Inorganic-organic composite synergistic turbidity and fluoride removal agent, its preparation method and application

Abstract

The present invention discloses an inorganic-organic composite synergistic turbidity and fluoride removal agent, a preparation method thereof and an application. The method includes: S1, mixing a heating agent in a self-heating food heating pack with water to obtain a first slurry, adjusting the pH of the first mixed slurry to 6.0-7.0 to obtain a reacted slurry; secondly, standing for stratification and taking the upper solution to obtain a first solution; in the heating agent, the weight percentage of calcium is 10-20%, and the weight percentage of aluminum is 10-45%; S2, mixing artemisia sphaerocephala powder with water and performing a heat treatment to obtain a second slurry, and filtering the second slurry to obtain an artemisia sphaerocephala water extract; S3, mixing the artemisia sphaerocephala water extract with the first solution to obtain an inorganic-organic composite synergistic turbidity and fluoride removal agent. The present invention solves the problems in the prior art that the efficiency of fluoride and turbidity removal from high-turbidity fluoride-containing mine water is not high, and the mine water resources, the self-heating food heating pack and the artemisia sphaerocephala resources are not fully utilized.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular, to an inorganic-organic composite synergistic turbidity and fluoride removal agent, a preparation method thereof, and an application thereof. Background Art

[0002] With the improvement of living standards and the acceleration of the pace of life, self-heating foods have attracted people's attention due to their convenient and fast characteristics. The sales volume in 2022 is expected to exceed 400 million boxes and is still growing continuously. Calculated according to the most common heating pack specifications, the discarded heating packs after use are about 140 g each, so the generated waste heating pack garbage can reach 50,000 tons. The popularity of self-heating foods is inseparable from the development of food self-heating technology, and the self-heating technology mainly includes quicklime type, aluminum-water type, etc. The quicklime type generates a large amount of heat during the reaction of CaO with H2O to form Ca(OH)2 to heat the food; the aluminum-water type is to react aluminum powder in an alkaline aqueous solution to form sodium aluminate and continuously release a large amount of heat to heat the food. According to different heat release principles, the heating agents in the self-heating food heating packs include calcium-based heating agents, aluminum-based heating agents, magnesium-based heating agents, etc. Currently, the self-heating food heating packs used in the market usually do not have a single-principle exothermic reaction. Commonly, they are composed of two or more components such as the quicklime type and the aluminum-water type. Such a huge usage amount of self-heating packs brings problems in treatment and disposal and the ecological environment. The main components of the discarded heating packs are calcium salts, aluminum salts, iron salts, diatomaceous earth, magnesium salts, etc. According to the turbidity and fluoride removal mechanisms, they are very suitable for treating high-turbidity fluoride-containing wastewater. However, the resource utilization of the effective components in the discarded heating packs is still far from sufficient.

[0003] Artemisia sphaerocephala is a good wild sand-fixing plant and is widely distributed in the northwestern region of China. According to research, the distribution area of Artemisia sphaerocephala in the northwestern desert area reaches 375 million mu, and it is estimated that the desert seed reserves are more than 5 million tons, with very rich resources. However, only a very small part of its seeds - Artemisia sphaerocephala seeds - are used by humans as feed and food thickeners, and most of them have not been effectively utilized.

[0004] On the other hand, according to statistics, the national coal output in 2021 was 4.07 billion tons, and the average water inflow per ton of coal in national mine water was about 2 cubic meters. In 2021 alone, the national mine water inflow exceeded 8 billion cubic meters. As an important unconventional water resource, the state promotes the comprehensive utilization of mine water resources and requires that the supplementary water, industrial production water, ecological environment water, etc. in mining areas give priority to using mine water in coal mines. Most of the mine water in coal mines in China has the characteristic of high suspended solids. The suspended solids in mine water are mainly coal powder, rock powder and other fine particulate matters generated during the coal mining process. Based on this, it is necessary to provide a turbidity removal agent that can efficiently remove turbidity from mine water.

[0005] Since fluorine is one of the most widely distributed elements on Earth and has extremely active chemical properties, it can interact with almost all elements. This has led to the presence of a certain concentration of fluoride ions in the mine water in the western coal mining areas of China, as well as in the wastewater generated during the utilization and processing of coal. Industrial production emissions and the high background value of soil fluorine have caused serious fluorine pollution in some parts of China. Excessive and non-compliant emissions have also made the fluorine pollution of groundwater increasingly serious. Excessive fluorine content in wastewater not only corrodes equipment, accelerates the equipment depreciation rate, and increases the economic burden on enterprises, but also seriously pollutes the ecological environment and has an adverse impact. In the "Surface Water Environment Quality Standard" of China, the fluoride ion concentration in Class III water bodies is required to be less than 1 mg / L. The conventional turbidity removal process for mine water consumes a large amount of conventional coagulants such as polyaluminum chloride (PAC) and polyacrylamide (PAM). The treatment cost is high, and PAC and PAM are prepared and added separately, resulting in many on-site dosing devices and complex operations.

