Sludge curing agent based on modified components as well as preparation method and application of sludge curing agent

Abstract

The invention relates to the field of water treatment, in particular to a sludge curing agent based on modified components and a preparation method and application thereof. The sludge curing agent based on the modified component comprises the following raw materials in parts by mass: 40-60 parts of an inorganic curing base material, 15-25 parts of a polymer modifier, 5-10 parts of a nano material, 2-5 parts of a pH regulator, 3-8 parts of a plasticizer, 0.5-1.2 parts of a water reducing agent, 2-5 parts of an anti-freezing agent, 2-5 parts of an expanding agent, 0.2-0.5 part of a preservative and 20-40 parts of water. The finally prepared sludge curing agent not only has good complex sludge adaptability, but also can greatly improve the problem of insufficient durability after use, effectively reduce the conditions of cracking, peeling and the like in long-term use, and maintain the water content after curing at a suitable stage, so that the curing requirement of the existing water treatment sludge is met, and the application prospect is wide. And the method has a very excellent application prospect.

Description

Technical Field

[0001] The present application relates to the field of water treatment, and in particular to a sludge solidifying agent based on a modified component, and a preparation method and application thereof. Background Art

[0002] With the acceleration of urbanization and industrial development, wastewater discharge continues to increase, resulting in a large amount of difficult-to-treat sludge. This sludge often contains high levels of moisture and organic matter, and may be contaminated with heavy metals and other hazardous substances. If improperly handled, it can cause serious environmental pollution. Traditional sludge treatment methods such as landfill and incineration not only consume land resources but also pose the risk of secondary pollution. Therefore, the development of efficient and environmentally friendly sludge treatment technologies is urgently needed.

[0003] In recent years, sludge solidification has garnered widespread attention as an effective treatment method. The solidification process involves the addition of specific chemicals (i.e., solidifying agents) to absorb or remove moisture from the sludge, forming a solid mass with a certain strength and stability. This not only reduces sludge volume but also prevents the migration and spread of contaminants, facilitating subsequent safe disposal.

[0004] Currently available sludge solidifiers on the market are primarily composed of inorganic components such as cement and lime. They can effectively reduce the water content of sludge and provide a certain degree of mechanical strength. However, traditional solidifiers have exposed several problems in practical applications: for example, due to their single composition, they are poorly adaptable to complex sludge from different sources. In addition, the solidified products often lack durability and are prone to cracking and flaking after long-term exposure to the natural environment, which can lead to the re-release of pollutants into the environment. Finally, the water content of the solidified products is prone to continuously increasing after solidification.

[0005] Therefore, to address the above-mentioned issues, the present application provides a sludge solidifying agent based on a modified component and a preparation method thereof. The sludge solidifying agent ultimately prepared in the present application not only has good adaptability to complex sludge, but also can significantly improve the durability problem after use, effectively reducing cracks and flaking during long-term use, and maintaining the moisture content at an appropriate level after solidification, thereby meeting the solidification needs of existing water treatment sludge and having excellent application prospects. Summary of the Invention

[0006] In order to solve the above problems, the first aspect of the present application provides a sludge solidifying agent based on modified components. The raw materials are, in parts by mass: 40 to 60 parts of inorganic solidifying substrate, 15 to 25 parts of polymer modifier, 5 to 10 parts of nanomaterial, 2 to 5 parts of pH regulator, 3 to 8 parts of plasticizer, 0.5 to 1.2 parts of water reducer, 2 to 5 parts of antifreeze, 2 to 5 parts of expander, 0.2 to 0.5 parts of preservative, and 20 to 40 parts of water.

[0007] As a preferred solution, the inorganic solidification base material is a composition of ordinary Portland cement, fly ash and slag powder.

[0008] As a preferred solution, the mass ratio of ordinary Portland cement, fly ash and slag powder is (25-35): (10-15): (5-10).

[0009] As a preferred solution, the mass ratio of ordinary Portland cement, fly ash and slag powder is (28~33): (12~14): (6~8).

[0010] As a preferred solution, the strength grade of the ordinary Portland cement is 42.5.

[0011] As a preferred solution, the fly ash is Class F fly ash or Class C fly ash.

[0012] As a preferred solution, the fly ash is Class F fly ash.

[0013] As a preferred solution, the average specific surface area of the slag powder is 500-700m 2 / kg.

[0014] As a preferred solution, the average specific surface area of the slag powder is 550-600m 2 / kg.

