Microfiller for culturing sewage treatment aerobic granular sludge and preparation method thereof

Abstract

The invention discloses a microfiller for culturing sewage treatment aerobic granular sludge and a preparation method of the microfiller, belongs to the technical field of sewage treatment, and relates to the microfiller for culturing the sewage treatment aerobic granular sludge. The invention aims to solve the problems of long granulation time and poor stability in the prior art. The microfiller for culturing the aerobic granular sludge for sewage treatment is prepared by uniformly mixing one or more of straw powder, beneficial metal salt and red mud with plastic particles, heating, melting and granulating to obtain fine particles rich in organic matters, and aging the fine particles rich in organic matters by ultraviolet light. According to the microfiller disclosed by the invention, an internal core of the aerobic granular sludge is formed in a form of rapid colonization of microorganisms, and a novel aerobic granular sludge system with a stable core is formed through induction, so that the bottleneck problems of long granulation time (2-5 months) and poor stability existing in an aerobic granular sludge technology at present are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment and relates to a micro filler used for cultivating aerobic granular sludge for sewage treatment. Background Art

[0002] The quality and quantity of domestic sewage in villages and towns in my country fluctuate greatly. The changes in sludge load caused by such fluctuations seriously affect the stability of activated sludge and effluent water quality. Aerobic granular sludge system is considered to be one of the most promising decentralized biological sewage treatment technologies in villages and towns due to its strong resistance to shock loads. However, the long sludge granulation time (2-5 months) and poor stability of aerobic granular sludge restrict the practical application of this process. Therefore, it is urgent to develop a strategy to achieve the rapid formation of aerobic granular sludge while ensuring the structural and functional stability of aerobic granular sludge during long-term operation, so as to solve the current bottleneck problems of aerobic granular sludge technology. Summary of the invention

[0003] The purpose of the present invention is to solve the existing technical problems of long granulation time (2-5 months) and poor stability, and to provide a micro filler for culturing aerobic granular sludge for sewage treatment and a preparation method thereof.

[0004] The micro-filler used for cultivating aerobic granular sludge for sewage treatment is prepared by uniformly mixing one or more of straw powder, beneficial metal salt and red mud with plastic particles, heating and melting granulation to obtain fine particles rich in organic matter, and then ultraviolet aging of the fine particles rich in organic matter, wherein the mass fractions of the plastic particles, straw powder, beneficial metal salt and red mud are 50-100%, 0-50%, 0-20% and 0-10% respectively.

[0005] The microfiller used for cultivating aerobic granular sludge for sewage treatment is porous spherical fine particles rich in organic matter, with a diameter of 0.1-10 mm.

[0006] The straw is the remaining part of wheat, rice, corn, potato, rape, cotton, and sugarcane after harvesting the seeds, which is formed into straw powder with a mesh size of less than 100 after mechanical crushing;

[0007] The tuber is sweet potato, white potato or potato.

[0008] The beneficial metal salt is one of sulfates, nitrates, phosphates and chlorides of iron, calcium, magnesium, manganese and potassium, or a combination of several thereof.

[0009] The red mud is one of Bayer process red mud, sintering process red mud and Bayer process and sintering process combined red mud or a mixture of several of them, wherein the mass fractions of silicon oxide, calcium oxide, aluminum oxide and ferric oxide are 3-23%, 2-50%, 5-20% and 5-60% respectively.

[0010] The plastic particles are one of polyvinyl chloride (PVC), polyethylene (PE), polystyrene (PS), polyamide (PA), polylactic acid (PLA), polypropylene (PP), polyethylene terephthalate (PET) or a combination of several thereof.

[0011] The ultraviolet light aging is to place the fine particles rich in organic matter under natural light, xenon lamp, mercury lamp or metal halide lamp light for light aging for 3-15 days.

[0012] The heating melting temperature is 150-350°C.

