Composite high-efficiency sludge conditioner with low water content

Abstract

The invention relates to a low-water-content composite high-efficiency sludge conditioner. The invention discloses a sludge dewatering conditioner and a production process thereof. Relates to the technical field of sludge treatment. The invention discloses a cationic water-based adhesive which is prepared from the following raw materials in parts by weight: 0.3 to 0.4 part of acrylamide, 80 to 100 parts of cationic monomer, 1.0 to 2.0 parts of surfactant, 0.5 to 1.5 parts of cosurfactant, 1.1 to 1.8 parts of initiator, 1.0 to 1.5 parts of polyamine and 150 to 170 parts of deionized water. The preparation method comprises the following steps: S1, mixing a surfactant accounting for 0.3-0.5% of the total weight and deionized water accounting for 20-35% of the total weight with acrylamide, then adding a cosurfactant, and stirring at the rotating speed of 300r / min for 10-15min to obtain an acrylamide solution; s2, sequentially adding a cationic monomer, the residual surfactant, the residual deionized water and an initiator into the acrylamide solution obtained in the step S1, and stirring at the temperature of 35-40 DEG C and the rotating speed of 200r / min for 10-15 minutes to obtain a mixed solution; and S3, cooling the mixed solution obtained in the step S2 to 5-8 DEG C, and continuously stirring at 60-100r / min for 1.5-2 hours to obtain a product. According to the invention, the sludge with more organic matters can be treated in a targeted manner, and the green and environment-friendly requirements are met.

Description

Technical Field

[0001] The present application relates to the technical field of sludge treatment, and in particular to a low-water-content composite high-efficiency sludge conditioner. Background Art

[0002] Currently, the main pollutants in sewage include pathogens, oxygen-depleting pollutants, plant nutrients, and toxic pollutants. Sludge is a solid sediment produced during the water and sewage treatment process. According to GB 24188-2009, "Sludge Properties from Municipal Wastewater Treatment Plants" and "Pollutant Discharge Standards for Municipal Wastewater Treatment Plants," the moisture content of dehydrated sludge should be less than 80%. For sludge intended for aerobic composting, mixed landfill, brickmaking, and other applications, the moisture content must be less than 60%.

[0003] In traditional processes, 100-200 kg of lime and approximately 340 kg of liquid PAC are generally added to every ton of absolute dry sludge. The moisture content of the sludge treated in this way is generally 65-80%, which is still relatively high and difficult to meet actual usage needs. Moreover, the addition of large amounts of lime and PAC can cause secondary pollution, resulting in excessive impurities in the sludge, which in turn reduces the calorific value of the sludge and increases transportation costs, making it difficult to meet green environmental protection requirements. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present application provides a low-moisture-content composite high-efficiency sludge conditioner.

[0005] The present application adopts the following technical solution: a low-moisture composite high-efficiency sludge conditioner, composed of the following raw materials in parts by weight:

[0006] 0.3-0.4 parts of acrylamide, 80-100 parts of cationic monomer, 1.0-2.0 parts of surfactant, 0.5-1.5 parts of cosurfactant, 1.1-1.8 parts of initiator, 1.0-1.5 parts of polyamine and 150-170 parts of deionized water;

[0007] Made by the following steps:

[0008] S1, taking 0.3%-0.5% of the total weight of a surfactant and 20-35% of the total weight of deionized water and mixing with acrylamide, then adding a co-surfactant, stirring at a speed of 300 rpm for 10-15 minutes to obtain an acrylamide solution;

[0009] S2. Adding the cationic monomer, the remaining surfactant, the remaining deionized water, and the initiator to the acrylamide solution obtained in step S1 in sequence, stirring at a temperature of 35-40° C. and a speed of 200 r / min for 10-15 minutes to obtain a mixed solution;

[0010] S3. Cool the mixed solution obtained in step S2 to 5-8°C, and continue stirring at 60-100 r / min for 1.5-2 h to obtain the product. Finish.

[0011] Optionally, the cationic monomer is a combination of one or more of trimethylpropylene ammonium chloride, dimethyl diallyl ammonium chloride, and vinyl trimethyl ammonium chloride.

