Organosilicon heavy metal soil remediation agent and preparation method thereof

Abstract

The invention relates to the technical field of soil remediation agents, and provides an organic silicon heavy metal soil remediation agent and a preparation method thereof. The organic silicon heavy metal soil remediation agent is prepared from the following raw materials in parts by weight: 40 to 60 parts of modified zeolite, 3 to 6 parts of sodium lignin sulfonate, 6 to 10 parts of potassium fulvate, 8 to 15 parts of chitosan derivative, 1 to 2 parts of organic silicon and 4 to 8 parts of potassium silicate. The modified zeolite is obtained by modifying zeolite with 4-mercaptophenyl acetic acid. According to the technical scheme, the problem that the heavy metal soil remediation agent is insufficient in adsorption and removal capacity on heavy metals in soil in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil remediation agents, in particular, relates to a kind of organic silicon heavy metal soil remediation agent and preparation method thereof. BACKGROUND

[0002] Soil heavy metal pollution, not only can destroy soil ecological structure, reduce soil fertility, also can be enriched through food chain, pose a threat to human health, therefore, research and development of efficient and environmentally friendly heavy metal soil remediation agent has become the urgent demand in the field of soil pollution control.However, the heavy metal soil remediation agent currently available on the market, such as inorganic minerals, traditional organic, microorganism, etc., the heavy metal soil remediation agent generally has the defect of insufficient adsorption and removal capacity of heavy metals in soil, and it is difficult to meet the management needs of heavy heavy metal contaminated soil.Therefore, it is necessary to propose a heavy metal soil remediation agent with better performance. SUMMARY

[0003] The present application proposes a kind of organic silicon heavy metal soil remediation agent and preparation method thereof, solve the problem of insufficient adsorption and removal capacity of heavy metals in soil in the related art heavy metal soil remediation agent.

[0004] The technical scheme of the present application is as follows: The present application proposes a kind of organic silicon heavy metal soil remediation agent, including the following components by weight of raw materials: modified zeolite 40~60 parts, sodium lignosulfonate 3~6 parts, potassium fulvate 6~10 parts, chitosan derivative 8~15 parts, organic silicon 1~2 parts, potassium silicate 4~8 parts; The modified zeolite is modified by 4-mercapto phenyl acetic acid.

[0005] As a further technical solution, the mass of 4-mercapto phenyl acetic acid is 2.5%~3.5% of the mass of zeolite.

[0006] As a further technical solution, the preparation method of the modified zeolite comprises the following steps: dispersing 4-mercapto phenyl acetic acid in a solvent, then adding zeolite and mixing, filtering, drying to obtain modified zeolite.

[0007] As a further technical solution, the mixing is mixed at 50~60℃ for 2~4h.

[0008] As a further technical solution, the mass-volume ratio of the zeolite and the solvent is 1g:8~10mL.

[0009] As a further technical solution, the solvent is anhydrous ethanol.

[0010] As a further technical solution, the organic silicon is water-soluble polyether modified dimethyl silicone, model number BYK306.

[0011] As a further technical solution, the chitosan derivative includes carboxymethyl chitosan and hydroxypropyl chitosan.

[0012] As a further technical solution, the degree of substitution of the carboxymethyl chitosan is 80%; and the degree of substitution of the hydroxypropyl chitosan is 85%.

[0013] In the organic silicon heavy metal soil remediation agent, when the carboxymethyl chitosan with a degree of substitution of 80% is used in combination with the hydroxypropyl chitosan with a degree of substitution of 85%, the complexation of the carboxymethyl and the hydrogen bond auxiliary adsorption of the hydroxypropyl cooperate with each other, can cover different forms of heavy metal ions in the soil, and the two can synergistically play a role, and improve the adsorption performance of the remediation agent on the heavy metals in the soil.

[0014] As a further technical solution, the mass ratio of the carboxymethyl chitosan and the hydroxypropyl chitosan is 1-2:1.