[0006] Currently, the commonly used treatment methods for fluoride-containing wastewater include chemical precipitation method, coagulation method, and adsorption method. The chemical precipitation method usually uses calcium salts as precipitants to form calcium fluoride precipitation to remove fluoride ions. However, this method usually adds an excessive amount of calcium salts, resulting in difficult and slow precipitation of calcium fluoride, making it difficult for the effluent to meet the limit requirements of various industries. It is only suitable for the preliminary treatment of high-concentration fluoride-containing wastewater. The coagulation method is to use the polymers formed by the hydrolysis of aluminum salts and iron salts to remove fluoride ions through adsorption and ion exchange. However, this method has a low fluoride removal efficiency and is only suitable for the treatment of low-concentration fluoride-containing wastewater. The adsorption method mainly uses adsorbents to adsorb fluoride ions in porous materials through physical and chemical adsorption to reduce the fluoride ion concentration in water. However, there are problems such as limited adsorption capacity, difficult regeneration of adsorbents, and secondary pollution of the regeneration liquid during the use of adsorption materials. Compared with the above fluoride removal methods, the fluoride removal method using chemicals has the advantages of fast reaction, simple operation, and small floor area.

[0007] However, most of the commonly used fluoride removal agents in China at present are single metal salts, with a single action mechanism and low efficiency. Therefore, it is imperative to develop high-efficiency fluoride removal agents and seek efficient and economical fluoride removal methods to effectively solve the problem of treating a large amount of fluoride-containing industrial wastewater in China.

[0008] In summary, it is necessary to provide a chemical agent that can exert multiple mechanisms and efficiently remove turbidity and fluoride; at the same time, it is also necessary to provide a method for the resource utilization of discarded self-heating food heating packs and Artemisia sphaerocephala seeds.

[0009] In view of this, the present invention is specifically proposed. Summary of the Invention

[0010] The main object of the present invention is to provide an inorganic-organic composite synergistic turbidity and fluoride removal agent, a preparation method thereof and an application, so as to solve the problems of low efficiency of fluoride and turbidity removal in high-turbidity fluorine-containing mine water, and the insufficient utilization of mine water resources, self-heating food heating packs and Artemisia sphaerocephala resources in the prior art.

[0011] To achieve the above object, according to one aspect of the present invention, there is provided a preparation method of an inorganic-organic composite synergistic turbidity and fluoride removal agent, which includes: S1, mixing the heating agent in the self-heating food heating pack with water to obtain a first slurry, adjusting the pH of the first mixed slurry to 6.0-7.0 to obtain a reacted slurry; secondly, standing for stratification and taking the upper layer solution to obtain a first solution; in the heating agent, the weight percentage content of calcium is 10-20%, and the weight percentage content of aluminum is 10-45%; S2, mixing Artemisia sphaerocephala powder with water and performing a heat treatment to obtain a second slurry, and filtering the second slurry to obtain an Artemisia sphaerocephala water extract; S3, mixing the Artemisia sphaerocephala water extract with the first solution to obtain an inorganic-organic composite synergistic turbidity and fluoride removal agent.

[0012] Further, the weight ratio of the Artemisia sphaerocephala water extract to the first solution is 1:(100-300).

[0013] Further, in step S1, the weight ratio of the heating agent to water is 1:(1-10).

[0014] Further, in step S2, the weight ratio of Artemisia sphaerocephala to water is 1:(100-500).

[0015] Further, the weight concentration of the Artemisia sphaerocephala water extract is 1-5 g / L.

[0016] Further, in step S2, the temperature of the heat treatment is 50-80 °C and the time is 10-30 min; preferably, the heat treatment is carried out under stirring, and more preferably, the stirring rate is 500-800 r / min.

[0017] Further, the Artemisia sphaerocephala powder is obtained by successively air-drying, removing impurities, pulverizing and sieving Artemisia sphaerocephala through a 200-mesh sieve.

[0018] Further, in step S3, the Artemisia sphaerocephala water extract and the first solution are mixed under stirring, the stirring rate is 120-200 r / min, and the stirring time is 10-15 min.

[0019] According to another aspect of the present invention, there is provided an inorganic-organic composite synergistic turbidity and fluoride removal agent, which is obtained according to the above preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent.

