Curing agent for conditioning anaerobic digestion sludge as well as conditioning method and application thereof

Abstract

The invention discloses a curing agent for conditioning anaerobic digestion sludge and a conditioning method and application thereof, the curing agent for conditioning anaerobic digestion sludge is prepared from the following raw materials in parts by mass: 60-80 parts of resin, 15-30 parts of catalyst and 5-10 parts of flocculant, the prepared curing agent is a non-toxic, non-corrosive, green and environment-friendly sludge curing agent, can be adhered to the surfaces of sludge particles through the effects of ion adsorption, cation bridging, hydrogen bonds and the like, has a relatively strong adhesion effect, so that the mechanical strength of cured sludge is improved, and the curing agent has the advantages of short curing time, small dosage, high resource utilization rate and the like; and meanwhile, pollution to water and soil is avoided, the method can be directly used for mine pit remediation, land utilization, embankment and side slope solidification and refuse landfill covering, and resource utilization of solid waste is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of environmental protection, and in particular to a solidifying agent for conditioning anaerobic digestion sludge, a conditioning method and an application thereof. Background Art

[0002] my country's urbanization process is accelerating, and the amount of urban sewage and wastewater is increasing. In the sewage treatment process, a large amount of sludge will be produced. In the sludge treatment process, thermal hydrolysis anaerobic digestion is a new technology for sludge reduction, resource utilization and harmlessness. With its advantages of small footprint, high digestion efficiency and large gas production, it has gradually attracted attention from all parties.

[0003] However, due to the significant reduction of sludge flocs after sludge digestion, the alkalinity and ammonia nitrogen content have increased significantly, and the flocculation performance of sludge has decreased significantly, resulting in a significant deterioration of its filtration behavior and difficulty in dehydration. At present, the sludge solidification agents widely used at home and abroad can be roughly divided into two categories: traditional solidification materials and new solidification materials. Among them, traditional solidification materials are mainly lime, cement, asphalt and industrial by-products such as fly ash, blast furnace slag, fly ash, etc. Although traditional solidification materials have good strength, water stability and antifreeze properties, they often have disadvantages such as large shrinkage, high risk of cracking, and poor engineering performance. At the same time, the large amount of humus organic matter contained in the sludge will hinder the hydrolysis and hydration reaction of traditional solidification materials and reduce their solidification effect. In addition, in the process of using traditional solidification agents to solidify sludge, the dosage of the agent is often too high, which can easily cause the solidified sludge and the surrounding water to be highly alkaline, causing secondary pollution to the surrounding soil and water, which conflicts with my country's concept of an environmentally friendly society.

[0004] Therefore, if we can explore an efficient and environmentally friendly sludge solidification agent, it can quickly and significantly change the physical and chemical properties of the sludge, making the sludge valuable for reuse, which is of great significance to the resource utilization of sludge. Summary of the invention

[0005] The main purpose of the present invention is to propose a solidifying agent for conditioning anaerobic digestion sludge and its conditioning method and application, aiming to solve the problem that the current dosage of sludge treatment agents is often too high, which easily causes the solidified sludge and the surrounding water to present a strong alkalinity, causing secondary pollution to the surrounding soil and water bodies, and it also meets the requirements.

[0006] To achieve the above object, the present invention provides a solidifying agent for conditioning anaerobic digestion sludge. The raw materials of the solidifying agent for conditioning anaerobic digestion sludge include 60-80 parts of resin, 15-30 parts of catalyst and 5-10 parts of flocculant by weight.

[0007] In some embodiments, the resin includes one or more of polypropylene, epoxy resin, polyethylene, and / or;

[0008] The catalyst comprises one or more of polyetheramine, phenolic amine, bisphenolamine A, and / or;

[0009] The flocculant includes one or more of polyacrylamide and polyacrylic acid.

[0010] In some embodiments, the HLB value of the resin is 10-12.

