Preparation method of zirconium modified nitrogen and phosphorus adsorption material

Abstract

The invention discloses a preparation method of a zirconium modified nitrogen and phosphorus adsorption material, which comprises the following steps: dissolving zirconium acetylacetonate in warm water, adding a polyvinyl alcohol resin aqueous solution, stirring, cooling to obtain a zirconium modified aqueous solution, adding a ceramsite matrix into the zirconium modified aqueous solution, dipping for several hours, filtering to obtain modified liquid ceramsite, and drying to obtain the zirconium modified nitrogen and phosphorus adsorption material. And drying the ceramsite of the modified liquid to obtain a ceramsite matrix containing organic zirconium cross-linked gel, finally heating the ceramsite matrix, preserving heat, and heating and sintering to obtain the zirconium modified nitrogen and phosphorus adsorption material with a porous structure. Water-soluble zirconium organic molecules are adopted as a modifier, washing treatment is not needed, wastewater discharge and cost are reduced, zirconium acetylacetonate and amino resin are cross-linked to generate porous zirconium dioxide, and the nitrogen and phosphorus adsorption capacity is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and particularly relates to a method for preparing a zirconium-modified nitrogen and phosphorus adsorption material. Background Art

[0002] With the rapid development of industry and agriculture, the discharge of industrial and domestic wastewater is increasing, and the demand for wastewater treatment is also rising, leading to a continuous increase in treatment costs. Excessive nitrogen and phosphorus content in discharged wastewater can lead to rapid microbial proliferation in the water, causing eutrophication and exacerbating water pollution. At the same time, with improved living standards and a growing public awareness of drinking water safety, reducing nitrogen and phosphorus content in water bodies has become a pressing issue. Reducing the concentrations of phosphate and ammonia nitrogen in water bodies using low-cost adsorption materials is a recognized and effective solution.

[0003] Ordinary nitrogen and phosphorus adsorption materials, such as diatomaceous earth, are limited by the surface adsorption capacity and specific surface area of their silicon dioxide, resulting in less than ideal adsorption effects. To solve this problem, a method of modifying the surface of the adsorption material is usually adopted. Zirconia has a good adsorption capacity for nitrogen and phosphorus, making it an excellent modified material for improving the performance of adsorption materials. However, most existing methods use water-soluble zirconium chloride or zirconium nitrate as raw materials, and deposit zirconium oxide on the inner surface of the porous adsorption material through a co-precipitation method combined with a subsequent sintering process. This type of method usually requires a large amount of water for repeated washing to remove chloride ions or nitrate ions in the solution, resulting in the consumption of a large amount of clean water resources when treating sewage.

[0004] In addition, the specific surface area of zirconia produced by the precipitation method is relatively small, which requires the use of a larger amount of zirconia, which not only increases production costs but also makes it difficult to obtain high adsorption performance.

[0005] Therefore, this paper proposes a preparation method of zirconium-modified nitrogen and phosphorus adsorption materials. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention proposes a preparation method of zirconium-modified nitrogen-phosphorus adsorption material, which simultaneously removes phosphate and ammonia nitrogen. In addition, the modification method does not require water washing and no wastewater is generated. It has the characteristics of low sintering temperature, short time and low production cost.

[0007] In order to achieve the above technical effects, the present invention is implemented by the following technical solution: a preparation method of a zirconium-modified nitrogen-phosphorus adsorption material, characterized in that the preparation method comprises the following steps:

[0008] S1: dissolving 10 to 50 parts of zirconium acetylacetonate in 500 parts of water at a temperature of 60 to 90° C., adding 2 to 30 parts of a polyvinyl alcohol resin aqueous solution, stirring uniformly, and cooling to room temperature to obtain an organic zirconium modified aqueous solution;

[0009] S2: adding 20 to 100 parts of ceramsite matrix to the zirconium modified aqueous solution, standing and impregnating for 4 to 12 hours to allow the modified liquid to fully enter the interior of the ceramsite matrix, and filtering to obtain ceramsite impregnated with the modified liquid;

[0010] S3: drying the ceramsite impregnated with the modified liquid at 120-250° C. for 5-60 minutes to obtain a ceramsite matrix containing an organic zirconium cross-linked gel resin;

[0011] S4: The ceramsite matrix containing the organic zirconium cross-linked gel resin is heated to 200-250°C and kept warm for 30-20 minutes, then heated to 280-300°C and kept warm for 30-20 minutes, and then heated to 450-750°C and sintered for 3-40 minutes to obtain a zirconium-modified nitrogen-phosphorus adsorption material with a porous structure.