[0020] According to another aspect of the present invention, a method for treating high-turbidity fluorine-containing mining wastewater is provided. The suspended solid concentration SS of the high-turbidity fluorine-containing mining wastewater is 100 - 4000 mg / L, the initial turbidity is 300 - 1000 NTU, the particle size of the suspended solids is 1 - 100 μm, the initial fluoride ion concentration is 1 - 10 mg / L, and the pH is 3 - 11. The above-mentioned inorganic-organic composite synergistic turbidity and fluoride removal agent is used to treat the high-turbidity fluorine-containing mining wastewater, and the turbidity of the treated effluent is 6 - 9 NTU, and the fluoride ion concentration is less than 1 mg / L.

[0021] Furthermore, the treatment method includes: adding an inorganic-organic composite synergistic turbidity and fluoride removal agent to the high-turbidity fluorine-containing mining wastewater, stirring, and standing; preferably, the dosage of the inorganic-organic composite synergistic turbidity and fluoride removal agent in the high-turbidity fluorine-containing mining wastewater is 100 - 900 mg / L; preferably, the stirring includes a first stirring and a second stirring carried out in sequence; wherein, the stirring speed of the first stirring is 100 - 200 r / min, and the stirring time is 5 - 15 min; the stirring speed of the second stirring is 50 - 100 r / min, and the time is 1 - 5 min; preferably, the standing time is 15 - 30 min.

[0022] By applying the technical solution of the present invention, an inorganic-organic composite synergistic turbidity and fluoride removal agent is prepared. Compared with the prior art, the present invention can simultaneously realize the resource utilization of self-heating food heating packs, Artemisia sphaerocephala seeds, and sewage. The organic-inorganic composite synergistic turbidity and fluoride removal agent prepared by the present invention has strong stability and a wide application range. Al in the self-heating food heating pack can form various forms of complexes, polymers, and Al(OH)3, etc. through hydrolysis, polymerization, or coordination reactions under different pH conditions, and can achieve fluoride and / or turbidity removal effects through multiple mechanisms; Ca therein also has the functions of fluoride and turbidity removal at the same time. Artemisia sphaerocephala gum has special chemical stability, is in a uniform gelatinous state, and has good turbidity removal effect. Generally speaking, the fluoride removal agent prepared according to the present invention has diverse mechanisms, good effects, and a wide application range, and can treat wastewater with a pH between 3 and 11. In addition, the preparation process of the organic-inorganic composite synergistic turbidity and fluoride removal agent of the present invention is simple, and only the first solution obtained by modulating the heating agent in the self-heating food heating pack in step S1 and the water extract of Artemisia sphaerocephala seeds obtained in step S2 need to be mixed. Compared with the traditional process of separately preparing solutions of PAC and PAM and separately adding them, it saves a lot of equipment costs. The amount of precipitated sludge generated after treating sewage with the fluoride removal agent of the present invention is reduced by more than 20% compared with the existing PAC and PAM, reducing the subsequent sludge dewatering pressure and saving energy consumption. Description of the Drawings

[0023] The accompanying drawings of the specification, which form a part of this application, are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0024] Figure 1 It shows a schematic diagram of the EDS energy spectrum analysis of the heat-generating agent in the self-heating food heating pack according to the present invention. Detailed implementation manners

[0025] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] In order to solve the above problems in the prior art, according to one aspect of the present invention, there is provided a preparation method of an inorganic-organic composite synergistic turbidity and fluoride removal agent, which includes: S1, mixing the heat-generating agent in the self-heating food heating pack with water to obtain a first slurry, adjusting the pH of the first mixed slurry to 6.0 - 7.0 to obtain a reacted slurry; secondly, standing for stratification and taking the upper solution to obtain a first solution; wherein, in the heat-generating agent, the weight percentage of calcium is 10 - 20%, and the weight percentage of aluminum is 10 - 45%; S2, mixing the Artemisia sphaerocephala powder with water and performing a heat treatment to obtain a second slurry, and filtering the second slurry to obtain an Artemisia sphaerocephala water extract; S3, mixing the Artemisia sphaerocephala water extract with the first solution to obtain an inorganic-organic synergistic turbidity and fluoride removal composite agent.

[0027] Compared with the prior art, the present invention can simultaneously realize the resource utilization of the self-heating food heating pack, Artemisia sphaerocephala, and sewage. The organic-inorganic composite synergistic turbidity and fluoride removal agent prepared by the present invention has strong stability and a wide application range. Al in the self-heating food heating pack can form various forms of complexes, polymers, and Al(OH)3, etc. through hydrolysis, polymerization, or coordination reactions under different pH conditions, and can achieve the effects of fluoride removal and / or turbidity removal through various mechanisms; Ca therein also has the functions of fluoride removal and turbidity removal at the same time. Artemisia sphaerocephala gum has special chemical stability, is in a uniform gel state, and has a good turbidity removal effect. Generally speaking, the fluoride removal agent prepared according to the present invention has diverse mechanisms, good effects, and a wide application range, and can treat wastewater with a pH between 3 and 11. In addition, the preparation process of the organic-inorganic composite fluoride removal agent of the present invention is simple, and only needs to mix the first solution prepared by modulating the heat-generating agent in the self-heating food heating pack through step S1 and the Artemisia sphaerocephala water extract obtained in step S2. Compared with the traditional process of separately preparing solutions of PAC and PAM and separately adding them, it saves a lot of equipment costs. The amount of sediment sludge generated after treating sewage with the fluoride removal agent of the present invention is reduced by more than 20% compared with the existing PAC and PAM, reducing the subsequent sludge dewatering pressure and saving energy consumption.