[0013] The method for preparing the microfiller for culturing aerobic granular sludge for sewage treatment is carried out according to the following steps:

[0014] After uniformly mixing straw powder, beneficial metal salt and one or more of red mud with plastic particles, the mixture is heated to 150-350° C. for melt granulation to obtain fine particles rich in organic matter, and then the fine particles rich in organic matter are aged by ultraviolet light for 3-15 days to obtain micro-filler for cultivating aerobic granular sludge for sewage treatment, wherein the mass fractions of plastic particles, straw powder, beneficial metal salt and red mud are 50-100%, 0-50%, 0-20% and 0-10% respectively.

[0015] The present invention provides a micro-filler for cultivating aerobic granular sludge for sewage treatment, which forms the internal core of aerobic granular sludge by rapidly colonizing microorganisms, thereby inducing the formation of a new aerobic granular sludge system with a stable inner core, thereby solving the bottleneck problems of the current aerobic granular sludge technology, such as long granulation time (2-5 months) and poor stability.

[0016] The beneficial effects of the present invention are:

[0017] (1) Through the construction of new microfillers, microorganisms can be quickly colonized on the surface of microfillers, and the microfillers become the internal core of aerobic granular sludge, thereby inducing the formation of an aerobic granular sludge system with a stable core, achieving the rapid formation of aerobic granular sludge. The aerobic granular sludge maintains stable structure and function during long-term operation;

[0018] (2) Through photoaging of microfillers, their hydrophilicity, surface roughness and oxidizability are increased, which is beneficial to microbial colonization and strengthens the rapid formation of the microbial community structure of aerobic granular sludge. The plastic particles in the aged microfillers are more easily degraded by microorganisms and provide a stable slow-release carbon source for aerobic granular sludge.

[0019] (3) It utilizes discarded biodegradable and non-biodegradable plastics, realizes the resource utilization of discarded plastics, reduces the cost of fillers, forms the induced degradation of discarded plastics in the biological treatment process, and reduces the white pollution generated by plastics;

[0020] (4) The porous structure of the new microfiller will quickly adsorb new soluble pollutants in sewage, such as persistent organic pollutants, endocrine disruptors and antibiotics. Through the formation and reproduction of microbial flora on the surface of the microfiller, the new pollutants adsorbed by the microfiller will be continuously degraded, reducing the risk of new pollutants exceeding the standard in the tail water and protecting the water ecological environment.

[0021] (5) Straw, beneficial metals and red mud provide nutrients and trace elements for the rapid colonization of aerobic granular sludge on the new micro-filler, and also provide the necessary conditions for maintaining efficient biological activity of aerobic granular sludge during long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a physical picture of the micro filler used for cultivating aerobic granular sludge for sewage treatment in Examples 1 to 4;

[0023] Figure 2 It is a microscope photo (4 times) of the microfiller used for cultivating aerobic granular sludge for sewage treatment in Examples 1 to 4;

[0024] Figure 3 These are microscope photographs of the rapidly colonizing microorganisms of the microfillers used for culturing aerobic granular sludge for sewage treatment in Example 4, wherein (a) is a 4-fold microscope photograph of the rapidly colonizing microorganisms of the microfillers used for culturing aerobic granular sludge for sewage treatment, and (b) is a 20-fold microscope photograph of the rapidly colonizing microorganisms of the microfillers used for culturing aerobic granular sludge for sewage treatment. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.

[0026] Specific implementation method 1: In this implementation method, straw powder, beneficial metal salts and one or more of red mud are uniformly mixed with plastic particles, heated and melted to granulate to obtain fine particles rich in organic matter, and then ultraviolet light is used to age the fine particles rich in organic matter, wherein the mass fractions of plastic particles, straw powder, beneficial metal salts and red mud are 50-100%, 0-50%, 0-20%, and 0-10%, respectively.

[0027] Specific embodiment 2: This embodiment is different from the specific embodiment 1 in that the microfiller used to cultivate the aerobic granular sludge for sewage treatment is porous spherical fine particles rich in organic matter with a diameter of 0.1-10 mm. The rest is the same as the specific embodiment 1.

