A heavy metal capture agent for treating pickling waste liquid and preparation method thereof

Abstract

The present invention provides a kind of heavy metal capture agent and preparation method for treating pickling waste liquid, the preparation method of the heavy metal capture agent for treating pickling waste liquid, comprising the steps: taking ferrosoferric oxide microparticles, adding silane coupling agent, azobisisobutyronitrile, obtaining ferrosoferric oxide microparticles loaded with azobisisobutyronitrile;It is mixed with 2-vinylnaphthalene monomer, allyl pyrrolidine dithiocarbamate monomer, 2,4-pentadienoic acid monomer, reacted, and obtained core-shell structure microparticles;The core-shell structure microparticles obtained, add trimethylolpropane-3-mercaptopropionic acid ester, click chemistry reaction, obtain the heavy metal capture agent for treating pickling waste liquid. The heavy metal capture agent obtained by the present invention, after mixing with waste liquid, does not need to be precipitated, and the magnetic property that it has itself can be used to realize separation with waste liquid, good stability under acidic conditions, and good capture effect is had to heavy metal ions, and heavy metals in pickling waste liquid can be effectively removed.

Description

Technical Field

[0001] The invention relates to the field of materials, and in particular to a heavy metal capture agent for treating pickling waste liquid and a preparation method thereof. Background Art

[0002] During the pickling and purification process of non-metallic material powders, a large amount of acidic wastewater, i.e., pickling waste liquid, is generated. In the prior art, resin is often used to treat the pickling waste liquid to achieve the reuse of the pickling waste liquid. However, these pickling waste liquids often contain a variety of heavy metals, and the heavy metals have a high content, a variety of types, and complex forms and valence states. Directly using resin for treatment will cause the resin to be saturated quickly, and the resin needs to be constantly replaced, resulting in increased costs. Therefore, using a heavy metal scavenger to pre-treat the pickling waste liquid before resin treatment can greatly reduce costs and processing efficiency.

[0003] Heavy metal scavengers can be divided into water-soluble polymer heavy metal scavengers and water-insoluble polymer heavy metal scavengers. Water-soluble polymer heavy metal scavengers have hydrophilic chelating groups on the polymer matrix, which can selectively react with heavy metal ions in water to form water-insoluble heavy metal complexes that precipitate and precipitate. Water-insoluble polymer heavy metal scavengers graft heavy metal scavenging groups onto natural or synthetic polymers.

[0004] In order to improve the pickling effect, surfactants are usually added to the pickling liquid. Therefore, the pickling waste liquid also contains a large amount of surfactants. The presence of surfactants will prevent the aggregation of precipitation particles, making it difficult for water-soluble polymer heavy metal scavengers to combine with heavy metal ions to form precipitation. In addition, the presence of surfactants also makes the existence form of heavy metals in the waste liquid more complicated. Some heavy metal ions may be encapsulated in the micelles formed by the surfactant, resulting in poor treatment effect of heavy metal scavengers for such waste liquids. Summary of the invention

[0005] The object of the present invention is to provide a heavy metal scavenger for treating pickling waste liquid, so as to solve the problem that the heavy metal scavenger in the prior art has poor treatment effect on pickling waste liquid of pickling purification of non-metallic material powder.

[0006] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0007] A method for preparing a heavy metal scavenger for treating pickling wastewater comprises the following steps:

[0008] S1, taking ferroferric oxide particles, adding a silane coupling agent and azobisisobutyronitrile to obtain ferroferric oxide particles loaded with azobisisobutyronitrile;

[0009] S2, mixing the ferrosoferric oxide particles loaded with azobisisobutyronitrile obtained in step S1 with 2-vinylnaphthalene monomer, allyl pyrrolidine dithiocarbamate monomer, and 2,4-pentadienoic acid monomer, and performing a polymerization reaction to coat the surface of the ferrosoferric oxide particles with the polymer, thereby obtaining core-shell structure particles;

[0010] S3. Take the core-shell structured particles obtained in step S2, add trimethylolpropane-3-mercaptopropionate, mix well, and perform click chemistry reaction to obtain a heavy metal capture agent for treating pickling waste liquid.

[0011] Specifically, the preparation method of the heavy metal capture agent for treating pickling waste liquid comprises the following steps:

[0012] S1, taking ferroferric oxide particles, adding a silane coupling agent and azobisisobutyronitrile to obtain ferroferric oxide particles loaded with azobisisobutyronitrile;

[0013] S2, dispersing the ferroferric oxide microparticles loaded with azobisisobutyronitrile obtained in step S1 in a toluene solvent, and then dropping a toluene solution of 2-vinylnaphthalene monomer therein, and reacting at 60-80° C. for 3-5 hours to obtain a prepolymer; then, taking allyl pyrrolidine dithiocarbamate monomer, 2,4-pentadienoic acid monomer and alkyl glycoside solution and mixing them evenly, adding them to the prepolymer, and then adding azobisisobutyronitrile therein, stirring and reacting at 60-80° C. for 12-24 hours under the protection of inert gas, so that the polymer is coated on the surface of the ferroferric oxide microparticles, and performing magnetic separation, washing, and drying to obtain core-shell structure microparticles;

[0014] S3. Take the core-shell structured particles obtained in step S2, add trimethylolpropane-3-mercaptopropionate, mix well, and perform click chemistry reaction to obtain a heavy metal capture agent for treating pickling waste liquid.

[0015] Preferably, in step S1, the ferrosoferric oxide particles are obtained by the following method:

[0016] Ferrous chloride and ferric chloride are dissolved in water at a molar ratio of 1:(2.0-2.5) to make the concentration of ferrous chloride in water be 1.5-2.2 mol / L. Under the protection of inert gas, 4-6 mol / L sodium hydroxide solution is added dropwise to the water until the pH value is 10-12. The reaction is stirred at 50-70°C for 1-2h. The precipitate is separated by magnetic separation, washed with water, and dried to obtain the ferrosoferric oxide particles.