[0028] In the present invention, the self-heating food heating pack can be selected from common commercial brands. In actual operation, only the surface packaging of the heating pack needs to be removed to obtain the solid heating agent therein.

[0029] The EDS energy spectrum analysis test results of a typical heating agent in a used self-heating food heating pack are as Figure 1 shown.

[0030] The organic-inorganic composite synergistic turbidity and fluoride removal agent of the present invention uses both organic Artemisia sphaerocephala seeds and inorganic self-heating food heating packs as raw materials, and has a rich mechanism of action for fluoride and turbidity removal and good treatment effects.

[0031] During the water treatment process, the mechanisms of fluoride and turbidity removal of the organic-inorganic composite synergistic turbidity and fluoride removal agent of the present invention include:

[0032] When pH < 3, Al mainly exists in the form of [Al(H2O)6] 3+ . To maintain the thickness of the diffusion layer required for colloidal charge neutralization, the colloidal double layer is compressed, thereby reducing the Zeta potential on the colloidal slip surface, and the colloid deviates from the stable state, thereby achieving turbidity removal. In addition, [Al(H2O)6] 3+ reacts with fluoride ions in water to form AlF3 precipitate for removal.

[0033] When pH is 3 - 7, the aluminum form in water is mainly mononuclear hydroxyl or polynuclear polyhydroxy complexes, such as Al 13 O4(OH) 24 7+ . On the one hand, it directly adsorbs polyions and macromolecules with opposite charges to achieve the effect of destabilization and coagulation to remove suspended solids. On the other hand, the hydroxyl groups in the formed complex are prone to ion exchange with fluoride ions in water. The fluoride ions can replace the hydroxyl groups in the Al-OH-Al group to form a strong Al-F-Al chemical bond and are removed by sedimentation with the flocs to achieve the effect of fluoride removal.

[0034] When pH reaches 7.0 - 11.0, the aluminum in water mainly exists in the form of aluminum hydroxide, which mainly plays roles such as adsorption bridging and net trapping, and at the same time also plays the role of adsorption charge neutralization of certain hydroxyl complexes to achieve the purpose of removing suspended solids in water. At the same time, aluminum hydroxide can adsorb fluoride ions in water to the surface through surface adsorption and coprecipitation and remove them from water through the precipitation process to achieve the effect of synchronous turbidity and fluoride removal. In such an environment, part of the Al in water also exists in the form of Al 13 O4(OH) 24 7+ as described above, which also promotes the turbidity removal effect.

[0035] Calcium exists in the form of free Ca at pH 3.0 - 11.02+ exists in a form that causes efficient swelling of particles due to the compression of the electric double layer during the water treatment process, which improves the coagulation efficiency for turbidity removal. At the same time, Ca 2+ combines with OH - to form a positively charged hydroxyl complex Ca(OH) + , which further adsorbs a large number of negatively charged particles present in the water, reduces the ξ potential of the particles in the wastewater, and performs turbidity removal. And the Ca 2+ in the water can also combine with fluoride ions to form calcium fluoride that is insoluble in water and is removed after flocculation precipitation, achieving the effect of fluoride removal.

[0036] In the turbidity and fluoride removal agent with synergistic effect, calcium exists in the form of Ca(OH)2 at a pH of 12.0 - 13.0, and fluoride ions in the water are removed together through the formation of calcium fluoride precipitation and surface adsorption. Therefore, the inorganic-organic composite synergistic turbidity and fluoride removal agent of the present invention can also achieve a certain fluoride removal effect at a pH of 12 - 13.

[0037] Artemisia sphaerocephala Krasch. gum shows a limited swelling state in excess water and forms a tough, slippery and viscous gel body, which has a very high viscosity and is non-toxic and side-effect-free to organisms. The molecular weight of Artemisia sphaerocephala Krasch. gum is very large (usually with a weight-average molecular weight above 70,000), and the molecules are connected into long molecular "chains" in a certain orientation to form a fibrous association structure, possessing the basic characteristics of an excellent high-molecular coagulant, and can remove suspended particles or colloidal substances in the wastewater through the mechanism of adsorption bridging.

