CN-121991700-A - Soil solidifying agent based on biological enzyme synergistic mineralization consolidation and preparation method thereof

CN121991700ACN 121991700 ACN121991700 ACN 121991700ACN-121991700-A

Abstract

The invention discloses a soil solidifying agent based on biological enzyme synergistic mineralization consolidation and a preparation method thereof, belonging to the technical field of soil solidifying agents. The soil curing agent comprises, by weight, 10-18 parts of a biological enzyme composite system, 60-82 parts of a mineralized base material, 5-10 parts of a multi-scale reinforcing system and 3-6 parts of an environment regulator, wherein the biological enzyme composite system comprises 2.0-3.5 parts of urease, 1.0-2.0 parts of manganese peroxidase and 7.0-12.5 parts of a biochar-montmorillonite composite carrier, the mineralized base material comprises 30-40 parts of steel slag powder, 20-25 parts of acid-washed fly ash, 5-10 parts of phosphogypsum after ball milling treatment, 5-7 parts of modified nano hydroxyapatite, the multi-scale reinforcing system comprises 1.5-3.0 parts of modified nano calcium carbonate and 3.5-7.0 parts of modified straw fibers, and the environment regulator comprises 1.0-2.0 parts of sodium carbonate, 0-1.0 parts of citric acid and 1.5-3.0 parts of calcium chloride. The soil solidifying agent constructs an integrated system of enzymatic reaction-mineralization crystallization-structure enhancement through the synergistic effect of biological enzyme catalysis and mineralization materials, and realizes the unification of efficient solidification and environmental friendliness of soil.

Inventors

ZHANG YONGGANG
FENG YANNA
WANG MENGYAO
ZHOU BO
YANG KAIXUAN
CHANG HONGTAO
Chai Chungang
PENG XIAOLONG
Li Danggang
LIANG RUIZHI
ZHANG YIBO
CAI HE
BAI ZHIPENG
JIA WURONG
XIE JIANGSHENG
ZHONG WEILING
LIU YUXIAN
FU JIANWEI
TIAN SISI

Assignees

中铁二十局集团有限公司
中铁建科检测有限公司

Dates

Publication Date: 20260508
Application Date: 20260123

Claims (10)