[0011] In some embodiments, the catalyst includes one or more of polyetheramine, phenolic amine, and bisphenol A, and the molecular weight of the catalyst is 1 million to 5 million.

[0012] In some embodiments, the ionicity of the flocculant is greater than 50%.

[0013] The present invention also provides a conditioning method for conditioning anaerobic digestion sludge, which comprises mixing the solidifying agent for conditioning anaerobic digestion sludge as described above with the sludge to be conditioned, and filtering the mixture to obtain solidified sludge.

[0014] In some embodiments, the amount of the solidifying agent added for conditioning the anaerobic digestion sludge is 5% to 10% of the mass of the sludge to be tested.

[0015] In some embodiments, the water content of the solidified sludge is below 60% and the density is greater than 1.2 g / cm 3 .

[0016] The present invention also provides a solidifying agent for conditioning anaerobic digestion sludge as described above for use in mine repair, land utilization, embankment and slope solidification, and landfill covering.

[0017] The curing agent used in the present invention for conditioning anaerobic digestion sludge includes 60-80 parts of resin, 15-30 parts of catalyst and 5-10 parts of flocculant. The present invention selects eco-friendly agents as curing materials to avoid the pollution to the environment during the sludge curing process. The curing agent contains a large number of functional groups, which are easy to react with the curing agent to form a network macromolecule, and a curing reaction occurs. It can adhere to the surface of sludge particles through ion adsorption, cationic bridging and hydrogen bonding, and has a strong adhesive effect, thereby improving the mechanical strength of the solidified sludge, and has the advantages of fast curing time, small dosage, high resource utilization rate, etc., and will not cause pollution to water and soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic flow chart of a conditioning method for conditioning anaerobic digestion sludge according to an embodiment of the present invention.

[0020] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0021] To make the purpose, technical scheme and advantages of the embodiment of the present invention clearer, the technical scheme in the embodiment of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiment, it is carried out according to the normal conditions or the conditions recommended by the manufacturer. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, taking "A and / or B" as an example, including scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention.

[0022] Since the sludge flocs are significantly reduced after sludge digestion, the alkalinity and ammonia nitrogen content are greatly increased, and the flocculation performance of the sludge is greatly reduced, resulting in a significant deterioration of its filtration behavior and difficulty in dehydration. The sludge solidification agents that are widely used at home and abroad can be roughly divided into two categories: traditional solidification materials and new solidification materials. Among them, traditional solidification materials are mainly lime, cement, asphalt and industrial by-products such as fly ash, blast furnace slag, fly ash, etc. Although traditional solidification materials have good strength, water stability and frost resistance, they often have disadvantages such as large shrinkage, high cracking risk and poor engineering performance. At the same time, the large amount of humus organic matter contained in the sludge will hinder the hydrolysis and hydration reaction of traditional solidification materials and reduce their solidification effect. In addition, in the process of using traditional solidification agents to solidify sludge, the output of the agent is often too high, which can easily cause the solidified sludge and the surrounding water to be highly alkaline, causing secondary pollution to the surrounding soil and water bodies, which conflicts with my country's concept of an environmentally friendly society.

[0023] In view of this, the present invention proposes a solidifying agent for conditioning anaerobic digestion sludge. The present invention proposes a solidifying agent for conditioning anaerobic digestion sludge. The raw materials of the solidifying agent for conditioning anaerobic digestion sludge include 60 to 80 parts of resin, 15 to 30 parts of catalyst and 5 to 10 parts of flocculant, calculated by weight.

[0024] The curing agent used in the present invention for conditioning anaerobic digestion sludge includes 60-80 parts of resin, 15-30 parts of catalyst and 5-10 parts of flocculant. The present invention selects eco-friendly agents as curing materials to avoid the pollution to the environment during the sludge curing process. In addition, the curing agent contains a large number of functional groups, which are easy to react with the curing agent to form a network macromolecule, and a curing reaction occurs. It can adhere to the surface of sludge particles through ion adsorption, cationic bridging and hydrogen bonding, and has a strong adhesive effect, thereby improving the mechanical strength of the solidified sludge, and has the advantages of fast curing time, small dosage, high resource utilization rate, etc., and will not cause pollution to water and soil.