[0038] In actual operation, it is preferred to use an acid solution to adjust the pH value. For example, typically, dilute hydrochloric acid or sulfuric acid with a weight concentration of 10% can be used to adjust the pH in actual operation.

[0039] In a preferred embodiment, the weight ratio of the water extract of Artemisia sphaerocephala Krasch. seeds to the first solution is 1:(100 - 300). Selecting the above weight ratio is more conducive to uniform mixing and more conducive to maintaining the stability of physical and chemical properties in acidic or alkaline solutions.

[0040] In a preferred embodiment, in step S1, the weight ratio of the self-heating food heating pack to water is 1:(1 - 10). Selecting the above weight ratio is more conducive to the full dissolution of the self-heating food heating pack in water and maintaining a certain concentration.

[0041] In a preferred embodiment, in step S2, the weight ratio of Artemisia sphaerocephala Krasch. seeds to water is 1:(100 - 500). The water absorption of Artemisia sphaerocephala Krasch. seed powder is very strong, reaching dozens of times its own weight. Using a large amount of water is preferably used to make the Artemisia sphaerocephala Krasch. gum in the Artemisia sphaerocephala Krasch. seed powder absorb water and swell more fully in water.

[0042] In a preferred embodiment, the mass concentration of the aqueous extract of Artemisia sphaerocephala Krasch seeds is 1-5 g / L. In the actual implementation process, it is preferred to use gauze to filter the second slurry, aiming to remove insoluble impurities during the water extraction process. Since the viscosity of the leaching solution is relatively high, it is preferred to use gauze for filtration and impurity removal. More preferably, it is preferred to use 4 layers of gauze to filter the second slurry. When the number of gauze layers is too small, the filtration effect is not good. If the number of gauze layers is too large, the filtration is difficult and it will cause waste.

[0043] In a preferred embodiment, the temperature of the heat treatment is 50-80 °C and the time is 10-30 min; preferably, the heat treatment is carried out under stirring conditions, and more preferably the stirring rate is 500-800 r / min. The above preferred conditions are more conducive to the water absorption and extraction of Artemisia sphaerocephala Krasch seeds. The heat treatment temperature should not be too high. When the temperature is too high, the main component in the leaching solution - polysaccharide substances will break and decompose. The above preferred stirring speed is more conducive to separating the colloid in the Artemisia sphaerocephala Krasch seed powder from the outer shell and the central grain by high-speed stirring, which is more conducive to increasing the concentration of the extraction solution for subsequent filtration and separation. In actual operation, it is preferred to use the water bath method for heat treatment to make the heating more uniform during the heat treatment.

[0044] In a preferred embodiment, the Artemisia sphaerocephala Krasch seed powder is obtained by successively air-drying, impurity-removing, pulverizing, and sieving Artemisia sphaerocephala Krasch seeds through a 200-mesh sieve. The Artemisia sphaerocephala Krasch seed powder prepared by the above preferred treatment method is more conducive to subsequent water extraction and obtaining a higher-concentration aqueous extract. If the particle size of the Artemisia sphaerocephala Krasch seed powder is too small, it is not conducive to the filtration and separation of the subsequent water extraction solution. The above method of removing impurities from Artemisia sphaerocephala Krasch seeds after air-drying is preferably dry impurity removal. For example, impurities are removed by a winnowing machine and a sieve. The purpose of impurity removal is to remove impurities such as gravel and broken leaves. The specific method of this step is well-known to those skilled in the art and will not be elaborated here.

[0045] In a preferred embodiment, in step S3, the aqueous extract of Artemisia sphaerocephala Krasch seeds is mixed with the first solution under stirring conditions, the stirring rate is 120-200 r / min, and the stirring time is 10-15 min. The above preferred stirring speed helps to mix evenly without destroying the structure of the coagulant. When used for water treatment, it can not only better exert the adsorption and electro-neutralization effect of the inorganic coagulant, but also be conducive to exerting the bridging adsorption effect of the organic component, greatly improving the coagulation treatment efficiency.

[0046] According to another aspect of the present invention, an inorganic-organic composite synergistic turbidity and fluoride removal agent is provided, which is obtained according to the preparation method of the above inorganic-organic composite synergistic turbidity and fluoride removal agent. The inorganic-organic composite synergistic turbidity and fluoride removal agent of the present invention has low cost, high resource utilization rate, and has the advantages of rich action mechanism, good coagulation effect, strong stability, wide application range, and less sediment sludge generated after treatment.

