Preparation Method and Application of an Efficient Heavy Metal Wastewater Treatment Agent

Abstract

The present invention relates to the technical field of wastewater treatment, and specifically discloses a preparation method and application of an efficient heavy metal wastewater treatment agent. The method includes: (1) mixing ore industrial solid waste powder, water and a pore-forming agent to form a wet mixture, granulating the obtained particulate matter, drying the granulated matter, and then performing calcination treatment to obtain adsorbent matrix particulate matter. (2) Mixing the adsorbent matrix particulate matter, coke powder, an alkaline substance and water, and performing a hydrothermal reaction, and separately reserving the obtained solid matter and liquid phase. (3) Performing microwave treatment on the solid matter to obtain a precursor. (4) Mixing the liquid phase with the precursor, TEAH, a saturated sodium silicate solution and / or a saturated sodium aluminate solution, performing a hydrothermal reaction, cooling to room temperature after completion, separating out the solid product, washing it to neutrality, and drying to obtain the product. The present invention not only effectively reduces the synthesis time of the treatment agent, but also the obtained treatment agent has excellent removal ability for heavy metal ions in wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and particularly relates to a preparation method and application of an efficient heavy metal wastewater treatment agent. Background Art

[0002] Disclosing the information of this background art section is only intended to enhance the overall understanding of the present invention, and it is not necessarily regarded as an admission or an implication in any form that this information has become the prior art well-known to those of ordinary skill in the art.

[0003] With the rise of industries such as mining and chemical engineering, the extensive use of chemical fertilizers and pesticides, and the unreasonable stacking of waste such as electronic waste, a large number of heavy metal ions have poured into water bodies such as rivers and lakes. How to effectively treat them has become one of the urgent problems to be solved currently. The current main treatment methods include: chemical precipitation method, membrane separation technology, electrolysis method, adsorption method, etc. Among them, the chemical precipitation method refers to adding agents such as sulfides, lime, and polyferric sulfate to the wastewater to form precipitates with heavy metal ions in the water, and then removing the heavy metals through sedimentation or filtration. However, it is prone to cause secondary pollution of the water body during the action process. In addition, in recent years, China's discharge standards for industrial wastewater containing heavy metals have become increasingly strict, and the simple chemical precipitation method has been difficult to meet the discharge requirements. The membrane separation technology is a method of separating and concentrating heavy metal ions in the liquid phase by using a semi-permeable membrane under certain pressure conditions, and has the characteristics of simple process, high selectivity, and the ability to recover heavy metals. However, it requires a large number of supporting equipment, resulting in a high treatment cost for this method and being not easy to be applied on a large scale. The electrolysis method is to reduce and precipitate heavy metal ions in the wastewater on the cathode plate, so as to achieve the purpose of removing heavy metals. This method has problems such as corrosion and loss of the plate, high power consumption, and unstable treatment effect.

[0004] The adsorption method mainly relies on specific adsorption materials to remove heavy metal ions in water. This method has been widely used in the field of wastewater treatment due to its many advantages such as simple operation and low energy consumption. There are many voids on the surface and inside of analcime, and its specific surface area is relatively large. It can remove heavy metal ions in the solution through ion exchange, and its framework is negatively charged, having a strong electrostatic attraction to cations in the water body. Therefore, analcime is considered to be an efficient adsorption material that can be used to treat heavy metal wastewater. Analcime can be prepared from industrial solid wastes rich in silicon and aluminum and natural minerals through hydrothermal reaction, but this method has a low reaction efficiency, resulting in a reaction time of up to more than 48 hours, and there are also problems of low yield and low purity of the generated crystal products, causing a large amount of waste of resources and energy. Summary of the Invention

[0005] The present invention provides a preparation method and application of a high-efficiency heavy metal wastewater treatment agent, which not only effectively reduces the synthesis time of the treatment agent, but also the obtained treatment agent has excellent removal ability for heavy metal ions in wastewater. Specifically, the technical solution of the present invention is as follows.

[0006] First, the present invention provides a preparation method of a high-efficiency heavy metal wastewater treatment agent, including the following steps:

[0007] (1) Mix ore industrial solid waste powder, water and pore-forming agent to form a wet mixture, granulate the obtained particulate matter, dry it, and then carry out calcination treatment. After completion, adsorbent matrix particulate matter is obtained and reserved for use.

