CN-121975530-A - Doped hydroxyapatite-based heavy metal mineralized material, and preparation method and application thereof

CN121975530ACN 121975530 ACN121975530 ACN 121975530ACN-121975530-A

Abstract

The invention discloses a doped hydroxyapatite-based heavy metal mineralized material, and a preparation method and application thereof, and belongs to the technical field of heavy metal contaminated soil restoration. In an alkaline environment with pH of 8-11, the mixed mineralized precursor, hydrophilic monomers and phosphate are subjected to in-situ polymerization and synchronous mineralization reaction under the action of a cross-linking agent and an initiator, fe-Mn co-doped hydroxyapatite and ferro-manganese oxide/hydroxide nanoclusters are induced to generate a flexible interpenetrating network, the doped hydroxyapatite-based heavy metal mineralized material is obtained through granulation, aging maintenance, washing and drying, and the anion and cation heavy metals are synchronously and deeply locked through an oxidation-reduction system and a lattice isomorphous substitution mechanism, so that the high water absorption component is utilized to self-heal soil cracks and slowly release active groups, and the long-acting repair performance of the material under the environment of acid erosion and physical structure damage is remarkably improved.

Inventors

NAN XIAOLONG
HE YOUYU
LI SHENGMIAO
Qiu Cuiyun
ZHU CHENGSHENG
Fan Renwu
XU RUI

Assignees

湖南省地质地理信息所(湖南省地质大数据中心)

Dates

Publication Date: 20260505
Application Date: 20260127

Claims (10)

1. The doped hydroxyapatite-based heavy metal mineralized material is characterized in that mixed mineralized precursors, hydrophilic monomers and phosphate are subjected to in-situ polymerization and synchronous mineralization reaction under the action of a cross-linking agent and an initiator in an alkaline environment with the pH value of 8-11, fe-Mn co-doped hydroxyapatite and ferro-manganese oxide/hydroxide nanoclusters are induced to generate a flexible interpenetrating network, and the flexible interpenetrating network is obtained through granulation, aging and maintenance; The mixed mineralized precursor is obtained by mixing a dispersed framework material, a biomass matrix and a humic acid source to form modified matrix slurry, and intercalating Ca 2+ source, fe 2+ source and Mn 2+ source in the interlayer domain of the dispersed framework material in the modified matrix slurry and loading the interlayer domain on the surface of the biomass matrix; the dispersion framework material is sodium montmorillonite, calcium montmorillonite, illite or vermiculite.
2. A doped hydroxyapatite based heavy metal mineralizing material according to claim 1, wherein the molar ratio of the Ca 2+ source, the Fe 2+ source and the Mn 2+ source is 3-8:1:1.
3. The doped hydroxyapatite-based heavy metal mineralization material according to claim 1, wherein the mass ratio of the biomass matrix to the dispersed framework material is 0.5-2:1, and the mass ratio of the total molar amount of the Ca 2+ source, the Fe 2+ source and the Mn 2+ source to the dispersed framework material is 10-30 mmol:1g.
4. A doped hydroxyapatite based heavy metal mineralizing material according to claim 1, wherein the molar ratio of the sum of the molar amounts of the Ca 2+ source, the Fe 2+ source and the Mn 2+ source to PO 4 3- in the phosphate is 1.5-8:1.
5. A doped hydroxyapatite-based heavy metal mineralized material according to claim 1, characterized in that the biomass matrix is soluble starch, sodium carboxymethyl cellulose or sodium alginate, and the humic acid source is sodium humate, fulvic acid or peat soil extract.
6. A doped hydroxyapatite-based heavy metal mineralized material according to claim 1, wherein the hydrophilic monomer is acrylic acid, acrylamide or 2-acrylamide-2-methylpropanesulfonic acid, and the mass of the hydrophilic monomer is 30% -60% of the total mass of solid phase in the mixed mineralized precursor liquid.
7. The method for preparing a doped hydroxyapatite-based heavy metal mineralized material according to any one of claims 1to 6, characterized by comprising the following steps: Mixing a dispersed framework material, a biomass matrix and a humic acid source to form modified matrix slurry, and intercalating Ca 2+ source, fe 2+ source and Mn 2+ source in the interlayer domain of the dispersed framework material in the modified matrix slurry, and loading the interlayer domain on the surface of the biomass matrix to obtain a mixed mineralized precursor; under the protection of inert gas and in an alkaline environment with pH value of 8-11, carrying out in-situ polymerization and synchronous mineralization reaction on the mixed mineralization precursor liquid, hydrophilic monomers and phosphate under the action of a cross-linking agent and an initiator to form Fe-Mn co-doped hydroxyapatite and ferro-manganese oxide/hydroxide nanoclusters, thereby obtaining an interpenetrating network gel product; granulating, aging and curing, washing and drying at low temperature the interpenetrating network gel product to obtain the doped hydroxyapatite-based heavy metal mineralized material.
8. The method for preparing a doped hydroxyapatite-based heavy metal mineralized material according to claim 7, wherein the in-situ polymerization and synchronous mineralization reaction is carried out at a temperature of 300-600 r/min and a temperature of 50-80 ℃ for 2-5 h. The granulation is performed by mechanical cutting or extrusion, the aging curing condition is that the aging curing is performed under the sealing condition of 20-40 ℃ for 12-36 hours, and the low-temperature drying condition is that the aging curing is performed under the sealing condition of 50-80 ℃.
9. The application of the doped hydroxyapatite-based heavy metal mineralization material in repairing heavy metal and/or heavy metal-like polluted soil, which is characterized in that the doped hydroxyapatite-based heavy metal mineralization material is added into the heavy metal and/or heavy metal-like polluted soil for repairing, and the heavy metal-like comprise Cd, pb, cu, zn, as, cr or Ni.
10. The application of the doped hydroxyapatite-based heavy metal mineralization material in repairing heavy metal and/or heavy metal-like polluted soil according to claim 9, wherein the addition amount of the doped hydroxyapatite-based heavy metal mineralization material is 0.5% -3% of the soil mass, the moisture content of the heavy metal and/or heavy metal-like polluted soil is 25% -60%, and the repairing time is 15 d-60 d.