[0028] Specific implementation method three: This implementation method is different from specific implementation method one or two in that the straw is the remaining part of wheat, rice, corn, potato, rape, cotton, and sugarcane after harvesting seeds, and is formed into straw powder with a mesh size of less than 100 by mechanical crushing; the potato is sweet potato, sweet potato, or potato. The rest is the same as specific implementation method one or two.

[0029] Specific embodiment 4: This embodiment is different from specific embodiments 1 to 3 in that the beneficial metal salt is one or a combination of sulfates, nitrates, phosphates and chlorides of iron, calcium, magnesium, manganese and potassium. The rest is the same as specific embodiments 1 to 3.

[0030] In this embodiment, when the beneficial metal salt is a composition, the ratios of the components are arbitrary.

[0031] Specific embodiment 5: This embodiment is different from specific embodiments 1 to 4 in that the red mud is one of Bayer process red mud, sintering process red mud and Bayer process and sintering process combined red mud or a mixture of several thereof, wherein the mass fractions of silicon oxide, calcium oxide, aluminum oxide and ferric oxide are 3-23%, 2-50%, 5-20% and 5-60% respectively. The rest is the same as specific embodiments 1 to 4.

[0032] Specific embodiment 6: This embodiment is different from specific embodiments 1 to 5 in that the plastic particles are one or a combination of polyvinyl chloride (PVC), polyethylene (PE), polystyrene (PS), polyamide (PA), polylactic acid (PLA), polypropylene (PP), polyethylene terephthalate (PET). Other aspects are the same as specific embodiments 1 to 5.

[0033] Specific implementation method 7: This implementation method is different from specific implementation methods 1 to 6 in that the ultraviolet light aging is to place the organic-rich fine particles under natural light, xenon lamp, mercury lamp or metal halide lamp light for 3-15 days. The rest is the same as specific implementation methods 1 to 6.

[0034] Specific embodiment 8: This embodiment is different from specific embodiments 1 to 7 in that the heating and melting temperature is 150-350° C. The rest is the same as specific embodiments 1 to 7.

[0035] Specific embodiment 9: The preparation method of the microfiller for cultivating aerobic granular sludge for sewage treatment described in specific embodiment 1 is carried out according to the following steps:

[0036] After uniformly mixing straw powder, beneficial metal salt and red mud with plastic particles, heating to 150-350°C for melting and granulation, fine particles rich in organic matter are obtained, and then ultraviolet light aging of the fine particles rich in organic matter is performed for 3-15 days to obtain micro-fillers for cultivating aerobic granular sludge for sewage treatment, wherein the mass fractions of plastic particles, straw powder, beneficial metal salt and red mud are 50-100%, 0-50%, 0-20% and 0-10% respectively. The rest is the same as the specific implementation methods one to eight.

[0037] Specific embodiment 10: This embodiment is different from specific embodiment 9 in that the microfiller used to cultivate aerobic granular sludge for sewage treatment is porous spherical fine particles rich in organic matter with a diameter of 0.1-10 mm;

[0038] The straw is the remaining part of wheat, rice, corn, potato, rape, cotton, and sugarcane after harvesting the seeds, which is formed into straw powder with a mesh size of less than 100 after mechanical crushing;

[0039] The tuber is sweet potato, white potato or potato;

[0040] The beneficial metal salt is one or a combination of sulfate, nitrate, phosphate and chloride of iron, calcium, magnesium, manganese and potassium;

[0041] The red mud is one of Bayer process red mud, sintering process red mud or Bayer process and sintering process combined red mud or a mixture of several thereof, wherein the mass fractions of silicon oxide, calcium oxide, aluminum oxide and ferric oxide are 3-23%, 2-50%, 5-20% and 5-60% respectively;

[0042] The plastic particles are one or a combination of polyvinyl chloride (PVC), polyethylene (PE), polystyrene (PS), polyamide (PA), polylactic acid (PLA), polypropylene (PP), polyethylene terephthalate (PET);

[0043] The ultraviolet light aging is to place the fine particles rich in organic matter under natural light, xenon lamp, mercury lamp or metal halide lamp light for light aging. Other aspects are the same as the ninth embodiment.