[0017] Preferably, step S1 specifically comprises: taking the ferrosoferric oxide particles, adding ethanol, adding the silane coupling agent and the azobisisobutyronitrile under the protection of an inert gas, and stirring the reaction at 30-40° C. for 3-5 hours, magnetically separating and precipitating, and vacuum drying at 30-40° C. for 10-30 minutes to obtain ferrosoferric oxide particles loaded with azobisisobutyronitrile.

[0018] Preferably, in step S1, the mass ratio of the ferrosoferric oxide particles, the silane coupling agent, and the azobisisobutyronitrile is 1: (0.10-0.15): (0.15-0.20);

[0019] Optionally, the concentration of the ferrosoferric oxide in the ethanol is 5-8 mg / ml;

[0020] Optionally, the silane coupling agent is γ-aminopropyltrimethoxysilane.

[0021] Preferably, in step S2, the alkyl glycoside is one of decyl alkyl glucoside and octyl alkyl glucoside.

[0022] Preferably, in step S2, the concentration of the ferrosoferric oxide particles loaded with azobisisobutyronitrile in the toluene is 10-14 mg / ml;

[0023] Optionally, in the toluene solution of the 2-vinylnaphthalene monomer, the concentration of the 2-vinylnaphthalene monomer is 5-10 mg / ml;

[0024] Optionally, the mass ratio of the ferrosoferric oxide particles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, allyl pyrrolidinedithiocarbamate monomer, 2,4-pentadienoic acid monomer, azobisisobutyronitrile, and alkyl glycoside solution is 1: (1.0-3.6): (4.0-6.5): (7.0-9.2): (0.05-0.08): (0.2-0.8);

[0025] Optionally, in the alkyl glycoside solution, the concentration of alkyl glycoside is 0.03-0.09 mol / L.

[0026] Preferably, step S3 specifically comprises: taking the core-shell structured particles obtained in step S2, adding methanol and trimethylolpropane-3-mercaptopropionate, and then adding azobisisobutyronitrile thereto, mixing evenly, stirring and reacting at 50-70° C. for 8-16 hours to obtain a heavy metal capture agent for treating pickling waste liquid.

[0027] Preferably, in step S3, the concentration of the core-shell structured particles in the methanol is 5-10 mg / ml;

[0028] Optionally, the mass ratio of the core-shell structured particles, trimethylolpropane-3-mercaptopropionate, and azobisisobutyronitrile is 1:(1.2-1.8):(0.01-0.03).

[0029] The present invention also provides a heavy metal capture agent for treating pickling waste liquid, which is obtained by the preparation method of the heavy metal capture agent for treating pickling waste liquid.

[0030] The above solution of the present invention includes at least the following beneficial effects:

[0031] (1) The preparation method of a heavy metal scavenger for treating pickling waste liquid of the present invention comprises the following steps: taking ferroferric oxide microparticles, adding a silane coupling agent and azobisisobutyronitrile to obtain ferroferric oxide microparticles loaded with azobisisobutyronitrile; mixing the obtained ferroferric oxide microparticles loaded with azobisisobutyronitrile with 2-vinylnaphthalene monomer, allyl pyrrolidine dithiocarbamate monomer and 2,4-pentadienoic acid monomer, and performing a polymerization reaction to coat the polymer on the surface of the ferroferric oxide microparticles to obtain core-shell structure microparticles; taking the obtained core-shell structure microparticles, adding trimethylolpropane-3-mercaptopropionate, mixing evenly, and performing a click chemistry reaction to obtain a heavy metal scavenger for treating pickling waste liquid. The preparation method of the heavy metal scavenger for treating pickling waste liquid described in the present invention can separate the heavy metal scavenger from the waste liquid without sedimentation after mixing with the waste liquid by utilizing its own magnetism, has good stability under acidic conditions, and has a good capture effect on heavy metal ions such as Cu, Zn, Pb, Ni, Cd, etc., and can effectively remove heavy metals in the pickling waste liquid of non-metallic material powder.

[0032] Specifically, by using the hydroxyl groups on the surface of the ferroferric oxide particles as active sites, combined with the effect of the silane coupling agent, the azobisisobutyronitrile can be effectively adsorbed, so that it is loaded on the surface of the ferroferric oxide particles. After the monomer is added, the monomer is initiated to undergo polymerization reaction on the surface of the ferroferric oxide particles to form core-shell structure particles. Among the three monomers involved in the polymerization reaction, the polymer chain formed after the double bond of the 2-vinylnaphthalene monomer is opened has good hydrophobicity and chemical inertness, and grows in situ on the surface of the particles to avoid the dissolution of ferroferric oxide in an acidic environment; the structural unit of the dithiocarbamic acid of the pyrrolidine dithiocarbamate allyl ester monomer is a multidentate ligand with strong coordination ability, which can achieve good heavy metal capture. The pyrrolidine group as a rigid structure can provide a certain steric hindrance for the polymer, prevent excessive aggregation between polymer chains, increase the chance of contact with heavy metal ions, and improve the ability to capture heavy metal ions. The 2,4-pentadienoic acid monomer can introduce a hydrophilic group carboxyl group to make the polymer more hydrophilic, which is conducive to full contact with heavy metal ions in the water phase when treating waste liquid. At the same time, the 2,4-pentadienoic acid monomer can add a certain length of flexible chain segment to the polymer to make the chain structure of the polymer more diverse, thereby providing a variety of different coordination environments and binding sites to capture heavy metal ions, thereby increasing the chance of contact with heavy metal ions encapsulated in micelles formed by surfactants, and through the entanglement and adsorption of flexible molecular chains, the micelle structure is destroyed, thereby releasing the encapsulated heavy metal ions, and achieving the capture of heavy metal ions.

[0033] In addition, after the polymerization reaction of the 2,4-pentadienoic acid monomer, the unreacted double bonds can be introduced into the flexible chain through the "alkenyl-thiol" click chemistry reaction after the addition of trimethylolpropane-3-mercaptopropionate, thereby forming a more stable and effective multi-dentate coordination structure.

