High-efficiency wastewater mercury removal agent and preparation method thereof

Abstract

The application discloses a high-efficiency wastewater mercury removal agent and a preparation method thereof, belongs to the field of wastewater mercury removal, and comprises 20-50 parts of inorganic particles, wherein the inorganic particles are at least one of bentonite, zeolite or molecular sieve, the surface of the inorganic particles is chemically modified by using 1-5 parts of a silane coupling agent, and then the surface is adsorbed by 1-10 parts of an organic thioamide reagent; the bentonite is calcium-based bentonite or sodium-based bentonite with a blue absorption capacity of 40-50 g / 100 g and an expansion ratio of 20-40, the zeolite is clinoptilolite or mordenite, and the molecular sieve is 3A or 4A molecular sieve; the silane coupling agent is at least one of gamma-aminopropyl triethoxysilane, gamma-glycidyl ether oxygen propyl trimethoxysilane, methacryloyl trimethoxysilane, 2-(3,4-epoxy cyclohexyl) ethyl trimethoxysilane and 3-mercapto propyl trimethoxysilane; and the organic thioamide reagent is one or both of thiosemicarbazide and dithizone.

Description

Technical Field

[0001] This invention relates to the field of mercury removal from wastewater, specifically to a highly efficient mercury removal agent for wastewater and its preparation method. Background Technology

[0002] Mercury, also known as quicksilver, is of great concern due to its extreme toxicity caused by binding to biological proteins in the human body and its ability to accumulate in organisms. Mercury is volatile, easily migrates, and is non-degradable, making it readily absorbed through the skin, respiratory tract, and digestive tract. Therefore, mercury is listed as one of the world's most concerning pollutants.

[0003] Mercury-containing wastewater is one of the main carriers of mercury and its derivatives. To ensure the safety of wastewater treatment and utilization, my country stipulates in relevant standards ("Water Quality Standard for Wastewater Discharge into Sewers" (CJ343-2010)) that the mercury concentration in urban wastewater discharged into sewers should be <20 μg / L, and the mercury concentration in treated urban wastewater effluent should be <5 μg / L. The main sources of mercury-containing wastewater in China are industrial wastewater generated by enterprises including coal combustion, non-ferrous metals, waste incineration, chlor-alkali, mining, and smelting. Among these, PVC production accounts for 50% to 60% of total mercury consumption, generating primarily mercury-containing wastewater, making the PVC production industry the most significant producer of mercury-containing wastewater.

[0004] Currently, mainstream methods for treating mercury-containing wastewater can be broadly categorized as follows: traditional chemical precipitation, ion exchange, reduction, adsorption, electrolysis, amalgam extraction, and microbial treatment. However, these methods suffer from drawbacks such as high difficulty or complex processes, making them unsuitable for the requirements of mercury-containing wastewater treatment. Traditional chemical precipitation is suitable for high-concentration mercury-containing wastewater, but its disadvantage lies in the formation of soluble mercury-sulfur complexes when sulfides are excessive, leading to residual sulfur pollution in the effluent. Ion exchange equipment is compact and requires little space, but its operating costs are high, and regeneration can easily cause secondary pollution. Reduction reacts rapidly, but it is susceptible to interference from other cations in the solution, making it difficult to achieve low levels of mercury in the effluent. Electrolysis has high removal efficiency, but it is difficult to achieve low levels of mercury ions, consumes a lot of electricity, and easily generates mercury vapor, causing secondary pollution. Amalgam extraction can obtain elemental metallic mercury, but its treatment effect is poor, requiring multi-stage filter beds in series, resulting in high costs. While microbial treatment can ensure thorough mercury removal, it has a long reaction time, requires microbial fixation and a high-quality living environment, and is highly susceptible to failure due to changes in the surrounding water.

