Preparation method of water treatment agent and dynamic temperature control system thereof

Abstract

The invention discloses a preparation method of a water treatment agent and a dynamic temperature control system thereof. A substrate material, an adsorption material and a magnetic material are compounded into the water treatment agent with a core-shell structure; wherein the substrate material is cellulose, and the cellulose comprises microcrystalline cellulose, microfiber cellulose, cellulose nanofibers, cellulose nanocrystals and biochar fibers; the adsorption material is a hydroxide adsorbent, and the hydroxide adsorbent comprises aluminum hydroxide, magnesium hydroxide, ferric hydroxide and calcium hydroxide; the magnetic material comprises gamma-ferric oxide, ferroferric oxide and nickel zinc ferrite. According to the preparation method and the dynamic temperature control system of the water treatment agent, the substrate material, the adsorption material and the magnetic material are compounded into the water treatment agent with the core-shell structure by adopting the preparation method and the dynamic temperature control system of the water treatment agent, so that the water treatment agent has excellent heavy metal ion removal performance; the precipitate can be separated from the water body by virtue of an external magnetic field, so that secondary pollution is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment agents, and in particular relates to a method for preparing a water treatment agent and a dynamic temperature control system used in the method for preparing the water treatment agent. Background Art

[0002] Water pollution is one of the most serious environmental problems, and industrial water pollution is one of them. Industrial wastewater contains a large amount of heavy metal ions, which are transmitted through the food chain and will eventually pose a threat to human health. Therefore, it is urgent to find an economical, effective and convenient method to remove heavy metal ions from industrial wastewater.

[0003] The adsorption method stands out among many water treatment methods because of its simple operation and high removal efficiency. It is of practical significance to explore the use of high-efficiency adsorbents for industrial wastewater treatment. At present, there are many adsorbents on the market that have the advantages of being green, environmentally friendly, rich in content and low in preparation cost, such as Mg(OH)2 adsorbents, etc. However, the disadvantage of this type of adsorbent is that after using the adsorbent to treat sewage, the heavy metal precipitates formed still exist in the water body, increasing the risk of the water body being polluted again.

[0004] In order to solve this problem, the present invention adopts a loading method to obtain a magnetic water treatment agent, which provides a guarantee for the efficient removal of heavy metal ions and rapid separation from the solution. After the water treatment is completed, it is placed in a magnetic field to carry heavy metal precipitation and separate from the water body.

[0005] In addition, in the preparation process of water treatment agent, hydrothermal treatment is a very important step, and the temperature control accuracy will have a great impact on the quality of water treatment agent. Therefore, the present invention also designs a dynamic temperature control system for accurately controlling the temperature in the preparation process of water treatment agent. Summary of the invention

[0006] Purpose of the invention: In order to overcome the above shortcomings, the purpose of the present invention is to provide a method for preparing a water treatment agent and a dynamic temperature control system thereof, which are reasonably designed. By using the above preparation method and its dynamic temperature control system, the base material, adsorption material and magnetic material are compounded into a water treatment agent with a core-shell structure, which not only has excellent heavy metal ion removal performance, but also can separate the precipitate from the water body with the help of an external magnetic field, without causing secondary pollution, and has broad application prospects.

[0007] The objective of the present invention is achieved through the following technical solutions: A method for preparing a water treatment agent comprises compounding a base material, an adsorbent material and a magnetic material into a water treatment agent having a core-shell structure; wherein the base material is cellulose, and the cellulose includes microcrystalline cellulose, microfiber cellulose, cellulose nanofiber, cellulose nanocrystal, and biochar fiber; the adsorbent material is a hydroxide adsorbent, and the hydroxide adsorbent includes aluminum hydroxide, magnesium hydroxide, iron hydroxide, and calcium hydroxide; and the magnetic material includes ferroferric oxide, γ-ferric oxide, and nickel-zinc ferrite.