[0034] (2) The preparation method of the heavy metal scavenger for treating pickling wastewater of the present invention, in step S2, first add the 2-vinylnaphthalene monomer to carry out polymerization reaction to obtain a prepolymer, and then add the pyrrolidine dithiocarbamate allyl ester monomer and 2,4-pentadienoic acid monomer to carry out polymerization reaction. The 2-vinylnaphthalene monomer forms a hydrophobic layer on the surface of the ferroferric oxide microparticles loaded with azobisisobutyronitrile, so that the area close to the ferroferric oxide microparticles presents a strong hydrophobicity to protect the ferroferric oxide from being damaged by the acidic environment. In the outer layer of the prepolymer, the incompletely reacted 2-vinylnaphthalene monomer is polymerized with the pyrrolidine dithiocarbamate allyl ester monomer and 2,4-pentadienoic acid monomer to form a functional layer with good hydrophilicity and heavy metal capture ability, and a thiol group is introduced at the active end of the 2,4-pentadienoic acid monomer to achieve a good heavy metal capture effect.

[0035] (3) In the preparation method of the heavy metal scavenger for treating pickling wastewater of the present invention, the alkyl glycoside is also added in step S2. The alkyl glycoside has good water solubility, can effectively reduce the interfacial tension, ensure the full contact between each monomer and the prepolymer, and reduce the peeling of the polymer during the process of coating the microparticles. More importantly, the alkyl glycoside has a regular structure and small steric hindrance, which can effectively regulate the polymerization process and affect the microstructure of the polymer, making the polymer more inclined to stretch in the solution, which is conducive to the heavy metal capture group to be better stretched on the outside of the polymer chain to achieve the capture of heavy metal ions. DETAILED DESCRIPTION

[0036] In the embodiments of the present invention, if the specific conditions are not specified, the conventional conditions or the conditions recommended by the manufacturer are followed. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially. Raw materials of different manufacturers and models do not affect the implementation of the technical solution of the present invention and the realization of the technical effects.

[0037] In the present invention, the CAS number of the azobisisobutyronitrile is 78-67-1, referred to as AIBN; the CAS number of the 2-vinylnaphthalene monomer is 827-54-3; the CAS number of the allyl pyrrolidine dithiocarbamate monomer is 701-13-3; and the CAS number of the 2,4-pentadienoic acid monomer is 21651-12-7.

[0038] Example 1

[0039] The preparation method of the heavy metal capture agent for treating pickling waste liquid of this embodiment comprises the following steps:

[0040] S1. Take the ferroferric oxide particles, add ethanol, add silane coupling agent and azobisisobutyronitrile under the protection of inert gas, and stir the reaction at 30° C. for 4 h, separate the precipitate by magnetic separation, and vacuum dry at 30° C. for 20 min to obtain ferroferric oxide particles loaded with azobisisobutyronitrile.

[0041] The mass ratio of the ferroferric oxide particles, the silane coupling agent, and the azobisisobutyronitrile is 1:0.10:0.18; the concentration of the ferroferric oxide in the ethanol is 5 mg / ml; and the silane coupling agent is γ-aminopropyltrimethoxysilane.

[0042] The ferroferric oxide particles are obtained by the following method: ferrous chloride and ferric chloride are dissolved in water at a molar ratio of 1:2.2, so that the concentration of ferrous chloride in water is 2.2 mol / L, 5 mol / L sodium hydroxide solution is added dropwise thereto under the protection of inert gas until the pH value is 10, the reaction is stirred at 60°C for 1 hour, magnetic separation precipitation is performed, washing with water, and drying to obtain the ferroferric oxide particles.

[0043] S2, dispersing the azobisisobutyronitrile-loaded ferrosoferric oxide microparticles obtained in step S1 in a toluene solvent, and then dripping a toluene solution of 2-vinylnaphthalene monomer therein, and reacting at 70° C. for 3 hours to obtain a prepolymer;

[0044] Allyl pyrrolidine dithiocarbamate monomer, 2,4-pentadienoic acid monomer and alkyl glycoside solution were mixed evenly, added to the prepolymer, and then azobisisobutyronitrile was added thereto. Under the protection of inert gas, the reaction was stirred at 70° C. for 12 hours to coat the surface of the ferrosoferric oxide particles with the polymer. After magnetic separation, washing and drying, core-shell structure particles were obtained.

[0045] Wherein, the alkyl glycoside is decyl alkyl glucoside. The concentration of the ferroferric oxide microparticles loaded with azobisisobutyronitrile in the toluene is 10 mg / ml; in the toluene solution of the 2-vinylnaphthalene monomer, the concentration of the 2-vinylnaphthalene monomer is 5 mg / ml; the mass ratio of the ferroferric oxide microparticles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, pyrrolidine dithiocarbamate allyl ester monomer, 2,4-pentadienoic acid monomer, azobisisobutyronitrile, and alkyl glycoside solution is 1:2.2:4.0:9.2:0.05:0.5; in the alkyl glycoside solution, the concentration of the alkyl glycoside is 0.03 mol / L.

[0046] S3. Take the core-shell structured particles obtained in step S2, add methanol and trimethylolpropane-3-mercaptopropionate, and then add azobisisobutyronitrile thereto, mix well, and stir the reaction at 60° C. for 16 hours to obtain a heavy metal capture agent for treating pickling waste liquid.

[0047] The concentration of the core-shell structured particles in the methanol is 6 mg / ml; the mass ratio of the core-shell structured particles, trimethylolpropane-3-mercaptopropionate, and azobisisobutyronitrile is 1:1.2:0.02.