[0005] Adsorption is currently the most popular research direction in the treatment of heavy metal-containing wastewater. Adsorption methods are effective for treating high-concentration, low-concentration, and trace mercury-containing wastewater. Mercury removal adsorbents can be divided into two main categories based on their adsorption mechanism: physical adsorbents and chemical adsorbents. Physical adsorbents typically have a large specific surface area and adsorb various forms of mercury through contact with wastewater, but their adsorption efficiency is relatively low and their selectivity is poor. Chemical mercury removal adsorbents generally adsorb mercury using materials containing functional groups such as thiol, amino, sulfonic acid, and hydroxyl groups. They can remove low concentrations of mercury ions from solution, but this method is easily affected by impurities in the wastewater, significantly impacting the selectivity. Furthermore, adsorption removal often requires the addition of flocculants and alkalis for precipitation, greatly affecting treatment efficiency and effectiveness.

[0006] Silicate minerals are inexpensive natural adsorbents with broad-spectrum adsorption effects. However, silicate minerals typically have a small specific surface area, resulting in poor adsorption performance without appropriate modification. Furthermore, due to the limited number of effective functional groups on the surface of silicate minerals, they cannot form good chemical bonds with the adsorbed medium, often leading to desorption due to adsorption saturation. This can cause secondary pollution during adsorbent treatment.

[0007] Methods for surface treatment of silicate minerals include intercalation, surface chemical modification, and corrosion. However, the effectiveness of surface modification of specific silicate minerals for adsorbing specific substances varies greatly. Patent CN102112415A describes intercalation modification using bentonite, montmorillonite, lithium montmorillonite, bedesite, soapstone, chloromontmorillonite, chromite, zinc montmorillonite, magnesia, and / or synthetic montmorillonite derivatives, especially fluorinated lithium montmorillonite and lithium soapstone; mixed layered clays and their synthetic derivatives, especially rettoite; vermiculite, illite, mica materials, and their synthetic derivatives. However, it does not describe the treatment effect on specific mercury- and arsenic-containing wastewater.

[0008] Therefore, how to combine the characteristics of physical and chemical adsorption, modify the surface of inexpensive natural adsorbents, and bond more effective agents or substances to the surface to bind mercury elements, thereby increasing the specific surface area and the number of effective specific functional groups of natural adsorbents, and preparing wastewater mercury removal agents with excellent and efficient adsorption performance has become one of the hot topics in the field of mercury-containing wastewater treatment and environmental remediation. Summary of the Invention

[0009] The purpose of this invention is to provide a highly efficient wastewater mercury removal agent and its preparation method, particularly a highly efficient wastewater mercury removal agent and its preparation method based on natural inorganic adsorbents such as bentonite, zeolite, and molecular sieves.

[0010] To achieve the above objectives, the first aspect of this invention employs natural inorganic adsorbents with large specific surface areas, such as bentonite, zeolite, and molecular sieves, and chemically modifies their surfaces using silane coupling agents. Subsequently, organic thioamide reagents are adsorbed onto their surfaces.

[0011] A highly efficient wastewater mercury removal agent comprises 20-50 parts of inorganic particles, wherein the inorganic particles are at least one of bentonite, zeolite, or molecular sieve. The surface of the inorganic particles is chemically modified with 1-5 parts of a silane coupling agent, followed by adsorption on the surface with 1-10 parts of an organic sulfur-containing amide reagent. The bentonite is calcium-based or sodium-based bentonite with a blue adsorption capacity of 40-50 g / 100 g and a swelling ratio of 20-40; the zeolite is clinoptilolite or mordenite; and the molecular sieve is 3A or 4A molecular sieve. The silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, methacryloyloxyfunctionalized silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane. The organic sulfur-containing amide reagent is one or both of thiocarbazine or dithizone.

[0012] The specific features of this scheme also include that the bentonite is sodium-based bentonite with a blue absorption capacity of 45-50g / 100g and an expansion ratio of 30-40, and the zeolite is clinoptilolite.

