Freeze-thaw resistant sludge curing agent as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of soil curing agents, and particularly relates to an anti-freeze-thaw sludge curing agent and a preparation method and application thereof. The sludge curing agent comprises the following raw materials in parts by mass: 40-60 parts of cement, 10-20 parts of an admixture, 10-20 parts of quicklime, 5-10 parts of gypsum, 5-8 parts of carboxylated porous resin, 0.5-0.8 part of a nonionic surfactant and 5-8 parts of activated carbon, and the carboxylated porous resin is of a three-dimensional network structure formed by condensation reaction of phenolated alkali lignin and dialdehyde. Meanwhile, porous resin microspheres are formed by utilizing a pore-foaming agent, and then the porous resin microspheres, chloroacetic acid and alkali are subjected to a reaction to prepare carboxylated porous resin microspheres. According to the non-ionic surface active agent disclosed by the invention, organic matters which are easy to migrate and free in the sludge are emulsified into micro-micelles, and the micro-micelles are adsorbed by the activated carbon, so that the micro-micelles are prevented from wrapping gel particles, hydration is hindered, a communicated pore network is prevented from being formed, and the freeze-thaw resistance of a sludge solidified body is improved. The inner surfaces of pores of carboxylated porous resin contain a large amount of phenolic hydroxyl groups and carboxyl groups, so that the migration activity of heavy metal ions is reduced.

Description

Technical Field

[0001] This invention belongs to the field of soil stabilizer technology, specifically relating to an antifreeze-thaw sludge stabilizer, its preparation method, and its application. Background Technology

[0002] Sludge is a sediment produced during wastewater treatment at wastewater treatment plants. It contains a large number of microorganisms, pathogens, heavy metals, and organic pollutants. Improper disposal can cause serious secondary pollution. Currently, the main methods for sludge treatment are conversion to agricultural use, incineration, and landfill. However, due to the high water content, poor mechanical properties, and high pollutant content of sludge, these treatment methods often lead to environmental pollution, excessively high treatment costs, or potential landfill disasters. Solidification technology is one of the effective methods to treat large quantities of sludge and achieve stabilization, harmlessness, and resource utilization. Through solidification, sludge can not only be transformed into a solidified body with excellent physical properties (such as high strength and low permeability), but more importantly, it can firmly fix pollutants such as heavy metals (e.g., phosphoric acid) through chemical passivation and physical encapsulation, blocking their migration pathways into the environment. The heavy metal leaching concentration of the treated sludge is far below the environmental limits, eliminating environmental risks. Therefore, solidified sludge can be safely landfilled or utilized as soil resources.

[0003] The solidification technology specifically involves adding a soil stabilizer to the sludge, which then undergoes a chemical reaction to form a stable solidified product. The solidified product exhibits high strength and low permeability. Soil stabilizers come in various types, classified by material form as liquid and powder; and by performance as Class A and Class B. Class A soil stabilizers cannot be used directly for soil solidification and must be used in conjunction with cement or other binding materials, while Class B can. Class A soil stabilizers are technologically mature and have a wide range of material sources, attracting extensive research and attention. For example, patent CN105254166B discloses a dewatered sludge stabilizer, its preparation method, and its usage method. In this stabilizer, phosphate rock, carbide slag, tailings slag, and marble slag are mixed in a mass percentage ratio of (1-3):(1-3):(1-3):(1-3). The preparation method includes washing, drying, crushing, and ball milling the phosphate rock, carbide slag, tailings slag, and marble slag separately, and then mixing them evenly in the specified proportions. Patent CN103387371B discloses a composite solidifying agent for the solidification / stabilization of urban sludge and its application. It is composed of cement, fly ash, anhydrous gypsum, lime, activated magnesium oxide, iron powder, and powdered activated carbon. The mass percentages of each raw material are as follows: cement 10%–25%, fly ash 45%–60%, anhydrous gypsum 5%–10%, lime (CaO) and activated magnesium oxide (MgO) 10%–20%, iron powder 1–2.5%, and powdered activated carbon 1–2.5%. The above are common Class A soil stabilizers. They achieve the solidification and stabilization of sludge through the hydration and cementation reaction of cement and other cementing materials. However, since sludge itself contains a large amount of organic matter, including easily migratable and free organic components, these components can encapsulate cementing particles, hinder the hydration reaction, and introduce interconnected pore networks. In cold environments, water that seeps into these interconnected pores expands in volume when it freezes, generating huge internal stress. This internal stress is rapidly transmitted and concentrated within the interconnected pore network, leading to the generation and propagation of microcracks. This process makes heavy metals that were originally encapsulated or fixed by dense hydration products more susceptible to leaching due to exposure to microcracks, significantly increasing the risk of secondary pollution.