[0025] It should be noted that the conditioning and solidification of sludge is achieved through the combination of resin, catalyst and flocculant. The resin provides a stable physical structure during the solidification process, the catalyst promotes the reaction speed, and the flocculant helps to aggregate the suspended matter and reduce the moisture. This formula can effectively improve the efficiency of the solidification process and reduce the moisture in the sludge, thereby obtaining a more compact solidified sludge with a lower moisture content, which is convenient for processing and transportation. The solidifying agents of the present invention are all neutral and will not affect the pH of the sludge. Traditional sludge solidifying agents are all alkaline, which easily cause sludge alkalinization, thereby affecting water bodies and soil.

[0026] In some embodiments of the present invention, the resin includes one or more of polypropylene, epoxy resin and polyethylene, that is, polypropylene can be used, or epoxy resin and polypropylene can be used at the same time. According to actual needs, epoxy resins generally use varieties such as EP-12, EP-13, EP-16 and EP-20. Since materials such as polypropylene, epoxy resin, and polyethylene have good corrosion resistance, strength and stability, they are suitable for matrix materials for sludge solidification. At the same time, they can also provide good physical strength to ensure the stability of the structure of the solidified sludge and maintain its performance in harsh chemical environments.

[0027] The catalyst includes one or more of polyetheramine, phenolic amine, and bisphenolamine A. By adding the catalyst during the conditioning process, the speed of the chemical reaction can be accelerated to improve the curing effect. These catalysts can speed up the curing process, shorten the sludge treatment time, and improve the treatment efficiency.

[0028] The flocculant includes one or more of polyacrylamide and polyacrylic acid. The flocculant aggregates the suspended solids in the sludge into larger flocs through charge neutralization and aggregation, which is convenient for solid-liquid separation. This can effectively reduce the moisture content in the sludge, make the sludge easier to solidify and handle, and reduce the difficulty of filtration and dehydration.

[0029] In some embodiments of the present invention, the HLB value of the resin is 10-12.

[0030] It should be noted that the HLB value (hydrophile-lipophile balance) can be 10, 11 or 12, preferably a resin of 12. This is because the resin has moderate hydrophilicity and lipophilicity, which allows it to maintain structural stability in an aqueous environment and to combine well with organic matter in the sludge. Preferably, setting the HLB value of the resin to 12 helps to improve the dispersibility and effectiveness of the curing agent in treating sludge and ensure a more uniform curing process.

[0031] In some embodiments of the present invention, the catalyst includes one or more of polyetheramine, phenolic amine and bisphenol A, and the molecular weight of the catalyst is 1 million to 5 million.

[0032] Since catalysts with larger molecular weight can provide stronger adhesion and reactivity and promote the bonding between resin and sludge particles, the use of high molecular weight catalysts can improve the strength and stability of solidified sludge, giving it better physical properties in its post-treatment use.

[0033] In some embodiments of the present invention, the ionicity of the flocculant is greater than 50%. Since the higher the ionicity of the flocculant, the stronger its ability to perform charge neutralization and polymerization in the sludge, and the more effectively it can coagulate suspended matter, the use of a flocculant with a high ionicity, that is, a flocculant with an ionicity greater than 50%, in the present invention is more conducive to the rapid formation of larger flocs, improving the solid-liquid separation effect, reducing the moisture content of the sludge, and enhancing the solidification effect.

[0034] The present invention also provides a method for conditioning anaerobic digestion sludge, such as Figure 1 As shown in step S10, the solidifying agent for conditioning anaerobic digestion sludge as described above is mixed with the sludge to be conditioned, and the mixture is filtered to obtain solidified sludge.