[0047] According to another aspect of the present invention, a method for treating high-turbidity fluorine-containing mining wastewater is provided. The suspended solid concentration SS of the high-turbidity fluorine-containing mining wastewater is 100 - 4000 mg / L, the initial turbidity is 300 - 1000 NTU, the particle size of the suspended solids is 1 - 100 μm, the initial fluoride ion concentration is 1 - 10 mg / L, and the pH is 3 - 11. The above-mentioned inorganic-organic composite synergistic turbidity-removing coagulant is used to treat the high-turbidity fluorine-containing mining wastewater. After treatment, the turbidity of the effluent is 6 - 9 NTU, and the fluoride ion concentration is less than 1 mg / L. The treated water meets the requirements of the "Surface Water Environmental Quality Standard".

[0048] In a preferred embodiment, the method for treating high-turbidity fluorine-containing mining wastewater includes: adding an inorganic-organic composite synergistic turbidity-removing and defluorinating agent to the high-turbidity fluorine-containing mining wastewater, stirring, and standing still; preferably, the dosage of the inorganic-organic composite synergistic turbidity-removing and defluorinating agent is 100 - 900 mg / L; preferably, the stirring includes a first stirring and a second stirring carried out in sequence; wherein, the stirring speed of the first stirring is 100 - 200 r / min, and the stirring time is 5 - 15 min; the stirring speed of the second stirring is 50 - 100 r / min, and the time is 1 - 5 min; preferably, the standing still time is 15 - 30 min. Among them, the first stirring is a relatively fast stirring, mainly for mixing, while the second stirring is a relatively slow stirring, mainly for flocculation.

[0049] The following further describes the present application in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present application.

[0050] In the following examples and comparative examples, unless otherwise specified, the heat-generating agent in the heat-generating pack contains Al: 15 wt%, Ca: 10 wt%.

[0051] In the following examples and comparative examples, unless otherwise specified, the method for removing impurities from Artemisia sphaerocephala seeds is to remove impurities using a vibrating screen to sieve out impurities such as gravel and broken leaves.

[0052] Example 1

[0053] The method for preparing an inorganic-organic composite synergistic turbidity-removing and defluorinating agent from agricultural solid waste - Artemisia sphaerocephala seeds and waste self-heating packs and the treatment of kaolin mine shaft water are as follows:

[0054] Step S1: Take 250 g of the heat-generating agent from the used and dried self-heating food heat-generating pack in a beaker, add 1250 mL of deionized water, and stir at 100 r / min for 10 min to fully dissolve it;

[0055] Step S2: Take about 100 mL of dilute hydrochloric acid with a mass concentration of 10%, add it to the beaker in Step S1, stir at 100 r / min for 20 min to fully react it with the acid, and adjust the final pH to 6;

[0056] Step S3: Let the solution after the full reaction in Step S2 stand for 30 min, and pour the upper-layer solution into a beaker;

[0057] Step S4: Air-dry, remove impurities, and crush Artemisia sphaerocephala seeds, then pass them through a 200-mesh sieve to make Artemisia sphaerocephala seed powder;

[0058] Step S5: Weigh 5.00 g of the Artemisia sphaerocephala seed powder prepared in Step 4, add 1 L of deionized water, and vigorously stir at 700 r / min in a water bath at 70 °C for 20 min;

[0059] Step S6: Filter the solution in Step S5 with four layers of gauze to obtain an Artemisia sphaerocephala seed aqueous extract with a concentration of 2.5 g / L;

[0060] Step S7: Take 4 mL of the Artemisia sphaerocephala seed aqueous extract prepared in Step S6 and add it to 1 L of the solution prepared in Step S3 (the weight ratio of the Artemisia sphaerocephala seed aqueous extract to the first solution is 1:250), stir at 120 r / min for 20 min to fully mix them, and it is the inorganic-organic composite synergistic turbidity and fluoride removal agent.

[0061] Use the inorganic-organic composite synergistic turbidity and fluoride removal agent of this example for the fluoride and turbidity removal of kaolin mine mine water. Among them, the suspended solid concentration SS, initial fluoride ion concentration, initial turbidity, initial pH value of the kaolin mine mine water; the dosage of the inorganic-organic composite synergistic turbidity and fluoride removal agent; and the fluoride ion concentration and effluent turbidity of the treated effluent are shown in Table 1.

[0062] In Table 1, for Samples 1-4, the particle size of the suspended solids in the kaolin mine mine water is about 1-100 μm, and the average particle size is 3.55 μm; for Samples 5-9, the particle size of the suspended solids is about 20-100 μm, and the average particle size is 74 μm.

[0063] In the coagulation process, a six-blade stirrer is used to carry out the rapid stirring of the mixing reaction and the slow stirring of the flocculation reaction respectively. The rapid stirring speed is 200 r / min, the rapid stirring time is 10 min, the slow stirring speed is 80 r / min, the slow stirring time is 1 min, and the standing time is 25 min.