Description

Doped hydroxyapatite-based heavy metal mineralized material, and preparation method and application thereof Technical Field The invention belongs to the technical field of heavy metal contaminated soil remediation. In particular to a doped hydroxyapatite-based heavy metal mineralized material, a preparation method and application thereof. Background With the acceleration of industrialization and urbanization, soil heavy metal pollution has become a focus of environmental problems. Particularly, due to the complex pollution input sources of urban greening lands, industrial legacy sites and surrounding areas, the urban greening system often has the characteristic of complex pollution of various heavy (metal-like) anions and cations. The pollutants have the characteristics of strong concealment, lasting toxicity and easy migration and diffusion through water and soil loss, and seriously threaten ecological safety and living environment. Therefore, developing a repair material capable of synchronously and efficiently fixing various complex-form heavy metals is a technical difficulty to be overcome in the current soil repair field. In situ chemical stabilization techniques are widely used because of their economical efficiency. At present, lime, fly ash, phosphate, metal oxide and biochar materials are widely applied to in-situ chemical stabilization restoration of soil, but when the composite heavy metal (namely, coexistence of cations and anions) pollution is treated, the prior art faces a remarkable chemical antagonism bottleneck, wherein the traditional restoration materials generally depend on adding alkaline matrixes to raise the pH value of the soil to induce Cd and Pb cations to form hydroxide or carbonate precipitates so As to realize solidification, however, the improvement of the pH value can lead to the great increase of the negative charge density of the surface of the soil colloid, thereby remarkably enhancing the electrostatic repulsive effect of the alkaline matrixes and As and Cr oxyacid anions, causing activation migration of the anion pollutants and leading to rapid rising of leaching risks. Although iron/manganese (hydro) oxides have a specific adsorption affinity for anions, in a purely physical mixed mode, the active sites are very easily occupied by competition of a large amount of coexisting ions in soil, and the active sites are mainly dependent on reversible surface adsorption, so that the long-term stability is insufficient, and secondary release is very easy to occur. In addition, when the existing stabilizing material is applied to repairing heavy metal pollution of soil, the existing stabilizing material has obvious short plates in the aspects of coping with complex environmental erosion and physical structure damage. In the natural environment, soil dry-wet alternation and freeze thawing circulation can crack the soil macrostructure and break microscopic aggregates, while the existing phosphate and clay mineral composite material lacks ductility and cannot adapt to the volume expansion and contraction change of the soil, so that the wrapped pollutants are re-exposed in an environmental medium and long-term restoration cannot be realized. More importantly, the existing phosphate and clay mineral composite repair materials are mostly limited to simple physical mixing or surface loading. The composite mode has the technical bottlenecks that phosphate crystals are only adsorbed on the surface of clay, are easy to fall off and have poor stability, and the interlayer domain of the clay is limited and cannot contain macromolecular pollutants, so that the repair effect is poor. Disclosure of Invention The invention provides a doped hydroxyapatite-based heavy metal ultrastable mineralized material with anti-crack and slow-release functions aiming at the technical problems of poor stability, electrostatic mutual exclusion of anions and cations, weak acid rain erosion resistance, failure caused by soil crack damage and lack of a long-acting repair mechanism of the conventional repair material, and the invention realizes long-acting and green repair of heavy metal contaminated soil. In order to achieve the above object, the technical scheme of the present invention is as follows. The first object of the invention is to provide a doped hydroxyapatite-based heavy metal mineralized material, which is obtained by carrying out in-situ polymerization and synchronous mineralization reaction on a mixed mineralized precursor, a hydrophilic monomer and phosphate under the action of a cross-linking agent and an initiator in an alkaline environment with pH value of 8-11, and inducing Fe-Mn co-doped hydroxyapatite and ferro-manganese oxide/hydroxide nanoclusters to construct a flexible interpenetrating network. The mixed mineralized precursor is obtained by mixing a dispersed framework material, a biomass matrix and a humic acid source to form modified matrix slurry, and intercalating Ca 2+ source, fe 2+ s