Method for wastewater treatment, diatomite-based microbial carrier and production method and application thereof

Abstract

The application provides a sewage treatment method, a diatomite-based microbial carrier and a production method and application thereof, wherein the sewage treatment method comprises the following steps: S1, diatomite-based microbial carriers are prepared, and the preparation of the diatomite-based microbial carriers comprises the following steps: diatomite raw soil is scrubbed to prepare a slurry; the slurry is screened through a 32-60 mesh screen to remove impurities, and a first undersize slurry is obtained; the first undersize slurry is screened through an 80-100 mesh screen to remove impurities, and a second undersize slurry is obtained; the second undersize slurry is subjected to sedimentation, pressure filtration and drying to obtain the diatomite-based microbial carriers; and S2, the diatomite-based microbial carriers are put into a sewage treatment biochemical tank, wherein the input amount of the diatomite-based microbial carriers is 4-6 g / L. The application effectively reduces the sewage treatment burden in the biochemical tank and improves the sewage treatment efficiency.

Description

Technical Field

[0001] This invention belongs to the field of non-metallic mineral processing, specifically relating to an industrial production method and application of a diatomaceous earth-based microbial carrier. Background Technology

[0002] Diatomaceous earth is a natural siliceous porous mineral with naturally distributed nanopores, large specific surface area, low bulk density, and amorphous SiO2 as its main component. It is widely used in the filtration of beer, beverages, drinking water, pharmaceuticals and biochemical products, as well as air conditioning and purification, coatings, pesticide and insecticide carriers, road asphalt modifiers, explosive density regulators, and functional fillers in rubber, plastics and papermaking. It is a valuable non-metallic mineral resource closely related to modern industry and human environmental protection and health industries.

[0003] To meet the demand for high-performance, high-value-added diatomite in mid-to-high-end fields, common technologies utilize purification and sorting techniques to enhance the performance and value of diatomite, producing high-quality and stable refined diatomite, which is then applied in fields such as medicine and aerospace.

[0004] In addition to the above applications, diatomaceous earth can also adsorb and remove ammonia nitrogen, total nitrogen, total phosphorus, COD, and heavy metals such as Co, Mn, and Hg from wastewater. In addition, its high specific surface area can provide abundant attachment sites for nutrients and microorganisms. Diatomaceous earth has broad application prospects as a microbial carrier in wastewater treatment.

[0005] Referring to the invention with publication number CN110577285B, a novel high-concentration powder carrier biological fluidized bed process for treating urban sewage is proposed. This process includes a sequentially connected HPB biological treatment tank, a high-efficiency clarification tank, a filtration tank, and a disinfection tank. The HPB biological treatment tank is divided into an anaerobic zone, an anoxic zone, an aerobic zone, and a concentration and separation zone along the sewage flow direction. Composite powder carriers are added to the anaerobic, anoxic, and aerobic zones respectively, and stirred to form a mixed liquid. A composite powder carrier cyclone separation and recovery system separates the composite powder carriers, which are then recycled back into the HPB biological treatment tank.

[0006] The aforementioned composite powder carriers typically have certain material and specification requirements. Most importantly, the addition of composite powder carriers should not increase the pollution treatment burden on the biological treatment tank.

[0007] Composite powder carriers are composed of microbial carrier materials and alternative carbon source functional materials. They are widely available. In common technologies using diatomaceous earth as the microbial carrier particle in composite powder carriers, air classification or chemical washing processes are typically employed. Air classification mainly includes the following steps: drying the raw diatomaceous earth, crushing it, and air classification to obtain diatomaceous earth-based microbial carriers. Chemical washing mainly includes the following steps: adding chemicals for washing and pulping, adding chemicals for stirring and dispersion, sieving to remove impurities, centrifuging, filtering, and drying to obtain diatomaceous earth-based microbial carriers.