[0004] Therefore, it is necessary to develop a freeze-thaw sludge solidification agent to achieve efficient stabilization, long-term freeze-thaw resistance, and environmental safety in sludge solidification treatment, and to meet the application needs in harsh environments such as cold and rainy conditions. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an antifreeze-thaw sludge solidifier, its preparation method, and its application. The nonionic surfactant of this invention reduces the surface tension of sludge, improves the dispersibility of activated carbon in sludge, promotes the adsorption of easily migrating and free organic matter by activated carbon, prevents it from encapsulating gel particles and hindering hydration, avoids the formation of interconnected pore networks, and improves the freeze-thaw resistance of the sludge solidified body. The inner surface of carboxylated porous resin contains a large number of phenolic hydroxyl and carboxyl groups, which can form stable chelates with heavy metal ions and fix them in the pores of the porous resin, reducing the migration activity of heavy metal ions. At the same time, because activated carbon has a smooth and inert surface, it is easy to slip or roll under shear force. Its extensive use will cause a decrease in the shear resistance of sludge solidification. The carboxyl and phenolic hydroxyl groups on the surface of carboxylated porous resin adsorb calcium ions in the cementitious material and induce hydration products to deposit on and around the surface of carboxylated porous resin, forming an organic / inorganic cross-linked network. This compensates for the shear resistance defects caused by the extensive use of activated carbon. In synergy with nonionic surfactants and activated carbon, the freeze-thaw resistance of the solidified body is improved without damaging the mechanical properties, reducing the risk of secondary pollution by heavy metals.

[0006] To achieve the above objectives, the following technical solution is adopted:

[0007] An antifreeze-thaw sludge solidifying agent comprises the following raw materials in parts by weight: 40-60 parts cement, 10-20 parts admixture, 10-20 parts quicklime, 5-10 parts gypsum, 5-8 parts carboxylated porous resin, 0.5-0.8 parts nonionic surfactant, and 5-8 parts activated carbon. The carboxylated porous resin is formed by the condensation reaction of phenolic alkali lignin and dialdehyde to form a three-dimensional network structure, and simultaneously by the formation of porous resin microspheres using a pore-forming agent. Then, the porous resin microspheres, chloroacetic acid, and alkali undergo a substitution reaction to obtain the carboxylated porous resin microspheres.

[0008] The mass ratio of phenolic alkali lignin, dialdehyde, and porogen is 1:0.1-0.2:0.7-0.85, preferably 1:0.1-0.15:0.7-0.8.

[0009] The pore-forming agent is selected from one or more combinations of toluene, dioctyl phthalate, octadecanol, and benzene.

[0010] The dialdehyde is selected from one or more of malondialdehyde, succinaldehyde, glutaraldehyde, and adipaldehyde.

[0011] The mass ratio of the porous resin microspheres, chloroacetic acid, and alkali is 1:2.5-3.5:2.5-3.6, preferably 1:3-3.5:2.8-3.6.

[0012] The alkali is selected from one or a combination of two of sodium hydroxide and potassium hydroxide.

[0013] The phenolized alkali lignin is prepared by modifying alkali lignin with phenol as the phenolizing agent under the action of a catalyst.

[0014] The mass ratio of alkali lignin, catalyst, and phenol is 1:0.03-0.1:1.5-2.5.

[0015] The alkali lignin has a phenolic hydroxyl content of 0.5-0.8% and a weight-average molecular weight of 1000-2000.

[0016] The alkali lignin is prepared by acid precipitation treatment of at least one of the following: bamboo, oak, poplar, eucalyptus, birch, and Masson pine.