[0064] It can be seen that the effluent F -The concentrations are all less than 1 mg / L, and the effluent turbidity is all less than 5 NTU, meeting the requirement of the fluoride concentration less than 1 mg / L in the Class III limit of the Environmental Quality Standards for Surface Water and the requirement of turbidity in the Standards for Reclaimed Water Quality for Urban Miscellaneous Water Use (GB / T 18920) and the Standards for Reclaimed Water Quality for Industrial Water Use (GB / T 19923).

[0065] Table 1

[0066]

[0067]

[0068] Comparative Example 1:

[0069] When treating the kaolinite ore mine water of Sample 1 in Table 1, commercially available PAC was used for coagulation treatment. The dosage of PAC was 2000 mg / L. The rapid stirring speed during the coagulation process was 100 r / min, the rapid stirring time was 10 min, the slow stirring speed was 80 r / min, the slow stirring time was 1 min, and the standing time was 25 min. The effluent turbidity was 8.64; the effluent fluoride ion concentration was 1.78 mg / L, and the removal efficiency of fluoride ions was 82.5%.

[0070] Example 2:

[0071] The preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent was the same as that in Example 1.

[0072] Fluoride removal treatment was carried out on the mine water of a certain coal mine in Shendong. The initial F - concentration was 10 mg / L.

[0073] 500 mL of fluoride-containing mine water was taken, and its initial F - concentration was about 10 mg / L, and the pH was about 7.0 (the specific measured values are shown in Table 2). When the dosage of the inorganic-organic composite synergistic turbidity and fluoride removal agent of the present invention was 1750 mg / L, the pH was adjusted to 6.0. During the coagulation process, a six-blade stirrer was used for rapid stirring and slow stirring respectively. The rapid stirring speed was 200 r / min, the rapid stirring time was 10 min, the slow stirring speed was 80 r / min, the slow stirring time was 1 min, and the standing time was 25 min. The effluent F - concentrations were all less than 1 mg / L, meeting the requirement of the fluoride concentration less than 1 mg / L in the Class III limit of the Environmental Quality Standards for Surface Water. The treatment results are shown in Table 2.

[0074] Table 2

[0075]

[0076] Comparative Example 2

[0077] When treating the fluorine-containing mine water of Sample 1 in Table 2, commercially available PAC was used for treatment. The dosage of PAC was 2000 mg / L, and a six-blade stirrer was used for rapid and slow stirring reactions during the coagulation process. Among them, the rapid stirring speed was 200 r / min, the rapid stirring time was 10 min, the slow stirring speed was 80 r / min, the slow stirring time was 1 min, and the standing time was 25 min. The F - concentration of the effluent was 2.25 mg / L, and the removal efficiency of fluoride ions was 77.5%.

[0078] Example 3

[0079] The difference from Example 1 was only that the weight ratio of the aqueous extract of Artemisia sphaerocephala Krasch. to the first solution was 1:300.

[0080] Example 4

[0081] The difference from Example 1 was only that the weight ratio of the aqueous extract of Artemisia sphaerocephala Krasch. to the first solution was 1:100.

[0082] Example 5

[0083] The difference from Example 1 was only that 1250 g of the heat-generating agent was taken.

[0084] Example 6

[0085] The difference from Example 1 was only that 125 g of the heat-generating agent was taken.

[0086] Example 7

[0087] The difference from Example 1 was only that the mass concentration of the aqueous extract of Artemisia sphaerocephala Krasch. was 1.0 g / L.

[0088] Example 8

[0089] The difference from Example 1 was only that the mass concentration of the aqueous extract of Artemisia sphaerocephala Krasch. was 5 g / L.

[0090] Example 9

[0091] The difference from Example 1 was only that in step S5: strong stirring was carried out at 800 r / min in a water bath at 80 °C for 30 min.

[0092] Example 10

[0093] The difference from Example 1 was only that in step S5: strong stirring was carried out at 500 r / min in a water bath at 60 °C for 10 min.

[0094] Comparative Example 3

[0095] The difference from Example 1 was only that the pH of the first mixed slurry was adjusted to 8.

[0096] Comparative Example 4

[0097] It is different from Example 1 in that the aqueous extract of Artemisia sphaerocephala seeds is not added.

[0098] Comparative Example 5

[0099] It is different from Example 1 in that the powder after use of the self-heating food heating pack is replaced with aluminum chloride powder.

[0100] Comparative Example 6

[0101] It is different from Example 1 in that the powder after use of the self-heating food heating pack is replaced with calcium chloride powder.

[0102] The defluorinating agent obtained from Examples 3 to 10 and Comparative Examples 3 to 6 was used to treat the mine water, and the treatment operation method was the same as that of Example 1. The water quality of the mine water and the comparison before and after are shown in Table 3.