[0008] The preparation method of the water treatment agent of the present invention comprises the following steps: a base material, an adsorbent material and a magnetic material are compounded into a water treatment agent with a core-shell structure; cellulose is selected as the base material; cellulose is rich in a large number of functional groups such as -OH, and provides convenient conditions for combining various substances; an adsorbent such as a hydroxide adsorbent is loaded; when the hydroxide adsorbent precipitates heavy metals, the formed heavy metal hydroxides interact with the cellulose, and the heavy metals attached to the cellulose are precipitated; and the magnetic material gives the water treatment agent magnetism; after the water treatment is completed, the water treatment agent is placed in a magnetic field; the cellulose can carry the magnetic material and the heavy metal precipitates and separate from the water body under the action of the magnetic material, and the secondary pollution of the water body is effectively avoided.

[0009] Cellulose includes but is not limited to microcrystalline cellulose (MCC), microfibril cellulose (MFC), cellulose nanofiber (CNF), cellulose nanocrystal (CNC), and biochar fiber. All of the above materials have excellent physical and chemical properties such as high specific surface area, high mechanical strength, biodegradability, and biocompatibility, and are rich in a large number of functional groups such as -OH.

[0010] Among them, the adsorption materials include but are not limited to aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), iron hydroxide (Fe(OH)3), and calcium hydroxide (Ca(OH)2). The above materials are low-priced, environmentally friendly, and have high efficiency in removing heavy metals.

[0011] Among them, magnetic materials include but are not limited to ferroferric oxide (Fe3O4), γ-ferric oxide (γ-Fe2O3), and nickel-zinc ferrite (Ni-Zn ferrite). The above materials all have good magnetic properties and relatively stable chemical properties. When combined with base materials and adsorption materials, they can be quickly separated under the action of a magnetic field, thereby separating the water treatment agent from the water body.

[0012] Furthermore, in the preparation method of the above-mentioned water treatment agent, in the water treatment agent, the mass ratio of the base material, the adsorption material and the magnetic material is 1-10:1-10:1-10.

[0013] The mass proportions of the base material, the adsorption material and the magnetic material in the water treatment agent are selected according to actual needs.

[0014] Furthermore, the preparation method of the water treatment agent comprises the following steps: S1: uniformly dispersing the base material into the solvent, and then adding the metal salt used to synthesize the magnetic material to obtain a mixed solution 1; S2: transferring the mixed solution to a reactor for hydrothermal treatment, cooling to room temperature after the hydrothermal treatment, centrifuging, washing, and drying to obtain a base material / magnetic material; S3: uniformly dispersing the base material / magnetic material in a solvent, and then simultaneously adding a solution of metal ions containing a hydroxide adsorbent and a precipitant, sodium hydroxide, to obtain a mixed solution II; S4: transferring the mixed solution 2 to a reactor for hydrothermal treatment, filtering, washing and drying after the hydrothermal treatment to obtain a base material / magnetic material / adsorption material, i.e., a water treatment agent.

[0015] In the presence of a base material, magnetic materials and adsorption materials are generated in situ on the surface of the base material to construct a ternary composite material of base material / magnetic material / adsorption material. The three components in the water treatment agent play different roles in the sewage treatment process, and have the functions of efficiently removing heavy metal ions and quickly separating from the solution.

[0016] Furthermore, in the preparation method of the above-mentioned water treatment agent, the dispersion is carried out by ultrasonic dispersion.

[0017] In order to prevent agglomeration, ultrasonic dispersion is used. Ultrasound can break the agglomeration force between substances and make them evenly dispersed in the solvent, which is beneficial to the loading on the base material.

[0018] Furthermore, in the above-mentioned method for preparing the water treatment agent, in S1, a silane coupling agent and a sodium acetate solution are also added.

[0019] For magnetic materials such as ferroferric oxide, γ-ferric oxide, nickel-zinc ferrite, etc., there may be some active functional groups such as hydroxyl groups on the surface. In order to better combine with the base material and adsorbent material, silane coupling agent is used to modify the surface of the magnetic material, introduce specific organic functional groups, and enhance the chemical bonding and physical adsorption capacity between the base material. The addition of sodium acetate can trigger a series of chemical reactions, causing the solution color to change. This color change often means the progress of the reaction and the generation of new substances. When the solution color changes significantly, the mixed solution is transferred to the reactor for hydrothermal treatment.