[0017] The catalyst is selected from one or more of aluminum chloride, zinc chloride, ferric chloride, tin tetrachloride, boron trifluoride, sulfur trioxide, and ferric bromide.

[0018] Further, the preparation method of the phenolized alkali lignin includes the following steps: dissolving alkali lignin in an alkaline solution, adding a catalyst and phenol, and reacting at a raised temperature to obtain phenolized lignin. The mass ratio of alkali lignin to alkaline solution is 1:5-10. The pH of the alkaline solution is 9-10. The alkaline solution is selected from one or a combination of two of sodium hydroxide solution and potassium hydroxide solution. The reaction conditions are 60-100℃, and the reaction time is 1-4 hours. The reaction also includes a distillation operation to remove the solvent.

[0019] The carboxylated porous resin is prepared by a method comprising the following steps:

[0020] 1) Add pore-forming agent and dispersant to phenolic alkali lignin solution, adjust pH, add dialdehyde, and react under controlled temperature to obtain porous resin microspheres;

[0021] 2) The porous resin microspheres were ultrasonically dispersed in water, chloroacetic acid and alkali were added, and the reaction was carried out under controlled temperature to obtain carboxylated porous resin microspheres.

[0022] In step 1), the mass ratio of phenolic alkali lignin to dispersant is 1:0.2-0.3. The weight-average molecular weight of the dispersant is 6000-13000, selected from one or a combination of polyvinyl alcohol and polyethylene glycol. The phenolic alkali lignin solution is prepared by dissolving phenolic alkali lignin in an alkaline solution with a pH of 9-10, and its solid content is 10-20 wt%. The alkaline solution is selected from one or a combination of sodium hydroxide solution and potassium hydroxide solution. The pH is adjusted to 9-12 using a 5-20 wt% alkaline solution, which is selected from one or a combination of sodium hydroxide solution and potassium hydroxide solution. The temperature-controlled reaction is carried out at 70-90℃ for 1-3 hours under ultrasonic stirring conditions with an ultrasonic frequency of 20-60 kHz, a power of 100-200 W, and a rotation speed of 500-1200 r / min. After the temperature-controlled reaction, the process includes filtration, extraction, washing, and drying. The extraction solvent is selected from one or a combination of two of acetone and ethanol. The washing is performed with water until the pH reaches 6.5-7.5.

[0023] In step 2), the mass ratio of the porous resin microspheres to water is 1:5-10. The ultrasonic dispersion conditions are a frequency of 20-60 kHz, a power of 100-200 W, and a time of 20-40 min. The temperature-controlled reaction is carried out at 40-60℃ for 1-3 h. After the temperature-controlled reaction, the process includes filtration, acid washing, water washing, and drying. The acid washing involves ultrasonically impregnating the filtered precipitate in 0.5-1 mol / L hydrochloric acid at a mass ratio of 1:5-10 for 5-10 min, with ultrasonic conditions of 40-60 kHz and a power of 100-200 W. The washing involves washing with water until the pH reaches 6.7-7.

[0024] The activated carbon has a specific surface area of ​​1000-1300 m². 2 / g, particle size 0.2-0.9mm.

[0025] The nonionic surfactant is selected from one or more of AEO-9, AEO-10, AEO-12, AEO-20, NP-10, NP-12, and NP-40.

[0026] Furthermore, the nonionic surfactant is AEO-10.

[0027] The cement is ordinary Portland cement with a strength grade of 42.5 or 52.5.

[0028] The admixture is selected from one or a combination of two of fly ash and slag powder.

[0029] The fly ash is selected from one or a combination of two of the following: Grade I fly ash and Grade II fly ash.

[0030] The slag powder is selected from one or a combination of two of the following: S95 grade slag powder and S105 grade slag powder.

[0031] A method for preparing a freeze-thaw sludge solidifying agent includes the following steps:

[0032] Cement, admixtures, quicklime, gypsum, carboxylated porous resin, nonionic surfactant, and activated carbon are mixed evenly to obtain an antifreeze-thaw sludge solidifying agent.

[0033] This invention also provides the application of the above-mentioned freeze-thaw sludge solidification agent, wherein the amount of the freeze-thaw sludge solidification agent added to the sludge is 30-60 kg / m³. 3 .

