A clarifier for black and odorous water body and a preparation method and application thereof

Abstract

This invention provides a clarifier for black and odorous water bodies, its preparation method, and its application. The preparation method includes the following steps: thoroughly mixing a polyacrylamide solution with a carrier at a mass ratio of polyacrylamide to carrier of 1:99 to 5:95; granulating, drying, grinding, and sieving to obtain a solid; and compounding the solid with the carrier to obtain the clarifier for black and odorous water bodies. The carrier is one or more of bentonite, diatomite, and kaolin that has passed through a 200-mesh sieve. In this invention, fine particles such as bentonite, diatomite, and kaolin are added to the prepared low-concentration polyacrylamide solution. After thorough mixing, granulation, drying, and grinding, the polyacrylamide forms a thin film on the surface of the bentonite, diatomite, and kaolin, which can be quickly dissolved in water. Therefore, the clarifier for black and odorous water bodies provided by this invention does not require pre-dissolution and can be directly added as dry powder to wastewater, making it more convenient and cost-effective.

Description

Technical Field

[0001] This invention relates to the field of water remediation technology, specifically to a clarifying agent for black and odorous water bodies, its preparation method, and its application. Background Technology

[0002] Black and odorous water bodies refer to water pollution caused by pollutants, exogenous factors, and ecosystem degradation, characterized by black coloration and foul odor. These water bodies not only directly impact daily life but also severely affect the ecological environment and aquatic life. Treatment methods for black and odorous water bodies are broadly categorized into physical, chemical, and biological methods.

[0003] Most existing technologies use coagulants to clarify black and odorous water bodies. However, coagulants usually need to be dissolved before use, or they need to be added in stages with bentonite and surfactants. For example, conventional polyacrylamide (PAM) requires 0.5 to 1 hour to dissolve before use, which is not only time-consuming but also requires fixed facilities such as dissolving and storage tanks, resulting in wasted time and high costs. Another example is a Chinese patent with publication number CN101254959B, which provides a bentonite wastewater treatment method. This method requires first adding bentonite to the wastewater to be treated and stirring for 5-20 minutes, then adding octadecyltrimethylammonium chloride (as a surfactant) and stirring rapidly for 5-20 minutes, followed by adding at least one of polyacrylamide, polymeric quaternary ammonium salt, or polymeric inorganic aluminum salt (as a flocculant), stirring for 5 minutes, and allowing sedimentation for 2-20 minutes. This method has disadvantages such as long operation time, slow sedimentation rate, and high chemical consumption. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art and provide a black and odorous water clarifier, its preparation method and application. It can produce a black and odorous water clarifier with the characteristics of fast dissolution and direct dry powder addition to sewage without pre-dissolution.

[0005] To achieve the above and other objectives, the present invention is implemented through the following technical solution: The present invention provides a method for preparing a black and odorous water clarifier, characterized by comprising the steps of: thoroughly mixing a polyacrylamide solution with a carrier at a mass ratio of polyacrylamide to carrier of 1:99 to 5:95, and obtaining a solid by granulation, drying, grinding, and sieving; compounding the solid with the carrier to obtain the black and odorous water clarifier; wherein the carrier is one or more of bentonite, diatomaceous earth, and kaolin that have passed through a 200-mesh sieve.

[0006] Further, by mass parts, the amount of the carrier compounded with the solid is 10% to 30% of the amount of the carrier mixed with the polyacrylamide solution.

[0007] Furthermore, the carrier mixed with the polyacrylamide solution is added as a powder or an aqueous solution with a concentration of 5% to 10%.

[0008] Further, the preparation steps of the polyacrylamide solution include: adding deionized water, acrylamide, cationic monomer, multifunctional UV monomer, chelating agent, and chain transfer agent sequentially to a mixing tank, stirring evenly to prepare a prepolymer liquid, adding an organic acid to the prepolymer liquid to adjust the pH of the solution, and obtaining a prepolymer solution; lowering the temperature of the prepolymer solution to 0-5°C, deoxygenating the prepolymer solution, and then transferring the prepolymer solution into a photoinitiator; adding poly-[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone] and an azo initiator to the pipeline into the photoinitiator, and mixing evenly using a static mixer; turning on the photoinitiator after 30 minutes to automatically carry out the photopolymerization reaction; and forming a viscous polyacrylamide solution through the polymerization reaction.