[0008] (2) Mix the adsorbent matrix particulate matter, coke powder, alkaline substance and water, and then carry out an activation reaction under microwave heating conditions. After completion, naturally cool to room temperature. Then carry out solid-liquid separation on the reaction system, and reserve the obtained solid matter and liquid phase respectively.

[0009] (3) Carry out secondary microwave activation treatment on the solid matter. After completion, a precursor is obtained and reserved for use.

[0010] (4) Mix the mixture of the liquid phase and the precursor, tetraethylammonium hydroxide (TEAH), saturated sodium silicate solution and / or saturated sodium aluminate solution, carry out a hydrothermal reaction. After completion, cool to room temperature, then separate out the solid product, wash it to neutral, dry it and grind it to obtain a powdery treatment agent.

[0011] Further, in step (1), the ore industrial solid waste includes at least one of coal gangue, fly ash, and kaolin. Optionally, the fineness of the ore industrial solid waste powder is 200-500 mesh.

[0012] Further, in step (1), the mass ratio of the ore industrial solid waste to the pore-forming agent is 1:0.0475-0.1. Optionally, the pore-forming agent includes at least one of β-polypropylene powder, polyethylene powder, rubber powder, etc. Optionally, the fineness of the pore-forming agent is 40-60 mesh. During this process, the pore-forming agent will uniformly adhere to the inside and surface of the particulate matter. Open pores will be formed inside and on the surface of the particulate matter during the subsequent calcination process. As the zeolite gradually crystallizes and grows, these pores will gradually close.

[0013] Further, in step (1), the water content in the wet mixture is 30-35 wt.%.

[0014] Further, in step (1), the particle size of the particulate matter is 10-15 mm, and other suitable particle sizes can also be selected according to needs.

[0015] Further, in step (1), the temperature of the calcination treatment is 600-900°C, and the time is 1.5-2 h.

[0016] Further, in step (2), the mass ratio of the adsorption matrix particles, coke powder, alkaline substance, and water is 1:0.2-0.5:0.13-0.22:0.38-0.6. Optionally, the fineness of the coke powder is 400-700 mesh. The coke powder can play a role in strongly absorbing microwaves and promoting the release of more silicon and aluminum elements from the adsorption matrix particles.

[0017] Further, in step (2), the alkaline substance includes at least one of sodium hydroxide, potassium hydroxide, and ammonia water.

[0018] Further, in step (2), the power of the microwave is 300-500 W, the temperature of the activation reaction is 100-200°C, and the reaction time is 50-90 min.

[0019] Further, in step (3), the power of the microwave heating treatment is 500-650 W, the heating temperature is 200-250°C, and the treatment time is 50-90 min.

[0020] Further, in step (4), the mass ratio of the mixture to tetraethylammonium hydroxide is 1:0.26-0.40.

[0021] Further, in step (4), the saturated sodium silicate solution and the saturated sodium aluminate solution are added according to a silicon-aluminum molar ratio of 1.4-3.3:1 in the reaction system.

[0022] Further, in step (4), the temperature of the hydrothermal reaction is 100-120°C, and the time is 8-12 h.

[0023] Further, in step (4), the fineness of the treatment agent is 100-300 mesh.

[0024] Secondly, the present invention provides the application of the heavy metal wastewater high-efficiency treatment agent obtained by the above preparation method in the fields of environment, chemical industry, water conservancy, wastewater treatment, etc. When in use, the treatment agent is added to the heavy metal-polluted water body to be treated and mixed evenly, and the addition ratio can be selected according to actual needs.