[0034] The sludge contains 15-30 wt% organic matter, 30-60 wt% moisture, 10-28 plasticity index, 1-1.8 liquidity index, and 2.2-2.8 specific gravity.

[0035] The sludge is selected from one or a combination of two types of municipal sludge and industrial sludge.

[0036] The organic matter content was obtained by testing the organic matter combustion oxidation-non-dispersive infrared absorption method in the CJ / T 221-2023 Standard Test Methods for Urban Sludge.

[0037] Compared with the prior art, the beneficial effects of the present invention are:

[0038] This invention utilizes a nonionic surfactant to reduce the surface tension of sludge, improve the dispersibility of activated carbon in sludge, promote the adsorption of easily migrating and free organic matter by activated carbon, prevent it from encapsulating gel particles and hindering hydration, avoid the formation of interconnected pore networks, and improve the freeze-thaw resistance of the sludge solidification. The carboxylated porous resin contains a large number of phenolic hydroxyl and carboxyl groups on its pore surface, which can form stable chelates with heavy metal ions and fix them within the pores of the porous resin, reducing the migration activity of heavy metal ions. Simultaneously, because activated carbon has a smooth and inert surface, it is prone to slippage or rolling under shear force, and its extensive use can lead to a decrease in the shear resistance of the sludge solidification. The carboxyl and phenolic hydroxyl groups on the surface of the carboxylated porous resin adsorb calcium ions in the gel material, inducing hydration products to deposit on and around the surface of the carboxylated porous resin, forming an organic / inorganic cross-linked network. This compensates for the shear resistance defects caused by the extensive use of activated carbon. Working synergistically with the nonionic surfactant and activated carbon, it improves the freeze-thaw resistance of the solidification without compromising mechanical properties, reducing the risk of secondary heavy metal pollution. Detailed Implementation

[0039] The present invention will be further described below with reference to specific embodiments, but is not limited to the contents of the specification. Unless otherwise specified, all "parts" mentioned in the embodiments of the present invention are parts by weight. All reagents used are commercially available in the art.

[0040] Activated carbon #1, with a specific surface area of ​​1000 m² 2 / g, particle size 0.2mm, from Jiangsu Xinchang Activated Carbon Co., Ltd.

[0041] Activated carbon #2, with a specific surface area of ​​1300 m² 2 / g, particle size 0.6mm, from Jiangsu Xinchang Activated Carbon Co., Ltd.

[0042] Urban sludge A, with an organic matter content of 28wt%, a water content of 60.3wt%, a plasticity index of 24.2, a liquidity index of 1.56, a specific gravity of 2.21, and a lead content of 400mg / kg, comes from the sludge treatment branch of the Xincheng Sewage Treatment Plant in Xingshan County.

[0043] Urban sludge B, with an organic matter content of 24.7 wt%, a moisture content of 30.5 wt%, a plasticity index of 20.7, a liquidity index of 1.23, a specific gravity of 2.52, and a lead content of 350 mg / kg, comes from the sludge treatment branch of the Xincheng Wastewater Treatment Plant in Xingshan County.

[0044] Alkali lignin is an alkali lignin prepared by acid precipitation of black liquor from bamboo alkali papermaking. It has a phenolic hydroxyl content of 0.8% and a weight-average molecular weight of 1910. It comes from Huadong Lignin Co., Ltd. in Luohe City.

[0045] Polyvinyl alcohol P434372 has a weight-average molecular weight of 9000 and is derived from Aladdin.

[0046] Example 1

[0047] 1) Dissolve 1 kg of alkali lignin in 5 kg of sodium hydroxide solution with pH 9, add 0.08 kg of ferric chloride catalyst, add 2.5 kg of phenol, heat to 100 °C and react for 1 h, then distill to remove the solvent to obtain phenolic lignin.

[0048] 2) Dissolve 1 kg of phenolic lignin in a sodium hydroxide solution with a pH of 9 to prepare a phenolic alkali lignin solution with a solid content of 10 wt%. Add 0.8 kg of porogen toluene and 0.3 kg of dispersant polyvinyl alcohol P434372 to the phenolic alkali lignin solution. Adjust the pH to 12 with 5 wt% sodium hydroxide solution. Add 0.15 kg of glutaraldehyde. React at 90℃ for 1 h under ultrasonic stirring conditions at a frequency of 40 kHz, a power of 200 W, and a rotation speed of 800 r / min. Filter, extract with acetone, wash with water until the pH reaches 7, and dry at 80℃ to constant weight to obtain porous resin microspheres.