[0008] However, diatomaceous earth produced by air separation, when used as a microbial carrier, whether added alone to the HPB biological treatment tank or combined with other carbon source replacement materials before being added, will generate a large amount of floating matter, increasing the burden on subsequent wastewater treatment. Diatomaceous earth produced by chemical washing, when used as a microbial carrier, will retain small amounts of alkali and phosphorus-containing agents, which will affect the biocompatibility and phosphorus removal efficiency of the diatomaceous earth-based microbial carrier. Summary of the Invention

[0009] To address the technical problem that diatomaceous earth-based microbial carriers prepared using the aforementioned commonly used techniques form floating debris after being added to an HPB biological treatment tank, thus increasing the burden on wastewater treatment, this invention provides a wastewater treatment method, comprising the following steps:

[0010] S1. Obtaining a diatomaceous earth-based microbial carrier, wherein the preparation of the diatomaceous earth-based microbial carrier includes:

[0011] The raw diatomaceous earth is scrubbed and pulped to obtain the pulp.

[0012] The slurry is screened through a 32-60 mesh screen to remove impurities, yielding the first slurry as the undersize material.

[0013] The first slurry is sieved through an 80-100 mesh screen to remove impurities, yielding the undersize second slurry.

[0014] The second slurry was subjected to sedimentation, pressure filtration, and drying to obtain a diatomaceous earth-based microbial carrier;

[0015] S2. The diatomaceous earth-based microbial carrier is added to the wastewater treatment biochemical tank, wherein the amount of the diatomaceous earth-based microbial carrier added is 4~6 g / L.

[0016] The present invention also provides a method for producing a diatomaceous earth-based microbial carrier for wastewater treatment, comprising the following steps:

[0017] The raw diatomaceous earth is scrubbed and pulped to obtain the pulp.

[0018] The slurry is screened through a 32-60 mesh screen to remove impurities, yielding the first slurry as the undersize material.

[0019] The first slurry is sieved through an 80-100 mesh screen to remove impurities, yielding the undersize second slurry.

[0020] The second slurry was subjected to sedimentation, pressure filtration, and drying to obtain a diatomaceous earth-based microbial carrier.

[0021] Furthermore, by mass fraction, the composition of the diatomaceous earth raw material includes: 35%~55% moisture, 1%~5% impurities, 1%~5% gravel, 0~5% fine mud, and 30%~63% diatomaceous earth-based microbial carrier.

[0022] Furthermore, the step of washing and pulping the raw diatomaceous earth to obtain a slurry includes crushing the raw diatomaceous earth to a size no larger than 50 mm, adding a first water to the raw diatomaceous earth, and washing and pulping at a solid-liquid ratio of 1:1 to 1:3, wherein the pH of the slurry is 6 to 8, and the washing time is 10 to 30 minutes.

[0023] Furthermore, the slurry is subjected to 32-60 mesh sieve screening to remove impurities, yielding the first slurry, which includes:

[0024] While the slurry is being screened through a 32-60 mesh screen to remove impurities, a second water wash is added, the amount of which is 5%-15% of the total mass of the slurry.

[0025] Furthermore, the first slurry is sieved through an 80-100 mesh screen to remove impurities, yielding the undersize material, the second slurry, which includes:

[0026] While the first slurry is being screened through an 80-100 mesh sieve to remove impurities, a third type of water is added for rinsing. The amount of the third type of water added is 30%-60% of the total mass of the first slurry.

[0027] Furthermore, the second slurry, after sedimentation, pressure filtration, and drying, to obtain the diatomaceous earth-based microbial carrier, also includes a drying time of 1-3 hours and a drying temperature of 100-200°C.

[0028] The present invention provides a diatomaceous earth-based microbial carrier, which is prepared by any of the preparation methods described above, wherein the silica content in the diatomaceous earth-based microbial carrier is greater than 70% by mass fraction.

[0029] This invention provides an application of the diatomaceous earth-based microbial carrier described above in wastewater treatment.

[0030] Furthermore, the diatomaceous earth-based microbial carrier is combined with an alternative carbon source and then introduced into a wastewater treatment biochemical tank.

[0031] Compared with the prior art, the present invention has at least the following advantages:

[0032] This invention involves scrubbing and pulping diatomaceous earth, followed by double sieving of the resulting slurry. Firstly, by controlling the sieve apertures of the two sieving processes to 32-60 mesh and 80-100 mesh respectively, both sieving processes ensure slurry throughput while precisely removing large particles, gravel, and mineral debris. Secondly, the sieve aperture selection meets the maximum allowable particle size requirement (≤200μm) for impurities, gravel, and debris in the diatomaceous earth-based microbial carrier under HPB technology, while minimizing the loss of the diatomaceous earth-based microbial carrier and ensuring its yield.