[0013] The silane coupling agent is selected from γ-aminopropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane. A method for preparing a highly efficient wastewater mercury removal agent is characterized by the following steps: First, 20-50g of inorganic particles are dispersed in 100g of water. The inorganic particles are at least one of bentonite, zeolite, or molecular sieve. The pH is adjusted to 10 with NaOH at room temperature, and the temperature is raised to 50℃. 1-5g of the silane coupling agent is added dropwise to the dispersion over 30 minutes. After the addition is complete, the temperature is maintained for 30 minutes. Then, 1-10g of an organic sulfur-containing amide reagent is added, and the mixture is stirred for 60 minutes. After cooling and filtration, the mixture is dried and then ground to obtain the highly efficient wastewater mercury removal agent.

[0014] The specific features of this scheme also include that the bentonite is sodium-based bentonite with a blue absorption capacity of 45-50g / 100g and an expansion ratio of 30-40, and the zeolite is clinoptilolite.

[0015] The silane coupling agent is selected from γ-aminopropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane.

[0016] The organic thioamide reagent is one or both of thiocarbazine or dithizone.

[0017] Compared with existing technologies, this invention has the following advantages: The preparation method employs an aqueous interface adsorption method. Under conditions where water is the continuous phase, the matrix material undergoes chemical surface modification, followed by chemical complexation adsorption with an organic thioamide reagent. The technical solution provided by this invention not only reduces the preparation cost of mercury removal adsorption agents but also significantly reduces raw material costs due to the use of inorganic materials with large specific surface areas. By using inorganic insoluble particles as the adsorption carrier, secondary pollution to wastewater caused by excessive reagent dosage in traditional precipitation adsorption is avoided. The sedimentation rate is fast, achieving good removal results without the need for other flocculants. Simultaneously, by fully utilizing the physical adsorption characteristics of inorganic adsorbents and the chemical complexation effect of organic thioamide reagents for mercury removal, the removal effect is significant for wastewater with complex pollutant compositions and trace mercury wastewater, demonstrating excellent prospects for widespread application. Mercury removal from wastewater is achieved through addition to the wastewater and stirring, a simple operation with a short cycle and high efficiency. Detailed Implementation

[0018] Example 1: A method for preparing a high-efficiency wastewater mercury removal agent. 20g of calcium-based bentonite with a blue absorption capacity of 40g / 100g and an expansion ratio of 20 times, and 10g of mordenite are dispersed in 100g of water. The pH is adjusted to 10 with NaOH at room temperature, and the temperature is raised to 50℃. 2g of γ-aminopropyltriethoxysilane and 2g of 3-mercaptopropyltrimethoxysilane are added dropwise to the dispersion over 30 minutes. The mixture is then kept at this temperature for 30 minutes. Next, 5g of thiocarbazine is added, and the mixture is stirred for 60 minutes. After cooling and filtration, the mixture is dried and ground to obtain the high-efficiency wastewater mercury removal agent.

[0019] The detection uses Hg 2+ A trace mercury solution of 100 ng / L (waste liquid 1), Hg 2+ The wastewater samples were a mercury solution with a concentration of 300 ug / L (waste liquid 2) and concentrated industrial wastewater (waste liquid 3) from a PVC granule manufacturer in Zibo, Shandong Province. The actual industrial wastewater contained Hg. 2+ The concentration of Pb was 227 ug / L. 2+ It was 57.02 ug / L, Cl -1 The mercury content was 237 ug / L, and the pH value was 8.13. During testing, 1 liter of different wastewater samples were taken, and 0.3 g of the high-efficiency wastewater mercury removal agent prepared in Example 1 was added. The mixture was stirred continuously for 30 minutes, then allowed to settle for 2 hours. After filtration using a plate and frame filter press, the mercury content in the filtrate was detected by ion chromatography.

[0020] Example 2: A method for preparing a highly efficient mercury removal agent for wastewater. 10g of sodium-based bentonite with a blue absorption capacity of 45g / 100g and an expansion ratio of 35 times, and 30g of clinoptilolite are dispersed in 100g of water. The pH is adjusted to 10 with NaOH at room temperature, and the temperature is raised to 50℃. 4g of γ-aminopropyltriethoxysilane is added dropwise to the dispersion over 30 minutes. The mixture is then kept at this temperature for 30 minutes. Next, 7g of dithizone is added, and the mixture is stirred for 60 minutes. After cooling and filtration, the mixture is dried and ground to obtain the highly efficient mercury removal agent for wastewater.

