A water treatment formulation and a method of making the same

Abstract

The application provides a water treatment preparation and a preparation method thereof, and relates to the field of sewage treatment.The preparation method comprises the following steps: uniformly mixing a liquid culture medium and nano activated carbon, adding a gelatin aqueous solution, performing ultrasonic oscillation treatment, drying, and obtaining a porous carrier; uniformly mixing a microbial agent and the liquid culture medium, adding mesoporous calcium carbonate and the porous carrier, uniformly mixing, and obtaining a suspension; mixing polyvinyl alcohol, agar and water, uniformly stirring under heating to 80-90 DEG C, cooling to 40-50 DEG C, adding the suspension, uniformly stirring, cooling to 30-35 DEG C, adding alum powder, uniformly stirring, cooling, and crushing to obtain granular substances; uniformly mixing chitosan and an acetic acid solution, adding an alcohol solution of glutaraldehyde and beta-cyclodextrin, stirring at 40-50 DEG C for 30-40 min, coating the granular substances, and drying. The water treatment preparation is coated by multiple layers, can slowly provide nutrient substances for the microbial agent, and can further prolong the effective time of the preparation for treating sewage.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and more specifically, to a water treatment agent and its preparation method. Background Technology

[0002] Microbial wastewater treatment is currently the most energy-efficient and effective method. It improves water quality through the metabolic activities of microorganisms, degrading organic matter, transforming harmful substances, and increasing dissolved oxygen levels, thereby purifying the water. Microbial wastewater treatment has the following advantages: No toxic side effects: Microbial agents are derived from nature and pose no pathogenicity to humans or aquatic organisms. No residue: No harmful substances are left in the water after use. No drug resistance: Unlike chemical drugs, microbial agents do not induce drug resistance in pathogens. Environmentally friendly: It maintains the balance of aquatic ecosystems and reduces environmental pollution.

[0003] Immobilized microbial technology is a microbial treatment technology that can be used to treat wastewater, effectively removing pollutants such as organic matter, nitrogen, and phosphorus. Utilizing methods such as physical adsorption, chemical reaction immobilization, porous carrier encapsulation, and self-crosslinking immobilization, enzymes, microbial cells, plant and animal cells, and organelles are confined or positioned within a specific spatial region, maintaining their activity and enabling continuous wastewater treatment. Compared to directly adding microbial agents, this method offers higher treatment efficiency.

[0004] Currently, most immobilized microbial technologies utilize polyvinyl alcohol (PVA) and sodium alginate to encapsulate and immobilize microbial agents. However, the strength of PVA and sodium alginate encapsulation is insufficient, and the encapsulation body has a high breakage rate as microorganisms grow, causing the internal microorganisms to lose their immobilization effect and thus reducing the efficiency of wastewater treatment. Summary of the Invention

[0005] The purpose of this invention is to provide a water treatment formulation that, through multi-layer coating, can slowly provide nutrients to microbial agents, prolong the existence time of microorganisms in the formulation, and increase the number of microorganisms; through microbial metabolic activities, it continuously degrades harmful substances in wastewater, thus extending the effective time of the formulation in treating wastewater.

[0006] Another objective of this invention is to provide a method for preparing a water treatment agent, in which the culture medium is adsorbed into the pores of mesoporous calcium carbonate and then coated multiple times, which can effectively extend the treatment time of the agent for wastewater.

[0007] The technical problem solved by this invention is achieved by the following technical solution.

[0008] On one hand, embodiments of the present invention provide a method for preparing a water treatment agent, comprising the following steps:

[0009] S1. Mix liquid culture medium with nano-activated carbon evenly, add gelatin aqueous solution, ultrasonically vibrate, and dry to obtain porous carrier.

[0010] S2, mix the microbial agent and liquid culture medium evenly, then add mesoporous calcium carbonate and the porous carrier from step S1, mix evenly to obtain a suspension;

[0011] S3: Mix polyvinyl alcohol, agar and water, heat to 80-90℃ and stir until homogeneous, cool to 40-50℃, add the suspension from step S2 and stir until homogeneous; cool to 30-35℃, add alum powder and stir until homogeneous, cool until the agar solidifies, pulverize to obtain granules.

[0012] S4. Chitosan and acetic acid solution are mixed evenly, and then glutaraldehyde alcohol solution and β-cyclodextrin are added. After stirring at 40-50℃ for 30-40 minutes, the mixture is coated on the surface of the particles from step S3 and dried to obtain the water treatment preparation.