[0049] 3) Disperse 1 kg of porous resin microspheres into 10 kg of water by ultrasonication at 40 kHz and 100 W for 40 min. Add 3.5 kg of chloroacetic acid and 3.6 kg of sodium hydroxide. Control the temperature at 40 ℃ and react for 3 h. Filter and ultrasonically impregnate the filtered precipitate in 1 mol / L hydrochloric acid at a mass ratio of 1:5 for 10 min. The ultrasonication conditions are 60 kHz and 200 W. Wash with water until pH reaches 7 and dry to obtain carboxylated porous resin microspheres.

[0050] 4) Mix 60kg of ordinary silicate cement with a strength grade of 42.5, 10kg of secondary fly ash, 20kg of quicklime, 5kg of gypsum, 8kg of carboxylated porous resin, 0.8kg of fatty alcohol polyoxyethylene ether AEO-10, and 8kg of activated carbon No. 1 evenly to obtain an antifreeze-thaw sludge solidifying agent.

[0051] 5) Solidify sludge A with an antifreeze-thaw sludge solidifying agent, the dosage of which is 60 kg / m³. 3 After mixing the two together, the sludge is naturally cured for 28 days to obtain solidified soil.

[0052] Example 2

[0053] The rest is the same as in Example 1, except that in step 1), the amount of phenol used is 1.5 kg.

[0054] Example 3

[0055] The rest is the same as in Example 1, except that in step 2), the amount of porogen toluene is 0.7 kg.

[0056] Example 4

[0057] The rest is the same as in Example 1, except that in step 2), the amount of porogen toluene is 0.85 kg.

[0058] Example 5

[0059] The rest is the same as in Example 1, except that in step 3), the amount of chloroacetic acid used is 3 kg.

[0060] Example 6

[0061] The rest is the same as in Example 1, except that in step 3), the amount of chloroacetic acid used is 2.5 kg.

[0062] Example 7

[0063] The rest is the same as in Example 1, except that in step 4), the amount of carboxylated porous resin used is 5 kg.

[0064] Example 8

[0065] The rest is the same as in Example 1, except that in step 4), the amount of activated carbon 1# is 5kg.

[0066] Example 9

[0067] The rest is the same as in Example 1, except that in step 4), activated carbon 2# is replaced with activated carbon 1# of equal mass.

[0068] Example 10

[0069] The rest is the same as in Example 1, except that in step 4), the amount of fatty alcohol polyoxyethylene ether AEO-10 ​​is 0.5 kg.

[0070] Example 11

[0071] 1) Dissolve 1 kg of alkali lignin in 5 kg of sodium hydroxide solution with pH 9, add 0.08 kg of ferric chloride catalyst, add 2.5 kg of phenol, heat to 100 °C and react for 1 h, then distill to remove the solvent to obtain phenolic lignin.

[0072] 2) Dissolve 1 kg of phenolic lignin in a sodium hydroxide solution with a pH of 9 to prepare a phenolic alkali lignin solution with a solid content of 10 wt%. Add 0.8 kg of porogen toluene and 0.3 kg of dispersant polyvinyl alcohol P434372 to the phenolic alkali lignin solution. Adjust the pH to 9 with 5 wt% sodium hydroxide solution. Add 0.1 kg of glutaraldehyde. React at 90℃ for 1 h under ultrasonic stirring conditions at a frequency of 40 kHz, a power of 200 W, and a rotation speed of 800 r / min. Filter, extract with acetone, wash with water until the pH reaches 7, and dry to obtain porous resin microspheres.