[0103] In Table 3, the particle size of the suspended matter in the kaolin mine mine water is about 20 - 100 μm, and the average particle size is 74 μm.

[0104] Table 3

[0105]

[0106]

[0107] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0108] This method realizes the resource recycling of waste self-heating food heating packs and Artemisia sphaerocephala seeds, turning waste into treasure, and provides a feasible solution for the low-cost and high-efficiency treatment of high-turbidity wastewater generated in the mining production process.

[0109] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of an inorganic-organic composite synergistic turbidity and fluoride removal agent, characterized in that, Comprising: S1, mixing the heat-generating agent in the self-heating food heating pack with water to obtain a first slurry, adjusting the pH of the first slurry to 6.0 - 7.0 to obtain a reacted slurry; secondly, standing for stratification and taking the upper-layer solution to obtain a first solution; in the heat-generating agent, the weight percentage content of calcium is 10 - 20%, and the weight percentage content of aluminum is 10 - 45%; S2, mixing artemisia sphaerocephala Krasch. seed powder with water and performing a heating treatment to obtain a second slurry, and filtering the second slurry to obtain an artemisia sphaerocephala Krasch. seed water extract; S3, mixing the artemisia sphaerocephala Krasch. seed water extract with the first solution to obtain the inorganic-organic composite synergistic turbidity and fluoride removal agent.

2. The preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent according to claim 1, characterized in that, The weight ratio of the artemisia sphaerocephala Krasch. seed water extract to the first solution is 1 : (100 - 300).

3. The preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent according to claim 1 or 2, characterized in that, In the step S1, the weight ratio of the heat-generating agent to water is 1:(1 - 10).

4. The preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent according to claim 1 or 2, characterized in that, In the step S2, the weight ratio of the artemisia sphaerocephala Krasch. seeds to water is 1 : (100 - 500).

5. The preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent according to claim 4, characterized in that, The weight concentration of the artemisia sphaerocephala Krasch. seed water extract is 1 - 5 g / L.

6. The preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent according to claim 1 or 2, characterized in that, In the step S2, the temperature of the heating treatment is 50 - 80 °C, and the time is 10 - 30 min.

7. The preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent according to claim 6, characterized in that, The heating treatment is carried out under stirring conditions.

8. The preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent according to claim 7, characterized in that, The stirring rate is 500 - 800 r / min.

9. The preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent according to claim 1 or 2, characterized in that, The artemisia sphaerocephala Krasch. seed powder is obtained by successively air-drying, impurity-removing, pulverizing, and sieving artemisia sphaerocephala Krasch. seeds through a 200-mesh sieve.

10. The preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent according to claim 1 or 2, characterized in that, In the step S3, the artemisia sphaerocephala Krasch. seed water extract is mixed with the first solution under stirring conditions, the stirring rate is 120 - 200 r / min, and the stirring time is 10 - 15 min.

11. An inorganic-organic composite synergistic turbidity and fluoride removal agent, characterized in that, Obtained by the preparation method of the inorganic-organic composite synergistic turbidity and fluoride removal agent according to any one of claims 1 to 10.

12. A treatment method for high-turbidity fluoride-containing mining wastewater, the suspended solid concentration SS of the high-turbidity fluoride-containing mining wastewater is 100~4000mg / L, the initial turbidity is 300~1000 NTU, the suspended solid particle size is 1~100μm, the initial fluoride ion concentration is 1~10mg / L, and the pH is 3~11, characterized in that, Using the inorganic-organic composite synergistic turbidity and fluoride removal agent described in claim 11 to treat the high-turbidity fluoride-containing mining wastewater, wherein the turbidity of the treated effluent is 6 - 9 NTU, and the fluoride ion concentration is less than 1 mg / L.

13. The treatment method for high-turbidity fluoride-containing mining wastewater according to claim 12, characterized in that, The treatment method includes: putting the inorganic-organic composite synergistic turbidity and fluoride removal agent into the high-turbidity fluoride-containing mining wastewater, stirring, and standing.

14. The treatment method of high-turbidity fluorine-containing mining wastewater according to claim 13, characterized in that, The dosage of the inorganic-organic composite synergistic turbidity and fluoride removal agent in the high-turbidity fluoride-containing mining wastewater is 100 - 900 mg / L.

15. The treatment method of high-turbidity fluorine-containing mining wastewater according to claim 13, characterized in that, The stirring includes first stirring and second stirring carried out in sequence; wherein, the stirring speed of the first stirring is 100 - 200 r / min, and the stirring time is 5 - 15 min; the stirring speed of the second stirring is 50 - 100 r / min, and the time is 1 - 5 min.

16. The treatment method of high-turbidity fluorine-containing mining wastewater according to claim 13, characterized in that, The standing time is 15 - 30 min.

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