[0013] In some embodiments of the present invention, the mesoporous calcium carbonate has a particle size of 0.5-1 mm and an average pore size of 100-200 μm, and the nano-activated carbon has a particle size of 80-100 nm.

[0014] In some embodiments of the present invention, the ultrasonic oscillation power is 50-80 kHz, and the treatment time is 10-30 min. High-frequency ultrasonic oscillation allows the activated carbon and liquid culture medium molecules to acquire sufficient energy, facilitating the entry of liquid culture medium molecules into the pores of the activated carbon and their loading within the pores. The loading effect is further improved under the action of ultrasonic oscillation.

[0015] In some embodiments of the present invention, the mass fraction of the gelatin aqueous solution is 5-10%. After drying, the low-concentration gelatin aqueous solution can form a local film on activated carbon, that is, it can form a coating or semi-coating state on the surface and pores of activated carbon, thus encapsulating the effective components of the culture medium within the pores of the activated carbon. When using the water treatment formulation of the present invention, after the gelatin film swells and decomposes in water, it can release the culture medium components in the activated carbon, continuing to provide nutrients required for the growth of microorganisms. Furthermore, the released activated carbon can also adsorb microorganisms in the water, providing a carrier for microbial growth.

[0016] In some embodiments of the present invention, the microbial agent includes one or more of ammonia nitrogen-degrading bacteria, COD-degrading bacteria, and phosphorus-removing bacteria, or a mixture thereof.

[0017] Ammonia nitrogen-degrading bacteria can efficiently degrade ammonia nitrogen in wastewater. These include bacteria such as *Pseudomonas* sp., *Alcaligenes faecalis*, *Bacillus* sp., *Acinetobacter* sp., *Rhodococcus* sp., *Paracoccus*, *Ochrobactrum* sp., and *Providencia*, as well as fungi such as yeasts, *Fusarium*, and *Penicillium*. The appropriate microorganism can be selected based on the specific circumstances. COD (Chemical Oxygen Demand)-degrading bacteria are mainly used to degrade COD in wastewater, improve water color, increase sludge floc particles, adjust sludge floc structure, and inhibit algae growth. These mainly include *Acinetobacter calciacetate*, *Bacillus*, nitrifying bacteria, denitrifying bacteria, *Pseudomonas*, and yeasts. Phosphorus-removing bacteria are a type of bacteria that removes phosphorus from water through biological metabolism. Examples include *Lampropedia aspp.*, *Microlunatus phosphovorus*, *Clostridium pasteurellii*, butyric acid bacteria, and *Pseudomonas spp.*.

[0018] In some embodiments of the present invention, the mass ratio of polyvinyl alcohol, agar, and water is (5-10):(1-5):(10-20). The addition of polyvinyl alcohol and agar can encapsulate microorganisms and porous carriers, and the combination with the internal mesoporous calcium carbonate can improve the mechanical strength of the particles.

[0019] In some embodiments of the present invention, the mass ratio of the alum to the microbial agent is 1:(1-2).

[0020] In some embodiments of the present invention, step S4 further includes adding activated carbon powder after stirring at 40-50°C until homogeneous, and stirring until homogeneous. Activated carbon is loaded onto the surface, utilizing its adsorption properties to initially adsorb suspended solids in the water, providing a favorable environment for subsequent microbial growth.

[0021] In some embodiments of the present invention, the mass ratio of the activated carbon powder to the particulate matter is 0.1-0.5:1.

[0022] On the other hand, embodiments of the present invention provide a water treatment formulation prepared by the above method.