[0035] Since the solidified sludge after filtration has low moisture content and high density, it is easier to store and transport, and also reduces the possibility of secondary pollution.

[0036] In some embodiments of the present invention, the amount of the solidifying agent added for conditioning the anaerobic digestion sludge is 5% to 10% of the mass of the sludge to be tested.

[0037] By controlling the amount of curing agent added, it is ensured that the sludge can be effectively solidified without causing excessive use of chemical substances and avoiding waste of resources. The amount of curing agent added in the present invention is set to 5% to 10% of the mass of the sludge to be tested, that is, the amount of curing agent is optimized, the economy and environmental friendliness of sludge treatment are ensured, and the curing effect is guaranteed at the same time.

[0038] In some embodiments of the present invention, the water content of the solidified sludge is below 60%, and the density is greater than 1.2 g / cm 3 .

[0039] The density and mechanical strength of solidified sludge can be improved by reducing the moisture content of solidified sludge, and the density greater than 1.2g / cm3 ensures the physical stability of solidified sludge and avoids collapse or failure in subsequent applications. The low moisture content and high density characteristics of solidified sludge ensure that it has good physical properties in subsequent treatment and application, such as long-term stability in landfill, soil improvement, etc.

[0040] The present invention also provides a solidifying agent for conditioning anaerobic digestion sludge as described above for use in mine repair, land utilization, embankment and slope solidification, and landfill covering.

[0041] The sludge conditioned with sludge solidifier has good strength, stability and environmental compatibility, and is suitable for a variety of geological remediation and environmental engineering applications. It broadens the application field of solidified sludge, not only reduces the burden of sludge treatment, but also can utilize solidified sludge as a resource to reduce environmental pollution.

[0042] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0043] Example 1

[0044] A curing agent for conditioning anaerobic digestion sludge, wherein the raw materials of the curing agent for conditioning anaerobic digestion sludge include 75 parts of resin, 20 parts of catalyst and 5 parts of flocculant, wherein the resin is epoxy resin EP-12 (HLB value is 10), the catalyst is polyetheramine (molecular weight is 1500), and the flocculant is polyacrylamide (ionic degree is 80%), and each part is 1g;

[0045] A conditioning method for conditioning anaerobic digestion sludge:

[0046] 1) Add polyacrylamide to the resin and stir evenly, let it stand for 2 hours, then add polyetheramine and stir to obtain a curing agent for conditioning anaerobic digestion sludge.

[0047] 2) Using the solidifying agent prepared in step (1) to treat the anaerobic digestion sludge, the amount of solidifying agent added is 10% of the mass of the anaerobic digestion sludge, and stirring for 2 minutes.

[0048] 3) The conditioned sludge was filtered using a plate and frame filter press to obtain solidified sludge. The test showed that the moisture content of the solidified sludge was 55% and the density was 1.4 g / cm 3 .

[0049] 4) The solidified sludge is used for land use.

[0050] Example 2

[0051] A curing agent for conditioning anaerobic digestion sludge, wherein the raw materials of the curing agent for conditioning anaerobic digestion sludge include 80 parts of resin, 15 parts of catalyst and 5 parts of flocculant, wherein the resin is epoxy resin EP-12 (HLB value is 10), the catalyst is polyetheramine (molecular weight is 1500), and the flocculant is polyacrylamide (ionic degree is 80%), and each part is 1g;

[0052] A conditioning method for conditioning anaerobic digestion sludge:

[0053] 1) Add polyacrylamide to the resin and stir evenly, let it stand for 2 hours, then add polyetheramine and stir to obtain a curing agent for conditioning anaerobic digestion sludge.

[0054] 2) Using the solidifying agent prepared in step (1) to treat the anaerobic digestion sludge, the amount of solidifying agent added is 10% of the mass of the anaerobic digestion sludge, and stirring for 2 minutes.