[0073] 3) Disperse 1 kg of porous resin microspheres into 10 kg of water by ultrasonication at 40 kHz and 100 W for 40 min. Add 2.5 kg of chloroacetic acid and 2.8 kg of sodium hydroxide. Control the temperature at 40 ℃ and react for 3 h. Filter and ultrasonically impregnate the filtered precipitate in 1 mol / L hydrochloric acid at a mass ratio of 1:5 for 10 min. The ultrasonication conditions are 60 kHz and 200 W. Wash with water until pH reaches 7 and dry at 80 ℃ to constant weight to obtain carboxylated porous resin microspheres.

[0074] 4) Mix 40kg of ordinary silicate cement with a strength grade of 42.5, 20kg of secondary fly ash, 10kg of quicklime, 10kg of gypsum, 8kg of carboxylated porous resin, 0.8kg of fatty alcohol polyoxyethylene ether NP-10, and 8kg of activated carbon No. 1 evenly to obtain an antifreeze-thaw sludge solidifying agent.

[0075] 5) Solidify sludge B using an antifreeze-thaw sludge solidifier, with an addition amount of 30 kg / m³. 3 After mixing the two together, the sludge is naturally cured for 28 days to obtain solidified soil.

[0076] Comparative Example 1

[0077] The rest is the same as in Example 1, except that in step 4), fatty alcohol polyoxyethylene ether AEO-10 ​​is not added.

[0078] Comparative Example 2

[0079] The rest is the same as in Example 1, except that in step 4), no carboxylated porous resin is added.

[0080] Comparative Example 3

[0081] The rest is the same as in Example 1, except that activated carbon 1# is not added in step 4).

[0082] The solidified soils prepared in the above examples and comparative examples were subjected to the following performance tests:

[0083] 1. Heavy metal leaching concentration: The leaching method was used in accordance with standard HJ 557-2010, "Leaching Toxicity of Solid Waste," for the horizontal oscillation method. The solidified soil was crushed and passed through a 3mm sieve. The Pb concentration was then tested. 2+ The leaching concentration.

[0084] 2. Shear resistance: Direct shear test according to Clause 21 of GB / T50123-2019 Geotechnical Testing Methods, rapid shear tests were conducted under four vertical pressures of 100 kPa, 200 kPa, 300 kPa, and 400 kPa, and the internal friction angle φ and cohesion c were recorded. The shear strength τ is calculated as τ = c + ptanφ, where c is cohesion (kPa), φ is the internal friction angle (°), and p is the vertical pressure. c and φ are referred to as indicators of shear strength.

[0085] 3. Freeze-thaw resistance: The rapid freezing method in GB / T50082-2024 standard for test methods of long-term performance and durability of ordinary concrete was used for freeze-thaw cycles, 250 cycles in total. After the cycle, the heavy metal leaching concentration was re-measured and the heavy metal leaching concentration increase rate η was calculated. The freezing temperature was -18℃, the thawing temperature was 5℃, the freezing time was 2-4h, the thawing time was 2-4h, the transition time between freezing and thawing was no more than 10min, and the thawing time was no less than 1 / 4 of the total freeze-thaw cycle time.

[0086] η = (C) 后 -C 前 ) / C 前 ×100%

[0087] η is the rate of increase in heavy metal leaching concentration, %; C 后 The leaching concentration of heavy metals (mg / L) after 250 freeze-thaw cycles; C 前 The leaching concentration of heavy metals before the freeze-thaw cycle is in mg / L.

[0088] Table 1 Performance Tests

[0089]

[0090] Table 1 shows the Pb after freeze-thaw cycles. 2+ The leaching increase rate shows that the Pb content of the solidified soil after 250 freeze-thaw cycles is significantly higher than that of the soil solidified in this invention. 2+ The leaching concentration increase rate was 30.6-43.4%, far lower than the 96.4-242.5% of the comparative example, indicating that the curing agent prepared in this invention has an excellent effect on improving the freeze-thaw resistance of cured soil. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 2+ The leaching concentration and its leaching rate show that the curing agent of the present invention has the effect of fixing heavy metals with long-term stability, and the heavy metal leaching concentration is less than the environmental protection limit, thus meeting the environmental safety requirements.

[0091] The shear strength of solidified soil consists of two parts: cohesion and internal friction. Within a certain range, the greater both are, the greater the shear strength. The most important and direct factor in improving the shear strength of solidified soil is cohesion. The shear performance test results show that the cohesion of the sludge solidified soil of this invention can reach 190.1-249.6 kPa, and the internal friction angle can reach 31-38.9°, representing a significant improvement in shear strength compared to the comparative example.