[0009] Furthermore, the multifunctional UV monomer is one or more of the following: pentaerythritol tetraacrylate, bisphenol A diacrylate ethoxylate, bisphenol A dimethacrylate ethoxylate, dimethacrylate, polyethylene glycol (200) dimethacrylate, polyethylene glycol (400) dimethacrylate, polyethylene glycol (600) dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate ethoxylate, propoxylated glycerol triacrylate, bis(trimethylolpropane) acrylate, bis(pentaerythritol hexaacrylate), and trimethylolpropane triacrylate.

[0010] Further, the cationic monomer is one or more of acryloyloxyethyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyldimethylbenzylammonium chloride, methacryloyloxyethyldimethylbenzylammonium chloride, acryloylpropyltrimethylammonium chloride, and dimethyldiallylammonium chloride.

[0011] Furthermore, the chain transfer agent is one or more of sodium bisulfite, sodium hypophosphite, sodium formate, dipropylene glycol, and isopropanol.

[0012] The present invention also provides a black and odorous water clarifier prepared by the above-mentioned method for preparing black and odorous water clarifier.

[0013] The present invention also provides an application of a black and odorous water clarifier, characterized in that the black and odorous water clarifier is directly dry-sprinkled at the aeration port of the water body to be treated, and the water is clarified by stirring.

[0014] Furthermore, the dosage range of the black and odorous water clarifier is 100ppm to 200ppm.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. By adding fine particles such as bentonite, diatomaceous earth, and kaolin to the prepared low-concentration polyacrylamide solution, and after thorough mixing, granulation, drying, and grinding, polyacrylamide will form a thin film on the surface of bentonite, diatomaceous earth, and kaolin. This film can be quickly dissolved in water. At the same time, by compounding the solid particles obtained after granulation, drying, and grinding with powders of bentonite, diatomaceous earth, and kaolin, a black and odorous water clarifying agent can be prepared. This can effectively avoid the problem of the polyacrylamide surface film being easily affected by moisture and solve the problem of solid particles becoming damp and clumping due to humid weather.

[0017] 2. Compared to conventional PAM, which requires 0.5 to 1 hour to dissolve before use and also requires fixed facilities such as dissolving and storage tanks, the black and odorous water clarifying agent prepared by this invention dissolves quickly, does not require pre-dissolving, and can be directly added to the wastewater as dry powder, making it more convenient to use and less costly.

[0018] 3. Using the macromolecular photoinitiator poly-[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone] to initiate the graft copolymerization of acrylamide, multifunctional UV monomers and cationic monomers, the multifunctionality of the macromolecular initiator serves as the crosslinking center. At the same time, the multifunctionality of the UV monomers can also serve as the crosslinking center to copolymerize with acrylamide, cationic monomers and bentonite. This can make the copolymer product form a highly branched structure, forming three-dimensional channels within and between molecular chains. Macroscopically, this makes the clarifying agent exhibit a high adsorption and desorption effect on most liquids.

[0019] 4. The black and odorous water clarifier of the present invention can purify river water and quickly remove water color, COD, ammonia nitrogen and other indicators; when applied to the treatment of sewage with low turbidity, the addition of diatomaceous earth and bentonite greatly increases the content of particulate matter in the water, that is, greatly increases the specific surface area of ​​active substances in the water used to capture impurities, making the agent particularly effective in the treatment of this type of low turbidity water; 5. The black and odorous water clarifier of the present invention is safe and friendly; it is biodegradable, non-corrosive, non-irritating, safe and environmentally friendly. Detailed Implementation

[0020] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention.

[0021] Unless otherwise specified, the experimental methods used in the embodiments of this invention are conventional methods. Unless otherwise specified, the materials and reagents used in the embodiments of this invention are commercially available.