[0012] Furthermore, the ceramsite matrix in S2 is at least one of diatomaceous earth ceramsite, zeolite ceramsite, fly ash ceramsite, shale ceramsite, sludge ceramsite, and coal gangue ceramsite.

[0013] Furthermore, the solid content of the polyvinyl alcohol resin aqueous solution in S1 is 1-5%.

[0014] The beneficial effects of the present invention are:

[0015] 1. The present invention uses water-soluble zirconium organic molecules as modifiers. No harmful impurity ions are generated during the modification process, and no water washing treatment is required. Therefore, no wastewater or waste liquid is discharged, which significantly reduces the waste of water resources and environmental pollution.

[0016] 2. The modified liquid used in the modification method of the present invention can be recycled and reused after solid-liquid separation, without generating waste liquid, further reducing the environmental burden, while reducing production costs and improving economic benefits;

[0017] 3. The present invention spontaneously forms an organic-inorganic polymer gel by heating zirconium acetylacetonate; the sintering temperature is low, and after sintering, amorphous porous zirconium dioxide is generated, whose specific surface area is greatly increased, and the adsorption capacity is significantly better than the zirconium oxide material generated by traditional precipitation method, especially in the adsorption of nitrogen and phosphorus, showing higher efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 This is a flow chart for preparing the zirconium-modified nitrogen-phosphorus adsorption material of the present invention. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] Example 1

[0022] (1) dissolving 10 parts of zirconium acetylacetonate in 500 parts of water at a temperature of 90 degrees Celsius, adding 30 parts of a polyvinyl alcohol aqueous solution with a solid content of 1%, stirring evenly and cooling to room temperature to prepare a zirconium-containing modified resin aqueous solution;

[0023] (2) immersing 20 parts of diatomite ceramsite substrate in a zirconium-containing modified resin aqueous solution, leaving it to soak for 12 hours to allow the modified liquid to fully enter the adsorption material, and then performing solid-liquid separation between the ceramsite and the modified liquid; the used modified liquid can be repeatedly used to modify the adsorption ceramsite according to the above solid-liquid ratio with the ceramsite;

[0024] (3) drying the ceramsite soaked in the modified liquid at 120° C. for 60 minutes to allow the zirconium acetylacetonate to be fully cross-linked to obtain a ceramsite matrix containing an organic zirconium cross-linked gel;

[0025] (4) The organic zirconium cross-linked resin modified ceramsite is heated to 200 degrees Celsius and kept warm for 30 minutes, then heated to 280 degrees Celsius and kept warm for 30 minutes, and finally heated to 450 degrees Celsius and sintered for 40 minutes to remove organic matter, thereby obtaining a finished zirconium-modified diatomite ceramsite for sewage treatment.

[0026] The zirconium-modified diatomite obtained by the above modification method has an adsorption saturation concentration of ammonia nitrogen increased by 140% and an adsorption saturation concentration of phosphorus increased by 200% compared with the unmodified diatomite.

[0027] Example 2

[0028] (1) dissolving 20 parts of zirconium acetylacetonate in 500 parts of water at 70 degrees Celsius, adding 20 parts of a polyvinyl alcohol aqueous solution having a solid content of 2%, stirring evenly and cooling to room temperature to prepare a zirconium-containing modified resin aqueous solution;

[0029] (2) immersing 30 parts of zeolite ceramsite substrate in a zirconium-containing modified resin aqueous solution, leaving it to soak for 6 hours to allow the modified liquid to fully enter the adsorption material, and then separating the ceramsite from the modified liquid; the used modified liquid can be repeatedly used to modify the adsorption ceramsite according to the above solid-liquid ratio with the ceramsite;

[0030] (3) drying the ceramsite soaked in the modified liquid at 150° C. for 40 minutes to allow the zirconium acetylacetonate to fully crosslink, thereby obtaining a ceramsite matrix containing an organic zirconium crosslinked gel resin;

[0031] (4) The organic zirconium cross-linked resin modified ceramsite is heated to 220 degrees Celsius and kept warm for 30 minutes, then heated to 290 degrees Celsius and kept warm for 25 minutes, and finally heated to 550 degrees Celsius and sintered for 30 minutes to remove organic matter, thereby obtaining a finished zirconium-modified zeolite ceramsite for sewage treatment.