[0015] As a preferred solution, the mass ratio of the inorganic curing substrate, polymer modifier and nanomaterial is (45~55): (16~22): (7~10).

[0016] As a preferred solution, the mass ratio of the inorganic curing substrate, polymer modifier and nanomaterial is (48~53): (18~20): (8~9).

[0017] As a preferred solution, the polymer modifier is a composition of polyvinyl alcohol and modified polyacrylamide.

[0018] As a preferred solution, the mass ratio of the polyvinyl alcohol to the modified polyacrylamide is (1.2-1.8): (4.5-5.5).

[0019] As a preferred solution, the mass ratio of the polyvinyl alcohol to the modified polyacrylamide is (1.4-1.6): (4.8-5.2).

[0020] As a preferred solution, the preparation method of the modified polyacrylamide specifically includes the following steps: S1: adding cyclohexyl methacrylate, glycidyl methacrylate and N,N'-methylenebisacrylamide to an acryloyl chloride solution, introducing nitrogen and adding ammonium persulfate, heating to 80-90°C and reacting for 3-4 hours, and filtering out the product to obtain a pre-product; S2: adding the pre-product, acrylamide, N-n-butylacrylamide and styrene to deionized water, introducing nitrogen and adding ammonium persulfate, reacting for 4-4.5 hours, and adding sodium hydroxide 0.5 hour before the end of the reaction to adjust the pH to 7-7.5; S3: after the reaction, cooling to room temperature, taking out the product and washing it with deionized water 2-3 times, placing the washed product in a vacuum drying oven, and drying it at 60-65°C for 12-16 hours until the moisture content is ≤2.5wt%.

[0021] As a preferred solution, the mass ratio of cyclohexyl methacrylate, glycidyl methacrylate and N,N'-methylenebisacrylamide is (5-6): (2-5): (0.5-1.2).

[0022] As a preferred solution, the mass ratio of cyclohexyl methacrylate, glycidyl methacrylate and N,N'-methylenebisacrylamide is (5-5.5): (2.5-3.5): (0.6-0.8).

[0023] As a preferred solution, the mass ratio of the pre-product, acrylamide, N-n-butylacrylamide and styrene is (8-12): (25-30): (2-3): (3-4).

[0024] In this application, the modified polyacrylamide added as a composite modifier raw material can effectively improve the durability and mechanical properties of the sludge solidifying agent after use, and effectively reduce cracks, peeling, etc., and can maintain the solidified sludge with a suitable water content for a long time, significantly improving the curing effect of the solidifying agent. The acrylamide segment in the modified polyacrylamide can assist in the adsorption of suspended microparticles in the sludge with N-n-butylacrylamide, thereby promoting the small particles in the sludge to condense into larger flocs faster. While constructing the curing system, the detachment of water molecules is added, and the three-dimensional network segment structure formed by the polyester segment and N, N'-methylenebisacrylamide increases the movement resistance of water molecules, and avoids excessive continuous aggregation of water molecules in the system, thereby stabilizing the water content of the system, and the construction of the three-dimensional network segment structure further gives the resistance to slippage between particle particles, between molecules, and between molecular segments after curing, thereby improving the overall mechanical strength and toughness after curing.

[0025] On the other hand, the cyclohexyl ester side chains contained in the modified polyacrylamide can achieve a certain degree of barrier to the penetration of water molecules in the three-dimensional network segment structure, and the styrene chain segments further increase the cross-linking density between polymer chains in the curing agent, increase the long-term stability of the system after curing, and improve cracking and peeling during use.

[0026] As a preferred solution, the nanomaterial is modified titanium-based nanoparticles.

[0027] As a preferred solution, the preparation method of the modified titanium-based nanoparticles specifically includes the following steps: S1: adding titanium dioxide and glutaric anhydride to a DMF solvent, heating the mixture to 65-70°C and keeping the temperature for 2-3 hours, centrifugally filtering the mixture, and washing with ethanol 2-3 times to obtain pretreated titanium dioxide; S2: adding the pretreated titanium dioxide and tetrabutyl titanate to a DMAc solvent, heating the mixture to 45-50°C, ultrasonically dispersing the mixture at 400-500W for 20-30 minutes, then adding 1,4-naphthalene dicarboxylic acid and p-aminobenzoic acid and continuing ultrasonically dispersing the mixture for 20-30 minutes to obtain a mixed solution; S3: adding hydrofluoric acid to the mixed solution, then transferring the mixed solution into a sealed reaction vessel, reacting the mixture at 120-130°C for 16-20 hours, and cooling the mixture naturally to room temperature after the reaction. The solid product obtained is collected by centrifugal filtration, washed with ethanol several times to remove unreacted raw materials and other impurities, and dried in a vacuum drying oven at 80-85°C overnight.