[0055] 3) The conditioned sludge was filtered using a plate and frame filter press to obtain a solidified sludge with a moisture content of 54% and a density of 1.4 g / cm 3 .

[0056] 4) The obtained solidified sludge is used for mine landfill.

[0057] Example 3

[0058] A curing agent for conditioning anaerobic digestion sludge, wherein the raw materials of the curing agent for conditioning anaerobic digestion sludge include 60 parts of resin, 30 parts of catalyst and 10 parts of flocculant, wherein the resin is epoxy resin EP-12 (HLB value is 12), the catalyst is polyetheramine (molecular weight is 1200), and the flocculant is polyacrylamide (ionic degree is 80%), and each part is 1g;

[0059] A conditioning method for conditioning anaerobic digestion sludge:

[0060] 1) Add polyacrylamide to the resin and stir evenly, let it stand for 2 hours, then add polyetheramine and stir to obtain a curing agent for conditioning anaerobic digestion sludge.

[0061] 2) Using the solidifying agent prepared in step (1) to treat the anaerobic digestion sludge, the amount of solidifying agent added is 10% of the mass of the anaerobic digestion sludge, and stirring for 2 minutes.

[0062] 3) The conditioned sludge was filtered using a plate and frame filter press to obtain a solidified sludge with a moisture content of 57% and a density of 1.5 g / cm 3 .

[0063] 4) The solidified sludge obtained is used for slope reinforcement.

[0064] Example 4

[0065] A curing agent for conditioning anaerobic digestion sludge, wherein the raw materials of the curing agent for conditioning anaerobic digestion sludge include 75 parts of resin, 20 parts of catalyst and 5 parts of flocculant, wherein the resin is epoxy resin EP-12 (HLB value is 10), the catalyst is polyetheramine (molecular weight is 2000), and the flocculant is polyacrylamide (ionic degree is 70%), and each part is 1g;

[0066] A conditioning method for conditioning anaerobic digestion sludge:

[0067] 1) Add polyacrylamide to the resin and stir evenly, let it stand for 2 hours, then add polyetheramine and stir to obtain a curing agent for conditioning anaerobic digestion sludge.

[0068] 2) Using the solidifying agent prepared in step (1) to treat the anaerobic digestion sludge, the amount of solidifying agent added is 10% of the mass of the anaerobic digestion sludge, and stirring for 2 minutes.

[0069] 3) The conditioned sludge was filtered using a plate and frame filter press to obtain a solidified sludge with a moisture content of 58% and a density of 1.5 g / cm 3 .

[0070] 4) The obtained solidified sludge is used for mine landfill.

[0071] Comparative Example 1

[0072] A sludge solidifying agent, wherein the resin content is 65 parts, the catalyst content is 20 parts, the flocculant content is 15 parts, and the rest is similar to that of Example 1.

[0073] A conditioning method for conditioning anaerobic digestion sludge:

[0074] 1) Add flocculant to the resin and stir evenly, let it stand for 2 hours, then add catalyst and stir.

[0075] 2) Using the sludge solidifying agent prepared in step (1) to treat the anaerobic digestion sludge, the amount of the sludge solidifying agent added is 10% of the mass of the anaerobic digestion sludge, and stirring for 2 minutes.

[0076] 3) The conditioned sludge was filtered using a plate and frame filter press to obtain a mud cake with a moisture content of 65% and a density of 1.1 g / cm 3 .

[0077] 4) Does not meet the recycling standards.

[0078] Comparative Example 2

[0079] A sludge solidifying agent, wherein the resin content is 75 parts, the catalyst content is 10 parts, the flocculant content is 15 parts, and the rest is similar to that of Example 1.

[0080] A conditioning method for conditioning anaerobic digestion sludge:

[0081] 1) Add flocculant to the resin and stir evenly, then add catalyst and stir.