[0020] Furthermore, in the preparation method of the above-mentioned water treatment agent, the base material is microcrystalline cellulose, the adsorption material is aluminum hydroxide, and the magnetic material is γ-ferric oxide.

[0021] Microcrystalline cellulose has a stable structure and can provide a good loading platform. Al(OH)3 has adsorption and precipitation effects on various heavy metal ions. The magnetism of γ-Fe2O3 enables the treated water treatment agent to be efficiently separated in a magnetic field.

[0022] Furthermore, in the preparation method of the above-mentioned water treatment agent, the base material is cellulose nanofibers, the adsorption material is magnesium hydroxide, and the magnetic material is ferrosoferric oxide.

[0023] Cellulose nanofibers have a large specific surface area and rich functional groups, and can effectively load magnesium hydroxide and ferroferric oxide. Magnesium hydroxide can precipitate heavy metal ions in water, and after treatment, it can be easily separated from the water under the magnetic effect of ferroferric oxide.

[0024] Furthermore, in the preparation method of the above-mentioned water treatment agent, the base material is biochar fiber, the adsorption material is iron hydroxide, and the magnetic material is nickel-zinc ferrite.

[0025] Biochar fiber contains rich pore structures and functional groups, which are conducive to the loading of iron hydroxide. Iron hydroxide has a good adsorption effect on heavy metal ions, and the magnetism of nickel-zinc ferrite can separate the water treatment agent from the water body to avoid secondary pollution.

[0026] The present invention also relates to a dynamic temperature control system of the preparation method of the water treatment agent, the dynamic temperature control system includes a temperature sensor, an A / D module, and a single-chip microcomputer. The dynamic temperature control system adopts a fuzzy RBF neural network PID intelligent control algorithm. A plurality of temperature sensors are arranged in the reactor. The temperature data collected by the plurality of temperature sensors are converted into digital quantities through the A / D module and transmitted to the single-chip microcomputer. The single-chip microcomputer calculates the received digital signal to obtain the real-time temperature, and finally controls the temperature of the heating device of the reactor through the fuzzy RBF neural network PID intelligent control algorithm.

[0027] In the process of preparing water treatment agent, hydrothermal treatment is a very important step. The temperature control accuracy will have a great impact on the quality of water treatment agent. Temperature control is easily affected by factors such as external environment, heating method, equipment container size, temperature transfer medium, etc. Therefore, the present invention designs a dynamic temperature control system, which adopts fuzzy RBF neural network PID intelligent control algorithm. Compared with the traditional algorithm, it not only has better performance in dynamic response, but also has better step and robustness of the system, which can meet the needs of different temperature control, and the temperature error fluctuates within ±0.2℃.

[0028] Compared with the prior art, the present invention has the following beneficial effects: (1) The preparation method of the water treatment agent disclosed in the present invention is reasonably designed to prepare a water treatment agent with a core-shell structure of base material / magnetic material / adsorbent material, which has a good coordination effect and not only has excellent heavy metal ion removal performance, but also can separate heavy metal salts precipitated by an external magnetic field from water, thereby solving the problem of secondary pollution of water bodies; (2) The preparation method of the water treatment agent disclosed in the present invention generates magnetic material and adsorption material in situ on the surface of the base material. The generated adsorption material and magnetic material have a close connection with the base material. Since they are directly generated on the surface of the base material, the distribution of the materials is more uniform, which is conducive to forming a stable core-shell structure. (3) The dynamic temperature control system applied to the preparation method of water treatment agent proposed in the present invention adopts fuzzy RBF neural network PID intelligent control algorithm. Compared with the traditional algorithm, it not only has better performance in dynamic response, but also has better step resistance and robustness of the system, which can meet the needs of different temperature control. The temperature error fluctuates within ±0.2℃, which can ensure the quality of water treatment agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the fuzzy RBF neural network PID intelligent control of the dynamic temperature control system of Example 2 of the present invention. DETAILED DESCRIPTION

[0030] The following will be attached Figure 1 In combination with Examples 1 and 2, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention. The following Example 1 provides a method for preparing a water treatment agent.

