Nitrogen and phosphorus removal adsorption material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of adsorption materials, and particularly relates to a nitrogen and phosphorus removal adsorption material and a preparation method and application thereof. The preparation method comprises the following steps: mixing a zeolite material, ferrous sulfate and calcium fluoride for first activation to obtain a first activated product; mixing the first activation product, ferroferric oxide and borax, and performing second activation to obtain a second activation product, the second activation including first-stage thermal insulation activation and second-stage thermal insulation activation in sequence; and carrying out ultrasonic oscillation treatment on the second activated product to obtain the nitrogen and phosphorus removal adsorbing material. The nitrogen and phosphorus removal adsorption material obtained by the preparation method provided by the invention can synchronously and specifically remove nitrogen and phosphorus in a targeted manner, meanwhile, the preparation method is simple, the condition is mild, the cost is low, ammonia nitrogen and phosphorus in a water body can be efficiently, economically and effectively removed in an environment-friendly manner, and the nitrogen and phosphorus removal adsorption material is suitable for industrial application.

Description

Technical Field

[0001] This invention belongs to the field of adsorption material technology, specifically relating to a nitrogen and phosphorus removal adsorption material, its preparation method, and its application. Background Technology

[0002] Ammonia nitrogen in wastewater mainly exists as free ammonia and ammonium ions, primarily originating from the decomposition of nitrogenous organic matter in domestic wastewater, as well as industrial wastewater and agricultural drainage. Ammonia nitrogen is both a major cause of aquatic organism poisoning and a nutrient in water bodies, leading to eutrophication. Long-term consumption of nitrites by humans can induce methemoglobinemia, and large amounts of wastewater with high ammonia nitrogen content increase the amount of chlorine used in water disinfection and industrial circulating water sterilization, exhibiting severe corrosive effects on copper, chromium, and mercury products. In recent years, excessive discharge of industrial wastewater, domestic sewage, and landfill leachate has led to a year-on-year increase in ammonia nitrogen levels in water bodies, becoming a major pollution factor affecting the normal use of water resources in my country.

[0003] There are three main methods for removing ammonia nitrogen from wastewater: biological, chemical, and physical methods. Biological methods have advantages such as wide applicability, low cost, and stable reactions; however, they require high biodegradability of the wastewater, and the microorganisms are sensitive to the environment, limiting their application. Chemical methods are diverse and technologically advanced, but they suffer from secondary pollution, expensive chemicals, and high costs, restricting their use in treating ammonia nitrogen in wastewater. Among physical methods, membrane separation removes relatively few substances, while adsorption methods are simple to operate, low in energy consumption, and environmentally friendly. The large specific surface area of ​​the adsorbent material allows ammonia nitrogen to be adsorbed onto the adsorbent surface, thus removing ammonia nitrogen from wastewater and making it widely applicable for treating ammonia nitrogen wastewater.

[0004] Phosphorus removal is a crucial part of wastewater treatment. Like ammonia nitrogen, phosphorus is a major contributor to eutrophication in water bodies. Excessive phosphorus promotes algal blooms, leading to oxygen depletion and impacting aquatic life. Common phosphorus removal technologies can be categorized into three types: biological, chemical, and physical. Biological methods utilize microorganisms to convert phosphorus in wastewater into organic matter within the microorganisms, thus removing it. Chemical methods involve adding chemical agents to the wastewater, causing a chemical reaction between phosphorus and the agents to form insoluble phosphorus compounds, thereby removing the phosphorus. Physical methods separate phosphorus from wastewater through filtration, sedimentation, and other processes.

[0005] However, existing adsorbents for the removal of ammonia nitrogen and phosphorus suffer from problems such as low adsorption rate and poor adsorption selectivity, or high treatment cost. Summary of the Invention

[0006] The purpose of this invention is to provide a nitrogen and phosphorus removal adsorption material, its preparation method, and its application. The nitrogen and phosphorus removal adsorption material obtained by the preparation method provided by this invention can simultaneously and specifically target nitrogen and phosphorus removal. At the same time, the preparation method is simple, the conditions are mild, and the cost is low. It can achieve efficient, economical, and environmentally friendly removal of ammonia nitrogen and phosphorus in water, and is suitable for industrial application.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention provides a method for preparing a nitrogen and phosphorus removal adsorption material, comprising the following steps:

[0009] Zeolite material, ferrous sulfate and calcium fluoride are mixed and first activated to obtain a first activated product. The holding temperature of the first activation is 200-600℃.