1. The soil curing agent based on the synergistic mineralization and consolidation of biological enzymes is characterized by comprising the following components, by weight, 10-18 parts of a biological enzyme composite system, 60-82 parts of a mineralized base material, 5-10 parts of a multi-scale reinforcing system and 3-6 parts of an environment regulating agent; The biological enzyme composite system comprises 2.0-3.5 parts of urease, 1.0-2.0 parts of manganese peroxidase and 7.0-12.5 parts of biochar-montmorillonite composite carrier, wherein the mineralized base material comprises 30-40 parts of steel slag powder, 20-25 parts of acid-washed fly ash, 5-10 parts of phosphogypsum after ball milling treatment and 5-7 parts of modified nano hydroxyapatite, the multi-scale reinforcing system comprises 1.5-3.0 parts of modified nano calcium carbonate and 3.5-7.0 parts of modified straw fibers, and the environment regulator comprises 1.0-2.0 parts of sodium carbonate, 0.5-1.0 parts of citric acid and 1.5-3.0 parts of calcium chloride.
2. The soil conditioner based on synergistic mineralization consolidation of biological enzymes according to claim 1, wherein the biological enzyme complex system is prepared by the following process: S11, activating the biochar by adopting an H 2 O 2 solution to prepare activated biochar; s12, modifying montmorillonite by sulfuric acid solution to obtain modified montmorillonite; S13, mixing activated biochar and modified montmorillonite to prepare a biochar-montmorillonite composite carrier; S14, uniformly mixing urease and manganese peroxidase to prepare a compound enzyme solution; s15, adding the complex enzyme solution into a charcoal-montmorillonite composite carrier, and stirring and adsorbing to obtain a mixture; s16, spray drying the mixture to obtain the biological enzyme composite system.
3. The soil solidifying agent based on the synergistic mineralization and consolidation of biological enzymes according to claim 2, wherein the mass ratio of activated biological carbon to modified montmorillonite is (1.5-3.0) 1, the mass ratio of urease to manganese peroxidase is 2:1, and the mass ratio of biological carbon-montmorillonite composite carrier to composite enzyme liquid is 3:1.
4. The soil stabilizer based on the synergistic mineralization and consolidation of biological enzymes according to claim 2, wherein the mass fraction of the H 2 O 2 solution is 30%, the temperature of the activation treatment is 60 ℃, the time of the activation treatment is 2 hours, the pore diameter of the activated biological carbon is 50-200nm, the mass concentration of substances of the sulfuric acid solution is 0.5mol/L, the time of the modification treatment is 2 hours, the interlayer spacing of the modified montmorillonite is 1.5-2.0nm, the air inlet temperature of the spray drying is 120 ℃, the particle size of the biological enzyme composite system is 80-120 mu m, and the enzyme half life of the biological enzyme composite system is more than 60 days.
5. The soil conditioner based on synergistic mineralization consolidation of biological enzymes according to claim 1, wherein the mineralized substrate is prepared by the process of: s21, performing ball milling treatment after calcining treatment on the steel slag to obtain steel slag powder; S22, carrying out acid leaching treatment on the fly ash, and then sequentially filtering, washing and drying to obtain acid-washed fly ash; s23, uniformly mixing steel slag powder and acid-washed fly ash to prepare compound industrial waste residues; s24, performing ball milling treatment on phosphogypsum to obtain ball-milled phosphogypsum; S25, carrying out surface modification treatment on the nano-hydroxyapatite by adopting sodium citrate to obtain modified nano-hydroxyapatite; S26, uniformly mixing phosphogypsum after ball milling treatment and modified nano hydroxyapatite to prepare an auxiliary mineralizer; And S27, uniformly mixing the compound industrial waste residue and the auxiliary mineralizer to prepare the mineralized base material.
6. The soil curing agent based on the synergistic mineralization consolidation of biological enzymes, which is disclosed in claim 5, is characterized in that the mass ratio of steel slag powder to acid-washed fly ash is 3:2, the calcination treatment temperature is 800 ℃, the time is 2 hours, the specific surface area of the steel slag powder is 450-550m 2 /kg, the fly ash is class II fly ash, the acid solution adopted in the acid-washing treatment is hydrochloric acid solution, the mass concentration of the acid solution is 10%, the liquid-solid ratio of the fly ash to the acid solution is 5:1, the water washing is carried out until the pH is 7.5-8.0, the D 50 of phosphogypsum after the ball milling treatment is 15 mu m, the particle size of the modified nano-hydroxyapatite is 50-100nm, the sodium citrate dosage is 3% of the mass of the nano-hydroxyapatite, and the surface modification treatment time is 1 hour.
7. The soil conditioner based on synergistic mineralization consolidation of biological enzymes according to claim 1, wherein the multi-scale reinforcement system is made by the process of: S31, performing first modification treatment on nano calcium carbonate by using a modifier stearic acid to prepare modified nano calcium carbonate, wherein the modified nano calcium carbonate is used as a nano filling phase; S32, performing scouring treatment on the straw by adopting NaOH solution, filtering, washing to be neutral, drying and cutting to obtain straw fiber, performing second modification treatment on the straw fiber by adopting silane coupling agent to obtain modified straw fiber, and taking the modified straw fiber as a fiber reinforcement phase; s33, uniformly mixing the nano filling phase and the fiber reinforced phase to obtain the multi-scale reinforced system.
8. The soil solidifying agent based on the synergistic mineralization and solidification of biological enzymes, which is characterized in that the grain diameter of nano calcium carbonate is 20-50nm, the dosage of stearic acid of the modifier is 1.5% of the mass of nano calcium carbonate, the stirring speed of the first modification treatment is not lower than 1500r/min, and the stirring time is 30-60min; the mass concentration of the NaOH solution is 10%, the boiling-off treatment temperature is 80 ℃ for 2 hours, the length of the straw fiber is 8-12mm, the silane coupling agent is KH-560, the dosage of the silane coupling agent is 2% of the mass of the straw fiber, and the second modification treatment temperature is 60-80 ℃ for 1 hour.
9. The soil conditioner based on synergistic mineralization consolidation of biological enzymes according to claim 1, wherein the environmental conditioner is prepared by the following process: S41, compounding sodium carbonate and citric acid to prepare a pH buffer system; S42, uniformly mixing the pH buffer system and the enzymatic reagent to prepare an environment regulator; the pH value of the environment regulator is controlled to be 7.8-8.5, and the enzymatic reagent is calcium chloride.
10. The method for preparing the soil conditioner based on the synergistic mineralization consolidation of biological enzymes according to any one of claims 1 to 9, comprising the following steps: Mixing and stirring the mineralized base material and the multi-scale reinforcing system, adding the biological enzyme composite system, continuously stirring, adding the environment regulator, and uniformly stirring to obtain the soil curing agent based on the synergistic mineralization and consolidation of the biological enzymes.