[0023] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0024] The water treatment preparation method provided by this invention first mixes liquid culture medium with nano-activated carbon. Under the action of ultrasonic vibration, the liquid culture medium can be loaded onto the surface and pores of the nano-activated carbon. During the drying process, gelatin can form a coating film on the surface of the nano-activated carbon, encapsulating the effective components of the culture medium inside. Then, activated carbon, microbial agents, and culture medium are loaded into the pores of mesoporous calcium carbonate, using mesoporous calcium carbonate as a carrier, which has high mechanical strength. Then, the coating effect of polyvinyl alcohol and agar is used to coat the microbial agents and culture medium onto the surface of the porous carrier, forming a double-layer core structure. When the agar is semi-solidified, alum powder is added and loaded between the agar and polyvinyl alcohol. Finally, a layer of chitosan polymer is coated on the surface to protect the microbial agents inside. When using the wastewater treatment agent of this invention, the agent is added to the wastewater. The chitosan, cyclodextrin, agar, polyethanol, etc., coating the microbial agent, slowly dissolve, releasing the microbial agent to degrade pollutants in the water. Secondly, alum hydrolyzes into colloidal substances in water, which can adsorb pollutants in the wastewater. Simultaneously, the adsorption effect of the colloids can also concentrate pollutants around the treatment agent, facilitating microbial metabolism and degradation. Thirdly, gelatin slowly swells in the water, releasing the culture medium from porous calcium carbonate, further providing nutrients to the microbial agent, thereby prolonging its activity and extending the effective time for wastewater treatment. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to specific embodiments.

[0027] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0028] Example 1

[0029] The water treatment formulation of this embodiment was prepared according to the following method:

[0030] S1. Mix liquid culture medium with nano-activated carbon (average particle size 100nm) evenly, add 5% gelatin aqueous solution, and sonicate at 50KHz for 30min. Dry to obtain porous carrier; wherein, the ratio of liquid culture medium, nano-activated carbon and gelatin aqueous solution is 1mL:1g:1mL.

[0031] S2, containing ammonia nitrogen-degrading bacteria (Bacillus, 8.0 × 10⁻⁶). 9 CFU / mL), COD-degrading bacteria (nitrifying bacteria, 5.0 × 10⁻⁶) 9 CFU / mL), phosphorus-sparing bacteria (Pseudomonas, 5.0 × 10⁻⁶). 9 The microbial agent (cfu / mL) and liquid culture medium are mixed evenly, and then mesoporous calcium carbonate (average particle size 0.8 mm, average pore size 100 μm) and the porous carrier from step S1 are added and mixed evenly to obtain a suspension; wherein the mass ratio of microbial agent, mesoporous calcium carbonate and porous carrier is 1:2:1.

[0032] S3, mix polyvinyl alcohol, agar and water, heat to 85°C and stir evenly, cool to 50°C, add the suspension from step S2 and stir evenly; cool to 35°C until the agar is in a semi-solid state, add alum powder, stir evenly, cool to solidify the agar, and crush to an average particle size of 2cm to obtain granules.

[0033] The mass ratio of polyvinyl alcohol, agar, and water is 10:5:10, the mass ratio of microbial inoculant to agar in the suspension is 1:1, and the mass ratio of alum to microbial inoculant is 1:1.

[0034] S4. Chitosan and a 10% acetic acid solution are mixed evenly at a mass-to-volume ratio of 1:2. Then, an alcoholic solution of glutaraldehyde (10wt%) with an equal volume of acetic acid and an equal mass of β-cyclodextrin with chitosan are added. The mixture is stirred at 50°C for 30 minutes. The mixture is then coated onto the surface of the particles from step S3 using a sprayer and allowed to air dry naturally at room temperature to obtain the water treatment preparation.

[0035] Example 2

[0036] The water treatment formulation of this embodiment was prepared according to the following method:

[0037] S1. Mix liquid culture medium with nano-activated carbon (average particle size 100nm) evenly, add 5% gelatin aqueous solution by mass, and sonicate at an ultrasonic frequency of 80KHz for 30min. Dry to obtain a porous carrier. The ratio of liquid culture medium, nano-activated carbon and gelatin aqueous solution is 1mL:1g:1mL.

[0038] S2, containing ammonia nitrogen-degrading bacteria (Bacillus, 8.0 × 10⁻⁶). 9 CFU / mL), COD-degrading bacteria (nitrifying bacteria, 5.0 × 10⁻⁶) 9 CFU / mL), phosphorus-sparing bacteria (Pseudomonas, 5.0 × 10⁻⁶). 9The microbial agent (cfu / mL) and liquid culture medium are mixed evenly, and then mesoporous calcium carbonate (average particle size 0.8 mm, average pore size 100 μm) and the porous carrier from step S1 are added and mixed evenly to obtain a suspension; wherein the mass ratio of microbial agent, mesoporous calcium carbonate and porous carrier is 1:3:1.