[0031] Example 1 The preparation method of the water treatment agent of Example 1 is as follows: S1: Add the dry base material (which may be microcrystalline cellulose, cellulose nanofiber, biochar fiber) into a solvent (which may be an alcohol solvent, water, or an ether solvent), and then perform ultrasonic dispersion until the base material is evenly dispersed in the solvent, thereby providing a uniform reaction environment for subsequent reactions.

[0032] S2: Add metal salts (which may be ferroferric oxide, iron salt FeCl3 corresponding to γ-Fe2O3 or nickel salt, zinc salt and iron salt corresponding to nickel zinc ferrite in appropriate proportions) used to synthesize magnetic materials (which may be ferroferric oxide, γ-ferric oxide, nickel zinc ferrite) to the above-mentioned uniformly dispersed base material solution, add silane coupling agent after it is completely dissolved, the silane coupling agent can stabilize the reaction system and enhance the connection with the base material, and add sodium acetate solution dropwise until the color of the solution changes significantly to obtain a mixed solution 1, transfer the mixed solution 1 to a reactor for hydrothermal treatment (150-250°C, 10-12 h), promote the synthesis of the magnetic material under high temperature and high pressure conditions and load it on the base material, cool to room temperature after hydrothermal treatment, separate the solid product by centrifugation, wash to remove impurities, and dry to obtain a pure base material / magnetic material; S3: The obtained base material / magnetic material is uniformly dispersed in a solvent (which may be an alcohol solvent, water, or an ether solvent), and then a solution of metal ions containing a hydroxide adsorbent (which may be MgCl2, AlCl3, FeCl3, etc.) and a precipitant (which may be sodium hydroxide) are added simultaneously, and the pH is adjusted to 10-11 to create an alkaline environment for generating a hydroxide adsorbent, thereby obtaining a mixed solution II; S4: The mixed solution 2 is transferred to a reactor for hydrothermal treatment (80-100°C, 3-6h). After the hydrothermal treatment, the solid product is separated by filtration, washed to remove impurities, and dried to obtain a pure base material / magnetic material / adsorption material (the mass ratio of the base material / magnetic material / adsorption material is 1-10:1-10:1-10, and the ratio is determined according to actual needs), i.e., a water treatment agent.

[0033] A magnetic water treatment agent with a core-shell layered structure of base material / magnetic material / adsorbent material is prepared by an in-situ generation method. When the adsorbent material hydroxide adsorbent adsorbs heavy metals in sewage, heavy metal precipitates are formed. The heavy metal precipitates interact with the base material cellulose and adhere to the cellulose. The magnetic material gives the water treatment agent magnetism. After the water treatment is completed, it is placed in a magnetic field. Under the action of the magnetic material, the cellulose can separate the heavy metal precipitates from the water body without causing secondary pollution.

[0034] The following Example 2 provides a dynamic temperature control system for use in a method for preparing a water treatment agent.

[0035] Example 2 A number of temperature sensors are installed in the reactor for hydrothermal treatment (contact temperature sensors, PT1000 resistance temperature sensors are used, the accuracy of which is one thousandth, and it has a good effect on system errors). The temperature data collected by the multiple temperature sensors are converted into digital quantities through the A / D module and transmitted to the single-chip microcomputer. The single-chip microcomputer calculates the real-time temperature from the received digital signal, and finally controls the temperature of the heating device of the reactor through the fuzzy RBF neural network PID intelligent control algorithm.