[0044] The following experiments were used to verify the effect of the present invention:

[0045] Embodiment 1:

[0046] The preparation method of microfiller for cultivating aerobic granular sludge for sewage treatment is carried out according to the following steps:

[0047] After uniformly mixing straw powder, beneficial metal salts and one or more of red mud with plastic particles, the mixture is heated to 150° C. for melt granulation to obtain fine particles rich in organic matter. The fine particles rich in organic matter are then aged by ultraviolet light for 15 days to obtain micro-fillers for cultivating aerobic granular sludge for sewage treatment, wherein the mass fractions of plastic particles, straw powder, beneficial metal salts and red mud are 60%, 20%, 10% and 10% respectively.

[0048] The microfiller used to cultivate aerobic granular sludge for sewage treatment is porous spherical fine particles rich in organic matter with a diameter of 0.1 mm;

[0049] The straw is the remaining part of corn after the kernels are harvested, and is formed into straw powder with a mesh size of less than 100 after mechanical crushing;

[0050] The beneficial metal salts are phosphates of iron, calcium, magnesium, manganese and potassium;

[0051] The red mud is Bayer red mud, wherein the mass fractions of silicon oxide, calcium oxide, aluminum oxide and ferric oxide are 10%, 20%, 20% and 50% respectively;

[0052] The plastic particles are polyethylene (PE);

[0053] The ultraviolet light aging is to place the fine particles rich in organic matter under natural light for light aging.

[0054] Embodiment 2:

[0055] The preparation method of microfiller for cultivating aerobic granular sludge for sewage treatment is carried out according to the following steps:

[0056] After uniformly mixing straw powder, beneficial metal salts and one or more of red mud with plastic particles, the mixture is heated to 180°C for melt granulation to obtain fine particles rich in organic matter, and then the fine particles rich in organic matter are aged by ultraviolet light for 15 days to obtain micro-fillers for cultivating aerobic granular sludge for sewage treatment, wherein the mass fractions of plastic particles, straw powder, beneficial metal salts and red mud are 80%, 14%, 1% and 5% respectively.

[0057] The microfiller used to cultivate aerobic granular sludge for sewage treatment is porous spherical fine particles rich in organic matter with a diameter of 1 mm;

[0058] The straw is the remaining part of wheat after harvesting the seeds, which is formed into straw powder with a mesh size of less than 100 after mechanical crushing;

[0059] The beneficial metal salts are chloride salts of iron, calcium, magnesium, manganese and potassium;

[0060] The red mud is Bayer red mud, wherein the mass fractions of silicon oxide, calcium oxide, aluminum oxide and ferric oxide are 20%, 50%, 10% and 20% respectively;

[0061] The plastic particles are polylactic acid (PLA);

[0062] The ultraviolet light aging is to place the fine particles rich in organic matter under natural light for light aging.

[0063] Embodiment 3:

[0064] The preparation method of microfiller for cultivating aerobic granular sludge for sewage treatment is carried out according to the following steps:

[0065] After uniformly mixing straw powder, beneficial metal salts and one or more of red mud with plastic particles, the mixture is heated to 220° C. for melt granulation to obtain fine particles rich in organic matter, and then the fine particles rich in organic matter are aged by ultraviolet light for 5 days to obtain micro-fillers for cultivating aerobic granular sludge for sewage treatment, wherein the mass fractions of plastic particles, straw powder, beneficial metal salts and red mud are 80%, 10%, 5% and 5% respectively.

[0066] The microfiller used to cultivate aerobic granular sludge for sewage treatment is porous spherical fine particles rich in organic matter with a diameter of 5 mm;

[0067] The straw is the remaining part of corn after the kernels are harvested, and is formed into straw powder with a mesh size of less than 100 after mechanical crushing;

[0068] The beneficial metal salts are nitrates of iron, calcium, magnesium, manganese and potassium;

[0069] The red mud is a mixture of Bayer red mud, sintered red mud and a combination of Bayer and sintered red mud, wherein the mass fractions of silicon oxide, calcium oxide, aluminum oxide and ferric oxide are 23%, 17%, 10% and 50% respectively;

[0070] The plastic particles are a combination of polylactic acid (PLA), polyethylene (PE) and polyethylene terephthalate (PET), with mass fractions of 40%, 30% and 30% respectively.

