1 and the inner hydrophobic Y molecular sieve 2 both have a plurality of pores, and nutrients such as starch, cellulose, glycine, phosphate, etc., which can provide carbon sources, nitrogen sources and inorganic salts for microorganisms, are bonded in the pores.

[0033] About the preparation of hollow columnar sustained-release biological fillers:

[0034] In this embodiment, 50 g of NaY molecular sieve was placed in a sealed container, and 500 ml of an aluminum chloride solution with a concentration of 0.2 mol / L was added.

[0035] In this example, the Y molecular sieve was modified under stirring for 20 min, heated to 40° C., subjected to ultrasonic microwave treatment for 20 min (microwave power 50 W, ultrasonic power 50 W), vacuum filtered, and washed with pure water until the filtrate was neutral.

[0036] In this embodiment, the washed filter cake is placed in a 100° C. oven and dried for 4 hours to obtain a finished product.

[0037] In this embodiment, the processed raw material is NaY molecular sieve, whose unit cell constant is 2.33nm, relative crystallinity is 98%, its framework silicon-aluminum ratio is 2, and non-framework silicon content is 15wt%.

[0038] In this embodiment, the modified Y molecular sieve was tested and the finished product framework silicon-aluminum ratio was reduced to 0.5, and the non-framework silicon content was 3.4wt%, indicating that the framework crystals of the modified molecular sieve were not destroyed, while the non-framework silicon was extracted by 11.6wt%.

[0039] In this embodiment, the nutrients are starch, cellulose, glycine and phosphate, and the total mass of the nutrients accounts for 10% of the mass of the biological filler, wherein the mass ratio of starch, cellulose, glycine and phosphate is 3.3: 1: 3.5:0.6.

[0040] In this embodiment, the aluminum phosphate dilution water used is pure water.

[0041] In this embodiment, the hydrophobic Y molecular sieve used has a silicon-aluminum ratio of 80 and a specific surface area of ​​930 m 2 / g.

[0042] In this embodiment, the drying temperature of the modified Y molecular sieve biological filler filled into the shaping mold is 105°C, and a gradient heating method is required, with the temperature rising by 1°C every minute. When the temperature rises to 75°C, the temperature needs to be maintained at 75°C for 2 hours, and when the temperature rises to 105°C, the temperature needs to be maintained at 105°C for 5 hours.

[0043] Embodiment 2:

[0044] Different from Example 1, the raw material components and processing time for preparing the hollow columnar sustained-release biological filler in Example 2 are different.

[0045] In this embodiment, 50 g of NaY molecular sieve was placed in a sealed container, and 500 ml of an aluminum chloride solution with a concentration of 0.3 mol / L was added.

[0046] In this example, the Y molecular sieve was modified under stirring for 40 min, heated to 50° C., subjected to ultrasonic microwave treatment for 20 min (microwave power 50 W, ultrasonic power 50 W), vacuum filtered, and washed with pure water until the filtrate was neutral.

[0047] In this embodiment, the washed filter cake is placed in a 100° C. oven and dried for 4 hours to obtain a finished product.

[0048] In this embodiment, the processed raw material is NaY molecular sieve, whose unit cell constant is 2.45nm, relative crystallinity is 95%, its framework silicon-aluminum ratio is 1.8, and non-framework silicon content is 14.6wt%.

[0049] In this embodiment, the modified Y molecular sieve was tested and the finished product framework silicon-aluminum ratio was reduced to 0.4, and the non-framework silicon content was 3.6wt%, indicating that the framework crystals of the modified molecular sieve were not destroyed, while the non-framework silicon was extracted by 11wt%.

[0050] In this embodiment, the nutrients are starch, cellulose, glycine and phosphate, and the total mass of the nutrients accounts for 10% of the mass of the biological filler, wherein the mass ratio of starch, cellulose, glycine and phosphate is 3: 1: 3.5:0.4.

[0051] In this embodiment, the aluminum phosphate dilution water used is pure water.

[0052] In this embodiment, the hydrophobic Y molecular sieve used has a silicon-aluminum ratio of 120 and a specific surface area of ​​910 m 2 / g.

[0053] In this embodiment, the drying temperature of the modified Y molecular sieve biological filler filled into the shaping mold is 105°C, and a gradient heating method is required, with the temperature rising by 1°C every minute. When the temperature rises to 75°C, the temperature needs to be maintained at 75°C for 2 hours, and when the temperature rises to 105°C, the temperature needs to be maintained at 105°C for 6 hours.