[0015] In the organic silicon heavy metal soil remediation agent, when the chitosan derivative is composed of the carboxymethyl chitosan and the hydroxypropyl chitosan with a mass ratio of 1-2:1, the adsorption performance of the remediation agent on the heavy metals in the soil can be further improved. When the mass ratio of the carboxymethyl chitosan and the hydroxypropyl chitosan is less than 1:1, the adsorption sites are insufficient, and the expected remediation effect cannot be achieved; when the mass ratio of the carboxymethyl chitosan and the hydroxypropyl chitosan is greater than 2:1, the agglomeration of inorganic components such as zeolite is easily caused, the adsorption sites are reduced, and the overall adsorption efficiency is reduced; when the mass ratio of the carboxymethyl chitosan and the hydroxypropyl chitosan is 1-2:1, the organic silicon heavy metal soil remediation agent can be given the best heavy metal adsorption and removal effect.

[0016] The application further provides a preparation method of the organic silicon heavy metal soil remediation agent, including the following steps: uniformly mixing raw materials of the organic silicon heavy metal soil remediation agent, granulating, and obtaining the organic silicon heavy metal soil remediation agent.

[0017] The working principle and beneficial effects of the application are as follows: The application can make full use of the excellent water dispersibility of the water-soluble polyether-modified dimethylsiloxane, reduce the agglomeration force between soil particles, and improve the soil compaction. At the same time, by adding the zeolite modified by 4-mercaptophenyl acetic acid, the adsorption and removal capacity of the organic silicon heavy metal soil repair agent for heavy metals in the soil is improved. Zeolite is often used for heavy metal repair in soil, but it has the problem of easy agglomeration, which leads to uneven distribution in the mixing process, resulting in shielding of effective adsorption sites and limited repair effect, and finally leading to the failure to achieve good repair effect on heavy metal soil. The 4-mercaptophenyl acetic acid is connected to the surface of the zeolite by hydrogen bonding, which can effectively inhibit the agglomeration phenomenon between zeolite particles, so that the zeolite can be uniformly dispersed in the repair agent system during mixing and granulation, thereby improving the adsorption and removal capacity of the organic silicon heavy metal soil repair agent for heavy metals in the soil. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0019] In the following examples and comparative examples, the particle size of the zeolite is 50 μm; the type of sodium lignosulfonate is 85A; the type of potassium fulvic acid is potassium fulvic acid with fulvic acid ≥58% and organic matter ≥70%; the type of polyether-modified dimethylsiloxane is BYK306; the degree of substitution of carboxymethyl chitosan is 80%; and the degree of substitution of hydroxypropyl chitosan is 85%.

[0020] Example 1 An organic silicon heavy metal soil repair agent, comprising the following components by weight: modified zeolite 40 parts, sodium lignosulfonate 3 parts, potassium fulvic acid 6 parts, chitosan derivative 8 parts, polyether-modified dimethylsiloxane 1 part, and potassium silicate 4 parts; wherein the chitosan derivative is carboxymethyl chitosan. A preparation method of modified zeolite, comprising the following steps: dispersing 4-mercaptophenyl acetic acid in anhydrous ethanol, then adding zeolite, mixing at 50℃ for 4h, filtering, and drying to obtain the modified zeolite; the mass of 4-mercaptophenyl acetic acid is 2.5% of the mass of the zeolite; and the mass-volume ratio of the zeolite and the anhydrous ethanol is 1g:8mL. A preparation method of an organic silicon heavy metal soil repair agent, comprising the following steps: uniformly mixing the raw materials of the organic silicon heavy metal soil repair agent, and granulating to obtain the organic silicon heavy metal soil repair agent.