[0048] Example 2

[0049] The preparation method of the heavy metal capture agent for treating pickling waste liquid of this embodiment comprises the following steps:

[0050] S1. Take the ferrosoferric oxide particles, add ethanol, add silane coupling agent and azobisisobutyronitrile under the protection of inert gas, and stir the reaction at 40° C. for 5 h, separate the precipitate by magnetic separation, and vacuum dry at 35° C. for 30 min to obtain ferrosoferric oxide particles loaded with azobisisobutyronitrile.

[0051] The mass ratio of the ferroferric oxide particles, the silane coupling agent and the azobisisobutyronitrile is 1:0.15:0.20; the concentration of the ferroferric oxide in the ethanol is 8 mg / ml; and the silane coupling agent is γ-aminopropyltrimethoxysilane.

[0052] The ferroferric oxide particles are obtained by the following method: ferrous chloride and ferric chloride are dissolved in water at a molar ratio of 1:2.5, so that the concentration of the ferrous chloride in the water is 1.5 mol / L, 6 mol / L sodium hydroxide solution is added dropwise thereto under the protection of an inert gas until the pH value is 12, the reaction is stirred at 70°C for 2 hours, the precipitate is separated by magnetic separation, washed with water, and dried to obtain the ferroferric oxide particles.

[0053] S2, dispersing the azobisisobutyronitrile-loaded ferrosoferric oxide microparticles obtained in step S1 in a toluene solvent, and then dripping a toluene solution of 2-vinylnaphthalene monomer therein, and reacting at 80° C. for 5 hours to obtain a prepolymer;

[0054] Allyl pyrrolidine dithiocarbamate monomer, 2,4-pentadienoic acid monomer and alkyl glycoside solution were mixed evenly, added to the prepolymer, and then azobisisobutyronitrile was added thereto. Under the protection of inert gas, the mixture was stirred and reacted at 80° C. for 18 hours to coat the surface of the ferrosoferric oxide particles with the polymer. After magnetic separation, washing and drying, core-shell structure particles were obtained.

[0055] Wherein, the alkyl glycoside is octyl alkyl glucoside. The concentration of the ferroferric oxide microparticles loaded with azobisisobutyronitrile in the toluene is 12 mg / ml; in the toluene solution of the 2-vinylnaphthalene monomer, the concentration of the 2-vinylnaphthalene monomer is 10 mg / ml; the mass ratio of the ferroferric oxide microparticles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, pyrrolidine dithiocarbamate allyl ester monomer, 2,4-pentadienoic acid monomer, azobisisobutyronitrile, and alkyl glycoside solution is 1:3.6:6.5:7.0:0.08:0.8; in the alkyl glycoside solution, the concentration of the alkyl glycoside is 0.09 mol / L.

[0056] S3. Take the core-shell structured particles obtained in step S2, add methanol and trimethylolpropane-3-mercaptopropionate, and then add azobisisobutyronitrile thereto, mix well, and stir the mixture at 70° C. for 8 hours to obtain a heavy metal capture agent for treating pickling wastewater.

[0057] The concentration of the core-shell structured particles in the methanol is 10 mg / ml; the mass ratio of the core-shell structured particles, trimethylolpropane-3-mercaptopropionate, and azobisisobutyronitrile is 1:1.8:0.03.

[0058] Example 3

[0059] The preparation method of the heavy metal capture agent for treating pickling waste liquid of this embodiment comprises the following steps:

[0060] S1. Take the ferroferric oxide particles, add ethanol, add silane coupling agent and azobisisobutyronitrile under the protection of inert gas, and stir the reaction at 35° C. for 3 h, separate the precipitate by magnetic separation, and vacuum dry at 40° C. for 10 min to obtain ferroferric oxide particles loaded with azobisisobutyronitrile.

[0061] The mass ratio of the ferroferric oxide particles, the silane coupling agent, and the azobisisobutyronitrile is 1:0.12:0.15; the concentration of the ferroferric oxide in the ethanol is 6 mg / ml; and the silane coupling agent is γ-aminopropyltrimethoxysilane.

[0062] The ferroferric oxide particles are obtained by the following method: ferrous chloride and ferric chloride are dissolved in water at a molar ratio of 1:2.0, so that the concentration of the ferrous chloride in the water is 2.0 mol / L, 4 mol / L sodium hydroxide solution is added dropwise thereto under the protection of an inert gas until the pH value is 11, the reaction is stirred at 50° C. for 1.5 hours, a magnetic separation precipitate is performed, the precipitate is washed with water, and the ferroferric oxide particles are obtained.

[0063] S2, dispersing the azobisisobutyronitrile-loaded ferrosoferric oxide microparticles obtained in step S1 in a toluene solvent, and then dripping a toluene solution of 2-vinylnaphthalene monomer therein, and reacting at 60° C. for 4 hours to obtain a prepolymer;

[0064] Allyl pyrrolidine dithiocarbamate monomer, 2,4-pentadienoic acid monomer and alkyl glycoside solution were mixed evenly, added to the prepolymer, and then azobisisobutyronitrile was added thereto. Under the protection of inert gas, the reaction was stirred at 60° C. for 24 hours to coat the polymer on the surface of the ferrosoferric oxide particles. After magnetic separation, washing and drying, core-shell structure particles were obtained.

[0065] Wherein, the alkyl glycoside is decyl alkyl glucoside. The concentration of the ferroferric oxide microparticles loaded with azobisisobutyronitrile in the toluene is 14 mg / ml; in the toluene solution of the 2-vinylnaphthalene monomer, the concentration of the 2-vinylnaphthalene monomer is 8 mg / ml; the mass ratio of the ferroferric oxide microparticles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, pyrrolidine dithiocarbamate allyl ester monomer, 2,4-pentadienoic acid monomer, azobisisobutyronitrile, and alkyl glycoside solution is 1:1.0:5.0:8.2:0.06:0.2; in the alkyl glycoside solution, the concentration of the alkyl glycoside is 0.05 mol / L.

[0066] S3. Take the core-shell structured particles obtained in step S2, add methanol and trimethylolpropane-3-mercaptopropionate, and then add azobisisobutyronitrile thereto, mix well, and stir the reaction at 50° C. for 12 hours to obtain a heavy metal capture agent for treating pickling waste liquid.