[0021] The detection method is the same as that in Example 1.

[0022] Example 3: A method for preparing a high-efficiency wastewater mercury removal agent. 20g of clinoptilolite and 20g of 4A molecular sieve are dispersed in 100g of water. The pH is adjusted to 10 with NaOH at room temperature, and the temperature is raised to 50℃. 1g of methacryloyloxytrimethoxysilane, 1g of γ-glycidyl etheroxypropyltrimethoxysilane, and 2g of 3-mercaptopropyltrimethoxysilane are added dropwise to the dispersion over 30 minutes. After the addition is complete, the temperature is maintained for 30 minutes. Then, 2g of thiocarbazine and 5g of dithizone are added. After stirring for 60 minutes, the mixture is cooled, filtered, dried, and then ground to obtain the high-efficiency wastewater mercury removal agent.

[0023] The detection method is the same as that in Example 1.

[0024] Example 4: A method for preparing a high-efficiency wastewater mercury removal agent. 20g of calcium-based bentonite with a blue absorption capacity of 45g / 100g and an expansion ratio of 35 times, and 20g of 4A molecular sieve are dispersed in 100g of water. The pH is adjusted to 10 with NaOH at room temperature, and the temperature is raised to 50℃. 1g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 2g of 3-mercaptopropyltrimethoxysilane are added dropwise to the dispersion over 30 minutes. After the addition is complete, the temperature is maintained for 30 minutes. Then, 5g of thiocarbazine and 2g of dithizone are added, and the mixture is stirred for 60 minutes. After cooling and filtration, the mixture is dried and ground to obtain the high-efficiency wastewater mercury removal agent.

[0025] The detection method is the same as that in Example 1.

[0026] Example 5: A method for preparing a high-efficiency wastewater mercury removal agent. 20g of calcium-based bentonite with a blue absorption capacity of 45g / 100g and an expansion ratio of 30, 10g of mordenite, and 10g of clinoptilolite are dispersed in 100g of water. The pH is adjusted to 10 with NaOH at room temperature, and the temperature is raised to 50℃. 3g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 1g of methacryloxytrimethoxysilane are added dropwise to the dispersion over 30 minutes. After the addition is complete, the mixture is kept at this temperature for 30 minutes. Then, 9g of thiocarbazine is added, and the mixture is stirred for 60 minutes. After cooling and filtration, the mixture is dried and ground to obtain the high-efficiency wastewater mercury removal agent.

[0027] The detection method is the same as that in Example 1.

[0028] Example 6: A method for preparing a highly efficient wastewater mercury removal agent. 40g of clinoptilolite is dispersed in 100g of water. The pH is adjusted to 10 with NaOH at room temperature. The temperature is then raised to 50℃. 2g of γ-aminopropyltriethoxysilane and 2g of 3-mercaptopropyltrimethoxysilane are added dropwise to the dispersion over 30 minutes. After the addition is complete, the mixture is kept at this temperature for 30 minutes. Then, 7g of dithizone is added, and the mixture is stirred for 60 minutes. After cooling and filtration, the mixture is dried and then ground to obtain the highly efficient wastewater mercury removal agent.

[0029] The detection method is the same as that in Example 1.

[0030] Example 7: A method for preparing a highly efficient mercury removal agent for wastewater. 40g of sodium-based bentonite with a blue absorption capacity of 45g / 100g and an expansion ratio of 40 times is dispersed in 100g of water. The pH is adjusted to 10 with NaOH at room temperature, and the temperature is raised to 50℃. 4g of methacryloyloxytrimethoxysilane is added dropwise to the dispersion over 30 minutes. The mixture is then kept at this temperature for 30 minutes. Next, 9g of dithizone is added, and the mixture is stirred for 60 minutes. After cooling and filtration, the mixture is dried and ground to obtain the highly efficient mercury removal agent for wastewater.

[0031] The detection method is the same as that in Example 1.