[0028] As a preferred solution, the mass ratio of titanium dioxide to glutaric anhydride is (1-1.2): (0.2-0.25).

[0029] As a preferred solution, the average particle size of the titanium dioxide is 15-25 nm.

[0030] As a preferred solution, the mass ratio of the pretreated titanium dioxide, tetrabutyl titanate, 1,4-naphthalene dicarboxylic acid and p-aminobenzoic acid is (0.5-0.6): (3.5-3.8): (4.2-4.5): (1.4-1.8).

[0031] As a preferred solution, the average particle size of the modified titanium-based nanoparticles is 400-500 nm.

[0032] In this application, the composite structure of modified titanium-based nanoparticles has a good specific surface area and uniform pore size, which can effectively adsorb heavy metal ions and organic pollutants in sludge. Moreover, through the guiding effect of surface titanium dioxide, the pore size between sludge particles in the curing agent system can be greatly improved, the appearance of large pores can be reduced, and a relatively stable connection network can be formed, thereby increasing the overall mechanical strength of the curing. On the other hand, the modified titanium-based nanoparticles can effectively capture small molecule pollutants, and chemically fix them by reacting surface functional groups with organic pollutant molecules, thereby reducing the effectiveness and mobility of the pollutant molecules in the curing system. Moreover, the overall structure of the modified particles can be embedded in the sludge matrix, playing the role of skeleton support, limiting the movement of sludge particles, and then stabilizing the supporting skeleton after curing, effectively enhancing the mechanical properties after curing.

[0033] As a preferred solution, the pH regulator is at least one of calcium hydroxide, potassium hydroxide and sodium hydroxide.

[0034] As a preferred solution, the pH regulator is calcium hydroxide.

[0035] As a preferred solution, the plasticizer is at least one of polyethylene glycol, phthalate, citrate and epoxidized soybean oil.

[0036] As a preferred solution, the plasticizer is a combination of phthalate and citrate.

[0037] As a preferred solution, the mass ratio of the phthalate ester to the epoxidized soybean oil is (2-2.2): (4-4.5).

[0038] As a preferred solution, the water reducer is at least one of a naphthalene-based high-efficiency water reducer, an aminosulfonate-based high-efficiency water reducer, a polycarboxylic acid-based high-performance water reducer, and an aliphatic high-efficiency water reducer.

[0039] As a preferred solution, the water reducer is an aminosulfonate high-efficiency water reducer or a polycarboxylic acid-based high-performance water reducer.

[0040] As a preferred solution, the antifreeze agent is a combination of calcium nitrate and propylene glycol.

[0041] As a preferred solution, the mass ratio of calcium nitrate to propylene glycol is (1-1.5): (5-6).

[0042] As a preferred solution, the expansion agent is at least one of calcium sulfoaluminate, magnesium oxide, silica fume, limestone powder and bentonite.

[0043] As a preferred solution, the expansion agent is calcium sulfoaluminate.

[0044] As a preferred solution, the preservative is boric acid or isothiazolinone.

[0045] As a preferred solution, the preservative is boric acid.

[0046] The second aspect of the present application provides a preparation method of the above-mentioned sludge solidifying agent based on modified components, which specifically includes the following steps: S1: mixing an inorganic solidifying substrate, a polymer modifier and part of the water, stirring at a speed of 100~150rpm for 30~40min, then adding the nanomaterial and stirring at a speed of 2000~3000rpm for 15~20min using a high-speed shearing machine; S2: adding the remaining water, plasticizer, water reducer, antifreeze, expander and preservative in sequence, each addition is accompanied by stirring at a speed of 600~800rpm for 15~20min, and finally adding a pH regulator to adjust the pH to 7.5~8 after completion; S3: mixing the S2 product with the sludge to be treated in a mass ratio of 1:(5~10), stirring thoroughly at a speed of 400~500rpm, and then standing for curing until solidified sludge is obtained.

[0047] The third aspect of the present application covers the application of the above-mentioned sludge solidifying agent based on modified components in municipal sewage sludge treatment, industrial wastewater sludge stabilization treatment and river sludge management.