[0025] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0026] The preparation process proposed by the present invention not only effectively reduces the synthesis time of the treatment agent, but also the obtained treatment agent has excellent removal ability for heavy metal ions in wastewater. The reasons are as follows: The present invention first prepares the porous adsorption matrix particles, which not only facilitate the penetration of the lye during the subsequent activation reaction, improve the activation efficiency of the adsorption matrix particles, but also provide a fixed site for the formation of analcime in the subsequent process, enabling the target product to be obtained more efficiently and quickly, and reducing the synthesis time and cost. Further, the present invention uses a liquid-assisted activation system formed by coke powder, alkaline substances and water to carry out activation reaction treatment on the adsorption matrix particles. After the coke powder assists in absorbing microwaves, it can trigger vibrations and frictions at the molecular level, transfer energy to the interior of the particles more uniformly and effectively, improve the efficiency of microwave activation while reducing energy consumption, and can significantly increase the activation degree of the adsorption matrix particles. More activated particles are conducive to releasing silicon and aluminum elements into the liquid-assisted activation system to form silicate and aluminate monomers. At the same time, during this process, the pores reserved by the pore-forming agent in the adsorption matrix particles provide a better penetration channel for the alkaline solution formed by the alkaline substances, increase the contact between the particles and the alkaline solution, and promote the release of the silicon and aluminum elements. In addition, after part of the coke powder becomes part of the final treatment agent, its good adsorption performance also helps to promote the ability of the adsorbent to absorb heavy metal ions. Further, the present invention performs secondary microwave activation on the adsorption matrix particles / solids after the microwave activation treatment, so that the insoluble substances therein undergo the activation process again, thereby releasing silicate and aluminate monomers to the greatest extent, facilitating their extraction by the alkaline liquid phase system in step (4) and providing active substances for the synthesis of zeolite. Finally, the present invention uses TEAH, saturated sodium silicate solution and / or saturated sodium aluminate solution, and uses the liquid phase obtained in step (2) and the precursor obtained in step (3) as the reaction system to directionally synthesize a treatment agent with excellent heavy metal ion removal ability. The reasons are as follows: During this process, the pores synthesized in the precursor provide a site for zeolite crystallization, enabling a large amount of alkaline solution and active ions required for the synthesis of analcime to flow in the precursor. The tetraethylammonium hydroxide enters the frameworks of silicate and aluminate using the advantages of its molecular structure and constructs a unique pore structure. After this pore structure is retained during the crystallization process, it forms the unique crystal morphology of analcime, improving its ability to adsorb heavy metal ions. At the same time, the tetraethylammonium hydroxide also helps to adjust the pH value of the reaction system and accelerate the synthesis of analcime. In addition, the saturated sodium silicate solution and / or saturated sodium aluminate solution effectively ensure the integrity and purity of the formed analcime structure, improving the adsorption ability for heavy metal ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings of the specification, which form a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0028] Figure 1 Sample diagrams of the treatment agents prepared for Examples 1-8 below.

[0029] Figure 2 XRD test results of the treatment agents prepared for Examples 1-8 below.

[0030] Figure 3 Relative crystallinity test results of the treatment agents prepared for Examples 1-8 below.

[0031] Figure 4 Adsorption rate test results of the treatment agents prepared for Examples 1-8 below for heavy metal ions. Detailed implementation manners

[0032] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. For the experimental methods without specific conditions noted in the following embodiments, they are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0033] Unless otherwise defined, all professional and scientific terms used in the present invention have the same meaning as those familiar to persons skilled in the art. The reagents or raw materials used in the present invention can be obtained through conventional channels. Unless otherwise specified, the reagents or raw materials used in the present invention are used in the conventional manner in the art or according to the product instructions. In addition, any methods and materials similar or equivalent to the described content can be applied to the method of the present invention. The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] A preparation method of a high-efficiency treatment agent for heavy metal wastewater includes the following steps:

[0036] (1) Mix pulverized coal gangue with a mesh size of 200 and β-polypropylene powder with a fineness of 50 in a mass ratio of 1:0.05, stir evenly with water to form a wet mixture with a water content of 32 wt.%, granulate, and place the obtained particulate matter (average diameter 10.5 ± 0.5 mm) in an oven and dry at 105 °C for 24 h. Then place the particulate matter in a muffle furnace, heat it to 600 °C at a heating rate of 300 °C / h, hold for 2 h, and after completion, naturally cool to room temperature to obtain adsorption matrix particulate matter for standby.

[0037] (2) Place the adsorbed matrix particulate matter, coke powder with a mesh size of 500, sodium hydroxide, and water in a reaction tank and stir them according to a mass ratio of 1:0.3:0.14:0.4. After the sodium hydroxide is fully dissolved, carry out an activation reaction under microwave heating conditions. The power of the microwave heating is 300 W, the temperature of the activation reaction is 100 °C, and the reaction time is 50 min. After completion, naturally cool to room temperature. Then place the obtained reaction system in a centrifuge (rotation speed 8000 r) and centrifuge for 5 min. The obtained lower-layer solid matter and upper-layer liquid phase are reserved separately.

[0038] (3) Carry out microwave heating treatment on the lower-layer solid matter (temperature 200 °C, power 650 w, heat preservation time 50 min). After completion, obtain a precursor and reserve it.