[0021] Example 2 An organosilicon heavy metal soil remediation agent comprises the following raw materials in parts by weight: 50 parts modified zeolite, 5 parts sodium lignosulfonate, 8 parts potassium humate, 12 parts chitosan derivative, 1.5 parts polyether-modified dimethylsiloxane, and 6 parts potassium silicate; wherein the chitosan derivative is carboxymethyl chitosan. The method for preparing modified zeolite includes the following steps: dispersing 4-mercaptophenylacetic acid in anhydrous ethanol, adding zeolite, mixing at 55°C for 3 hours, filtering, and drying to obtain modified zeolite; the mass of 4-mercaptophenylacetic acid is 2.5% of the mass of zeolite; the mass-volume ratio of zeolite to anhydrous ethanol is 1 g: 9 mL. A method for preparing an organosilicon heavy metal soil remediation agent includes the following steps: mixing the raw materials of the organosilicon heavy metal soil remediation agent evenly, granulating them, and obtaining the organosilicon heavy metal soil remediation agent.

[0022] Example 3 An organosilicon heavy metal soil remediation agent comprises the following raw materials in parts by weight: 60 parts modified zeolite, 6 parts sodium lignosulfonate, 10 parts potassium humate, 15 parts chitosan derivative, 2 parts polyether-modified dimethylsiloxane, and 8 parts potassium silicate; wherein the chitosan derivative is carboxymethyl chitosan. The method for preparing modified zeolite includes the following steps: dispersing 4-mercaptophenylacetic acid in anhydrous ethanol, adding zeolite, mixing at 60°C for 2 hours, filtering, and drying to obtain modified zeolite; the mass of 4-mercaptophenylacetic acid is 2.5% of the mass of zeolite; the mass-volume ratio of zeolite to anhydrous ethanol is 1 g: 10 mL. A method for preparing an organosilicon heavy metal soil remediation agent includes the following steps: mixing the raw materials of the organosilicon heavy metal soil remediation agent evenly, granulating them, and obtaining the organosilicon heavy metal soil remediation agent.

[0023] Example 4 An organosilicon heavy metal soil remediation agent comprises the following raw materials in parts by weight: 40 parts modified zeolite, 3 parts sodium lignosulfonate, 6 parts potassium humate, 8 parts chitosan derivative, 1 part polyether-modified dimethylsiloxane, and 4 parts potassium silicate; wherein the chitosan derivative is carboxymethyl chitosan. The method for preparing modified zeolite includes the following steps: dispersing 4-mercaptophenylacetic acid in anhydrous ethanol, then adding zeolite, mixing at 50°C for 4 hours, filtering, and drying to obtain modified zeolite; the mass of 4-mercaptophenylacetic acid is 3% of the mass of zeolite; the mass-volume ratio of zeolite to anhydrous ethanol is 1 g: 8 mL. A method for preparing an organosilicon heavy metal soil remediation agent includes the following steps: mixing the raw materials of the organosilicon heavy metal soil remediation agent evenly, granulating them, and obtaining the organosilicon heavy metal soil remediation agent.

[0024] Example 5 An organosilicon heavy metal soil remediation agent comprises the following raw materials in parts by weight: 40 parts modified zeolite, 3 parts sodium lignosulfonate, 6 parts potassium humate, 8 parts chitosan derivative, 1 part polyether-modified dimethylsiloxane, and 4 parts potassium silicate; wherein the chitosan derivative is carboxymethyl chitosan. The method for preparing modified zeolite includes the following steps: dispersing 4-mercaptophenylacetic acid in anhydrous ethanol, adding zeolite, mixing at 50°C for 4 hours, filtering, and drying to obtain modified zeolite; the mass of 4-mercaptophenylacetic acid is 3.5% of the mass of zeolite; the mass-volume ratio of zeolite to anhydrous ethanol is 1 g: 8 mL. A method for preparing an organosilicon heavy metal soil remediation agent includes the following steps: mixing the raw materials of the organosilicon heavy metal soil remediation agent evenly, granulating them, and obtaining the organosilicon heavy metal soil remediation agent.