[0012] Optionally, the surfactant is a combination of one or more of octadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, and alkylphenol polyoxyethylene ether, and the co-surfactant is a combination of one or more of fatty alcohol polyoxyethylene ether, sorbitan monooleate, and fatty acid glyceride.

[0013] Optionally, the cooling process in step S3 adopts a gradient cooling method, first cooling to 20°C at a rate of 5°C / min, and then cooling to the target temperature at a rate of 2°C / min.

[0014] Optionally, when added to absolutely dry sludge at a dosage of 1-4‰, the moisture content of the sludge can be reduced by 25-30%.

[0015] In summary, this application includes at least one of the following beneficial technical effects:

[0016] 1. A conditioning agent made from specific weight fractions of raw materials through specific steps, which helps to reduce the moisture content of sludge;

[0017] 2. When the conditioner is added to absolutely dry sludge at a dosage of 1-4‰, the moisture content of the sludge can be reduced by 25-30%, thereby improving the sludge dehydration efficiency;

[0018] 3. Reducing the moisture content of sludge can reduce subsequent treatment costs, meet environmental protection requirements, and avoid sludge pollution to the surrounding environment. DETAILED DESCRIPTION

[0019] The present application is further described below. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0020] This application mainly adopts specific raw material ratios and processes to prepare sludge conditioners, which effectively reduces the moisture content of sludge and meets environmental protection requirements. The following is a further detailed description of this application.

[0021] The low-moisture composite, high-efficiency sludge conditioner provided herein consists of two parts: raw materials and preparation steps. The raw materials consist of acrylamide, a cationic monomer, a surfactant, a co-surfactant, an initiator, and deionized water. These raw materials are mixed in specific weight proportions. This mixing method allows the raw materials to work together to achieve optimal conditioning effects, resulting in the prepared conditioner effectively reducing the moisture content of sludge.

[0022] Example 1

[0023] A low-moisture composite high-efficiency sludge conditioner, composed of the following raw materials in parts by weight:

[0024] 0.3 parts of acrylamide, 80 parts of cationic monomer, 1.0 parts of surfactant, 0.5 parts of co-surfactant, 1.1 parts of initiator, 1.0 parts of polyamine and 150 parts of deionized water.

[0025] Example 2

[0026] A low-moisture composite high-efficiency sludge conditioner, composed of the following raw materials in parts by weight:

[0027] 0.3 parts of acrylamide, 90 parts of cationic monomer, 1.5 parts of surfactant, 1 part of co-surfactant, 1.4 parts of initiator, 1.3 parts of polyamine and 160 parts of deionized water.

[0028] Example 3

[0029] A low-moisture composite high-efficiency sludge conditioner, composed of the following raw materials in parts by weight:

[0030] 0.4 parts of acrylamide, 100 parts of cationic monomer, 2.0 parts of surfactant, 1.5 parts of co-surfactant, 1.8 parts of initiator, 1.0-1.5 parts of polyamine and 170 parts of deionized water.

[0031] The above three embodiments are synthesized according to the following steps:

[0032] S1. Take 0.3%-0.5% of the total weight of a surfactant and 20-35% of the total weight of deionized water and mix them with acrylamide, then add a co-surfactant and stir at a speed of 300r / min for 10-15min to obtain an acrylamide solution. In this step, the appropriate amount of surfactant and co-surfactant added, as well as the stirring speed and time, can fully dissolve the acrylamide and form a stable solution. The hydrophilic and hydrophobic groups of the surfactant interact with acrylamide and water respectively, and the co-surfactant further enhances the stability of the solution. For example, if the stirring speed is too fast, it may cause too many bubbles in the solution, affecting subsequent reactions; if the stirring time is too short, acrylamide may not be fully dissolved, resulting in an uneven solution.