[0048] This application has the following beneficial effects: 1. The sludge solidifying agent based on modified components provided in this application not only has good adaptability to complex sludge, but also can greatly improve the problem of insufficient durability after use, effectively reduce cracks, peeling, etc. during long-term use, and maintain the water content after solidification at an appropriate stage, thereby meeting the solidification needs of existing water treatment sludge, and has very excellent application prospects.

[0049] 2. The present application provides a sludge solidifying agent based on a modified component. The acrylamide segment in the modified polyacrylamide added can assist in the adsorption of suspended microparticles in the sludge together with N-n-butylacrylamide, thereby promoting the small particles in the sludge to condense into larger flocs faster. While constructing the solidification system, the detachment of water molecules is added, and the three-dimensional network segment structure formed by the polyester segment and N,N'-methylenebisacrylamide increases the movement resistance of water molecules, avoids excessive continuous aggregation of water molecules in the system, and stabilizes the water content of the system. The construction of the three-dimensional network segment structure further gives the resistance to slippage between particles, between molecules, and between molecular segments after solidification, thereby improving the overall mechanical strength and toughness after solidification.

[0050] 3. The sludge solidifying agent based on modified components provided in this application has a good specific surface area and uniform pore size through the composite structure of modified titanium-based nanoparticles, which can effectively adsorb heavy metal ions and organic pollutants in the sludge. Moreover, through the guiding effect of surface titanium dioxide, it can greatly improve the pore size between sludge particles in the solidifying agent system, reduce the occurrence of large pores, and form a relatively stable connection network, thereby enhancing the overall mechanical properties and water resistance, weather resistance and other properties after solidification. DETAILED DESCRIPTION

[0051] The following text further illustrates and demonstrates the technical solutions described in the above-mentioned summary of the invention in the form of specific implementation plans. The following examples are merely practical examples used to illustrate and explain the technical solutions in the specification and should not limit the scope of the claims to be protected by this application. All technical products based on the technical solutions described in the summary of the invention in this application should be included in the scope of protection to be protected by this application.

[0052] In the following examples, unless otherwise specified, the raw materials are all commercially available products or can be prepared by methods well known to those skilled in the art.

[0053] Example 1 Example 1 The first aspect provides a sludge solidifying agent based on modified components. The raw materials are, in parts by mass: 52 parts of inorganic solidifying substrate, 18.8 parts of polymer modifier, 8.5 parts of nanomaterial, 2.8 parts of pH regulator, 6.5 parts of plasticizer, 0.8 parts of water reducer, 3.4 parts of antifreeze, 3.2 parts of expander, 0.3 parts of preservative, and 32.5 parts of water.

[0054] The inorganic solidifying matrix is a composition of ordinary Portland cement, fly ash and slag powder, with the mass ratio of the three being 32:12:8.

[0055] The strength grade of ordinary Portland cement is 42.5.

[0056] The fly ash is Class F fly ash.

[0057] The average specific surface area of slag powder is 580m 2 / kg, purchased from Shijiazhuang Zhouting Mineral Products Co., Ltd., China, which sold S95 grade slag powder products.

[0058] The polymer modifier is a composition of polyvinyl alcohol PVA2488 and modified polyacrylamide, and the mass ratio of the two is 1.5:4.9.

[0059] The preparation method of modified polyacrylamide specifically includes the following steps, calculated in parts by mass: S1: adding 5.4 parts of cyclohexyl methacrylate, 3.1 parts of glycidyl methacrylate and 0.68 parts of N,N'-methylenebisacrylamide to 60 parts of acryloyl chloride solution, passing nitrogen and adding 0.14 parts of ammonium persulfate, heating to 85°C and reacting for 3.5 hours, filtering out the product to obtain a pre-product; S2: adding 10.2 parts of the pre-product, 28.8 parts of acrylamide, 2.6 parts of N-n-butylacrylamide and 3.3 parts of styrene to 280 parts of deionized water, passing nitrogen and adding 0.26 parts of ammonium persulfate, reacting for 4.5 hours, and adding sodium hydroxide 0.5 hour before the end of the reaction to adjust the pH to 7.2; S3: after the reaction is completed, cooling to room temperature, taking out the product and washing it with deionized water three times, placing the washed product in a vacuum drying oven, and drying it at 65°C for 15 hours until the moisture content is ≤2.5wt%.