[0092] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A freeze-thaw sludge solidifying agent, characterized in that, The raw materials include the following parts by weight: 40-60 parts cement, 10-20 parts admixture, 10-20 parts quicklime, 5-10 parts gypsum, 5-8 parts carboxylated porous resin, 0.5-0.8 parts nonionic surfactant, and 5-8 parts activated carbon. The carboxylated porous resin is formed by the condensation reaction of phenolic alkali lignin and dialdehyde to form a three-dimensional network structure. At the same time, a pore-forming agent is used to form porous resin microspheres. Then, the porous resin microspheres, chloroacetic acid, and alkali undergo a substitution reaction to obtain the carboxylated porous resin microspheres.

2. The freeze-thaw sludge solidifying agent according to claim 1, characterized in that, The mass ratio of phenolic alkali lignin, dialdehyde, and porogen is 1:0.1-0.2:0.7-0.85, preferably 1:0.1-0.15:0.7-0.

8.

3. The freeze-thaw sludge solidifying agent according to claim 1, characterized in that, The porogen is selected from one or more of toluene, dioctyl phthalate, octyl alcohol, and benzene; and / or the dialdehyde is selected from one or more of malondialdehyde, succinal, glutaraldehyde, and adipaldehyde.

4. The freeze-thaw sludge solidifying agent according to claim 1, characterized in that, The mass ratio of the porous resin microspheres, chloroacetic acid, and alkali is 1:2.5-3.5:2.5-3.6, preferably 1:3-3.5:2.8-3.6; the alkali is selected from one or a combination of two of sodium hydroxide and potassium hydroxide.

5. The freeze-thaw sludge solidifying agent according to claim 1, characterized in that, The phenolized alkali lignin is prepared by modifying alkali lignin with phenol as the phenolizing agent under the action of a catalyst; the mass ratio of alkali lignin, catalyst, and phenol is 1:0.03-0.1:1.5-2.5; the alkali lignin has a phenolic hydroxyl content of 0.5-0.8% and a weight average molecular weight of 1000-2000; the catalyst is selected from one or more of aluminum chloride, zinc chloride, ferric chloride, tin tetrachloride, boron trifluoride, sulfur trioxide, and ferric bromide.

6. The freeze-thaw sludge solidifying agent according to claim 1, characterized in that, The carboxylated porous resin is prepared by a method comprising the following steps: 1) Add pore-forming agent and dispersant to phenolic alkali lignin solution, adjust pH, add dialdehyde, and react under controlled temperature to obtain porous resin microspheres; 2) The porous resin microspheres were ultrasonically dispersed in water, chloroacetic acid and alkali were added, and the reaction was carried out under controlled temperature to obtain carboxylated porous resin microspheres.

7. The freeze-thaw sludge solidifying agent according to claim 6, characterized in that, In step 1), the mass ratio of phenolic alkali lignin to dispersant is 1:0.2-0.3; the weight average molecular weight of the dispersant is 6000-13000, and it is selected from one or a combination of two of polyvinyl alcohol and polyethylene glycol; after the temperature-controlled reaction is completed, the process also includes filtration, extraction, washing, and drying.

8. The freeze-thaw sludge solidifying agent according to claim 1, characterized in that, The activated carbon has a specific surface area of ​​1000-1300 m². 2 / g, particle size 0.2-0.9mm; the nonionic surfactant is selected from one or more of AEO-9, AEO-10, AEO-12, AEO-20, NP-10, NP-12, NP-40; preferably AEO-10.

9. A method for preparing the freeze-thaw sludge solidifying agent according to any one of claims 1-8, characterized in that, Includes the following steps: Cement, admixtures, quicklime, gypsum, carboxylated porous resin, nonionic surfactant, and activated carbon are mixed evenly to obtain an antifreeze-thaw sludge solidifying agent.

10. The application of the freeze-thaw sludge solidifying agent according to any one of claims 1-8, characterized in that, The amount of the freeze-thaw sludge solidifying agent added to the sludge is 30-60 kg / m³. 3 .

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