[0039] (4) First mix the liquid phase in step (2) with the precursor in step (3) to form a mixture, then mix the mixture with tetraethylammonium hydroxide according to a mass ratio of 1:0.3 and stir evenly. Then add saturated sodium silicate solution and saturated sodium aluminate solution to adjust the silicon-aluminum molar ratio in the reaction system to 1.5:1. Then heat the obtained reaction system to 100 °C and keep it warm for 12 hours for hydrothermal reaction. After completion, naturally cool to room temperature. Place the obtained reaction system and the precursor in a centrifuge (rotation speed 8000 r) and centrifuge for 5 min. Wash the obtained lower-layer solid product with clear water until it is neutral, then place it in an oven at 105 °C and dry for 12 h, then grind it and pass through a 200-mesh sieve to obtain the treatment agent, as Figure 1 shown.

[0040] Example 2

[0041] A preparation method of a heavy metal wastewater high-efficiency treatment agent includes the following steps:

[0042] (1) Mix kaolin with a mesh size of 500 and polyethylene powder with a fineness of 60 mesh according to a mass ratio of 1:0.0475, stir evenly with water to form a wet mixture with a moisture content of 30 wt.%, granulate, and place the obtained particulate matter (average diameter 12.5 ± 0.5 mm) in an oven and dry at 105 °C for 24 h. Then place the particulate matter in a muffle furnace, heat it to 800 °C at a heating rate of 300 °C / h, keep it warm for 2 h, and after completion, naturally cool to room temperature to obtain adsorbed matrix particulate matter and reserve it.

[0043] (2) Place the adsorbed matrix particulate matter, coke powder of 700 mesh, sodium hydroxide, and water in a reaction tank according to a mass ratio of 1:0.2:0.13:0.38, stir, and carry out an activation reaction under microwave heating conditions after the sodium hydroxide is fully dissolved. The power of the microwave heating is 400 W, the temperature of the activation reaction is 150 °C, and the reaction time is 70 min. After completion, naturally cool to room temperature. Then place the obtained reaction system in a centrifuge (rotation speed 8000 r) for centrifugation for 5 min, and reserve the lower-layer solid matter and the upper-layer liquid phase separately.

[0044] (3) Carry out microwave heating treatment on the lower-layer solid matter (temperature 250 °C, power 500 w, heat preservation time 75 min), and obtain a precursor after completion, and reserve it.

[0045] (4) First mix the liquid phase in step (2) with the precursor in step (3) to form a mixture, then mix the mixture with tetraethylammonium hydroxide in a mass ratio of 1:0.4 and stir evenly, and then add saturated sodium silicate solution and saturated sodium aluminate solution to adjust the silicon-aluminum molar ratio in the reaction system to 3.3:1. Then heat the obtained reaction system to 105 °C and keep it warm for 10 hours for hydrothermal reaction. After completion, naturally cool to room temperature. Place the obtained reaction system and the precursor in a centrifuge (rotation speed 8000 r) for centrifugation for 5 min, wash the obtained lower-layer solid product with clear water until it is neutral, then place it in an oven at 105 °C for drying for 10 h, then grind it, and pass through a 300-mesh sieve to obtain the treatment agent, as Figure 1 shown.

[0046] Example 3

[0047] A preparation method of a heavy metal wastewater high-efficiency treatment agent includes the following steps:

[0048] (1) Mix fly ash of 300 mesh and waste rubber powder with a fineness of 40 mesh in a mass ratio of 1:0.1, stir evenly with water to form a wet mixture with a moisture content of 35 wt.%, granulate, and place the obtained particulate matter (average diameter 14.5 ± 0.5 mm) in an oven at 105 °C for drying for 24 h. Then place the particulate matter in a muffle furnace, heat it to 900 °C at a heating rate of 300 °C / h, and keep it warm for 1.5 h. After completion, naturally cool to room temperature to obtain the adsorbed matrix particulate matter, and reserve it.

[0049] (2) Mix the adsorbed matrix particulate matter, 400-mesh coke powder, potassium hydroxide, and water in a mass ratio of 1:0.5:0.22:0.6 in a reaction tank and stir. After the potassium hydroxide is fully dissolved, carry out an activation reaction under microwave heating conditions. The power of the microwave heating is 500 W, the temperature of the activation reaction is 200 °C, and the reaction time is 90 min. After completion, naturally cool to room temperature. Then place the obtained reaction system in a centrifuge (rotation speed 8000 r) and centrifuge for 5 min. The lower-layer solid matter and the upper-layer liquid phase obtained are reserved for use respectively.

