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CN-121990807-A - Anti-freeze-thawing sludge curing agent and preparation method and application thereof

CN121990807ACN 121990807 ACN121990807 ACN 121990807ACN-121990807-A

Abstract

The invention belongs to the technical field of soil curing agents, and particularly relates to an anti-freeze-thawing sludge curing agent, a preparation method and application thereof. The sludge curing agent comprises the following raw materials, 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 nonionic surfactant and 5-8 parts of activated carbon, wherein the carboxylated porous resin is formed into a three-dimensional network structure by condensation reaction of phenolated alkali lignin and dialdehyde, and porous resin microspheres are formed by using a pore-forming agent, and then the porous resin microspheres, chloroacetic acid and alkali react to prepare carboxylated porous resin microspheres. The nonionic surfactant of the invention emulsifies the easily-migrated and free organic matters in the sludge to form micro-micelles, and the micro-micelles are adsorbed by the activated carbon to prevent the micro-micelles from wrapping gelled particles and blocking hydration, so that a communicated pore network is avoided, and the freeze-thawing resistance of the sludge solidified body is improved. The carboxylated porous resin contains a large number of phenolic hydroxyl groups and carboxyl groups on the inner surfaces of the pores, so that the migration activity of heavy metal ions is reduced.

Inventors

  • LIU GUODONG
  • MA QINGHAO

Assignees

  • 商洛学院
  • 北京慕湖外加剂有限公司

Dates

Publication Date
20260508
Application Date
20260304

Claims (10)

  1. 1. The freeze-thawing resistant sludge curing agent is characterized by comprising, 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, wherein the carboxylated porous resin is formed into a three-dimensional network structure by condensation reaction of phenolated alkali lignin and dialdehyde, and porous resin microspheres are formed by using a pore-forming agent, and then the porous resin microspheres, chloroacetic acid and alkali undergo substitution reaction to prepare carboxylated porous resin microspheres.
  2. 2. The freeze-thawing resistant sludge curing agent according to claim 1, wherein the mass ratio of phenolated 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. 3. The freeze-thawing resistant sludge curing agent according to claim 1, wherein the pore-forming agent is selected from one or a combination of two or more of toluene, dioctyl phthalate, stearyl alcohol and benzene, and/or the dialdehyde is selected from one or a combination of two or more of malondialdehyde, succinaldehyde, glutaraldehyde and hexanedial.
  4. 4. The freeze-thawing resistant sludge curing agent according to claim 1, wherein the mass ratio of the porous resin microspheres to chloroacetic acid to alkali is 1:2.5-3.5:2.5-3.6, preferably 1:3-3.5:2.8-3.6, and the alkali is one or a combination of two of sodium hydroxide and potassium hydroxide.
  5. 5. The freeze-thawing resistant sludge curing agent according to claim 1 is characterized in that phenol is used as a phenolization reagent for modifying alkali lignin under the action of a catalyst, the mass ratio of the alkali lignin to the catalyst to the phenol is 1:0.03-0.1:1.5-2.5, the content of phenolic hydroxyl in the alkali lignin is 0.5-0.8%, the weight average molecular weight is 1000-2000, and the catalyst is one or a combination of more than two of aluminum chloride, zinc chloride, ferric chloride, tin tetrachloride, boron trifluoride, sulfur trioxide and ferric bromide.
  6. 6. The freeze-thaw resistant sludge solidification agent of claim 1, wherein the carboxylated porous resin is prepared by a process comprising: 1) Adding a pore-forming agent and a dispersing agent into the phenolized alkali lignin solution, adjusting the pH value, adding dialdehyde, and performing temperature control reaction to obtain porous resin microspheres; 2) Dispersing the porous resin microsphere into water by ultrasonic, adding chloroacetic acid and alkali, and controlling the temperature to react to obtain carboxylated porous resin microsphere.
  7. 7. The freeze-thawing resistant sludge curing agent according to claim 6, wherein in the step 1), the mass ratio of the phenolized alkali lignin to the dispersant is 1:0.2-0.3, the weight average molecular weight of the dispersant is 6000-13000, and the heat-resistant sludge curing agent is one or the combination of two of polyvinyl alcohol and polyethylene glycol, and the heat-resistant sludge curing agent further comprises the operations of filtering, extracting, washing and drying after the temperature control reaction is finished.
  8. 8. The freeze-thawing resistant sludge curing agent according to claim 1, wherein the activated carbon has a specific surface area of 1000-1300m 2 /g and a particle size of 0.2-0.9mm, and the nonionic surfactant is selected from one or more of AEO-9, AEO-10, AEO-12, AEO-20, NP-10, NP-12, NP-40, and preferably AEO-10.
  9. 9. The method for preparing the freeze-thawing resistant sludge solidifying agent according to any one of claims 1 to 8, which is characterized by comprising the following steps: Cement, admixture, quicklime, gypsum, carboxylated porous resin, nonionic surfactant and activated carbon are uniformly mixed to obtain the freeze-thawing resistant sludge curing agent.
  10. 10. Use of the freeze-thaw resistant sludge solidification agent according to any one of claims 1-8, wherein the addition amount of the freeze-thaw resistant sludge solidification agent in sludge is 30-60kg/m 3 .