[0036] Specifically, Figure 1 As shown, the fuzzy RBF neural network PID intelligent control algorithm described in the present invention adopts a control strategy through superposition of fuzzy control and RBF neural network. Its structure is a control system with dual-input and three-output neural networks. The system generates a deviation e and a deviation change ec signal, which is transmitted to the fuzzy RBF neural network controller. Then, the fuzzy RBF neural network controller adjusts the three PID output parameters through online self-tuning, thereby achieving an ideal control effect on the controlled object.

[0037] The dynamic temperature control system adopts the fuzzy RBF neural network PID intelligent control algorithm. Compared with the traditional algorithm, it not only has better performance in dynamic response, but also has better step and robustness of the system, which can meet the needs of different temperature control, and the temperature error fluctuates within ±0.2℃.

[0038] The present invention has many specific application paths, and the above is only a preferred embodiment of the present invention. It should be pointed out that the above embodiments are only used to illustrate the present invention, and are not used to limit the protection scope of the present invention. For those of ordinary skill in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a water treatment agent, characterized in that: The base material, the adsorbent material and the magnetic material are compounded into a water treatment agent with a core-shell structure; wherein the base material is cellulose, and the cellulose includes microcrystalline cellulose, microfiber cellulose, cellulose nanofiber, cellulose nanocrystal, and biochar fiber; the adsorbent material is a hydroxide adsorbent, and the hydroxide adsorbent includes aluminum hydroxide, magnesium hydroxide, iron hydroxide, and calcium hydroxide; and the magnetic material includes ferroferric oxide, γ-ferric oxide, and nickel-zinc ferrite.

2. The method for preparing a water treatment agent according to claim 1, characterized in that: In the water treatment agent, the mass ratio of the base material, the adsorption material and the magnetic material is 1-10:1-10:1-10.

3. The method for preparing a water treatment agent according to claim 1, characterized in that: The specific steps include: S1: uniformly dispersing the base material into the solvent, and then adding the metal salt used to synthesize the magnetic material to obtain a mixed solution 1; S2: transferring the mixed solution to a reactor for hydrothermal treatment, cooling to room temperature after the hydrothermal treatment, centrifuging, washing, and drying to obtain a base material / magnetic material; S3: uniformly dispersing the base material / magnetic material in a solvent, and then simultaneously adding a solution of metal ions containing a hydroxide adsorbent and a precipitant, sodium hydroxide, to obtain a mixed solution II; S4: transferring the mixed solution 2 to a reactor for hydrothermal treatment, filtering, washing and drying after the hydrothermal treatment to obtain a base material / magnetic material / adsorption material, i.e., a water treatment agent.

4. The method for preparing a water treatment agent according to claim 3, characterized in that: The dispersion is carried out by ultrasonic dispersion.

5. The method for preparing a water treatment agent according to claim 3, characterized in that: When the magnetic material is added to S1, a silane coupling agent and a sodium acetate solution are also added.

6. The method for preparing a water treatment agent according to claim 1, characterized in that: The base material is microcrystalline cellulose, the adsorption material is aluminum hydroxide, and the magnetic material is gamma-ferric oxide.

7. The method for preparing a water treatment agent according to claim 1, characterized in that: The base material is cellulose nanofiber, the adsorption material is magnesium hydroxide, and the magnetic material is ferrosoferric oxide.

8. The method for preparing a water treatment agent according to claim 1, characterized in that: The base material is biochar fiber, the adsorption material is iron hydroxide, and the magnetic material is nickel-zinc ferrite.

9. A dynamic temperature control system for the preparation method of a water treatment agent according to any one of claims 1 to 8, characterized in that: The dynamic temperature control system includes a temperature sensor, an A / D module, and a single-chip microcomputer. The dynamic temperature control system adopts a fuzzy RBF neural network PID intelligent control algorithm. Several temperature sensors are arranged in the reactor. The temperature data collected by the temperature sensors are converted into digital quantities through the A / D module and transmitted to the single-chip microcomputer. The single-chip microcomputer calculates the received digital signal to obtain the real-time temperature, and finally controls the temperature of the heating device of the reactor through the fuzzy RBF neural network PID intelligent control algorithm.

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