[0022] This invention provides a method for preparing a clarifier for black and odorous water bodies, comprising the following steps: thoroughly mixing a polyacrylamide solution with a carrier at a mass ratio of polyacrylamide to carrier of 1:99 to 5:95, followed by granulation, drying, grinding, and sieving to obtain a solid; compounding the solid with the carrier to obtain the clarifier for black and odorous water bodies; wherein the carrier is one or more of bentonite, diatomaceous earth, and kaolin that have passed through a 200-mesh sieve.

[0023] Furthermore, the carrier mixed with the polyacrylamide solution is added in the form of powder or aqueous solution. When added in the form of aqueous solution, its concentration can be 5% to 10%. The carrier compounded with the solid is added in the form of powder.

[0024] Further, by mass parts, the amount of the carrier compounded with the solid is 10% to 30% of the amount of the carrier mixed with the polyacrylamide solution.

[0025] Since commercially available polyacrylamide solutions are mostly chain-like in structure, their structural stability and adsorption capacity are relatively poor. Therefore, inspired by the principle of the applicant's earlier application (publication number CN113754832B), a self-made polyacrylamide solution can be developed to improve the structural stability and adsorption capacity of polyacrylamide. The principle of the method is as follows: acrylamide, multifunctional UV monomer, and cationic monomer are graft copolymerized using the macromolecular photoinitiator poly-[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone]. The multifunctionality of the macromolecular photoinitiator serves as the crosslinking center, and the multifunctionality of the multifunctional UV monomer can also serve as the crosslinking center for copolymerization with acrylamide and cationic monomer. This allows the copolymer to form a highly branched structure, creating three-dimensional channels within and between molecular chains. Macroscopically, this copolymer exhibits high adsorption and desorption effects on most liquids.

[0026] The specific preparation steps of the polyacrylamide solution include:

[0027] Deionized water, acrylamide, cationic monomer, multifunctional UV monomer, chelating agent, and chain transfer agent are sequentially added to a mixing tank and stirred evenly to prepare a prepolymer liquid. An organic acid is added to the prepolymer liquid to adjust the pH of the solution to obtain a prepolymer solution.

[0028] The temperature of the prepolymer solution is lowered to 0-5°C, the prepolymer solution is deoxygenated, and then the prepolymer solution is transferred to the photoinitiator.

[0029] Add polymer [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone] and azo initiator to the pipeline into the photoinitiator, and mix them evenly using a static mixer;

[0030] After 30 minutes, the light source is turned on to automatically initiate the photopolymerization reaction; the polymerization reaction forms a viscous polyacrylamide solution.

[0031] Example 1

[0032] Add 3000 kg of deionized water to the mixing tank and start stirring. Add 30 kg of 40% acrylamide aqueous solution, 30 kg of acryloyloxyethyltrimethylammonium chloride, 0.03 kg of multifunctional UV monomer PETA, 0.03 kg of disodium ethylenediaminetetraacetate, and 0.01 kg of sodium bisulfite. Stir until homogeneous to prepare a prepolymer liquid of a certain concentration. Add citric acid to adjust the pH of the solution to about 4.00. Start cooling to lower the material to 0°C. Transfer the prepolymer liquid to a deoxygenation device at a rate of 3 tons / hour for deoxygenation. Add 0.02 kg of multifunctional photoinitiator and 0.02 kg of azo initiator to the pipeline at flow rates of 1.34 kg / hour and 0.40 kg / hour, respectively. After mixing evenly, enter the UV irradiation belt device for photo-initiated polymerization reaction. The polymerization reaction forms a viscous polyacrylamide solution (usually with a mass concentration not exceeding 50%. The polyacrylamide solutions prepared by this method are used in Examples 2-3 and Comparative Example 1 below).

[0033] 100 kg of the above polyacrylamide solution (mass concentration of about 30%) was added to a stirred tank, and 2700 kg of bentonite aqueous solution passed through a 200-mesh sieve was added. After stirring thoroughly for 2 hours, a relatively viscous liquid was obtained. The liquid was then granulated, dried, ground, and sieved to obtain a solid. 300 kg of bentonite powder passed through a 200-mesh sieve was then added and mixed to finally obtain a solid black and odorous water clarifier product.