[0067] The concentration of the core-shell structured particles in the methanol is 5 mg / ml; the mass ratio of the core-shell structured particles, trimethylolpropane-3-mercaptopropionate, and azobisisobutyronitrile is 1:1.5:0.01.

[0068] Example 4

[0069] The preparation method of the heavy metal capture agent for treating pickling waste liquid of this embodiment comprises the following steps:

[0070] S1. Take the ferroferric oxide particles, add ethanol, add silane coupling agent and azobisisobutyronitrile under the protection of inert gas, and stir the reaction at 30° C. for 3 h, separate the precipitate by magnetic separation, and vacuum dry at 30° C. for 30 min to obtain ferroferric oxide particles loaded with azobisisobutyronitrile.

[0071] The mass ratio of the ferroferric oxide particles, the silane coupling agent and the azobisisobutyronitrile is 1:0.14:0.16; the concentration of the ferroferric oxide in the ethanol is 7 mg / ml; and the silane coupling agent is γ-aminopropyltrimethoxysilane.

[0072] The ferroferric oxide particles are obtained by the following method: ferrous chloride and ferric chloride are dissolved in water at a molar ratio of 1:2.4, so that the concentration of ferrous chloride in water is 1.8 mol / L, 6 mol / L sodium hydroxide solution is added dropwise thereto under the protection of inert gas until the pH is 10, the reaction is stirred at 70°C for 2h, the precipitate is separated by magnetic separation, washed with water, and dried to obtain the ferroferric oxide particles.

[0073] S2, dispersing the azobisisobutyronitrile-loaded ferrosoferric oxide microparticles obtained in step S1 in a toluene solvent, and then dripping a toluene solution of 2-vinylnaphthalene monomer therein, and reacting at 80° C. for 5 hours to obtain a prepolymer;

[0074] Allyl pyrrolidine dithiocarbamate monomer, 2,4-pentadienoic acid monomer and alkyl glycoside solution were mixed evenly, added to the prepolymer, and then azobisisobutyronitrile was added thereto. Under the protection of inert gas, the reaction was stirred at 60° C. for 24 hours to coat the polymer on the surface of the ferrosoferric oxide particles. After magnetic separation, washing and drying, core-shell structure particles were obtained.

[0075] Wherein, the alkyl glycoside is decyl alkyl glucoside. The concentration of the ferroferric oxide microparticles loaded with azobisisobutyronitrile in the toluene is 12 mg / ml; in the toluene solution of the 2-vinylnaphthalene monomer, the concentration of the 2-vinylnaphthalene monomer is 8 mg / ml; the mass ratio of the ferroferric oxide microparticles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, allyl pyrrolidine dithiocarbamate monomer, 2,4-pentadienoic acid monomer, azobisisobutyronitrile, and alkyl glycoside solution is 1:2.5:5.5:8.5:0.06:0.6; in the alkyl glycoside solution, the concentration of the alkyl glycoside is 0.09 mol / L.

[0076] S3. Take the core-shell structured particles obtained in step S2, add methanol and trimethylolpropane-3-mercaptopropionate, and then add azobisisobutyronitrile thereto, mix well, and stir the reaction at 70° C. for 16 hours to obtain a heavy metal capture agent for treating pickling waste liquid.

[0077] The concentration of the core-shell structured particles in the methanol is 8 mg / ml; the mass ratio of the core-shell structured particles, trimethylolpropane-3-mercaptopropionate, and azobisisobutyronitrile is 1:1.6:0.02.

[0078] Comparative Example 1

[0079] The raw materials and preparation method of the heavy metal scavenger for treating pickling wastewater in this comparative example are the same as those in Example 4, and the only difference is that in step S1, the step of adding azobisisobutyronitrile and silane coupling agent is not included, and the ferrosoferric oxide particles are directly used to perform steps S2 and S3.

[0080] Comparative Example 2

[0081] The raw materials and preparation method of the heavy metal scavenger for treating pickling waste liquid in this comparative example are the same as those in Example 4, and the only difference is that in step S1, the step of adding azobisisobutyronitrile is not included, and in step S2, azobisisobutyronitrile is directly added to the toluene solvent.

[0082] In this comparative example, steps S1 and S2 specifically include:

[0083] S1. Take the ferroferric oxide particles, add ethanol, add a silane coupling agent under the protection of an inert gas, and stir the reaction at 30° C. for 3 h, separate the precipitate by magnetic separation, and vacuum dry at 30° C. for 30 min to obtain ferroferric oxide particles loaded with a silane coupling agent.

[0084] S2, dispersing the ferrosoferric oxide particles loaded with a silane coupling agent obtained in step S1 in a toluene solvent, and then dripping a toluene solution of a 2-vinylnaphthalene monomer therein, and reacting at 80° C. for 5 hours to obtain a prepolymer;

[0085] Allyl pyrrolidine dithiocarbamate monomer, 2,4-pentadienoic acid monomer and alkyl glycoside solution were mixed evenly, added to the prepolymer, and then azobisisobutyronitrile was added thereto. Under the protection of inert gas, the reaction was stirred at 60° C. for 24 hours to coat the polymer on the surface of the ferrosoferric oxide particles. After magnetic separation, washing and drying, core-shell structure particles were obtained.

[0086] Comparative Example 3

[0087] The raw materials and preparation method of the heavy metal scavenger for treating pickling wastewater in this comparative example are the same as those in Example 4, and the only difference is that in step S1, the step of adding the silane coupling agent is not included.

[0088] In this comparative example, step S1 specifically includes:

[0089] S1. Take the ferroferric oxide particles, add ethanol, add azobisisobutyronitrile under the protection of inert gas, and stir the reaction at 30° C. for 3 h, separate the precipitate by magnetic separation, and vacuum dry at 30° C. for 30 min to obtain ferroferric oxide particles loaded with azobisisobutyronitrile.