[0032] The zirconium-modified zeolite ceramsite obtained by the above modification method has an adsorption saturation concentration of ammonia nitrogen increased by 160% and an adsorption saturation concentration of phosphorus increased by 200% compared with the unmodified zeolite ceramsite.

[0033] Example 3

[0034] (1) Dissolve 30 parts of zirconium acetylacetonate in 500 parts of water at 75 degrees Celsius, add 15 parts of a polyvinyl alcohol aqueous solution with a solid content of 3%, stir evenly, and cool to room temperature to prepare a zirconium-containing modified resin aqueous solution;

[0035] (2) 50 parts of fly ash ceramsite matrix were immersed in the above-mentioned zirconium-containing modified resin aqueous solution, and allowed to stand for 5 hours to allow the modified liquid to fully enter the adsorption material, and then the ceramsite and the modified liquid were separated; the used modified liquid can be repeatedly used to modify the adsorption ceramsite according to the above-mentioned solid-liquid ratio with the ceramsite;

[0036] (3) drying the ceramsite soaked in the modified liquid at 160° C. for 20 minutes to allow the zirconium acetylacetonate to fully crosslink, thereby obtaining a ceramsite matrix containing an organic zirconium crosslinked gel resin;

[0037] (4) The organic zirconium cross-linked resin modified ceramsite is heated to 220 degrees Celsius and kept warm for 30 minutes, then heated to 290 degrees Celsius and kept warm for 25 minutes, and finally heated to 600 degrees Celsius and sintered for 25 minutes to remove organic matter, thereby obtaining a finished product of zirconium-modified fly ash ceramsite for sewage treatment.

[0038] The zirconium-modified fly ash ceramsite obtained by the above modification method has an 80% higher adsorption saturation concentration of ammonia nitrogen and a 350% higher adsorption saturation concentration of phosphorus compared to the unmodified fly ash ceramsite.

[0039] Example 4

[0040] (1) Dissolve 40 parts of zirconium acetylacetonate in 500 parts of water at 80 degrees Celsius, add 10 parts of a polyvinyl alcohol aqueous solution having a solid content of 4%, stir evenly, and cool to room temperature to prepare a zirconium-containing modified resin aqueous solution;

[0041] (2) 80 parts of shale ceramsite matrix were immersed in a zirconium-containing modified resin aqueous solution and allowed to stand for 6 hours to allow the modified liquid to fully enter the adsorption material, and then the ceramsite and the modified liquid were separated; the used modified liquid can be repeatedly used to modify the adsorption ceramsite according to the above solid-liquid ratio with the ceramsite;

[0042] (3) drying the ceramsite soaked in the modified liquid at 180° C. for 20 minutes to allow the zirconium acetylacetonate to fully crosslink, thereby obtaining a ceramsite matrix containing an organic zirconium crosslinked gel resin;

[0043] (4) The organic zirconium cross-linked gel resin modified ceramsite is heated to 220 degrees Celsius and kept warm for 20 minutes, then heated to 300 degrees Celsius and kept warm for 20 minutes, and finally heated to 650 degrees Celsius and sintered for 15 minutes to remove organic matter, thereby obtaining a finished zirconium-modified shale ceramsite for sewage treatment.

[0044] The zirconium-modified shale ceramsite obtained by the above modification method has an 80% increase in the adsorption saturation concentration of ammonia nitrogen and a 350% increase in the adsorption saturation concentration of phosphorus compared to the unmodified shale ceramsite.