[0032] Example 8: A method for preparing a high-efficiency wastewater mercury removal agent. 20g of mordenite zeolite and 20g of 3A molecular sieve are dispersed in 100g of water. The pH is adjusted to 10 with NaOH at room temperature, and the temperature is raised to 50℃. 2g of γ-aminopropyltriethoxysilane, 1g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 1g of 3-mercaptopropyltrimethoxysilane, and 1g of methacryloyloxytrimethoxysilane are added dropwise to the dispersion over 30 minutes. After the addition is complete, the mixture is kept at this temperature for 30 minutes. Then, 5g of thiocarbazine and 4g of dithizone are added. The mixture is stirred for 60 minutes, cooled, filtered, dried, and then ground to obtain the high-efficiency wastewater mercury removal agent.

[0033] The detection method is the same as that in Example 1.

[0034] Example 9: A method for preparing a high-efficiency wastewater mercury removal agent, wherein 20g of 3A molecular sieve is dispersed in 100g of water, the pH value is adjusted to 10 with NaOH at room temperature, the temperature is raised to 50℃, 1g of 3-mercaptopropyltrimethoxysilane is added dropwise to the dispersion, the addition is completed in 30 minutes, and the temperature is maintained for 30 minutes. Then 5g of thiocarbazine and 4g of dithizone are added, the mixture is stirred for 60 minutes, cooled and filtered, dried and then ground to obtain the high-efficiency wastewater mercury removal agent.

[0035] The detection method is the same as that in Example 1.

[0036] Example 10: A method for preparing a highly efficient wastewater mercury removal agent. 30g of sodium-based bentonite with a blue absorption capacity of 50g / 100g and an expansion ratio of 35 times is dispersed in 100g of water. The pH is adjusted to 10 with NaOH at room temperature, and the temperature is raised to 50℃. 2g of methacryloyloxytrimethoxysilane and 2g of 3-mercaptopropyltrimethoxysilane are added dropwise to the dispersion over 30 minutes. The mixture is then kept at this temperature for 30 minutes. Next, 5g of dithizone and 5g of thiocarbazine are added. The mixture is stirred for 60 minutes, cooled, filtered, dried, and then ground to obtain the highly efficient wastewater mercury removal agent.

[0037] The detection method is the same as that in Example 1.

[0038] Comparative Example 1: Commercially available mercury removal agent 1, with Na2S content of 120 mg / g.

[0039] The detection method is the same as that in Example 1.

[0040] Comparative Example 2: 5g of clinoptilolite and 10g of 4A molecular sieve were dispersed in 100g of water. The pH was adjusted to 10 with NaOH at room temperature, and the temperature was raised to 50℃. 0.3g of γ-aminopropyltriethoxysilane and 0.5g of 3-mercaptopropyltrimethoxysilane were added dropwise to the dispersion over 30 minutes. After the addition was complete, the temperature was maintained for 30 minutes. Then, 0.5g of thiocarbazine and 0.2g of dithizone were added, and the mixture was stirred for 60 minutes. After cooling and filtration, the product was dried and ground to obtain the wastewater mercury removal agent. The detection method was the same as in Example 1.

[0041] Comparative Example 3: 10g of calcium-based bentonite with a blue absorption capacity of 20g / 100g and an expansion ratio of 10, and 5g of mordenite were dispersed in 100g of water. The pH was adjusted to 10 with NaOH at room temperature, the temperature was raised to 50℃, and 0.5g of thiocarbazine was added. After stirring for 60 minutes, the mixture was cooled, filtered, dried, and then ground into powder for later use. The detection method was the same as in Example 1.

[0042] Comparative Example 4: 2g of γ-aminopropyltriethoxysilane, 1g of 3-mercaptopropyltrimethoxysilane, and 1g of methacryloxytrimethoxysilane were added dropwise to 100g of water over 30 minutes. After the addition was complete, the mixture was kept warm for 30 minutes. Then, 3g of thiocarbazine was added, and the mixture was stirred for 60 minutes. After cooling and filtration, the mixture was dried, ground, and pulverized for later use. The detection method was the same as in Example 1.