Description

Anti-freeze-thawing sludge curing agent and preparation method and application thereof Technical Field The invention belongs to the technical field of soil curing agents, and particularly relates to an anti-freeze-thawing sludge curing agent, a preparation method and application thereof. Background Sludge is a precipitate substance generated in the sewage treatment process of a sewage treatment plant, has a large amount of microorganisms, pathogens, heavy metals and organic pollutants, and can cause serious secondary pollution if improperly treated. At present, the sludge treatment mode is mainly changed into agriculture, incineration and landfill. However, due to the characteristics of high water content, poor mechanical properties, high pollutant content and the like of the sludge, the treatment modes often have the problems of environmental pollution, high treatment cost or easy occurrence of landfill engineering disasters and the like. The solidification technology is one of effective methods capable of meeting the requirements of treating a large amount of generated sludge and realizing stabilization, harmless and recycling utilization. By the solidification treatment, not only can the sludge be converted into a solidified body with excellent physical properties (such as high strength and low permeability), but also the sludge can be firmly fixed by chemical passivation and physical wrapping action to block the path of the heavy metal and other pollutants (such as Pb) migrating to the environment. The leaching concentration of heavy metals in the treated sludge is far lower than the environment-friendly limit value, so that the environment risk is eliminated. Therefore, the solidified sludge can be safely buried or used as soil resources. The solidification technology is specifically that a soil solidifying agent is added into the sludge, and a stable solidified substance is formed through chemical reaction, so that the solidified product has higher strength and lower water permeability. The soil curing agent is various, and can be classified into a liquid soil curing agent and a powder soil curing agent according to the form of the material, and can be classified into a type A soil curing agent and a type B soil curing agent according to the performance, wherein the type A soil curing agent cannot be directly used for soil curing and needs to be matched with cementing materials such as cement and the like for use, and the type B soil curing agent can be used. The A-type soil curing agent has mature technology and wide material sources, is widely researched and paid attention to, and is prepared from 1-3 mass percent of phosphate ore, 1-3 mass percent of carbide slag, 1-3 mass percent of tailing slag and 1-3 mass percent of marble slag through the steps of respectively washing, drying, crushing and ball milling the phosphate ore, the carbide slag, the tailing slag and the marble slag, and uniformly mixing the phosphate ore, the carbide slag, the tailing slag and the marble slag according to a proportion. The patent CN103387371B discloses a composite curing agent for curing/stabilizing municipal sludge and application thereof, which is prepared by mixing 10-25% of cement, 45-60% of fly ash, 5-10% of anhydrous gypsum, 10-20% of lime CaO and active magnesium oxide MgO, 1-2.5% of iron powder and 1-2.5% of powdered activated carbon. The above is a common A-type soil curing agent, the curing and stabilization treatment of the sludge is realized through hydration and gelation reaction of cementing materials such as cement and the like, but the sludge contains a large amount of organic matters which are not easy to migrate and free organic matters, the cementing particles are wrapped by the sludge, the hydration reaction is blocked, a communicated pore network is introduced, the volume expansion of water permeated into the communicated pores generates huge internal stress when the water is frozen in a cold environment, the internal stress is rapidly transferred and concentrated in the communicated pore network, microcracks are generated and expanded, and the process can lead heavy metals which are wrapped or fixed by dense hydration products to be more easily leached out due to the exposure of the microcracks, so that the risk of secondary pollution is obviously increased. Therefore, it is necessary to develop an anti-freeze-thawing sludge curing agent, which realizes efficient stabilization, long-acting anti-freeze-thawing and environmental safety of sludge curing treatment and meets application requirements in severe environments such as cold, rainy and the like. Disclosure of Invention In order to solve the technical problems, the invention provides an anti-freeze thawing sludge curing agent, a preparation method and application thereof, the nonionic surfactant of the invention reduces the surface tension of sludge, improves the dispersibility of activated carbon in the sludge, promoting the adsorption of t