[0060] The nanomaterial is modified titanium-based nanoparticles. The preparation method of the modified titanium-based nanoparticles specifically includes the following steps, calculated by mass: S1: 1.1 parts of titanium dioxide and 0.24 parts of glutaric anhydride are mixed and added to 50 parts of DMF solvent, heated to 70°C and kept warm for 3 hours, after which centrifugation and filtration are completed, and ethanol is washed three times to obtain pretreated titanium dioxide; S2: 0.55 parts of pretreated titanium dioxide and 3.6 parts of tetrabutyl titanate are mixed and added to 80 parts of DMAc solvent, heated to 50°C, and ultrasonically separated at 450W. S3: add 0.6 parts of hydrofluoric acid to the mixed solution, then transfer the mixed solution into a sealed reaction vessel and react at 120°C for 19 hours. After the reaction is completed, cool naturally to room temperature, collect the obtained solid product by centrifugal filtration, wash with ethanol several times to remove unreacted raw materials and other impurities, and dry in a vacuum drying oven at 85°C overnight.

[0061] The average particle size of titanium dioxide is 22 nm, and the average particle size of modified titanium-based nanoparticles is 460 nm.

[0062] The pH regulator is calcium hydroxide; the plasticizer is a combination of phthalate and citrate, and the mass ratio of the two is 2:4.5.

[0063] The water reducer is a polycarboxylate high-performance water reducer, which was purchased from Shanxi Kaidi Building Materials Co., Ltd. in China and sold under the model KDSP.

[0064] The antifreeze is a composition of calcium nitrate and propylene glycol, with a mass ratio of 1.2:5.5.

[0065] The preservative is boric acid; the expander is calcium sulfoaluminate.

[0066] The second aspect of this embodiment provides a preparation method of the above-mentioned sludge solidifying agent based on modified components, which specifically includes the following steps: S1: mixing an inorganic solidifying substrate, a polymer modifier and part of the water (70 wt% of the total water), stirring at a speed of 120 rpm for 35 minutes, then adding the nanomaterial and stirring at a speed of 2500 rpm for 18 minutes using a high-speed shearing machine; S2: adding the remaining water (30 wt% of the total water), plasticizer, water reducer, antifreeze agent, expander and preservative in sequence, each addition accompanied by stirring at a speed of 800 rpm for 15 minutes, and finally adding a pH adjuster to adjust the pH to 7.5 after completion; S3: mixing the S2 product with the sludge to be treated in a mass ratio of 1:7, stirring thoroughly at a speed of 450 rpm, and then standing for curing until solidified sludge is obtained.

[0067] Example 2 The specific implementation of this embodiment is basically the same as that of Example 1, except that: the sludge solidifying agent based on the modified component, in parts by mass, the raw materials are: 46.5 parts of inorganic solidifying base material, 16.5 parts of polymer modifier, 7.2 parts of nanomaterial, 2.4 parts of pH regulator, 6.3 parts of plasticizer, 0.6 part of water reducer, 2.8 parts of antifreeze, 2.9 parts of expander, 0.28 part of preservative, and 31.6 parts of water.

[0068] The inorganic solidifying matrix is a composition of ordinary Portland cement, fly ash and slag powder, with the mass ratio of the three being 30.5:10:6.

[0069] The polymer modifier is a composition of polyvinyl alcohol PVA2488 and modified polyacrylamide, and the mass ratio of the two is 1.8:4.5.

[0070] Example 3 The specific implementation of this embodiment is basically the same as that of Example 1, except that: the sludge solidifying agent based on the modified component, in parts by mass, the raw materials are: 55 parts of inorganic solidifying base material, 21.5 parts of polymer modifier, 10 parts of nanomaterial, 2.6 parts of pH regulator, 5.2 parts of plasticizer, 0.6 parts of water reducer, 3.1 parts of antifreeze, 2.2 parts of expander, 0.25 parts of preservative, and 30.8 parts of water.

[0071] The inorganic solidifying matrix is a composition of ordinary Portland cement, fly ash and slag powder, with the mass ratio of the three being 35:15:5.

[0072] The polymer modifier is a composition of polyvinyl alcohol PVA2488 and modified polyacrylamide, and the mass ratio of the two is 1.5:5.5.

[0073] Comparative Example 1 The specific implementation of this comparative example is basically the same as that of Example 1, except that: the sludge solidifying agent based on the modified component, in parts by mass, the raw materials are: 60.5 parts of inorganic solidifying substrate, 8.5 parts of polymer modifier, 15.2 parts of nanomaterial, 2.1 parts of pH regulator, 7.5 parts of plasticizer, 0.8 parts of water reducer, 3.6 parts of antifreeze, 4.1 parts of expander, 0.26 parts of preservative, and 34.5 parts of water.