[0034] Example 2

[0035] 100 kg of the above polyacrylamide solution (mass concentration of about 30%) was added to a stirred tank, and 1000 kg of bentonite and diatomaceous earth mixed solution that had passed through a 200-mesh sieve was added. After stirring thoroughly for 2 hours, a relatively viscous liquid was obtained. The liquid was then granulated, dried, ground, and sieved to obtain a solid. 300 kg of bentonite and diatomaceous earth mixed powder that had passed through a 200-mesh sieve was added and mixed to obtain a solid black and odorous water clarifier product.

[0036] Example 3

[0037] 100 kg of the above polyacrylamide solution (mass concentration of about 30%) was added to a stirred tank, and 600 kg of a mixed solution of bentonite, diatomite and kaolin that had passed through a 200-mesh sieve was added. After stirring thoroughly for 2 hours, a relatively viscous liquid was obtained. The liquid was then granulated, dried, ground and sieved to obtain a solid. 300 kg of a mixed powder of bentonite, diatomite and kaolin that had passed through a 200-mesh sieve was added and mixed to obtain a solid black and odorous water clarifier product.

[0038] Comparative Example 1

[0039] 100 kg of the above polyacrylamide solution (mass concentration of about 30%) was added to a stirred tank, and 1000 kg of a mixed solution of bentonite and diatomaceous earth that had passed through a 200-mesh sieve was added. After stirring thoroughly for 2 hours, a relatively viscous liquid was obtained. The liquid was then granulated, dried, ground, and sieved to obtain a solid product.

[0040] Comparative Example 2

[0041] An aqueous solution containing 30 kg of commercially available polyacrylamide was added to a mixing tank. Then, 1000 kg of a mixed solution of bentonite and diatomaceous earth that had passed through a 200-mesh sieve was added. After stirring thoroughly for 2 hours, a relatively viscous liquid was obtained. The liquid was then granulated, dried, ground, and sieved to obtain a solid. Finally, 300 kg of a mixed powder of bentonite and diatomaceous earth that had passed through a 200-mesh sieve was added and mixed to obtain a solid black and odorous water clarifier product.

[0042] Experimental Discussion

[0043] Experimental Method: Six cups (1000g each) of river water were weighed, with one cup serving as the raw water control group. The remaining five cups were placed on a six-unit stirrer, and 100mg of the clarifying agent product prepared in Examples 1-3 and Comparative Examples 1-2 was added to each cup. The raw water cup and the five cups of treated river water were then stirred rapidly at 350 rpm for 2 minutes, followed by slow stirring at 120 rpm for 3 minutes. After stopping the stirring, the flocculation effect, settling velocity, and clarity of the supernatant were observed. After standing for 5 minutes, the COD, turbidity, total nitrogen, and total phosphorus concentrations in the supernatant from the same height were measured. The experimental results are shown in the table below.

[0044]

[0045] According to the experimental results in the table above, the clarifying agent products prepared in Examples 1-3 can be directly applied dry to the aeration inlets of rivers. With a certain mixing force, they can naturally settle, making the water clear and transparent, effectively reducing COD, total nitrogen, turbidity, and total phosphorus levels in black water. This also conforms to the basic principle that the higher the proportion of polyacrylamide in the carrier dosage, the better the flocculation effect. Furthermore, the actual dosage of the clarifying agent can be determined through small-scale testing to optimize the dosage for different water qualities; a dosage between 100-200 ppm is recommended.