[0050] (3) Carry out microwave heating treatment on the lower-layer solid matter (temperature 220 °C, power 450 w, heat preservation time 90 min). After completion, obtain a precursor and reserve it for use.

[0051] (4) First mix the liquid phase in step (2) with the precursor in step (3) to form a mixture, then mix the mixture with tetraethylammonium hydroxide in a mass ratio of 1:0.26 and stir evenly. Then add saturated sodium silicate solution and saturated sodium aluminate solution to adjust the silicon-aluminum molar ratio in the reaction system to 1.4:1. Then heat the obtained reaction system to 120 °C and keep it warm for 8 hours for hydrothermal reaction. After completion, naturally cool to room temperature. Place the obtained reaction system and the precursor in a centrifuge (rotation speed 8000 r) and centrifuge for 5 min. Wash the obtained lower-layer solid product with clear water until it is neutral, then place it in an oven at 120 °C and dry for 8 h, then grind it and pass through a 100-mesh sieve to obtain the treatment agent, as Figure 1 shown.

[0052] Example 4

[0053] A preparation method of a heavy metal wastewater high-efficiency treatment agent includes the following steps:

[0054] (1) Mix 200-mesh coal gangue powder and 50-mesh β-polypropylene powder in a mass ratio of 1:0.05, stir evenly with water to form a wet mixture with a moisture content of 32 wt.%, granulate, and place the obtained particulate matter (average diameter 10.5 ± 0.5 mm) in an oven and dry at 105 °C for 24 h. Then place the particulate matter in a muffle furnace, heat it to 600 °C at a heating rate of 300 °C / h, and keep it warm for 2 h. After completion, naturally cool to room temperature to obtain the adsorbed matrix particulate matter and reserve it for use.

[0055] (2) Place the adsorbed matrix particles, coke powder with a mesh size of 500, sodium hydroxide, and water in a reaction tank according to a mass ratio of 1:0.3:0.14:0.4 and stir. After the sodium hydroxide is fully dissolved, carry out an activation reaction under microwave heating conditions. The power of the microwave heating is 300 W, the temperature of the activation reaction is 100 °C, and the reaction time is 50 min. After completion, naturally cool to room temperature. Then place the obtained reaction system in a centrifuge (rotation speed 8000 r) for centrifugation for 5 min, and reserve the lower-layer solid and the upper-layer liquid phase separately.

[0056] (3) Carry out microwave heating treatment on the lower-layer solid (temperature 200 °C, power 650 w, heat preservation time 50 min). After completion, obtain a precursor and reserve it.

[0057] (4) First mix the liquid phase in step (2) and the precursor in step (3) to form a mixture, and then add a saturated sodium silicate solution and a saturated sodium aluminate solution to adjust the silicon-aluminum molar ratio in the reaction system to 1.5:1. Then heat the obtained reaction system to 100 °C and keep it warm for 12 hours for hydrothermal reaction. After completion, naturally cool to room temperature. Place the obtained reaction system and the precursor in a centrifuge (rotation speed 8000 r) for centrifugation for 5 min. Wash the obtained lower-layer solid product with clear water until it is neutral, then place it in an oven at 105 °C for drying for 12 h, then grind it, and pass through a 200-mesh sieve to obtain the treatment agent, as Figure 1 shown.

[0058] Example 5

[0059] A preparation method of a heavy metal wastewater high-efficiency treatment agent includes the following steps:

[0060] (1) Mix fly ash with a mesh size of 300 and waste rubber powder with a fineness of 40 in a mass ratio of 1:0.1, then stir evenly with water to form a wet mixture with a moisture content of 35 wt.%. After granulation, place the obtained particles (average diameter 14.5 ± 0.5 mm) in an oven and dry at 105 °C for 24 h. Then place the particles in a muffle furnace and heat to 900 °C at a heating rate of 300 °C / h, then keep it warm for 1.5 h. After completion, naturally cool to room temperature to obtain adsorbed matrix particles and reserve them.

[0061] (2) Place the adsorbed matrix particles, coke powder with a mesh size of 400, potassium hydroxide, and water in a reaction tank according to a mass ratio of 1:0.5:0.22:0.6 and stir. After the potassium hydroxide is fully dissolved, carry out an activation reaction under microwave heating conditions. The power of the microwave heating is 500 W, the temperature of the activation reaction is 200 °C, and the reaction time is 90 min. After completion, naturally cool to room temperature, and reserve the obtained solid-liquid reaction system.