[0033] That is, the diatomaceous earth-based microbial carrier prepared by the present invention can avoid the phenomenon of impurity floating after the diatomaceous earth-based microbial carrier is added to the HPB biochemical tank after air separation in commonly used technologies, as well as the technical problem of phosphorus introduction in the chemical washing process, while ensuring application efficiency, and effectively reducing the pollution treatment burden in the HPB biochemical tank.

[0034] The water washing process of this invention is short and the processing temperature is low, which will not damage the biocompatibility and integrity of diatoms, and is conducive to microbial attachment and carrier recovery. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0036] Figure 1 Flowchart of the operation for preparing diatomaceous earth carriers by wind separation.

[0037] Figure 2 This is a flowchart illustrating the process of preparing the diatomaceous earth-based microbial carrier in Example 1 of the present invention.

[0038] Figure 3 This is a microscopic image of the sediment prepared in Example 1 of the present invention under a 160x microscope.

[0039] Figure 4 This is a microscopic image of the sediment prepared in Example 1 of the present invention under a 640x microscope.

[0040] Figure 5 This is a microscopic structure diagram of the second slurry prepared in Example 2 of the present invention under a 160x microscope.

[0041] Figure 6 This is a microscopic structure diagram of the second slurry prepared in Example 2 of the present invention under a 640x microscope.

[0042] Figure 7 This is a microscopic image of the sediment prepared in Example 2 of the present invention under a 160x microscope.

[0043] Figure 8 This is a microscopic image of the sediment prepared in Example 2 of the present invention under a 640x microscope.

[0044] Figure 9 This is a microscopic structure diagram of the upper liquid obtained in Example 2 of the present invention under a 640x microscope.

[0045] Figure 10 This is a microscopic image of the mud cake prepared in Example 2 of the present invention under a 640x microscope.

[0046] Figure 11 This is a microscopic image of the mud cake prepared in Example 2 of the present invention under a 640x microscope.

[0047] Figure 12 This is a photograph of the material on the 80-mesh sieve in Embodiment 3 of the present invention.

[0048] Figure 13 This is a microscopic image of the slurry prepared in Example 1 of the present invention under a 160x microscope.

[0049] Figure 14 This is a microscopic image of the slurry prepared in Example 1 of the present invention under a 640x microscope.

[0050] Figure 15 This is a microscopic image of the slurry prepared in one embodiment of the present invention under a 640x microscope. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0053] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention.

[0054] In HPB biochemical pool technology, the composite powder carrier comes from various sources, generally consisting of microbial carrier particles and alternative carbon sources. The composite methods include wet mixing and vacuum loading, which will not be elaborated here. The microbial carrier particles typically possess high specific surface area and often include attapulgite clay and expanded perlite.

[0055] The alternative carbon source, when incorporated onto the carrier particles, provides nutrients for the growth of nitrogen-removing and phosphorus-removing bacteria, thereby promoting the enrichment and growth of beneficial bacteria (including nitrogen-removing and phosphorus-removing bacteria) on the composite powder carrier and accelerating the biofilm formation and sludge particle formation. In other words, microbial carrier particles can also be added to the HPB biological treatment tank alone, but their sludge particle formation effect and efficiency are inferior to those of composite powder carrier particles.

[0056] Similarly, after the addition of diatomaceous earth-based microbial carrier particles, beneficial bacteria attach and grow on their surface and in their pores, forming sludge particles through biofilm formation; the combination of diatomaceous earth-based microbial carrier particles with micron-sized pyrite ultrafine powder can further promote this formation process.

[0057] like Figure 1 As shown, in commonly used technologies, air separation is often employed to screen the raw diatomaceous earth to obtain a diatomaceous earth carrier for use in the HPB biological treatment tank. When the diatomaceous earth obtained from this process is added to the HPB biological treatment tank as a microbial carrier, a large number of fine solid particles will float to the surface, increasing the treatment burden on wastewater.