[0082] 2) Using the sludge solidifying agent prepared in step (1) to treat the anaerobic digestion sludge, the amount of the sludge solidifying agent added is 10% of the mass of the anaerobic digestion sludge, and stirring for 2 minutes.

[0083] 3) The conditioned sludge was filtered using a plate and frame filter press to obtain a mud cake with a moisture content of 66% and a density of 1.0 g / cm 3 .

[0084] 4) Does not meet the recycling standards.

[0085] Comparative Example 3

[0086] A sludge solidifying agent, wherein the resin content is 85 parts, the catalyst content is 5 parts, the flocculant content is 10 parts, and the rest is similar to that of Example 1.

[0087] A conditioning method for conditioning anaerobic digestion sludge:

[0088] 1) Add flocculant to the resin and stir evenly, let it stand for 2 hours, then add catalyst and stir.

[0089] 2) Using the sludge solidifying agent prepared in step (1) to treat the anaerobic digestion sludge, the amount of the sludge solidifying agent added is 10% of the mass of the anaerobic digestion sludge, and stirring for 2 minutes.

[0090] 3) The conditioned sludge was filtered using a plate and frame filter press to obtain a mud cake with a moisture content of 68% and a density of 0.9 g / cm 3 .

[0091] 4) Does not meet the recycling standards.

[0092] In summary, it should be noted that the specific utilization standards for sludge used for resource utilization are: the moisture content must be less than 65%, the density must be greater than 1.2g / cm 3Within this range, the obtained sludge strength is relatively high and can be applied to a variety of resource utilization options. This experiment proves that the curing agent used for conditioning anaerobic digestion sludge in the present invention includes 60-80 parts of resin, 15-30 parts of catalyst and 5-10 parts of flocculant. The prepared curing agent is a non-toxic, non-corrosive, green and environmentally friendly sludge curing agent. The obtained solidified sludge has sufficient strength and can be directly used for mine repair, land utilization, embankment and slope solidification and landfill covering, realizing the resource utilization of solid waste.

[0093] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A solidifying agent for conditioning anaerobic digestion sludge, characterized in that: Calculated by weight, the raw materials of the curing agent for conditioning anaerobic digestion sludge include 60-80 parts of resin, 15-30 parts of catalyst and 5-10 parts of flocculant.

2. The solidifying agent for conditioning anaerobic digestion sludge according to claim 1, characterized in that: The resin includes one or more of polypropylene, epoxy resin, polyethylene, and / or; The catalyst includes one or more of polyetheramine, phenolic amine, bisphenol A, and / or; The flocculant includes one or more of polyacrylamide and polyacrylic acid.

3. The solidifying agent for conditioning anaerobic digestion sludge according to claim 1, characterized in that: The HLB value of the resin is 10-12.

4. The solidifying agent for conditioning anaerobic digestion sludge according to claim 1, characterized in that: The catalyst comprises one or more of polyetheramine, phenolic amine and bisphenol A, and the molecular weight of the catalyst is 1 million to 5 million.

5. The solidifying agent for conditioning anaerobic digestion sludge according to claim 1, characterized in that: The ionicity of the flocculant is greater than 50%.

6. A method for conditioning anaerobic digestion sludge, characterized in that: The solidifying agent for conditioning anaerobic digestion sludge as claimed in any one of claims 1 to 5 is mixed with the sludge to be conditioned, and then filtered to obtain solidified sludge.

7. The method for conditioning anaerobic digestion sludge according to claim 6, characterized in that: The amount of the solidifying agent added for conditioning the anaerobic digestion sludge is 5% to 10% of the mass of the sludge to be tested.

8. The method for conditioning anaerobic digestion sludge according to claim 6, characterized in that: The water content of the solidified sludge is below 65% and the density is greater than 1.2g / cm 3 .

9. A solidifying agent for conditioning anaerobic digestion sludge as claimed in any one of claims 1 to 5, for use in mine restoration, land utilization, embankment and slope solidification, and landfill covering.

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