[0074] Comparative Example 2 The specific implementation of this comparative example is basically the same as that of Example 1, except that: the sludge solidifying agent based on the modified component, in parts by mass, the raw materials are: 58.8 parts of inorganic solidifying substrate, 25.5 parts of polymer modifier, 2.1 parts of nanomaterial, 2.4 parts of pH regulator, 5.5 parts of plasticizer, 0.7 parts of water reducer, 3.1 parts of antifreeze, 2.6 parts of expander, 0.24 parts of preservative, and 33.2 parts of water.

[0075] Comparative Example 3 The specific implementation of this comparative example is basically the same as that of Example 1, except that the polymer modifier is a composition of polyvinyl alcohol PVA2488 and modified polyacrylamide, and the mass ratio of the two is 1.5:1.9.

[0076] Comparative Example 4 The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified polyacrylamide specifically comprises the following steps, calculated in parts by mass: S1: adding 1.2 parts of cyclohexyl methacrylate, 5.5 parts of glycidyl methacrylate and 0.22 parts of N,N'-methylenebisacrylamide to 60 parts of acryloyl chloride solution, introducing nitrogen and adding 0.11 parts of ammonium persulfate, heating to 85°C and reacting for 3.5 hours, filtering out the product to obtain a pre-product; S2: adding 10.2 parts of cyclohexyl methacrylate, 5.5 parts of glycidyl methacrylate and 0.22 parts of N,N'-methylenebisacrylamide to 60 parts of acryloyl chloride solution, introducing nitrogen and adding 0.11 parts of ammonium persulfate, heating to 85°C and reacting for 3.5 hours, and filtering out the product to obtain a pre-product; The pre-product, 28.8 parts of acrylamide, 2.6 parts of N-n-butylacrylamide and 3.3 parts of styrene were added to 280 parts of deionized water, nitrogen was introduced and 0.26 parts of ammonium persulfate were added, and the reaction was carried out for 4.5 hours. 0.5 hours before the end of the reaction, sodium hydroxide was added to adjust the pH to 7.2; S3: After the reaction, the mixture was cooled to room temperature, the product was taken out and washed with deionized water three times, and the washed product was placed in a vacuum drying oven and dried at 65°C for 15 hours until the moisture content was ≤2.5wt%.

[0077] Comparative Example 5 The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified polyacrylamide specifically comprises the following steps, calculated in parts by mass: S1: adding 5.4 parts of cyclohexyl methacrylate, 3.1 parts of glycidyl methacrylate and 0.68 parts of N,N'-methylenebisacrylamide to 60 parts of acryloyl chloride solution, introducing nitrogen and adding 0.14 parts of ammonium persulfate, heating to 85°C and reacting for 3.5 hours, filtering out the product to obtain a pre-product; S2: adding 5.5 parts of cyclohexyl methacrylate, 3.1 parts of glycidyl methacrylate and 0.68 parts of N,N'-methylenebisacrylamide to 60 parts of acryloyl chloride solution, passing nitrogen and adding 0.14 parts of ammonium persulfate, heating to 85°C and reacting for 3.5 hours, and filtering out the product to obtain a pre-product; The pre-product, 36.5 parts of acrylamide, 3.2 parts of N-n-butylacrylamide and 1.5 parts of styrene were added to 300 parts of deionized water, nitrogen was introduced and 0.24 parts of ammonium persulfate were added, and the reaction was carried out for 4.5 hours. 0.5 hours before the end of the reaction, sodium hydroxide was added to adjust the pH to 7.2; S3: After the reaction, the mixture was cooled to room temperature, the product was taken out and washed with deionized water three times, and the washed product was placed in a vacuum drying oven and dried at 65°C for 15 hours until the moisture content was ≤2.5wt%.