[0043] Comparative Example 5: 80g of calcium-based bentonite with a blue absorption capacity of 40g / 100g and a swelling ratio of 30 times, and 15g of 4A molecular sieve were dispersed in 100g of water. The pH was adjusted to 10 with NaOH at room temperature, and the temperature was raised to 50℃. 1.5g of 3-mercaptopropyltrimethoxysilane was added dropwise to the dispersion over 30 minutes. After the addition was complete, the temperature was maintained for 30 minutes. Then, 5.5g of thiocarbazine was added, and the mixture was stirred for 60 minutes. The mixture was then cooled, filtered, dried, and ground for later use. The detection method was the same as in Example 1.

[0044] Comparative Example 6: 40g of sodium bentonite with a blue absorption capacity of 40g / 100g and a swelling ratio of 40 times was dispersed in 100g of water. The pH was adjusted to 10 with NaOH at room temperature, and the temperature was raised to 50℃. 10g of methacryloxytrimethoxysilane was added dropwise to the dispersion over 30 minutes. After the addition was complete, the temperature was maintained for 30 minutes. Then, 15g of dithizone was added, and the mixture was stirred for 60 minutes. After cooling and filtration, the product was dried and ground to obtain the wastewater mercury removal agent. The detection method was the same as in Example 1.

[0045] Comparative Example 7: 20g of sodium bentonite with a blue absorption capacity of 40g / 100g and an expansion ratio of 35 times, and 15g of clinoptilolite were dispersed in 100g of water. The pH was adjusted to 10 with NaOH at room temperature, and the temperature was raised to 50℃. 10g of 3-mercaptopropyltrimethoxysilane was added dropwise to the dispersion. After the addition was completed in 30 minutes, the mixture was kept at the temperature for 30 minutes. After drying, it was ground and pulverized to obtain the wastewater mercury removal agent.

[0046] The detection method is the same as that in Example 1.

[0047] Comparative Example 8 (prepared according to patent CN102112415A)

[0048] 800.0 g of bentonite (preferably with a particle size less than 75 μm and a moisture content of less than 8%) was mixed with 160.0 g of deionized water until a homogeneous mixture was obtained. 2600.0 g of quaternary ammonium salt and 130 g of bis(hydrogenated tallow alkyl)dimethylammonium chloride were added to the bentonite-water mixture and mixed for 5 minutes. 40.0 g of silane reagent (γ-mercaptopropyltrimethoxysilane) was premixed with 20.0 g of ethanol and 2.0 g of water. This prepared solution was added to the above clay-water-quaternary ammonium salt mixture and mixed for 5 minutes. The mixture was extruded three times using a laboratory-grade extruder with a template, and the final extrudate was oven-dried at 85°C until it contained less than 5% moisture by weight. The dried extrudate was ground and collected to a mesh size of 18 to 40.

[0049] The detection method is the same as that in Example 1.

[0050] The test results are shown in the table below.

[0051]

[0052] The results above demonstrate that the adsorption experiments conducted using the embodiments of this invention exhibit outstanding overall performance. For solutions containing trace amounts of mercury, the adsorption results all achieved undetectable levels of mercury. Furthermore, it demonstrates excellent mercury removal effects for wastewater with high mercury content and wastewater with specific complex components, meeting the standards of the "Water Quality Standard for Wastewater Discharged into Sewers" (CJ343-2010), which requires that the mercury concentration in urban wastewater discharged into sewers be <20 μg / L and the mercury concentration in treated urban wastewater effluent be <5 μg / L. In particular, Examples 2 and 6 utilize mercury removal agents prepared by modifying specific amounts of selected inorganic components and silane coupling agents, achieving significant results for Hg removal. 2+ A trace mercury solution of 100 ng / L (waste liquid 1), Hg 2+ The adsorption of mercury in a 300 μg / L mercury solution (waste liquid 2) all achieved undetectable results, indicating that the mercury removal agent prepared by surface modification of specific inorganic components followed by organic hybridization has a significant mercury removal effect. Therefore, from the perspective of the relationship between the technical solutions of the examples and the mercury removal effect, the surface modification of inorganic particles using specific silane coupling agents and thioamide reagents generally shows a normal distribution trend as the dosage of the two components changes within the scope of the claims. In the comparative examples, the dosage of specific silane coupling agent and thioamide in Comparative Example 2 is lower than the scope of the claims, Comparative Example 3 does not perform surface modification of inorganic components, Comparative Example 4 does not use inorganic components, Comparative Example 5 has an inorganic component exceeding the scope of the claims, Comparative Example 6 uses silane coupling agent and thioamide components exceeding the scope of the claims, and Comparative Example 7 does not use thioamide components for modification. None of these examples achieved a good mercury removal effect. Comparative Example 1 used a commercially available mercury removal agent, while Comparative Example 8 used a mercury removal agent prepared according to patent CN102112415A. However, neither of these methods achieved the mercury removal effect described in this claim.