[0058] The wet separation process, a commonly used technique, is often used to process raw diatomite to produce refined diatomite for use in fine processing. Due to the liquid environment of the wet separation process, the refined diatomite can be evenly dispersed with the addition of dispersants, which is beneficial for the subsequent separation and purification of the refined diatomite.

[0059] However, when the diatomaceous earth produced by this process is used in the HPB biological treatment tank to treat sewage, firstly, it will introduce phosphorus into the HPB biological treatment tank, which is contrary to the process requirements of this invention to solve the technical problem of carrier particles adding treatment burden to the HPB biological treatment tank; secondly, the diatomaceous earth treatment process is complicated and costly, and its feasibility for application in sewage treatment is not high.

[0060] It should be noted that the main indicators for wastewater treatment include pH value, suspended solids (SS), five-day biochemical oxygen demand (BOD5), ammonia nitrogen (NH3-N), total phosphorus (TP), and color.

[0061] These indicators reflect the types and concentrations of pollutants in wastewater and are important bases for evaluating wastewater treatment effectiveness. Through appropriate wastewater treatment processes and technologies, the values ​​of these indicators can be effectively reduced, thereby achieving the goals of water purification and environmental protection.

[0062] To address the technical problem that the diatomaceous earth products obtained by the aforementioned process cause secondary pollution when applied to HPB biological treatment tanks, thus placing a burden on wastewater treatment, this invention provides a wastewater treatment method, comprising the following steps:

[0063] S1. Obtaining a diatomaceous earth-based microbial carrier, wherein the preparation of the diatomaceous earth-based microbial carrier includes:

[0064] The raw diatomaceous earth is scrubbed and pulped to obtain the pulp.

[0065] The slurry is screened through a 32-60 mesh screen to remove impurities, yielding the first slurry as the undersize material.

[0066] The first slurry is sieved through an 80-100 mesh screen to remove impurities, yielding the undersize second slurry.

[0067] The second slurry was subjected to sedimentation, pressure filtration, and drying to obtain a diatomaceous earth-based microbial carrier;

[0068] S2. The diatomaceous earth-based microbial carrier is added to the wastewater treatment biochemical tank, wherein the amount of the diatomaceous earth-based microbial carrier added is 4~6 g / L.

[0069] This invention provides a method for producing a diatomaceous earth-based microbial carrier, comprising the following steps:

[0070] S11. Wash and pulp the diatomaceous earth to obtain the pulp.

[0071] In some embodiments, the composition of the diatomaceous earth, by mass fraction, includes: 40% water, 1.8% impurities, 2.8% gravel, 0.5% fine mud, and 54.9% diatomaceous earth-based microbial carrier.

[0072] The content of impurities, gravel, debris, fine mud, and the yield of diatomaceous earth-based microbial carriers are greatly affected by the quality of the diatomaceous earth raw material. Therefore, it is necessary to limit the source and composition of the diatomaceous earth raw material.

[0073] Among them, impurities refer to impurities with a particle size greater than 40 mesh, including stones, leaves, grass roots, etc.

[0074] Gravel and debris can be defined according to the particle size of the gravel and debris that can enter the HPB biological treatment tank, and usually refers to impurities with a particle size of 40~100 mesh.

[0075] Fine mud refers to fine mud particles that are suspended in water.

[0076] In some embodiments, the process of washing and preparing diatomaceous earth slurry further includes crushing the diatomaceous earth slurry to a size not exceeding 50 mm, adding a first water to the diatomaceous earth slurry, and washing and preparing slurry at a solid-liquid ratio of 1:1 to 1:3, wherein the pH of the slurry is 6 to 8, and the washing time is 10 to 30 minutes.

[0077] In some specific embodiments, the diatomaceous earth can be crushed to 50mm, and water can be added to the crushed diatomaceous earth. The amount of water added is calculated according to a solid-liquid ratio of 1:2, and the mixture is scrubbed and pulped for 20 minutes.

[0078] Among them, scrubbing and pulping usually includes the non-metallic mineral scrubbing machine step.

[0079] S12. The slurry is screened through a 32-60 mesh screen to remove impurities, and the sieved material is used to obtain the first slurry.