[0054] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A hollow columnar sustained-release biological filler, characterized in that: The invention comprises a hydrophilic modified Y molecular sieve (1) on the outside and a hydrophobic Y molecular sieve (2) on the inside, nutrients and a binder. The Y molecular sieves of the hydrophilic modified Y molecular sieve (1) on the outside and the hydrophobic Y molecular sieve (2) on the inside have a plurality of pores, and nutrients are bonded in the pores. The nutrients are starch, cellulose, glycine and phosphate. The composition ratio of the nutrients is starch: cellulose: glycine: phosphate = (1-3): (0.5-2): (2-4): (0-2); the nutrients account for 10%-50% of the total mass of the filler, and the binder accounts for 0.05%-0.1% of the total mass of the filler. The modification process of the hydrophilic modified Y molecular sieve comprises adding NaY molecular sieve into a sealed container, adding AlCl3 solution, wherein the liquid-solid ratio of AlCl3 solution to molecular sieve is 2 ml / g-100 ml / g, stirring and mixing, and then subjecting to ultrasonic microwave treatment for 10 min to 24 h at 20°C-300°C under sealed conditions, wherein the energy of ultrasound and microwave is used to make the surface silicon and non-framework silicon easier to separate during the aluminum chloride modification process of the molecular sieve, and the aluminum oxide tetrahedral structure is not damaged, and finally the product is obtained by separation, washing and drying; The hydrophilic modified Y molecular sieve (1) on the outside has a unit cell constant of 2.33 nm-2.5 nm, a relative crystallinity of 98%-99.5%, and a SiO2 / Al2O3 molar ratio of 0.1-0.9; The hydrophobic Y molecular sieve has a silicon-to-aluminum ratio of 70-150.

2. The hollow columnar sustained-release biological filler according to claim 1, characterized in that: The specific surface area of ​​the outer hydrophilic modified Y molecular sieve (1) is 800 m 2 / g-950 m 2 / g.

3. The hollow columnar sustained-release biological filler according to claim 1, characterized in that: The specific surface area of ​​the hydrophobic Y molecular sieve is 700 m 2 / g-1000 m 2 / g.

4. The method for preparing a hollow columnar sustained-release biological filler according to claim 1, characterized in that: The following steps are involved: S1: Add NaY molecular sieve into a closed container, add AlCl3 solution, wherein the liquid-to-solid ratio of AlCl3 solution to molecular sieve is 2 ml / g-100 ml / g, stir and mix to obtain a mixed solution; S2: Under closed conditions, the temperature is maintained at 20°C-300°C, and the mixed solution is subjected to ultrasonic microwave treatment for 10 minutes to 24 hours; S3: separating and washing the mixed solution after the ultrasonic microwave treatment to obtain a filter cake; S4: drying the filter cake in an oven at 95°C-150°C for 4h-16h to obtain a hydrophilic modified Y molecular sieve modified by AlCl3 solution; S5: adding nutrients into the pores of the hydrophilic modified Y molecular sieve, mixing with a small amount of aluminum phosphate aqueous solution for bonding the hydrophilic modified Y molecular sieve and the nutrients, stirring evenly, and obtaining a semi-wet biofiller; S6: filling the semi-wet biofiller into a corresponding mold, and forming a hollow columnar hydrophilic biofiller after drying; S7: The inner side of the hollow columnar hydrophilic biological filler is supplemented with a hydrophobic Y molecular sieve, extruded into a mold and dried into a finished product.

5. The method for preparing the hollow columnar sustained-release biological filler according to claim 4, characterized in that: The liquid-to-solid ratio of the AlCl3 solution to the molecular sieve in the S1 is 10 ml / g-30 ml / g.

6. The method for preparing the hollow columnar sustained-release biological filler according to claim 4, characterized in that: The dilution water used for the aluminum phosphate aqueous solution in S5 is tap water or pure water.

7. The method for preparing the hollow columnar sustained-release biological filler according to claim 4, characterized in that: The drying temperature of the mold in S6 is between 100°C and 105°C, and a gradient heating method is required, with the temperature increasing by 1°C to 10°C every minute; when the temperature is increased to 75°C, the temperature of 75°C needs to be maintained for 2-4 hours; when the temperature is increased to 105°C, the temperature of 105°C needs to be maintained for 4-8 hours.

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