[0090] Comparative Example 4

[0091] The raw materials and preparation method of the heavy metal scavenger for treating pickling wastewater in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the step of adding the allyl pyrrolidine dithiocarbamate monomer is not included.

[0092] Comparative Example 5

[0093] The raw materials and preparation method of the heavy metal scavenger for treating pickling wastewater in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the step of adding the 2,4-pentadienoic acid monomer is not included.

[0094] Comparative Example 6

[0095] The raw materials and preparation method of the heavy metal scavenger for treating pickling wastewater in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the step of adding the 2-vinylnaphthalene monomer is not included.

[0096] In this comparative example, step S2 specifically comprises: dispersing the ferroferric oxide particles loaded with azobisisobutyronitrile obtained in step S1 in a toluene solvent to obtain a suspension;

[0097] Allyl pyrrolidine dithiocarbamate monomer, 2,4-pentadienoic acid monomer and alkyl glycoside solution were mixed evenly, added to the suspension, and then azobisisobutyronitrile was added thereto. Under the protection of inert gas, the mixture was stirred and reacted at 60° C. for 24 hours to coat the surface of the ferrosoferric oxide particles with the polymer. After magnetic separation, washing and drying, core-shell structure particles were obtained.

[0098] Comparative Example 7

[0099] The raw materials and preparation method of the heavy metal scavenger for treating pickling waste liquid in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the mass ratio of the ferrosoferric oxide particles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, allyl pyrrolidine dithiocarbamate monomer, and 2,4-pentadienoic acid monomer is 1:0.5:5.5:8.5.

[0100] Comparative Example 8

[0101] The raw materials and preparation method of the heavy metal scavenger for treating pickling waste liquid in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the mass ratio of the ferrosoferric oxide particles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, allyl pyrrolidine dithiocarbamate monomer, and 2,4-pentadienoic acid monomer is 1:4.0:5.5:8.5.

[0102] Comparative Example 9

[0103] The raw materials and preparation method of the heavy metal scavenger for treating pickling waste liquid in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the mass ratio of the ferrosoferric oxide particles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, allyl pyrrolidine dithiocarbamate monomer, and 2,4-pentadienoic acid monomer is 1:2.5:3.0:8.5.

[0104] Comparative Example 10

[0105] The raw materials and preparation method of the heavy metal scavenger for treating pickling waste liquid in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the mass ratio of the ferrosoferric oxide particles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, allyl pyrrolidine dithiocarbamate monomer, and 2,4-pentadienoic acid monomer is 1:2.5:7.5:8.5.

[0106] Comparative Example 11

[0107] The raw materials and preparation method of the heavy metal scavenger for treating pickling waste liquid in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the mass ratio of the ferrosoferric oxide particles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, allyl pyrrolidine dithiocarbamate monomer, and 2,4-pentadienoic acid monomer is 1:2.5:5.5:6.0.

[0108] Comparative Example 12

[0109] The raw materials and preparation method of the heavy metal scavenger for treating pickling waste liquid in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the mass ratio of the ferrosoferric oxide particles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, allyl pyrrolidine dithiocarbamate monomer, and 2,4-pentadienoic acid monomer is 1:2.5:5.5:9.8.

[0110] Comparative Example 13

[0111] The raw materials and preparation method of the heavy metal scavenger for treating pickling wastewater in this comparative example are the same as those in Example 4, and the only difference is that step S3 is not included.

[0112] Comparative Example 14

[0113] The raw materials and preparation method of the heavy metal scavenger for treating pickling wastewater in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the alkyl glycoside solution is replaced by an equal volume of water.

[0114] Comparative Example 15

[0115] The raw materials and preparation method of the heavy metal scavenger for treating pickling wastewater in this comparative example are the same as those in Example 4, and the only difference is that in step S2, the alkyl glycoside solution is replaced by an equal volume of alkyl glycoside quaternary ammonium salt.

[0116] The alkyl glucoside quaternary ammonium salt can be prepared by butyl glucoside and 3-chloro-2-hydroxypropyl dimethyl dodecyl ammonium salt.

[0117] Effect experiment example

[0118] In order to verify the technical effect of the preparation method of the heavy metal capture agent for treating pickling waste liquid described in the present invention, the following experiments were carried out:

[0119] 2 g of heavy metal scavengers for treating pickling waste liquid were prepared by the methods in Examples 1-4 and Comparative Examples 1-15, respectively, and added to 1 L of four simulated waste liquids, respectively, and stirred at room temperature for 10 min. The solid was magnetically separated, and the heavy metal content in the treated waste liquid was detected. The removal rate of each heavy metal ion in different simulated waste liquids was calculated according to the following formula: heavy metal ion removal rate = (C0-C1) / C0×100%;

[0120] Wherein, C0 is the concentration of heavy ions in the simulated waste liquid before treatment with the heavy metal scavenger; C1 is the concentration of heavy ions in the simulated waste liquid after treatment with the heavy metal scavenger.

[0121] There are four types of simulated waste liquids, namely, the first simulated waste liquid, the second simulated waste liquid, the third simulated waste liquid, and the fourth simulated waste liquid. The original components of each simulated waste liquid are as follows:

[0122] The first simulated waste liquid: Pb 2+ The concentration of ions is 30mg / L, Ni 2+ The ion concentration is 120 mg / L and the pH value is 7.0; the first simulated waste liquid is an aqueous solution of lead nitrate and nickel chloride, and the pH value is adjusted to 7.0 using sodium hydroxide;

[0123] Second simulated waste liquid: Pb 2+ The concentration of ions is 30mg / L, Ni 2+ The ion concentration is 120 mg / L and the pH value is 2.0; the second simulated waste liquid is an aqueous solution of lead nitrate and nickel chloride, and the pH value is adjusted to 2.0 using nitric acid;