[0033] S2. Add the cationic monomer, remaining surfactant, remaining deionized water, and initiator to the acrylamide solution obtained in step S1 in this order. Stir at 200 rpm and a temperature of 35-40°C for 10-15 minutes to obtain a mixed solution. During this stage, the cationic monomer and acrylamide undergo polymerization, and the surfactant further promotes the mixing and reaction of the components. Appropriate temperature and stirring speed help control the reaction rate and extent. Excessively high temperatures may result in an overly vigorous reaction and an unstable product; excessively low temperatures may slow the reaction rate, affecting production efficiency.

[0034] S3. Cool the mixture obtained in step S2 to 5-8°C and continue stirring at 60-100 rpm for 1.5-2 hours to obtain the product. This is done. The cooling process can stop the reaction and make the product structure more stable. Controlling the stirring speed and time is also important. Continuous stirring can make the product more uniform.

[0035] The working principle of this embodiment is as follows: This sludge conditioner utilizes a rational raw material ratio and precise preparation process to achieve synergistic effects among its components. The cationic monomers bind to sludge particles through electrostatic interaction, while the surfactants reduce surface tension, promoting dispersion and agglomeration of the sludge particles. This synergistic effect makes the sludge particles easier to dehydrate, effectively reducing the sludge moisture content. Compared with traditional sludge conditioners, this conditioner is more effective in reducing sludge moisture content, meeting increasingly stringent environmental protection requirements and reducing sludge treatment costs and environmental pollution.

[0036] The cooling process in step S3 uses a gradient cooling method, first cooling the temperature to 20°C at a rate of 5°C / min, and then to the target temperature at a rate of 2°C / min. This gradient cooling method can make the reaction system transition to a low temperature state more smoothly, avoiding uneven product structure or the presence of impurities due to excessive cooling. When the temperature is quickly cooled to 20°C, the reaction rate decreases rapidly, and then the temperature is slowly cooled to the target temperature, which can make the product's molecular structure more orderly and improve the product's stability and performance.

[0037] When added to bone-dry sludge at a dosage of 1-4‰, the sludge's moisture content can be reduced by 25-30%. This specific dosage range is the optimal range determined through extensive experimentation. When the dosage is less than 1‰, the conditioning agent is insufficient and cannot fully interact with the sludge particles, resulting in poor sludge dehydration. When the dosage is higher than 4‰, although the sludge moisture content may continue to decrease, the increase is limited and treatment costs will increase.

[0038] In the three aforementioned embodiments, acrylamide is one of the fundamental components of the entire conditioning agent system. It typically appears as a white crystal and is readily soluble in water. While methacrylamide is sometimes used as a partial replacement for acrylamide in other related chemical formulations, acrylamide is an indispensable component in this sludge conditioning agent due to its unique chemical properties and reactivity. A cationic monomer is also a key component and can be a combination of one or more of trimethylammonium chloride, dimethyldiallylammonium chloride, and vinyltrimethylammonium chloride. Trimethylammonium chloride is a colorless to pale yellow liquid with good solubility in water. It carries a positive charge, enabling electrostatic interactions with negatively charged particles in sludge, promoting sludge coagulation. Dimethyldiallylammonium chloride is also a commonly used cationic monomer. It is a colorless, transparent, viscous liquid with a relatively stable molecular structure, making it effective under diverse environmental conditions. Vinyltrimethylammonium chloride is a white crystalline powder with strong reactivity. These cationic monomers can be formulated to suit different types of sludge. For example, for sludge containing more negatively charged impurities, the proportion of trimethylpropylene ammonium chloride can be appropriately increased because it has a higher positive charge density and can better neutralize the charge of sludge particles.