[0045] Example 5

[0046] (1) Dissolve 50 parts of zirconium acetylacetonate in 500 parts of water at 90 degrees Celsius, add 2 parts of a polyvinyl alcohol aqueous solution with a solid content of 5%, stir evenly, and cool to room temperature to prepare a zirconium-containing modified resin aqueous solution;

[0047] (2) 40 parts of sludge ceramsite matrix, 30 parts of shale ceramsite, and 30 parts of coal gangue mixed ceramsite are immersed in a zirconium-containing modified resin aqueous solution and allowed to stand for 4 hours to allow the modified liquid to fully enter the adsorption material, and then the ceramsite and the modified liquid are separated; the used modified liquid can be repeatedly used to modify the adsorption ceramsite according to the above solid-liquid ratio with the ceramsite;

[0048] (3) drying the mixed ceramsite soaked in the modified liquid at 250° C. for 10 minutes to allow the zirconium acetylacetonate to fully crosslink, thereby obtaining a ceramsite matrix containing an organic zirconium crosslinked gel resin;

[0049] (4) The organic zirconium cross-linked gel resin modified ceramsite is heated to 220 degrees Celsius and kept warm for 30 minutes, then heated to 280 degrees Celsius and kept warm for 25 minutes, and finally heated to 750 degrees Celsius and sintered for 3 minutes to remove organic matter, thereby obtaining a finished zirconium-modified mixed ceramsite for sewage treatment.

[0050] The zirconium-modified mixed ceramsite obtained by the above modification method has an adsorption saturation concentration of ammonia nitrogen increased by 80% and an adsorption saturation concentration of phosphorus increased by 350% compared with the unmodified mixed ceramsite.

[0051] Example 6

[0052] (1) Dissolve 20 parts of zirconium chloride in 500 parts of water, add 100 parts of diatomaceous earth ceramsite, stir thoroughly, then adjust the pH value of the solution to 10 with 5% sodium hydroxide solution to allow the zirconium chloride to hydrolyze and precipitate, and continue stirring for 24 hours;

[0053] (2) The obtained ceramsite was subjected to solid-liquid separation, rinsed with clean water, and filtered, and the process was repeated 5 times until no Cl ions were detected;

[0054] (3) The obtained ceramsite is sintered at 800 degrees Celsius for 2 hours to obtain zirconium-modified ceramsite.

[0055] (4) Compared with the unmodified ceramsite, the above-mentioned modified ceramsite has an increased saturated concentration of ammonia nitrogen adsorption by 60%, and an increased saturated concentration of phosphorus adsorption by 150%. However, during the production process, due to the washing to remove harmful impurity ions, a large amount of wastewater containing chloride ions is generated, which is more than ten times the amount of ceramsite. At the same time, the modified liquid can only be used once, which not only causes serious pollution and waste, but also takes time to produce, consumes a lot of energy, and has high costs.

Claims

1. A method for preparing a zirconium-modified nitrogen and phosphorus adsorption material, characterized in that: The preparation method comprises the following steps: S1: dissolving 10 to 50 parts of zirconium acetylacetonate in 500 parts of water at a temperature of 60 to 90° C., adding 2 to 30 parts of a polyvinyl alcohol resin aqueous solution, stirring uniformly, and cooling to room temperature to obtain a zirconium-modified aqueous solution; S2: adding 20 to 100 parts of ceramsite matrix to the zirconium modified aqueous solution, standing and impregnating for 4 to 12 hours to allow the modified liquid to fully enter the interior of the ceramsite matrix, and filtering to obtain ceramsite impregnated with the modified liquid; S3: drying the ceramsite impregnated with the modified liquid at 90 to 250° C. for 5 to 60 minutes to obtain a ceramsite matrix containing an organic zirconium cross-linked gel resin; S4: The ceramsite matrix containing the organic zirconium cross-linked gel resin is first heated to 200-250°C and kept warm for 20-30 minutes, then heated to 280-300°C and kept warm for 20-30 minutes, and finally sintered at 450-750°C for 10-40 minutes to obtain a zirconium-modified nitrogen-phosphorus adsorption material with a porous structure.

2. The method for preparing a zirconium-modified nitrogen and phosphorus adsorption material according to claim 1, characterized in that: The ceramsite matrix in S2 is at least one of diatomaceous earth ceramsite, zeolite ceramsite, fly ash ceramsite, shale ceramsite, sludge ceramsite, and coal gangue ceramsite.

3. The method for preparing a zirconium-modified nitrogen and phosphorus adsorption material according to claim 1, characterized in that: The solid content of the polyvinyl alcohol resin aqueous solution in S1 is 1-5%.

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