[0071] The ultraviolet light aging is to place the fine particles rich in organic matter under the light of a mercury lamp for light aging.

[0072] Embodiment 4:

[0073] The preparation method of microfiller for cultivating aerobic granular sludge for sewage treatment is carried out according to the following steps:

[0074] After uniformly mixing straw powder, beneficial metal salt and one or more of red mud with plastic particles, the mixture is heated to 260°C for melt granulation to obtain fine particles rich in organic matter, and then the fine particles rich in organic matter are aged by ultraviolet light for 8 days to obtain micro-filler for cultivating aerobic granular sludge for sewage treatment, wherein the mass fractions of plastic particles, straw powder, beneficial metal salt and red mud are 60%, 20%, 10% and 10% respectively.

[0075] The microfiller used to cultivate aerobic granular sludge for sewage treatment is porous spherical fine particles rich in organic matter with a diameter of 10 mm;

[0076] The straw is the remaining part of rice after the seeds are harvested, and is formed into straw powder with a mesh size of less than 100 after mechanical crushing;

[0077] The beneficial metal salts are phosphates of iron, calcium, magnesium, manganese and potassium;

[0078] The red mud is a mixture of three kinds of red mud from the Bayer process, sintering process and red mud from the combined process of the Bayer process and sintering process, wherein the mass fractions of silicon oxide, calcium oxide, aluminum oxide and ferric oxide are 18%, 12%, 20% and 50% respectively;

[0079] The plastic particles are polyethylene terephthalate (PET);

[0080] The ultraviolet light aging is to place the fine particles rich in organic matter under natural light, xenon lamp, mercury lamp or metal halide lamp light for light aging.

[0081] A cylindrical intermittent reactor was used as a reaction device to acclimate aerobic granular sludge. The effective volume of the reactor was 2L, the operation cycle was 4h, the drainage ratio was 50%, and the microfiller filling ratio was 50%. The air in the aeration stage was introduced into the reactor by a sand core aeration head installed at the bottom, and the aeration volume was controlled by a gas flow meter at 2-2.5L / min. The hydraulic retention time was 8h. The sludge retention time was 20-25 days. The reactor was operated under indoor environmental conditions, and the water inlet, aeration, and drainage processes during the test were automatically controlled by the control system.

[0082] SVI 30 The ratio of SVI / SVI5 is considered to be one of the indicators for judging sludge granulation. 30 A / SVI5 ratio greater than 0.85 indicates a high degree of granulation, and a ratio equal to 1 indicates that granulation is complete. In addition, the particle size of activated sludge is generally below 150um, while the particle size of aerobic granular sludge is generally between 300-800μm, and the smallest particle size of granular sludge is 200μm. The granulation degree of sludge is usually measured by the proportion of sludge with a particle size of >200μm in the sludge. The greater the proportion of sludge with an average particle size of more than 500μm, the faster the granulation degree of the sludge.

[0083] It can be seen from Table 1 that the time for acclimating aerobic granular sludge with the microfillers in the above embodiments in the cylindrical intermittent reactor is shorter than that of the blank group and the pure microplastic group, indicating that the microfillers of the present invention can effectively shorten the time for acclimating aerobic granular sludge and solve the bottleneck problems of long granulation time and poor stability in the current aerobic granular sludge technology.

[0084] Table 1. Days when the granulation index of activated sludge in the SBR reactor was completed in the experimental group and the blank control group

[0085]

Claims

1. A microfiller for cultivating aerobic granular sludge for sewage treatment, characterized in that The micro-filler for cultivating aerobic granular sludge for sewage treatment is prepared by uniformly mixing one or more of straw powder, beneficial metal salt and red mud with plastic particles, heating and melting granulation to obtain fine particles rich in organic matter, and then ultraviolet aging of the fine particles rich in organic matter, wherein the mass fractions of the plastic particles, straw powder, beneficial metal salt and red mud are 50-100%, 0-50%, 0-20% and 0-10% respectively.