[0025] Example 6 An organosilicon heavy metal soil remediation agent comprises the following raw materials in parts by weight: 40 parts modified zeolite, 3 parts sodium lignosulfonate, 6 parts potassium humate, 8 parts chitosan derivative, 1 part polyether-modified dimethylsiloxane, and 4 parts potassium silicate; wherein the chitosan derivative is composed of carboxymethyl chitosan and hydroxypropyl chitosan in a mass ratio of 1:1. The method for preparing modified zeolite includes the following steps: dispersing 4-mercaptophenylacetic acid in anhydrous ethanol, adding zeolite, mixing at 50°C for 4 hours, filtering, and drying to obtain modified zeolite; the mass of 4-mercaptophenylacetic acid is 2.5% of the mass of zeolite; the mass-volume ratio of zeolite to anhydrous ethanol is 1 g: 8 mL. A method for preparing an organosilicon heavy metal soil remediation agent includes the following steps: mixing the raw materials of the organosilicon heavy metal soil remediation agent evenly, granulating them, and obtaining the organosilicon heavy metal soil remediation agent.

[0026] Example 7 An organosilicon heavy metal soil remediation agent comprises the following raw materials in parts by weight: 40 parts modified zeolite, 3 parts sodium lignosulfonate, 6 parts potassium humate, 8 parts chitosan derivative, 1 part polyether-modified dimethylsiloxane, and 4 parts potassium silicate; wherein the chitosan derivative is composed of carboxymethyl chitosan and hydroxypropyl chitosan in a mass ratio of 1.5:1. The method for preparing modified zeolite includes the following steps: dispersing 4-mercaptophenylacetic acid in anhydrous ethanol, adding zeolite, mixing at 50°C for 4 hours, filtering, and drying to obtain modified zeolite; the mass of 4-mercaptophenylacetic acid is 2.5% of the mass of zeolite; the mass-volume ratio of zeolite to anhydrous ethanol is 1 g: 8 mL. A method for preparing an organosilicon heavy metal soil remediation agent includes the following steps: mixing the raw materials of the organosilicon heavy metal soil remediation agent evenly, granulating them, and obtaining the organosilicon heavy metal soil remediation agent.

[0027] Example 8 An organosilicon heavy metal soil remediation agent comprises the following raw materials in parts by weight: 40 parts modified zeolite, 3 parts sodium lignosulfonate, 6 parts potassium humate, 8 parts chitosan derivative, 1 part polyether-modified dimethylsiloxane, and 4 parts potassium silicate; wherein the chitosan derivative is composed of carboxymethyl chitosan and hydroxypropyl chitosan in a mass ratio of 2:1. The method for preparing modified zeolite includes the following steps: dispersing 4-mercaptophenylacetic acid in anhydrous ethanol, adding zeolite, mixing at 50°C for 4 hours, filtering, and drying to obtain modified zeolite; the mass of 4-mercaptophenylacetic acid is 2.5% of the mass of zeolite; the mass-volume ratio of zeolite to anhydrous ethanol is 1 g: 8 mL. A method for preparing an organosilicon heavy metal soil remediation agent includes the following steps: mixing the raw materials of the organosilicon heavy metal soil remediation agent evenly, granulating them, and obtaining the organosilicon heavy metal soil remediation agent.

[0028] Example 9 An organosilicon heavy metal soil remediation agent comprises the following raw materials in parts by weight: 40 parts modified zeolite, 3 parts sodium lignosulfonate, 6 parts potassium humate, 8 parts chitosan derivative, 1 part polyether-modified dimethylsiloxane, and 4 parts potassium silicate; wherein the chitosan derivative is hydroxypropyl chitosan. The method for preparing modified zeolite includes the following steps: dispersing 4-mercaptophenylacetic acid in anhydrous ethanol, adding zeolite, mixing at 50°C for 4 hours, filtering, and drying to obtain modified zeolite; the mass of 4-mercaptophenylacetic acid is 2.5% of the mass of zeolite; the mass-volume ratio of zeolite to anhydrous ethanol is 1 g: 8 mL. A method for preparing an organosilicon heavy metal soil remediation agent includes the following steps: mixing the raw materials of the organosilicon heavy metal soil remediation agent evenly, granulating them, and obtaining the organosilicon heavy metal soil remediation agent.