[0039] The surfactant is a combination of one or more of octadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, and alkylphenol polyoxyethylene ether. Sodium lauryl sulfate is a white or light yellow powder that is easily soluble in water and exhibits excellent emulsification, foaming, and detergency. In this conditioner, it reduces the surface tension at the oil-water interface, allowing for better mixing of the ingredients. Sodium dodecylbenzenesulfonate is a common anionic surfactant, a white or slightly yellow powder with stable chemical properties and strong dispersing and emulsifying properties. Alkylphenol polyoxyethylene ether is a nonionic surfactant that appears as a colorless to light yellow liquid or paste. It is stable to acids and bases and maintains activity in varying pH environments. The co-surfactant is a combination of one or more of fatty alcohol polyoxyethylene ether, sorbitan monooleate, and fatty acid glycerides. Fatty alcohol polyoxyethylene ether is generally a colorless to light yellow liquid or solid with excellent solubilizing and emulsifying properties. Sorbitan monooleate is a nonionic surfactant, an amber to brown viscous liquid, that improves solution stability. Fatty acid glycerides are esters formed by the esterification of fatty acids and glycerol, and have excellent lubricating and emulsifying properties. Polyamines, combined with surfactants and co-surfactants, can significantly increase sludge density, thereby enhancing dewatering effectiveness.

[0040] The initiator plays a key role in initiating the polymerization reaction throughout the entire preparation process. Different initiators have different initiation efficiencies and reaction conditions. Common initiators include potassium persulfate and ammonium persulfate. The choice and dosage of the initiator affect the performance and quality of the final product. Deionized water serves as a solvent, providing a uniform environment for the mixing and reaction of the raw materials. It removes various ionic impurities in the water, preventing them from interfering with the reaction.

[0041] The sludge conditioners prepared in the above three embodiments were used to condition the sludge, and the conditioned sludge was transported to a fully automatic filter cloth walking pressurized plate-frame dehydrator for dehydration. The moisture content of the dehydrated mud cake was measured to obtain the following table:

[0042] Serial number Initial sludge moisture content (%) Moisture content of sludge after conditioning (%) Example 1 95.3 52.3 Example 2 94.2 53.4 Example 3 96.7 51.7

[0043] In summary, after the sludge is conditioned using the sludge conditioner described in this application and treated using sludge dewatering treatment equipment, the moisture content of the sludge is significantly reduced, which makes up for the defect that the moisture content of the sludge after treatment by the existing process is still at a high state.

[0044] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A low-water content composite high-efficiency sludge conditioner, characterized in that: It is composed of the following raw materials in parts by weight: 0.3-0.4 parts of acrylamide, 80-100 parts of cationic monomer, 1.0-2.0 parts of surfactant, 0.5-1.5 parts of cosurfactant, 1.1-1.8 parts of initiator, 1.0-1.5 parts of polyamine and 150-170 parts of deionized water; Made by the following steps: S1, taking 0.3%-0.5% of the total weight of a surfactant and 20-35% of the total weight of deionized water and mixing with acrylamide, then adding a co-surfactant, stirring at a speed of 300 rpm for 10-15 minutes to obtain an acrylamide solution; S2. Adding the cationic monomer, the remaining surfactant, the remaining deionized water, and the initiator to the acrylamide solution obtained in step S1 in sequence, stirring at a temperature of 35-40° C. and a speed of 200 r / min for 10-15 minutes to obtain a mixed solution; S3. Cool the mixed solution obtained in step S2 to 5-8°C, and continue stirring at 60-100 r / min for 1.5-2 h to obtain the product. Finish.

2. A low-water content composite high-efficiency sludge conditioner according to claim 1, characterized in that: The cationic monomer is a combination of one or more of trimethylpropylene ammonium chloride, dimethyl diallyl ammonium chloride, and vinyl trimethyl ammonium chloride.

3. A low-water content composite high-efficiency sludge conditioner according to claim 1, characterized in that: The surfactant is a combination of one or more of octadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, and alkylphenol polyoxyethylene ether; the co-surfactant is a combination of one or more of fatty alcohol polyoxyethylene ether, sorbitan monooleate, and fatty acid glyceride.

4. A low-water content composite high-efficiency sludge conditioner according to claim 1, characterized in that: The cooling process in step S3 adopts a gradient cooling method, first cooling to 20°C at a rate of 5°C / min, and then cooling to the target temperature at a rate of 2°C / min.

5. A low-moisture composite high-efficiency sludge conditioner according to any one of claims 1 to 4, characterized in that: When added at a dosage of 1-4‰ to absolutely dry sludge, the moisture content of the sludge can be reduced by 25-30%.