[0078] Comparative Example 6 The specific implementation of this comparative example is basically the same as that of Example 1, except that the preparation method of the modified titanium-based nanoparticles specifically comprises the following steps, calculated in parts by mass: S1: 2.5 parts of titanium dioxide and 0.15 parts of glutaric anhydride are mixed and added to 60 parts of DMF solvent, and the temperature is raised to 70°C and kept warm for 3 hours. After completion, centrifugation is performed and the mixture is washed with ethanol three times to obtain pretreated titanium dioxide; S2: 1.1 parts of pretreated titanium dioxide and 3.6 parts of tetrabutyl titanate are mixed and added to 80 parts of DMAc solvent, and the temperature is raised to 50°C. Ultrasonic dispersion was performed at 450W for 25 minutes, and then 4.4 parts of 1,4-naphthalenedicarboxylic acid and 1.6 parts of p-aminobenzoic acid were added and ultrasonic dispersion was continued for 30 minutes to obtain a mixed solution; S3: 0.6 parts of hydrofluoric acid was added to the mixed solution, and then the mixed solution was transferred into a sealed reaction vessel and reacted at 120°C for 19 hours. After the reaction was completed, it was naturally cooled to room temperature, and the solid product was collected by centrifugal filtration, washed with ethanol several times to remove unreacted raw materials and other impurities, and dried in a vacuum drying oven at 85°C overnight.

[0079] Comparative Example 7 The specific implementation of this comparative example is basically the same as that of Example 1, except that the preparation method of the modified titanium-based nanoparticles specifically comprises the following steps, calculated in parts by mass: S1: 1.1 parts of titanium dioxide and 0.24 parts of glutaric anhydride are mixed and added to 50 parts of DMF solvent, and the mixture is heated to 70°C and kept warm for 3 hours. After completion, centrifugation and filtration are performed, and the mixture is washed with ethanol three times to obtain pretreated titanium dioxide; S2: 0.25 parts of pretreated titanium dioxide and 5.2 parts of tetrabutyl titanate are mixed and added to 80 parts of DMAc solvent, and the mixture is heated to 50°C. , ultrasonically disperse at 450W for 25 minutes, then add 4.8 parts of 1,4-naphthalenedicarboxylic acid and 2 parts of p-aminobenzoic acid and continue ultrasonically disperse for 30 minutes to obtain a mixed solution; S3: add 0.8 parts of hydrofluoric acid to the mixed solution, then transfer the mixed solution into a sealed reaction vessel, react at 120°C for 19 hours, and after the reaction is completed, naturally cool to room temperature, collect the obtained solid product by centrifugal filtration, wash with ethanol several times to remove unreacted raw materials and other impurities, and dry in a vacuum drying oven at 85°C overnight to obtain.

[0080] Performance evaluation The sludge in the Examples and Comparative Examples is industrial wastewater sludge (the Examples and Comparative Examples are from the same batch). The solidified sludge in the Examples and Comparative Examples was cured for 28 days at a temperature of 25±2°C and a relative humidity of 80±3%. Thereafter, the unconfined compressive strength of the solidified sludge at 7 days and 28 days, the direct shear strength at 28 days, and the moisture content at 7 days were tested in accordance with the reference standards GBT23485-2009 and GB50869-2013, respectively. The results were averaged over 10 tests and recorded in Table 1.

[0081] It can be seen from the examples and comparative examples of the present application and the data results in Table 1 that Examples 1 to 3 of the present application have obvious advantages over comparative examples 1 to 7 in terms of curing mechanical properties, durable weather resistance, water resistance, etc. This is mainly due to the combined effect of the functional resin modification, modified nanoparticles and other matching schemes specified in the present application. Comparative examples 1 to 7 did not adopt the technical solution specified in the present application, resulting in obvious disadvantages in the above performance tests. This further proves the necessity of the technical solution specified in the present application for the technical effect of the present application and solving the technical problems.

Claims

1. A sludge solidifying agent based on a modified component, characterized in that: The raw materials are as follows, by mass: 40-60 parts of inorganic curing base material, 15-25 parts of polymer modifier, 5-10 parts of nanomaterial, 2-5 parts of pH adjuster, 3-8 parts of plasticizer, 0.5-1.2 parts of water reducer, 2-5 parts of antifreeze agent, 2-5 parts of expander, 0.2-0.5 parts of preservative, and 20-40 parts of water; The inorganic solidifying base material is a composition of ordinary Portland cement, fly ash and slag powder; the mass ratio of the ordinary Portland cement, fly ash and slag powder is (25-35): (10-15): (5-10); The polymer modifier is a composition of polyvinyl alcohol and modified polyacrylamide; the mass ratio of the polyvinyl alcohol to the modified polyacrylamide is (1.2-1.8): (4.5-5.5); The preparation method of the modified polyacrylamide specifically includes the following steps: S1: adding cyclohexyl methacrylate, glycidyl methacrylate and N,N'-methylenebisacrylamide to an acryloyl chloride solution, introducing nitrogen and adding ammonium persulfate, heating to 80-90°C for reaction for 3-4 hours, and filtering out the product to obtain a pre-product; S2: adding the pre-product, acrylamide, N-n-butylacrylamide and styrene to deionized water, introducing nitrogen and adding ammonium persulfate, reacting for 4-4.5 hours, and adding sodium hydroxide 0.5 hour before the end of the reaction to adjust the pH to 7-7.5; S3: after the reaction is completed, cooling to room temperature, taking out the product and washing it with deionized water for 2-3 times, placing the washed product in a vacuum drying oven, and drying it at 60-65°C for 12-16 hours until the moisture content is ≤2.5wt%. The mass ratio of the cyclohexyl methacrylate, glycidyl methacrylate and N,N'-methylenebisacrylamide is (5-5.5): (2.5-3.5): (0.6-0.8); The mass ratio of the pre-product, acrylamide, N-n-butylacrylamide and styrene is (8-12): (25-30): (2-3): (3-4).