[0039] S3, mix polyvinyl alcohol, agar and water, heat to 85°C and stir evenly, cool to 50°C, add the suspension from step S2 and stir evenly; cool to 35°C until the agar is in a semi-solid state, add alum powder, stir evenly, cool to solidify the agar, and crush to an average particle size of 2cm to obtain granules.

[0040] The mass ratio of polyvinyl alcohol, agar, and water is 10:3:10, the mass ratio of microbial inoculant to agar in the suspension is 1:1, and the mass ratio of alum to microbial inoculant is 1:1.5.

[0041] S4. Chitosan and a 10% acetic acid solution are mixed evenly at a mass-to-volume ratio of 1:2. Then, an alcoholic solution of glutaraldehyde (10wt%) with an equal volume of acetic acid and an equal mass of β-cyclodextrin with chitosan are added. The mixture is stirred at 50°C for 30 minutes. The mixture is then coated onto the surface of the particles from step S3 using a sprayer and allowed to air dry naturally at room temperature to obtain the water treatment preparation.

[0042] Example 3

[0043] The water treatment formulation of this embodiment was prepared according to the following method:

[0044] S1. Mix the liquid culture medium with nano-activated carbon (average particle size 80nm) evenly, add 5% gelatin aqueous solution by mass, and sonicate at an ultrasonic frequency of 80KHz for 10min. Dry to obtain a porous carrier. The ratio of liquid culture medium, nano-activated carbon and gelatin aqueous solution is 1mL:1g:1mL.

[0045] S2, mix the microbial agent containing ammonia nitrogen-degrading bacteria (Bacillus, 8.0×10⁹ cfu / mL), COD-degrading bacteria (nitrifying bacteria, 5.0×10⁹ cfu / mL), and phosphorus-removing bacteria (Pseudomonas, 5.0×10⁹ cfu / mL) with the liquid culture medium, then add mesoporous calcium carbonate (average particle size 0.8 mm, average pore size 100 μm) and the porous carrier from step S1, mix well to obtain a suspension; wherein the mass ratio of microbial agent, mesoporous calcium carbonate, and porous carrier is 1:3:2.

[0046] S3, mix polyvinyl alcohol, agar and water, heat to 90°C and stir evenly, cool to 50°C, add the suspension from step S2 and stir evenly; cool to 35°C until the agar is in a semi-solid state, add alum powder, stir evenly, cool to solidify the agar, and crush to an average particle size of 2cm to obtain granules.

[0047] The mass ratio of polyvinyl alcohol, agar, and water is 5:5:10; the mass ratio of microbial inoculant to agar in the suspension is 1:1; and the mass ratio of alum to microbial inoculant is 1:1.5.

[0048] S4. Chitosan and a 10% acetic acid solution are mixed evenly at a mass-to-volume ratio of 1:2. Then, an alcoholic solution of glutaraldehyde (10wt%) with an equal volume of acetic acid and an equal mass of β-cyclodextrin with chitosan are added. The mixture is stirred at 40°C for 30 minutes. The mixture is then coated onto the surface of the particles from step S3 using a sprayer and allowed to air dry naturally at room temperature to obtain the water treatment preparation.

[0049] Example 4

[0050] The difference from Example 1 is that in step S4, after stirring at 50°C for 30 minutes, activated carbon powder (average particle size 200 nm) is added to the system. After stirring evenly, the mixture is coated onto the surface of the particles from step S3 using a sprayer, and then naturally dried in a ventilated environment at room temperature to obtain the water treatment formulation. The mass ratio of activated carbon powder to the particles from step S3 is 0.5:1.

[0051] Example 5

[0052] The difference from Example 4 is that in step S4, the mass ratio of the activated carbon powder added to the particles in step S3 is 0.1:1.

[0053] Comparative Example 1

[0054] The difference from Example 1 is that, in step S1, no gelatin aqueous solution is added, while the remaining steps and raw materials are the same as in Example 1.

[0055] Comparative Example 2

[0056] The difference from Example 1 is that mesoporous calcium carbonate is not added in step S2, while the remaining steps and raw materials are the same as in Example 1.

[0057] Comparative Example 3

[0058] The difference from Example 1 is that in step S3, alum powder is not added, while the remaining steps and raw materials are the same as in Example 1.

[0059] Comparative Example 4

[0060] The difference from Example 1 is that β-cyclodextrin is not added in step S2, while the remaining steps and raw materials are the same as in Example 1.