[0080] In some embodiments, step S2 further includes:

[0081] While the slurry is being screened through a 32-60 mesh screen to remove impurities, a second water wash is added, the amount of which is 5%-15% of the total mass of the slurry.

[0082] In some specific embodiments, the slurry is rinsed with a second type of water while being screened through a 40-mesh sieve to remove impurities. The amount of the second type of water added is 9.25% of the total mass of the slurry, and the flow rate of the slurry passing through a 32-60 mesh sieve can be 12-15 t / h.

[0083] For example, the flow rate of the slurry passing through a 32-60 mesh sieve can be 13.08 t / h.

[0084] By limiting the sieve aperture, impurities, as well as some sand and debris, in the slurry can be effectively removed.

[0085] For example, during the sieving process in step S2, the sieve aperture can be 40 mesh.

[0086] By synergistically limiting the amount of water added and the flow rate of the slurry, the slurry is diluted to a certain extent while avoiding blockage and poor flow when passing through the sieve, thereby further reducing the loss of diatomaceous earth-based microbial carriers.

[0087] S13. The first slurry is sieved through an 80-100 mesh screen to remove impurities, and the sieved material is used to obtain the second slurry.

[0088] In some embodiments, step S13 further includes:

[0089] After adding the third water to the first slurry, it is then screened through an 80-100 mesh sieve to remove impurities. The amount of the third water added can be 40% to 60% of the total mass of the first slurry, and the flow rate of the first slurry passing through the 80-100 mesh sieve can be 13 to 16 t / h.

[0090] The amount of the third water added can be 45.21% of the total mass of the first slurry, and the flow rate of the first slurry passing through an 80-100 mesh sieve can be 14.09 t / h.

[0091] By limiting the sieve aperture in step S13, sand and debris in the first slurry can be effectively removed.

[0092] It should be noted that the sieve particle size can be adjusted according to the allowable gravel size in the HPB biological treatment tank.

[0093] By synergistically limiting the amount of third water added and the flow rate of the first slurry, the first slurry is diluted while avoiding blockage and poor flow when passing through the sieve, further reducing the loss of diatomaceous earth-based microbial carriers.

[0094] S14. The second slurry is filtered and dried to obtain a diatomaceous earth-based microbial carrier.

[0095] In some embodiments, step S14 further includes: the second slurry is separated by sedimentation to obtain bottom mud, and the bottom mud is filtered and dried to obtain the diatomaceous earth-based microbial carrier; wherein the sedimentation separation time is 30~90min.

[0096] Specifically, after sedimentation and separation for 60 minutes, bottom sediment and supernatant are obtained. The bottom sediment is then filtered and dried to obtain diatomaceous earth-based microbial carriers.

[0097] The upper layer of liquid is periodically cleaned of fine mud to obtain mud cake and water, which can be recycled as primary and secondary water.

[0098] For example, filter press can be a plate and frame filter press.

[0099] For example, the product after pressure filtration can be treated by low-temperature drying, wherein the low-temperature drying time can be 1 to 3 hours and the temperature can be 100 to 200°C.

[0100] By limiting the drying temperature, the biocompatibility of the resulting diatomaceous earth as a microbial carrier can be avoided. Excessive temperature will destroy the hierarchical pore structure of diatoms, thus affecting their biocompatibility.

[0101] Compared with commonly used technologies, the present invention achieves at least the following effects:

[0102] This invention involves scrubbing and pulping diatomaceous earth, followed by double sieving of the resulting slurry. Firstly, by controlling the sieve apertures of the two sieving processes to 32-60 mesh and 80-100 mesh respectively, both sieving processes ensure slurry throughput while precisely removing impurities, gravel, and debris. Secondly, the sieve aperture selection meets the maximum allowable particle size requirements (≤200μm) for impurities, gravel, debris, and fine mud in the diatomaceous earth-based microbial carrier under HPB technology, while minimizing the loss of the diatomaceous earth-based microbial carrier and ensuring its yield.

[0103] That is, the diatomaceous earth-based microbial carrier prepared by the present invention can avoid the phenomenon of impurities floating after the diatomaceous earth-based microbial carrier is added to the HPB biochemical tank after air separation in commonly used technologies, while ensuring application efficiency, and effectively reducing the pollution treatment burden in the HPB biochemical tank.