[0062] (3) Mix the solid-liquid reaction system in step (2) with tetraethylammonium hydroxide at a mass ratio of 1:0.26, stir evenly, then add saturated sodium silicate solution and saturated sodium aluminate solution to adjust the silicon-aluminum molar ratio in the reaction system to 1.4:1. Then heat the obtained reaction system to 120 °C and keep it warm for 8 hours for hydrothermal reaction. After completion, cool it naturally to room temperature. Place the obtained reaction system and the precursor in a centrifuge (rotation speed 8000r) for centrifugation for 5 minutes. Wash the obtained lower-layer solid product with clear water until it is neutral, then place it in an oven at 120 °C for drying for 8 hours, then grind it, and pass through a 100-mesh sieve to obtain the treatment agent, as Figure 1 shown.

[0063] Example 6

[0064] A preparation method of a high-efficiency treatment agent for heavy metal wastewater, comprising the following steps:

[0065] (1) Mix kaolin with a mesh size of 500 and polyethylene powder with a fineness of 60 mesh at a mass ratio of 1:0.0475, stir evenly with water to form a wet mixture with a moisture content of 30 wt.%, granulate, and place the obtained particulate matter (average diameter 12.5 ± 0.5 mm) in an oven at 105 °C for drying for 24 hours. Then place the particulate matter in a muffle furnace, heat it to 800 °C at a heating rate of 300 °C / h, keep it warm for 2 hours, and after completion, cool it naturally to room temperature to obtain adsorption matrix particulate matter for standby.

[0066] (2) Place the adsorption matrix particulate matter, coke powder with a mesh size of 700, sodium hydroxide, and water in a reaction tank according to a mass ratio of 1:0.2:0.13:0.38, stir, and carry out an activation reaction under microwave heating conditions after the sodium hydroxide is fully dissolved. The power of the microwave heating is 400 W, the temperature of the activation reaction is 150 °C, and the reaction time is 70 minutes. After completion, cool it naturally to room temperature. Then place the obtained reaction system in a centrifuge (rotation speed 8000r) for centrifugation for 5 minutes to obtain the lower-layer solid matter and the upper-layer liquid phase. Then replace the upper-layer liquid phase with the same volume of clear water for standby.

[0067] (3) Carry out microwave heating treatment on the lower-layer solid matter (temperature 250 °C, power 500w, heat preservation time 75 minutes). After completion, obtain a precursor for standby.

[0068] (4) Mix the clear water in step (2) with the precursor in step (3) first to form a mixture, then mix the mixture with tetraethylammonium hydroxide in a mass ratio of 1:0.4 and stir evenly. Then add saturated sodium silicate solution and saturated sodium aluminate solution to adjust the silicon-aluminum molar ratio in the reaction system to 3.3:1. Then heat the obtained reaction system to 105 °C and keep it warm for 10 hours for hydrothermal reaction. After completion, cool it naturally to room temperature. Place the obtained reaction system and the precursor in a centrifuge (rotation speed 8000r) for centrifugation for 5 minutes. Wash the obtained lower-layer solid product with clear water until it is neutral, then place it in an oven at 105 °C and dry it for 10h, then grind it and pass through a 300-mesh sieve to obtain the treatment agent, as Figure 1 shown.

[0069] Example 7

[0070] A preparation method of a highly efficient treatment agent for heavy metal wastewater, comprising the following steps:

[0071] (1) Mix coal gangue powder with a mesh size of 200 and β-polypropylene powder with a fineness of 50 in a mass ratio of 1:0.05, stir evenly with water to form a wet mixture with a moisture content of 32 wt.%, granulate, and place the obtained particulate matter (average diameter 10.5 ± 0.5 mm) in an oven and dry it at 105 °C for 24 h. Then place the particulate matter in a muffle furnace, heat it to 600 °C at a heating rate of 300 °C / h, keep it warm for 2 h, and after completion, cool it naturally to room temperature to obtain adsorption matrix particulate matter for standby.

[0072] (2) Place the adsorption matrix particulate matter, coke powder with a mesh size of 500, and water in a reaction tank in a mass ratio of 1:0.3:0.4 and stir, then carry out an activation reaction under microwave heating conditions. The power of the microwave heating is 300 W, the temperature of the activation reaction is 100 °C, and the reaction time is 50 min. After completion, cool it naturally to room temperature. Then place the obtained reaction system in a centrifuge (rotation speed 8000r) for centrifugation for 5 minutes, and reserve the obtained lower-layer solid matter and upper-layer liquid phase respectively.