[0061] Example of effect

[0062] Using the water treatment formulations prepared in Examples 1-5 and Comparative Examples 1-4 as the research object, and using sewage from a certain town as the sewage to be treated, the following tests were conducted.

[0063] 1. The water treatment formulations of Examples 1-5 and Comparative Examples 1-4 were respectively added to 500m³ of water treatment solution. 3 The dosage in the wastewater meter is 0.5 kg / m³. 3 After adding the water treatment agent, air was pumped into the wastewater at a rate of 50 L / h. After 48 hours of treatment, the nitrified nitrogen and COD values ​​in the wastewater were measured, and the results are shown in Table 1.

[0064] Table 1. Detection results before and after treatment

[0065]

[0066] As can be seen from Table 1 above, the wastewater treatment formulations of Examples 1-5 have significantly better wastewater treatment capabilities than those of Comparative Examples 1-4. In Comparative Example 1, no gelatin solution was added, and the impact on microbial activity was minimal within 48 hours, resulting in a wastewater treatment capacity not significantly different from that of Examples 1-5. In Comparative Example 2, no mesoporous calcium carbonate was added. When the treatment agent was added to the water, the agar and polyvinyl alcohol decomposed, causing the microbial agent and culture medium to separate, resulting in a slower microbial reproduction rate and metabolic activity, and a lower wastewater treatment capacity compared to Examples 1-5.

[0067] In summary, the water treatment formulation provided in this invention uses mesoporous calcium carbonate as a carrier, which has high mechanical strength. The microbial agent and culture medium are coated onto the porous carrier surface using polyvinyl alcohol and agar, forming a double-layer core structure. Alum powder is added when the agar is semi-solidified, loaded between the agar and polyvinyl alcohol. A chitosan polymer is then coated on the surface to protect the internal microbial agent. When using the wastewater treatment formulation of this invention, it is added to wastewater. The chitosan, cyclodextrin, agar, polyvinyl alcohol, etc., coating the microbial agent slowly dissolve, releasing the microbial agent to degrade pollutants in the water. Secondly, alum hydrolyzes into colloidal substances in water, which can adsorb pollutants in the wastewater. Simultaneously, the adsorption effect of the colloids can gather pollutants around the water treatment formulation, facilitating microbial metabolic degradation. Thirdly, gelatin slowly swells in water, releasing the culture medium from the porous calcium carbonate, further providing nutrients to the microbial agent to prolong its activity and extend the effective time for wastewater treatment.

[0068] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for preparing a water treatment agent, characterized in that, Includes the following steps: S1. Mix liquid culture medium with nano-activated carbon evenly, add gelatin aqueous solution, ultrasonically vibrate, and dry to obtain porous carrier. S2, mix the microbial agent and liquid culture medium evenly, then add mesoporous calcium carbonate and the porous carrier from step S1, mix evenly to obtain a suspension; S3: Mix polyvinyl alcohol, agar and water, heat to 80-90℃ and stir until homogeneous, cool to 40-50℃, add the suspension from step S2 and stir until homogeneous; cool to 30-35℃, add alum powder and stir until homogeneous, cool until the agar solidifies, pulverize to obtain granules. S4. Chitosan and acetic acid solution are mixed evenly, and then glutaraldehyde alcohol solution and β-cyclodextrin are added. After stirring at 40-50℃ for 30-40 min, the mixture is coated on the surface of the particles in step S3 and dried to obtain the water treatment preparation. The mesoporous calcium carbonate has a particle size of 0.5-1 mm and an average pore size of 100-200 μm. The power of the ultrasonic oscillation is 50-80KHz, and the processing time is 10-30min; The mass fraction of the gelatin aqueous solution is 5-10%; The microbial agent includes one or more of ammonia nitrogen-degrading bacteria, COD-degrading bacteria, and phosphorus-removing bacteria; The mass ratio of polyvinyl alcohol, agar and water is (5-10):(1-5):(10-20); The mass ratio of alum to the microbial agent is 1:(1-2). In step S4, the process further includes adding activated carbon powder after stirring at 40-50°C until homogeneous, and stirring until homogeneous. The mass ratio of the activated carbon powder to the particulate matter is 0.1-0.5:

1.

2. A water treatment formulation, characterized in that, It is prepared by the preparation method described in claim 1.

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