[0104] Furthermore, the diatomaceous earth-based microorganisms prepared by this invention do not introduce phosphorus or alkali agents, thereby minimizing the wastewater treatment load, improving wastewater treatment efficiency, and optimizing phosphorus removal effect.

[0105] The present invention also provides a diatomaceous earth-based microbial carrier, which is prepared by any of the preparation methods described above, wherein the silica content of the diatoms in the diatom carrier is greater than 70% by mass fraction.

[0106] Diatomaceous earth, used as a carrier, possesses characteristics such as large specific surface area, porous structure, good biocompatibility, and good chemical stability. This invention, through process improvement and optimization, confines the entire process to a low-temperature, humid environment, maximizing the retention of beneficial substances in the diatomaceous earth carrier and ensuring its unaffected biocompatibility. Furthermore, the chemical composition of diatoms is amorphous silica, and the silica content characterizes the diatom content.

[0107] In some embodiments, the specific surface area of ​​the diatomaceous earth-based microbial carrier prepared by the present invention can be 15-30 m². 2 / g, tapped bulk density ≤0.60g / cm³ 3 The moisture content should not exceed 30%.

[0108] In some embodiments, the diatomaceous earth-based microbial carrier naturally accumulates into a loose, powdery product, which is white, gray, or light yellow in color.

[0109] like Figure 15As shown, when observed under optical and electron microscopes, the diatomaceous earth-based microbial carrier products mainly consist of complete diatom shells with geometric shapes and pore structures, with a small number of diatom shell fragments. The diatoms are primarily *Cyclocarya paliurus*.

[0110] When sampling diatomaceous earth-based microbial carrier products using wet sieving with a Taylor standard sieve, the mass percentage of material on a 40-mesh sieve is less than 0.05%.

[0111] When particle size distribution of diatomaceous earth-based microbial carrier products is detected using a laser particle size analyzer, the volume ratio of particles with an equivalent particle size of 10~50μm is greater than 60%.

[0112] The present invention also provides the application of a diatomaceous earth-based microbial carrier prepared by any of the above methods, or the diatomaceous earth-based microbial carrier as described above, in a wastewater treatment biochemical tank.

[0113] In some embodiments, referring to the invention with publication number CN110577285B, the wastewater treatment biochemical tank can be an HPB biochemical tank.

[0114] The HPB biological treatment tank is a fluidized bed system in which composite powder carrier biofilm and suspended activated sludge coexist. Through the growth of nitrogen and phosphorus removal bacteria, it improves the deep phosphorus and nitrogen removal capacity of wastewater biological treatment. The design of the HPB biological treatment tank also emphasizes convection and mass transfer to ensure that the composite powder carrier biofilm and suspended activated sludge attached to the mixed liquor of the HPB biological treatment tank are fully mixed with the treated municipal wastewater at all times.

[0115] Diatomaceous earth-based microbial carriers can function as the aforementioned composite carriers, providing sufficient attachment points for the growth of nitrogen and phosphorus removal bacteria and promoting the formation of a dual-sludge symbiosis in the HPB biological treatment pond.

[0116] Because the HPB biological treatment tank is in a fluidized state, it can also be called a fluidized bed. In commonly used technologies, when diatomaceous earth-based microbial carriers containing fine solid impurities are introduced into the HPB biological treatment tank, these impurities will continuously rise and fall, becoming difficult to remove. However, the diatomaceous earth-based microbial carrier of this invention does not present this technical problem, reducing the difficulty of wastewater treatment and alleviating the burden on the process.

[0117] To facilitate a further understanding of the present invention by those skilled in the art, the following examples are provided:

[0118] Example 1

[0119] Take 4.36 tons of diatomaceous earth, crush the diatomaceous earth, add 8.72 tons of water, and scrub and slurry it at a solid-liquid ratio of 1:2 to obtain slurry. The composition of the diatomaceous earth is as follows: 0.02 tons of fine mud, 2.40 tons of diatomaceous earth-based microbial carrier (dry weight), 0.08 tons of impurities, 1.74 tons of water, and 0.12 tons of sand, gravel, and debris.