2. The microfiller for cultivating aerobic granular sludge for sewage treatment according to claim 1, characterized in that The microfiller used for cultivating aerobic granular sludge for sewage treatment is porous spherical fine particles rich in organic matter, with a diameter of 0.1-10 mm.

3. The microfiller for cultivating aerobic granular sludge for sewage treatment according to claim 1, characterized in that The straw is the remaining part of wheat, rice, corn, potato, rape, cotton, and sugarcane after harvesting the seeds, which is formed into straw powder with a mesh size of less than 100 after mechanical crushing; The tuber is sweet potato, white potato or potato.

4. The microfiller for cultivating aerobic granular sludge for sewage treatment according to claim 1, characterized in that The beneficial metal salt is one of sulfates, nitrates, phosphates and chlorides of iron, calcium, magnesium, manganese and potassium, or a combination of several of them.

5. The microfiller for culturing aerobic granular sludge for sewage treatment according to claim 1, characterized in that The red mud is one of Bayer process red mud, sintering process red mud and Bayer process and sintering process combined red mud or a mixture of several of them, wherein the mass fractions of silicon oxide, calcium oxide, aluminum oxide and ferric oxide are 3-23%, 2-50%, 5-20% and 5-60% respectively.

6. The microfiller for cultivating aerobic granular sludge for sewage treatment according to claim 1, characterized in that The plastic particles are one of polyvinyl chloride, polyethylene polystyrene, polyamide polylactic acid, polypropylene, polyethylene terephthalate or a combination of several thereof.

7. The microfiller for cultivating aerobic granular sludge for sewage treatment according to claim 1, characterized in that The ultraviolet light aging is to place the fine particles rich in organic matter under natural light, xenon lamp, mercury lamp or metal halide lamp light for light aging for 3-15 days.

8. The microfiller for cultivating aerobic granular sludge for sewage treatment according to claim 1, characterized in that The heating melting temperature is 150-350°C.

9. The method for preparing the microfiller for culturing aerobic granular sludge for sewage treatment according to claim 1, characterized in that The method for preparing the microfiller for culturing aerobic granular sludge for sewage treatment is carried out according to the following steps: After uniformly mixing straw powder, beneficial metal salt and one or more of red mud with plastic particles, the mixture is heated to 150-350° C. for melt granulation to obtain fine particles rich in organic matter, and then the fine particles rich in organic matter are aged by ultraviolet light for 3-15 days to obtain micro-filler for cultivating aerobic granular sludge for sewage treatment, wherein the mass fractions of plastic particles, straw powder, beneficial metal salt and red mud are 50-100%, 0-50%, 0-20% and 0-10% respectively.

10. The method for preparing a microfiller for culturing aerobic granular sludge for sewage treatment according to claim 9, characterized in that The microfiller used to cultivate aerobic granular sludge for sewage treatment is porous spherical fine particles rich in organic matter with a diameter of 0.1-10 mm; The straw is the remaining part of wheat, rice, corn, potato, rape, cotton, and sugarcane after harvesting seeds, which is formed into straw powder with a mesh size of less than 100 after mechanical crushing; The tuber is sweet potato, white potato or potato; The beneficial metal salt is one or a combination of sulfate, nitrate, phosphate and chloride of iron, calcium, magnesium, manganese and potassium; The red mud is one of Bayer process red mud, sintering process red mud or Bayer process and sintering process combined red mud or a mixture of several thereof, wherein the mass fractions of silicon oxide, calcium oxide, aluminum oxide and ferric oxide are 3-23%, 2-50%, 5-20% and 5-60% respectively; The plastic particles are one or a combination of polyvinyl chloride, polyethylene, polystyrene, polyamide, polylactic acid, polypropylene, polyethylene terephthalate; The ultraviolet light aging is to place the fine particles rich in organic matter under natural light, xenon lamp, mercury lamp or metal halide lamp light for light aging.

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