[0073] (3) Carry out microwave heating treatment on the lower-layer solid matter (temperature 200 °C, power 650w, holding time 50 min), and after completion, obtain a precursor for standby.

[0074] (4) Mix the liquid phase in step (2) with the precursor in step (3) first to form a mixture, then mix the mixture with tetraethylammonium hydroxide at a mass ratio of 1:0.3 and stir evenly. Then add saturated sodium silicate solution and saturated sodium aluminate solution to adjust the silicon-aluminum molar ratio in the reaction system to 1.5:1. Then heat the obtained reaction system to 100 °C and keep it warm for 12 hours for hydrothermal reaction. After completion, naturally cool it to room temperature. Place the obtained reaction system and the precursor in a centrifuge (rotation speed 8000r) for centrifugation for 5 minutes. Wash the obtained lower-layer solid product with clear water until it is neutral, then place it in an oven at 105 °C for drying for 12 hours, then grind it, and pass through a 200-mesh sieve to obtain the treatment agent, as Figure 1 shown.

[0075] Example 8

[0076] A preparation method of a highly efficient treatment agent for heavy metal wastewater, comprising the following steps:

[0077] (1) Mix kaolin with a mesh size of 500 and polyethylene powder with a fineness of 60 mesh at a mass ratio of 1:0.0475, stir evenly with water to form a wet mixture with a water content of 30 wt.%, granulate, and place the obtained particulate matter (average diameter 12.5 ± 0.5 mm) in an oven at 105 °C for drying for 24 hours. Then place the particulate matter in a muffle furnace and heat it to 800 °C at a heating rate of 300 °C / h and keep it warm for 2 hours. After completion, naturally cool it to room temperature to obtain adsorption matrix particulate matter for standby.

[0078] (2) Place the adsorption matrix particulate matter, coke powder with a mesh size of 700, sodium hydroxide, and water in a reaction tank at a mass ratio of 1:0.2:0.13:0.38 and stir. After the sodium hydroxide is fully dissolved, carry out an activation reaction under microwave heating conditions. The power of the microwave heating is 400 W, the temperature of the activation reaction is 150 °C, and the reaction time is 70 minutes. After completion, naturally cool it to room temperature. Then place the obtained reaction system in a centrifuge (rotation speed 8000r) for centrifugation for 5 minutes. The obtained lower-layer solid matter and upper-layer liquid phase are respectively reserved for standby.

[0079] (3) Carry out microwave heating treatment on the lower-layer solid matter (temperature 250 °C, power 500w, holding time 75 minutes). After completion, obtain a precursor for standby.

[0080] (4) Mix the liquid phase in step (2) with the precursor in step (3) first to form a mixture, and then mix the mixture with tetraethylammonium hydroxide in a mass ratio of 1:0.4 and stir evenly. Then heat the obtained reaction system to 105 °C and keep it warm for 10 hours for hydrothermal reaction, and after completion, cool it naturally to room temperature. Place the obtained reaction system and the precursor in a centrifuge (rotation speed 8000 r) for centrifugation for 5 min, wash the obtained lower-layer solid product with clear water until neutral, then place it in an oven at 105 °C for drying for 10 h, then grind it, and pass through a 300-mesh sieve to obtain the treatment agent, as Figure 1 shown.

[0081] Performance test:

[0082] (1) Grind the treatment agent prepared in the above Examples 1-8 in an agate mortar and pass through a 200-mesh sieve. Use an X-ray diffractometer (XRD) of the Bruker D8 ADVANCE model to perform a phase test on the sample, and the results are as Figure 2 shown. The test conditions are Cu target, tube voltage 40 kV, tube current 40 mA, scanning speed 0.12(°) / min, and scanning range 5-60°. The test results are analyzed using software, and the relative crystallinity is calculated to verify the purity of analcime in the treatment agent (Example 1 is set as the reference sample, that is, the crystallinity in Example 1 is 100%). The calculation formula for relative crystallinity is:

[0083] (1).

[0084] Among them, Sn: the characteristic peak area of the sample; Sni: the characteristic peak area of the reference sample. Select 9 main characteristic peaks of analcime at 2 =15.82°, 18.30°, 25.97°, 30.55°, 33.29°, 35.83°, 40.50°, 47.78°, 52.47° to calculate the relative crystallinity. The relative crystallinity results of Examples 1-8 are as follows in the table and Figure 3 shown. It can be seen that the crystallinity of the treatment agents prepared in Examples 1-3 is significantly higher than that of other examples.