[0120] Add 1.21 tons of second water to the slurry, and then sieve it through a 40-mesh screen to remove impurities. The first slurry, which is the undersize, has a mass of 14.09 tons and a solid content of 18%. The oversize consists of impurities including pebbles and leaves, with a mass of 0.20 tons and a solid content of 40%.

[0121] After washing the first slurry, 6.37 tons of water were added, and the mixture was sieved through a 100-mesh sieve to remove impurities, yielding the second slurry, which had a mass of 20.17 tons and a solid content of 12%. The material remaining on the sieve consisted of sand and gravel, with a mass of 0.29 tons and a solid content of 40%.

[0122] The second slurry was separated by sedimentation to obtain bottom mud and supernatant; the bottom mud weighed 12 tons with a solid content of 20%, and the supernatant weighed 8.17 tons with a solid content of 0.24%.

[0123] The bottom sediment was filtered through a plate and frame filter press to obtain a moist diatomaceous earth-based microbial carrier and reclaimed water. The mass of the moist diatomaceous earth-based microbial carrier was 4.8 tons, and the solid content was 50%. The upper liquid was filtered to remove fine mud to obtain a mud cake and reclaimed water. The mass of the mud cake was 0.06 tons, and the solid content was 33%.

[0124] The diatomaceous earth-based microbial carrier was obtained by moistening and low-temperature drying. The total mass of the diatomaceous earth-based microbial carrier was 3 tons, with a solid content of 80%. The electron micrograph of the sediment is shown below. Figure 4 As shown.

[0125] Example 2

[0126] Take 8 tons of diatomaceous earth, crush the diatomaceous earth, add 12.8 tons of water, and scrub and slurry it at a solid-liquid ratio of 1:1.6 to obtain slurry. The composition of the diatomaceous earth is as follows: 0.05 tons of fine mud, 3.75 tons of diatomaceous earth-based microbial carrier, 0.16 tons of impurities, 3.84 tons of water, and 0.20 tons of sand, gravel, and debris.

[0127] The slurry was sieved through a 40-mesh screen to remove impurities, yielding the first slurry as the undersize, which had a mass of 22.48 tons and a solid content of 17.8%. The remaining material, consisting of impurities including pebbles and leaves, had a mass of 0.40 tons and a solid content of 40%.

[0128] After washing the first slurry, 7.32 tons of water were added, and the mixture was sieved through an 80-mesh sieve to remove impurities, yielding the second slurry, which consisted of 29.3 tons of material with a solid content of 12.97%. The material remaining on the sieve, consisting of sand and debris, weighed 0.5 tons and had a solid content of 40%. An electron micrograph of the second slurry is shown below. Figure 5 As shown.

[0129] The second slurry was separated by sedimentation to obtain bottom sediment and supernatant; the bottom sediment weighed 16.67 tons with a solid content of 22.5%, and the supernatant weighed 12.63 tons with a solid content of 0.4%; the electron micrograph of the bottom sediment is shown below. Figure 6 As shown in the image, the upper liquid electron microscopy image is as follows: Figure 7 As shown.

[0130] The sediment was filtered through a plate and frame filter press to obtain moistened diatomaceous earth-based microbial carriers and reclaimed water. The mass of the moistened diatomaceous earth-based microbial carriers was 7.21 tons, with a solid content of 52%. The supernatant was periodically desludged to obtain mud cakes and reclaimed water. The mass of the mud cakes was 0.13 tons, with a solid content of 31%. The electron micrograph of the mud cakes is shown below. Figure 8 As shown.

[0131] The diatomaceous earth-based microbial carrier was moistened and then dried at low temperature to obtain the diatomaceous earth-based microbial carrier. The mass of the diatomaceous earth-based microbial carrier was 5.0 tons, and the solid content was 75%.

[0132] On a dry basis, the original diatomaceous earth contains the following components: 3.85% impurities, 4.81% gravel and debris, 1.20% fine mud, and 90.14% diatomaceous earth-based microbial carrier.

[0133] Example 3

[0134] The study investigated the sieving results of 80-mesh, 100-mesh, 150-mesh, and 200-mesh sieves and the yield of sand and debris during secondary screening for impurity removal.