[0046] Compared to Example 2, Comparative Example 1 did not include carrier powder for compounding. Due to the strong adsorption capacity of the polyacrylamide film on the carrier surface, in humid weather, the uncompounded solid surface absorbs water and becomes sticky, causing clumping. However, after granulation, drying, grinding, and sieving, a certain amount of bentonite or diatomaceous earth powder is mixed in. This allows the diatomaceous earth or bentonite, which lacks polyacrylamide on its surface, to act as a barrier, preventing the product from absorbing moisture and clumping. Comparative Example 2 used commercially available polyacrylamide, while Example 2 used a polyacrylamide solution synthesized with a macromolecular photoinitiator. The multifunctionality of the macromolecular photoinitiator during synthesis serves as a crosslinking center, improving the overall adsorption performance of the clarifying agent. Although no comparative examples are provided, those skilled in the art should understand that a low proportion of polyacrylamide in the carrier leads to poor flocculation, while a high proportion results in an excessively thick polyacrylamide film on the carrier particles, affecting dissolution and ultimately the product's performance.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a clarifier for black and odorous water bodies, characterized in that, Including the following steps: The polyacrylamide solution and the carrier are thoroughly mixed at a mass ratio of polyacrylamide to carrier of 1:99 to 5:95, and then granulated, dried, ground and sieved to obtain a solid. By combining solids with a carrier, a clarifying agent for black and odorous water bodies can be obtained; The carrier is one or more of bentonite, diatomite and kaolin that have passed through a 200-mesh sieve; The preparation steps of the polyacrylamide solution include: Deionized water, acrylamide, cationic monomer, multifunctional UV monomer, chelating agent, and chain transfer agent are sequentially added to a mixing tank and stirred evenly to prepare a prepolymer liquid. An organic acid is added to the prepolymer liquid to adjust the pH of the solution to obtain a prepolymer solution. The temperature of the prepolymer solution is lowered to 0~5℃, the prepolymer solution is deoxygenated, and then the prepolymer solution is transferred to the photoinitiator. Poly-[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone] and azo initiator were added to the pipe into the photoinitiator and mixed evenly using a static mixer; The light source will be activated after 30 minutes to automatically initiate the photopolymerization reaction. A viscous polyacrylamide solution is formed through polymerization.

2. The method for preparing the clarifier for black and odorous water bodies according to claim 1, characterized in that, The amount of the carrier compounded with the solid is 10% to 30% of the amount of the carrier mixed with the polyacrylamide solution, based on parts by mass.

3. The method for preparing the clarifier for black and odorous water bodies according to claim 1, characterized in that, The carrier mixed with the polyacrylamide solution is added in the form of powder or an aqueous solution with a concentration of 5% to 10%.

4. The method for preparing the clarifier for black and odorous water bodies according to claim 1, characterized in that, The multifunctional UV monomer is one or more of the following: pentaerythritol tetraacrylate, bisphenol A diacrylate ethoxylate, bisphenol A dimethacrylate ethoxylate, dimethacrylate, polyethylene glycol (200) dimethacrylate, polyethylene glycol (400) dimethacrylate, polyethylene glycol (600) dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate ethoxylate, propoxylated glycerol triacrylate, bis(trimethylolpropane) acrylate, bis(pentaerythritol hexaacrylate), and trimethylolpropane triacrylate.

5. The method for preparing the clarifier for black and odorous water bodies according to claim 1, characterized in that, The cationic monomer is one or more of acryloyloxyethyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyldimethylbenzylammonium chloride, methacryloyloxyethyldimethylbenzylammonium chloride, acryloylpropyltrimethylammonium chloride, and dimethyldiallylammonium chloride.

6. The method for preparing the clarifier for black and odorous water bodies according to claim 1, characterized in that, The chain transfer agent is one or more of sodium bisulfite, sodium hypophosphite, sodium formate, dipropylene glycol, and isopropanol.

7. A clarifier for black and odorous water bodies, characterized in that, It is prepared by the method of any one of claims 1 to 6 for the preparation of black and odorous water clarifying agent.

8. An application of a clarifier for black and odorous water bodies, characterized in that, The black and odorous water clarifier as described in claim 7 is directly dry-spread at the aeration port of the water body to be treated, and the water is stirred for clarification treatment.

9. The application of the clarifier for black and odorous water bodies according to claim 8, characterized in that, The dosage range of the black and odorous water clarifier is 100ppm to 200ppm.

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