Description

Soil solidifying agent based on biological enzyme synergistic mineralization consolidation and preparation method thereof Technical Field The invention belongs to the technical field of soil solidifying agents, and particularly relates to a soil solidifying agent based on biological enzyme synergistic mineralization consolidation and a preparation method thereof. Background In the field of soil solidification and polluted soil restoration, the traditional solidification technology mainly relies on inorganic cementing materials such as cement, lime and the like as a curing agent, and calcium silicate (C-S-H) gel or calcium carbonate crystals are generated through hydration reaction of the inorganic cementing materials to strengthen the structural strength of a soil body. In recent years, along with the promotion of recycling of industrial waste residues, materials rich in active silicon-aluminum components such as steel slag, fly ash and the like are widely used for replacing part of traditional gel components so as to improve the solidification effect and realize recycling of solid wastes. In addition, in order to promote the mineralization reaction process, part of the technical proposal introduces chemical excitants (such as alkaline activators or sulfates) to accelerate the dissolution of the silicon aluminum phase and the precipitation of the product. Meanwhile, aiming at the treatment of heavy metal contaminated soil, a mode of adding a stabilizing agent (such as phosphogypsum, hydroxyapatite and the like) is adopted, and the immobilization of heavy metal is realized through an ion exchange, coprecipitation or surface adsorption mechanism. The existing soil solidification technology is mostly dependent on traditional cementing materials such as cement, lime and the like, and has the problems of high carbon emission, limited heavy metal stabilization effect, easy cracking of solidified bodies and the like. Biological enzymes are used as green catalytic materials, have potential in soil improvement, but the single biological enzyme has low action efficiency and is difficult to form a stable mineralized structure, and the mineralization consolidation technology is often dependent on chemical excitants, so that secondary pollution is easy to cause. However, the mineralization process based on chemical excitation in the prior art generally has the problems of difficult reaction rate regulation and slow early strength development, and the strong alkaline environment is easy to cause enzyme inactivation, so that the application of a biocatalysis means is limited, and meanwhile, the use of a chemical excitant possibly causes secondary pollution risks, and potential ecological hazards exist in the groundwater environment in particular. In addition, the traditional curing system has poor adaptability to multi-source complex polluted soil, and is difficult to synchronously realize the aim of improving high-efficiency chemical performance and stabilizing heavy metals, and the traditional curing system still faces challenges in constructing a stable mineralized structure under low-energy consumption and environment-friendly conditions. At present, a soil solidification technical scheme capable of cooperatively driving enzymatic reaction and mineral crystallization under a mild pH condition and fusing a multi-scale enhancement mechanism to consider both structural compactness and durability is not available. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide a soil curing agent based on the synergistic mineralization and consolidation of biological enzymes and a preparation method thereof, and a 'enzymatic reaction-mineralization crystallization-structure enhancement' integrated system is constructed through the synergistic effect of biological enzymes and mineralization materials, so that the unification of efficient soil curing and environmental friendliness is realized, and the technical problems of synchronous implementation of efficient soil curing and stabilization of heavy metal pollutants on the premise of avoiding using a strong excitant are solved, and meanwhile, the early strength, the impervious performance and the environmental friendliness of a cured body are improved. In order to achieve the above purpose, the invention is realized by adopting the following technical scheme: The invention provides a soil curing agent based on synergistic mineralization and consolidation of biological enzymes, which comprises the following components, by weight, 10-18 parts of a biological enzyme composite system, 60-82 parts of a mineralized base material, 5-10 parts of a multi-scale enhancement system and 3-6 parts of an environment regulating agent; The biological enzyme composite system comprises 2.0-3.5 parts of urease, 1.0-2.0 parts of manganese peroxidase and 7.0-12.5 parts of biochar-montmorillonite composite carrier, wherein the mineralized base material co