[0029] Comparative Example 1 An organosilicon heavy metal soil remediation agent comprises the following raw materials in parts by weight: 40 parts zeolite, 3 parts sodium lignosulfonate, 6 parts potassium humate, 8 parts chitosan derivative, 1 part polyether-modified dimethylsiloxane, and 4 parts potassium silicate; wherein the chitosan derivative is carboxymethyl chitosan. A method for preparing an organosilicon heavy metal soil remediation agent includes the following steps: mixing the raw materials of the organosilicon heavy metal soil remediation agent evenly, granulating them, and obtaining the organosilicon heavy metal soil remediation agent.

[0030] Experimental Example The organosilicon heavy metal soil remediation agents prepared in Examples 1-9 and Comparative Example 1 were tested according to the following methods: 500 kg of soil contaminated with heavy metals such as Cd and Pb was taken, mixed thoroughly, and samples were taken to test the Cd and Pb contents. The Cd content was 15.25 mg / kg, and the Pb content was 17.10 mg / kg. The soil was divided into 10 equal portions (50 kg each), and 0.5 kg of organosilicon heavy metal soil remediation agent was added to each portion. After mixing, the soil was hydrated and cured for 3 days. Samples were taken again to test the Cd and Pb contents. The test results are shown in Table 1. Table 1. Remediation Effect of Organosilicon Heavy Metal Soil Remediation Agent

[0031] The data in Table 1 show that the addition of 4-mercaptophenylacetic acid modified zeolite can enhance the adsorption and removal capacity of the organosilicon heavy metal soil remediation agent of the present invention for Cd and Pb in the soil; and when the chitosan derivative is composed of carboxymethyl chitosan and hydroxypropyl chitosan, the adsorption and removal capacity of the organosilicon heavy metal soil remediation agent for Cd and Pb in the soil can be further enhanced.

[0032] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An organosilicon heavy metal soil remediation agent, characterized in that, The raw materials include the following components in parts by weight: 40-60 parts modified zeolite, 3-6 parts sodium lignosulfonate, 6-10 parts potassium humate, 8-15 parts chitosan derivative, 1-2 parts organosilicon, and 4-8 parts potassium silicate; wherein the modified zeolite is obtained by modifying zeolite with 4-mercaptophenylacetic acid.

2. The organosilicon heavy metal soil remediation agent according to claim 1, characterized in that, The mass of the 4-mercaptophenylacetic acid is 2.5% to 3.5% of the mass of the zeolite.

3. The organosilicon heavy metal soil remediation agent according to claim 1, characterized in that, The method for preparing the modified zeolite includes the following steps: dispersing 4-mercaptophenylacetic acid in a solvent, adding zeolite and mixing, filtering, and drying to obtain the modified zeolite.

4. The organosilicon heavy metal soil remediation agent according to claim 3, characterized in that, The mixing process involves mixing at 50-60°C for 2-4 hours.

5. The organosilicon heavy metal soil remediation agent according to claim 3, characterized in that, The mass-to-volume ratio of the zeolite to the solvent is 1g:8~10mL.

6. The organosilicon heavy metal soil remediation agent according to claim 3, characterized in that, The solvent is anhydrous ethanol.

7. The organosilicon heavy metal soil remediation agent according to claim 1, characterized in that, The chitosan derivatives include carboxymethyl chitosan and hydroxypropyl chitosan.

8. The organosilicon heavy metal soil remediation agent according to claim 7, characterized in that, The degree of substitution of the carboxymethyl chitosan is 80%; the degree of substitution of the hydroxypropyl chitosan is 85%.

9. The organosilicon heavy metal soil remediation agent according to claim 8, characterized in that, The mass ratio of carboxymethyl chitosan to hydroxypropyl chitosan is 1~2:

1.

10. A method for preparing an organosilicon heavy metal soil remediation agent, used to prepare an organosilicon heavy metal soil remediation agent as described in any one of claims 1 to 9, characterized in that, Includes the following steps: After the raw materials of the organosilicon heavy metal soil remediation agent are mixed evenly, they are granulated to obtain the organosilicon heavy metal soil remediation agent.

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