[0124] The third simulated waste liquid: Pb 2+ The concentration of ions is 30mg / L, Ni 2+ The ion concentration is 120 mg / L, sodium dodecyl sulfate is 0.1 mol / L, and the pH value is 2.0; the third simulated waste liquid is an aqueous solution of lead nitrate, nickel chloride, and sodium dodecyl sulfate, and the pH value is adjusted to 2.0 using nitric acid;

[0125] (Note: After magnetic separation of solids, before testing the heavy metal ion content, add 3 mol of NaCl to the waste liquid to destroy the micellar structure of sodium dodecyl sulfate before testing);

[0126] The fourth simulated waste liquid: Pb 2+ The concentration of ions is 30mg / L, Ni 2+ The ion concentration is 120 mg / L, sodium dodecyl sulfate is 0.1 mol / L, NaCl concentration is 5 mol / L, and the pH value is 2.0; the third simulated waste liquid is an aqueous solution of lead nitrate, nickel chloride, and sodium dodecyl sulfate, and nitric acid is used to adjust the pH value to 2.0.

[0127] After the experiments, the heavy metal capture agents of Examples 1-4 and Comparative Examples 1-15 were used to treat four kinds of simulated wastewater respectively, and the Pb 2+ Ions and Ni 2+ The removal rate of ions, the specific results are as follows:

[0128] Table 1 Pb content of four simulated wastewaters after treatment with heavy metal capture agents 2+、 Ni 2+ Removal rate

[0129]

[0130] According to the results of Examples 1-4 and Comparative Examples 1-14, the heavy metal scavenger for treating pickling waste liquid described in the present invention does not need to be precipitated after mixing with the waste liquid, and can be separated from the waste liquid by utilizing its own magnetism. It has good stability under acidic conditions and has a good capture effect on heavy metal ions, and can effectively remove heavy metals in the pickling waste liquid.

[0131] According to the results of Examples 1-4, the acidic environment has little effect on the removal effect of lead ions and nickel ions of the heavy metal scavenger for treating pickling waste liquid described in the present invention. The presence of surfactants in the waste liquid has a certain effect on the removal effect of lead ions and nickel ions. NaCl has a destructive effect on the micellar structure of the surfactant, which slightly improves the removal effect of lead ions and nickel ions compared to the waste liquid containing surfactants but without adding NaCl.

[0132] According to the results of Example 4 and Comparative Examples 1-3, in Comparative Example 1, only the active groups such as hydroxyl groups on the surface of the ferroferric oxide microparticles are relied on to enrich monomers for polymerization reaction; In Comparative Example 2, azobisisobutyronitrile is not added, but a silane coupling agent is added, and active groups can be increased on the surface of the ferroferric oxide microparticles, and more monomers are enriched on its surface for polymerization reaction; In Comparative Example 3, the silane coupling agent is not added, but azobisisobutyronitrile is added, so that it can load azobisisobutyronitrile to a certain extent, but the load capacity is small. From the effect of removing heavy metal ions, azobisisobutyronitrile is not fully loaded on the surface of the ferroferric oxide microparticles, so that polymers can be difficult to be completely coated on the surface of the ferroferric oxide microparticles, or the bonding strength with the surface of the ferroferric oxide microparticles is weaker. Whether it is a neutral environment or an acidic environment, whether there are a large number of micellar structures, its removal effect for lead ions and nickel ions is relatively poor.

[0133] According to the results of Example 4 and Comparative Examples 4-6, the 2-vinylnaphthalene monomer plays an important role in maintaining the stability of the ferroferric oxide particles, maintaining the bonding strength between the polymer and the ferroferric oxide particles, and preventing the polymer from separating from the ferroferric oxide particles, thereby having a certain impact on the removal effect of lead ions and nickel ions. The heavy metal scavenger (Comparative Example 6) that does not contain the 2-vinylnaphthalene monomer has a large performance degradation caused by the influence of the acidic environment, and a relatively small performance degradation caused by the influence of the large number of micelle structures. The pyrrolidine dithiocarbamate allyl ester monomer contains rich heavy metal capture groups, which has a great impact on the capture effect of heavy metal ions. The heavy metal scavenger (Comparative Example 4) that does not contain the pyrrolidine dithiocarbamate allyl ester monomer has a significant overall decrease in heavy metal capture ability, a small performance degradation caused by the influence of the acidic environment, and a relatively large performance degradation caused by the influence of the large number of micelle structures. The 2,4-pentadienoic acid monomer has an important influence on improving the hydrophilicity of the scavenger and the terminal active functional groups of the heavy metal scavenger. The heavy metal capture agent (Comparative Example 5) that does not contain the 2,4-pentadienoic acid monomer is difficult to fully contact with the waste liquid to be treated, resulting in an unsatisfactory heavy metal capture effect.

[0134] According to the results of Example 4 and Comparative Examples 7-12, the ratio of the above three monomers will also have a complex impact on the comprehensive performance of the polymer. The proportion of the three monomers in the polymer is too low and cannot fully play a role. Too high will lead to different results. If the amount of the 2-vinylnaphthalene monomer is too high (Comparative Example 8), the poly-2-vinylnaphthalene layer will be too thick, the hydrophobicity of the heavy metal scavenger will be enhanced, and the specific surface area will be reduced, thereby affecting its capture effect on heavy metal ions; due to the change in the conformation of the polymer, the influence of the large number of micelle structures on it will also increase. If the amount of the pyrrolidine dithiocarbamate allyl ester monomer is too high (Comparative Example 10), the hydrophilicity of the heavy metal scavenger will be insufficient, and there will be too much rigid structure, which will make it difficult to adapt to different coordination environments and binding sites, resulting in a decrease in the ability to capture heavy metal ions, and the influence of the large number of micelle structures will be enhanced. If the amount of the 2,4-pentadienoic acid monomer is too high (Comparative Example 12), it is also difficult to achieve good results. This may be due to the aggregation of a small amount of flexible chains, which leads to a decrease in comprehensive performance. It can be seen that the ratio of the above three monomers has a complex influence on the structure and conformation of the final polymer. When the three are in the optimal ratio, the heavy metal capture agent obtained is the most ideal.