[0053] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical concept of the present invention, the technical solutions of the present invention can be combined in various ways, including various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these combinations should also be considered as the content disclosed in the sub-invention and are all within the protection scope of the present invention.

Claims

1. A wastewater mercury removal agent, characterized in that, The preparation method of the wastewater mercury removal agent includes the following steps: First, disperse 20-50g of inorganic particles in 100g of water. The inorganic particles are at least one of bentonite, zeolite or molecular sieve. Adjust the pH value to 10 with NaOH at room temperature, raise the temperature to 50℃, add 1-5g of silane coupling agent dropwise to the dispersion, and keep it warm for 30 minutes after the dropwise addition is completed. Then add 1-10g of organic thioamide reagent, stir for 60 minutes, cool down and filter, dry and grind to obtain the wastewater mercury removal agent. The bentonite is calcium-based or sodium-based bentonite, with a blue absorption capacity of 40-50 g / 100 g and a swelling ratio of 20-40; the zeolite is clinoptilolite or mordenite; the molecular sieve is 3A molecular sieve and / or 4A molecular sieve; the silane coupling agent is at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, methacryloyloxytrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane; the organic thioamide reagent is one or both of thiocarbazine or dithizone.

2. The wastewater mercury removal agent according to claim 1, characterized in that, The bentonite is sodium-based bentonite with a blue absorption capacity of 45-50g / 100g and an expansion ratio of 30-40, and the zeolite is clinoptilolite.

3. The wastewater mercury removal agent according to claim 1, characterized in that, The silane coupling agent is γ-aminopropyltriethoxysilane and / or 3-mercaptopropyltrimethoxysilane.

4. A method for preparing the wastewater mercury removal agent according to claim 1, characterized in that, The process includes the following steps: First, disperse 20-50g of inorganic particles in 100g of water. The inorganic particles are at least one of bentonite, zeolite, or molecular sieve. Adjust the pH to 10 with NaOH at room temperature, raise the temperature to 50℃, add 1-5g of silane coupling agent dropwise to the dispersion, and keep it warm for 30 minutes after the addition is completed. Then add 1-10g of organic thioamide reagent, stir for 60 minutes, cool and filter, dry, and grind to obtain the wastewater mercury removal agent. The bentonite is calcium-based or sodium-based bentonite, with a blue absorption capacity of 40-50 g / 100 g and a swelling ratio of 20-40; the zeolite is clinoptilolite or mordenite; the molecular sieve is 3A molecular sieve and / or 4A molecular sieve; the silane coupling agent is at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, methacryloyloxytrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane; the organic thioamide reagent is one or both of thiocarbazine or dithizone.

5. The method for preparing the wastewater mercury removal agent according to claim 4, characterized in that, The bentonite is sodium-based bentonite with a blue absorption capacity of 45-50g / 100g and an expansion ratio of 30-40, and the zeolite is clinoptilolite.

6. The method for preparing the wastewater mercury removal agent according to claim 4, characterized in that, The silane coupling agent is γ-aminopropyltriethoxysilane and / or 3-mercaptopropyltrimethoxysilane.

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