[0135] It can be seen that when using 80-mesh and 100-mesh sieves to remove sand and debris, the slurry can pass through normally. However, when using 150-mesh and 200-mesh sieves, the slurry cannot pass through and requires simultaneous vibration and rinsing with a large amount of water (more than 10 times the volume of rinsing water). Although the yield (removal rate) of sand and debris increases with the larger the sieve mesh number, the yield at 80-mesh already reaches 3.58%. The sand and debris passing through the 80-mesh sieve can meet the particle size requirements for inorganic particles in wastewater and will not have an adverse impact on its application. The product on the 80-mesh sieve is as follows: Figure 9 As shown.

[0136] Example 4

[0137] The study investigated the yield of fine mud and bottom mud and the solid content in the bottom mud at different settling times (10 min, 30 min, 60 min, 90 min) for 80-mesh sieve slurry during sedimentation separation. Fine mud is the suspended solids in the upper liquid.

[0138] It can be seen that the bottom mud yield of the slurry under the 80-mesh sieve reaches more than 98% after settling for 30 minutes, and the solid content in the bottom mud is close to 20%.

[0139] Analysis example 1

[0140] When the diatomaceous earth in Example 1 was prepared as a slurry with a solid content of 1%, its optical microscope image is shown below. Figure 10 As shown.

[0141] Comparative Example 1

[0142] The diatomaceous earth carrier obtained by the air separation process includes the following components: 16.3% moisture, 0.5% impurities, 3.5% gravel and debris, 2.7% fine mud, and 77% diatomaceous earth-based microbial carrier.

[0143] After adding the diatom carrier, the amount of floating sludge in the biochemical pond doubled, and impurities from the original diatom soil could be seen in the floating sludge.

[0144] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for treating HPB wastewater, characterized in that, Including the following steps: S1. A diatomaceous earth-based microbial carrier is prepared, wherein the diatomaceous earth-based microbial carrier is prepared as follows: The raw diatomaceous earth is scrubbed and pulped to obtain the pulp. The slurry is screened through a 32-60 mesh screen to remove impurities, yielding the first slurry as the undersize material. The first slurry is sieved through an 80-100 mesh screen to remove impurities, yielding the undersize second slurry. The second slurry was subjected to sedimentation, pressure filtration, and drying to obtain a diatomaceous earth-based microbial carrier; the silica content of the diatomaceous earth-based microbial carrier was greater than 70%. S2. The diatomaceous earth-based microbial carrier is added to the HPB wastewater treatment biochemical tank, wherein the amount of the diatomaceous earth-based microbial carrier added is 4~6g / L; While the slurry is being screened through a 32-60 mesh sieve to remove impurities, a second water wash is added, the amount of which is 5%-15% of the total mass of the slurry. While the first slurry is being screened through an 80-100 mesh sieve to remove impurities, a third type of water is added for rinsing. The amount of the third type of water added is 30% to 60% of the total mass of the first slurry.

2. The HPB wastewater treatment method according to claim 1, characterized in that, By mass fraction, the composition of the diatomaceous earth raw soil includes: 35%~55% moisture, 1%~5% impurities, 1%~5% gravel, 0~5% fine mud, and 30%~63% diatomaceous earth-based microbial carrier.

3. The HPB wastewater treatment method according to claim 1, characterized in that, The step of washing and preparing slurry from raw diatomaceous earth includes: crushing the raw diatomaceous earth to a size no larger than 50 mm, adding a first water to the raw diatomaceous earth, and washing and preparing slurry at a solid-liquid ratio of 1:1 to 1:3, wherein the pH of the slurry is 6 to 8, and the washing time is 10 to 30 minutes.

4. The HPB wastewater treatment method according to claim 1, characterized in that, The second slurry, after sedimentation, pressure filtration, and drying, yields a diatomaceous earth-based microbial carrier, wherein the drying time is 1-3 hours and the drying temperature is 100-200℃.

5. The application of the HPB wastewater treatment method as described in any one of claims 1 to 4 in HPB wastewater treatment.

6. The application according to claim 5, characterized in that, The diatomaceous earth-based microbial carrier, combined with an alternative carbon source, is then introduced into the HPB wastewater treatment biochemical tank.

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