[0135] According to the results of Example 4 and Comparative Example 13, the thiol group at the active end of the polymer also has a significant impact on the performance of the heavy metal scavenger.

[0136] According to the results of Example 4 and Comparative Examples 14-15, alkyl polyglycosides can play a certain regulatory role in the process of synthesizing polymers from monomers, which is conducive to forming a microstructure with strong heavy metal capture ability. However, the role played by alkyl polyglycoside quaternary ammonium salts as cationic surfactants in the process of synthesizing polymers from monomers is not conducive to the function of heavy metal capture agents. This may be due to the fact that compared with alkyl polyglycosides of nonionic surfactants, cationic surfactants are charged and have different modes of action during the polymerization reaction, which leads to differences in the performance of the obtained heavy metal capture agents.

[0137] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are encompassed by the present invention.

Claims

1. A method for preparing a heavy metal scavenger for treating pickling wastewater, characterized in that: The steps include: S1, taking ferroferric oxide particles, adding a silane coupling agent and azobisisobutyronitrile to obtain ferroferric oxide particles loaded with azobisisobutyronitrile; S2, dispersing the ferroferric oxide microparticles loaded with azobisisobutyronitrile obtained in step S1 in a toluene solvent, and then dropping a toluene solution of 2-vinylnaphthalene monomer therein, and reacting at 60-80° C. for 3-5 hours to obtain a prepolymer; then, taking allyl pyrrolidine dithiocarbamate monomer, 2,4-pentadienoic acid monomer and alkyl glycoside solution and mixing them evenly, adding them to the prepolymer, and then adding azobisisobutyronitrile therein, stirring and reacting at 60-80° C. for 12-24 hours under the protection of inert gas, so that the polymer is coated on the surface of the ferroferric oxide microparticles, and performing magnetic separation, washing, and drying to obtain core-shell structure microparticles; The alkyl glucoside is one of decyl alkyl glucoside and octyl alkyl glucoside; S3. Take the core-shell structured particles obtained in step S2, add trimethylolpropane-3-mercaptopropionate, mix well, and perform click chemistry reaction to obtain a heavy metal capture agent for treating pickling waste liquid.

2. The method for preparing a heavy metal scavenger for treating pickling wastewater according to claim 1, characterized in that: In step S1, the ferroferric oxide particles are obtained by the following method: Ferrous chloride and ferric chloride are dissolved in water at a molar ratio of 1:(2.0-2.5) to make the concentration of ferrous chloride in water be 1.5-2.2 mol / L. Under the protection of inert gas, 4-6 mol / L sodium hydroxide solution is added dropwise to the water until the pH value is 10-12. The reaction is stirred at 50-70°C for 1-2h. The precipitate is separated by magnetic separation, washed with water, and dried to obtain the ferrosoferric oxide particles.

3. The method for preparing a heavy metal scavenger for treating pickling wastewater according to claim 2, characterized in that: Step S1 specifically includes: taking the ferroferric oxide particles, adding ethanol, adding the silane coupling agent and the azobisisobutyronitrile under the protection of an inert gas, and stirring the reaction at 30-40° C. for 3-5 hours, magnetically separating and precipitating, and vacuum drying at 30-40° C. for 10-30 minutes to obtain ferroferric oxide particles loaded with azobisisobutyronitrile.

4. The method for preparing a heavy metal scavenger for treating pickling wastewater according to claim 3, characterized in that: In step S1, the mass ratio of the ferrosoferric oxide particles, the silane coupling agent, and the azobisisobutyronitrile is 1:(0.10-0.15):(0.15-0.20).

5. The method for preparing a heavy metal scavenger for treating pickling wastewater according to claim 4, characterized in that: In step S1, the concentration of the ferrosoferric oxide in the ethanol is 5-8 mg / ml; Optionally, the silane coupling agent is γ-aminopropyltrimethoxysilane.

6. The method for preparing a heavy metal scavenger for treating pickling wastewater according to claim 5, characterized in that: In step S2, the concentration of the ferrosoferric oxide particles loaded with azobisisobutyronitrile in the toluene is 10-14 mg / ml; Optionally, in the toluene solution of the 2-vinylnaphthalene monomer, the concentration of the 2-vinylnaphthalene monomer is 5-10 mg / ml; Optionally, the mass ratio of the ferrosoferric oxide particles loaded with azobisisobutyronitrile, 2-vinylnaphthalene monomer, allyl pyrrolidinedithiocarbamate monomer, 2,4-pentadienoic acid monomer, azobisisobutyronitrile, and alkyl glycoside solution is 1: (1.0-3.6): (4.0-6.5): (7.0-9.2): (0.05-0.08): (0.2-0.8); Optionally, in the alkyl glycoside solution, the concentration of the alkyl glycoside is 0.03-0.09 mol / L.

7. The method for preparing a heavy metal scavenger for treating pickling wastewater according to claim 6, characterized in that: Step S3 specifically includes: taking the core-shell structured particles obtained in step S2, adding methanol and trimethylolpropane-3-mercaptopropionate, and then adding azobisisobutyronitrile thereto, mixing evenly, stirring and reacting at 50-70° C. for 8-16 hours to obtain a heavy metal capture agent for treating pickling waste liquid.

8. The method for preparing a heavy metal scavenger for treating pickling wastewater according to claim 7, characterized in that: In step S3, the concentration of the core-shell structured particles in the methanol is 5-10 mg / ml; Optionally, the mass ratio of the core-shell structured particles, trimethylolpropane-3-mercaptopropionate, and azobisisobutyronitrile is 1:(1.2-1.8):(0.01-0.03).

9. A heavy metal scavenger for treating pickling wastewater, characterized in that: The heavy metal scavenger for treating pickling waste liquid is obtained by the preparation method of any one of claims 1 to 8.

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