2. The sludge solidifying agent based on the modified component according to claim 1, characterized in that: The average specific surface area of the slag powder is 500-700m 2 / kg.

3. The sludge solidifying agent based on the modified component according to claim 2, characterized in that: The strength grade of the ordinary Portland cement is 42.5; the fly ash is Class F fly ash or Class C fly ash.

4. The sludge solidifying agent based on the modified component according to claim 3, characterized in that: The mass ratio of the inorganic curing substrate, the polymer modifier and the nanomaterial is (45-55): (16-22): (7-10).

5. The sludge solidifying agent based on the modified component according to claim 4, characterized in that: The nanomaterial is modified titanium-based nanoparticles; the preparation method of the modified titanium-based nanoparticles is specifically The following steps are involved: S1: Titanium dioxide and glutaric anhydride were mixed and added to DMF solvent, and the temperature was raised to 65-70°C and kept for 2-3 hours. After completion, centrifugation and filtration were performed, and the mixture was washed with ethanol 2-3 times to obtain pretreated titanium dioxide; S2: Mix the pretreated titanium dioxide and tetrabutyl titanate and add them to DMAc solvent, raise the temperature to 45~50°C, and ultrasonically disperse at 400~500W for 20~30min, then add 1,4-naphthalene dicarboxylic acid and p-aminobenzoic acid and continue ultrasonically dispersing for 20~30min to obtain a mixed solution; S3: Add hydrofluoric acid to the mixed solution, then transfer the mixed solution into a sealed reaction vessel, react at 120~130°C for 16~20h, and after the reaction is completed, naturally cool to room temperature, collect the obtained solid product by centrifugal filtration, wash with ethanol several times to remove unreacted raw materials and other impurities, and dry in a vacuum drying oven at 80~85°C overnight to obtain.

6. The sludge solidifying agent based on the modified component according to claim 5, characterized in that: The mass ratio of the titanium dioxide to glutaric anhydride is (1-1.2): (0.2-0.25); and the average particle size of the titanium dioxide is 15-25 nm.

7. The sludge solidifying agent based on the modified component according to claim 6, characterized in that: The mass ratio of the pretreated titanium dioxide, tetrabutyl titanate, 1,4-naphthalene dicarboxylic acid and p-aminobenzoic acid is (0.5-0.6): (3.5-3.8): (4.2-4.5): (1.4-1.8); and the average particle size of the modified titanium-based nanoparticles is 400-500 nm.

8. The sludge solidifying agent based on the modified component according to claim 7, characterized in that: The antifreeze agent is a composition of calcium nitrate and propylene glycol; the mass ratio of the calcium nitrate to propylene glycol is (1-1.5): (5-6).

9. A method for preparing a sludge solidifying agent based on a modified component according to any one of claims 1 to 8, characterized in that: The specific steps include: S1: Mix the inorganic solidifying substrate, polymer modifier and part of the water, stir at 100~150rpm for 30~40min, then add the nanomaterial and stir at 2000~3000rpm for 15~20min using a high-speed shear; S2: Add the remaining water, plasticizer, water reducer, antifreeze, expander and preservative in sequence, each addition accompanied by stirring at 600~800rpm for 15~20min, and finally add the pH regulator to adjust the pH to 7.5~8; S3: Mix the S2 product with the sludge to be treated in a mass ratio of 1:(5~10), stir thoroughly at 400~500rpm, and then let it stand for curing until solidified sludge is obtained.

10. Use of the sludge solidifying agent based on the modified component according to any one of claims 1 to 8 in municipal sewage sludge treatment, industrial wastewater sludge stabilization treatment and river sludge management.

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