[0085]

[0086] (2) Prepare a Pb 2+ solution with a mass concentration of 150 mg / L (adjust the solution pH = 4 with 0.1 mol / L HCl) to simulate the discharged heavy metal wastewater. Accurately transfer 100 ml of this solution to a conical flask for each group, and add 1 g of the treatment agent prepared in the above examples respectively. Place the conical flask on a magnetic stirrer and oscillate at a speed of 150 r / min at room temperature. Take samples at different times to measure Pb in the filtrate 2+Concentration, calculate the adsorption rate. The calculation formula for the adsorption rate is: α = (C 1 - C 2 ) / C 1 . Among them, α: adsorption rate; C 1 : initial heavy metal concentration; C 2 : heavy metal concentration at equilibrium. The adsorption rate test results of each example are as Figure 4 shown. It can be seen from this that the adsorption rates of the treatment agents prepared in Examples 1 to 3 can all reach more than 90%, and the time to reach adsorption saturation is all more than 155 min. The adsorption rates of other examples are all below 78%, indicating that the heavy metal adsorption ability of the treatment agents prepared in Examples 1 to 3 is significantly better than that of other examples.

[0087] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a high-efficiency heavy metal wastewater treatment agent, characterized in that: The steps include: (1) Mixing ore industrial solid waste powder, water and pore-forming agent to form a wet mixture, drying the obtained particles after granulation, and then calcining them to obtain adsorption matrix particles for standby use; (2) mixing the adsorption matrix particles, coke powder, alkaline substance and water, and then performing an activation reaction under microwave heating conditions, and then naturally cooling to room temperature after completion; then performing solid-liquid separation on the reaction system, and the obtained solid and liquid phases are separately used; (3) subjecting the solid to a secondary microwave activation treatment, and obtaining a precursor for later use; (4) mixing the liquid phase with the mixture of the precursor, tetraethylammonium hydroxide, saturated sodium silicate solution and / or saturated sodium aluminate solution, and then subjecting the mixture to a hydrothermal reaction. After the reaction is completed, the mixture is cooled to room temperature, and then a solid product is separated, washed to neutrality, dried, and ground to obtain a powdery treatment agent. In step (2), the mass ratio of the adsorption matrix particles, coke powder, alkaline substance and water is 1:0.2-0.5:0.13-0.22:0.38-0.6; In step (2), the alkaline substance includes at least one of sodium hydroxide, potassium hydroxide, and ammonia water; In step (4), the mass ratio of the mixture to tetraethylammonium hydroxide is 1:0.26-0.40; In step (4), the sodium silicate saturated solution and / or sodium aluminate saturated solution are added according to the silicon-aluminum molar ratio of 1.4 to 3.3:1 in the reaction system; In step (4), the temperature of the hydrothermal reaction is 100-120° C. and the time is 8-12 hours.

2. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: In step (1), the mineral industrial solid waste includes at least one of coal gangue, fly ash and kaolin.

3. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: The fineness of the ore-based industrial solid waste powder is 200-500 meshes.

4. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: In step (1), the moisture content of the wet mix is ​​30-35 wt.%.

5. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: In step (1), the particle size of the particles is 10-15 mm.

6. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: In step (1), the mass ratio of the ore-based industrial solid waste to the pore-forming agent is 1:0.0475-0.

1.

7. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: In step (1), the pore-forming agent includes at least one of β-polypropylene powder, polyethylene powder, and rubber powder.

8. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: In step (1), the fineness of the pore-forming agent is 40-60 mesh.

9. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: In step (1), the calcination treatment is carried out at a temperature of 600-900°C and for a time of 1.5-2 hours.

10. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: In step (2), the fineness of the coke powder is 400-700 mesh.

11. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: In step (2), the power of the microwave is 300-500 W, the temperature of the activation reaction is 100-200° C., and the reaction time is 50-90 min.

12. The method for preparing a high-efficiency heavy metal wastewater treatment agent according to claim 1, characterized in that: In step (3), the power of the microwave heating treatment of the solid object is 500-650 W, the heating temperature is 200-250° C., and the treatment time is 50-90 min.

13. Use of the high-efficiency heavy metal wastewater treatment agent obtained by the preparation method according to any one of claims 1 to 12 in the fields of environment, chemical industry, water conservancy or wastewater treatment.

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