[0010] The first activated product, iron oxide and borax are mixed and then subjected to a second activation to obtain a second activated product. The second activation includes sequentially performing a first stage of heat preservation activation and a second stage of heat preservation activation. The temperature of the first stage of heat preservation activation is 250-350℃, and the temperature of the second stage of heat preservation activation is 600-700℃.

[0011] The second activated product is subjected to ultrasonic vibration to obtain the nitrogen and phosphorus removal adsorption material.

[0012] The present invention provides a denitrification and phosphorus removal adsorption material prepared by the preparation method described in the above technical solution.

[0013] This invention provides the application of the nitrogen and phosphorus removal adsorption material described in the above technical solution in nitrogen and phosphorus removal in water bodies.

[0014] This invention provides a method for preparing a nitrogen and phosphorus removal adsorbent. Compared with traditional activated carbon adsorbents and zeolite adsorbents, the nitrogen and phosphorus removal adsorbent prepared by this invention has the following beneficial effects:

[0015] First, the nitrogen and phosphorus removal adsorbent material prepared in this invention possesses the ability to simultaneously remove nitrogen and phosphorus. Experimental data show that the adsorbent material prepared in this invention achieves an adsorption efficiency of up to 85% for ammonia nitrogen and an adsorption rate of 73% for phosphorus. This result indicates that the nitrogen and phosphorus removal adsorbent material prepared in this invention can effectively remove both nitrogen and phosphorus pollutants during wastewater treatment, thus avoiding the cumbersome steps of separately treating nitrogen and phosphorus in traditional processes. This highly efficient simultaneous nitrogen and phosphorus removal performance not only improves the efficiency of wastewater treatment but also reduces treatment costs, enhancing the feasibility of industrial applications.

[0016] Secondly, the nitrogen and phosphorus removal adsorbent material prepared by this invention has excellent environmental friendliness. Unlike some traditional adsorbents, the nitrogen and phosphorus removal adsorbent material prepared by this invention exhibits strong selectivity, specifically adsorbing ammonia nitrogen without adsorbing heavy metals; no heavy metals were absorbed during the series of experiments. Furthermore, the nitrogen and phosphorus removal adsorbent material prepared by this invention is non-toxic, harmless, and highly safe. This green and pollution-free characteristic allows the nitrogen and phosphorus removal adsorbent material prepared by this invention to be fully utilized as fertilizer for soil improvement and environmental greening after saturation adsorption of ammonia nitrogen and phosphorus.

[0017] Furthermore, the preparation method provided by this invention does not pose any potential threat to the environment or human health during production and application, meeting the safety and sustainability requirements of modern environmentally friendly materials. The production process is mild and does not generate secondary pollutants. Finally, the raw materials for the nitrogen and phosphorus removal adsorption materials prepared by this invention are widely available, inexpensive, and readily available, significantly reducing the production cost of the adsorbent. Compared to the high raw material costs of traditional adsorbents, the nitrogen and phosphorus removal adsorption materials prepared by this invention utilize readily available and inexpensive raw materials, demonstrating significant economic benefits and promotional value.

[0018] The preparation method provided by this invention, through first and second activation, significantly alters the microstructure of the material particles, resulting in a significant increase in specific surface area, an increase in active sites, and a uniform distribution of nanoscale pores. The large pores exhibit water permeability, while the small pores possess enhanced adsorption capacity, giving the overall material specific, efficient, and multi-mechanism adsorption properties. This further enhances the ion exchange capacity of the adsorbent, enabling it to remove ammonia nitrogen and phosphate from water more efficiently.

[0019] In summary, the nitrogen and phosphorus removal adsorbent material prepared by this invention lays a solid foundation for the large-scale production and practical application of adsorbents. It can provide adsorbent materials for nitrogen and phosphorus removal in various water supply and wastewater treatment processes containing ammonia nitrogen and phosphorus, reducing treatment costs. The nitrogen and phosphorus removal adsorbent material prepared by this invention can be used for in-situ simultaneous removal of nitrogen and phosphorus at the end of water treatment processes such as lakes and bays. It can be produced in fully mixed, bagged, or filtered forms, is easy to separate from water, and is convenient to use. It can also be used at the front or end of urban wastewater treatment plants to remove nitrogen and phosphorus from the source, reducing emissions and significantly lowering the concentration and total amount of ammonia nitrogen and phosphorus. After the nitrogen and phosphorus removal adsorbent material prepared by this invention is saturated with ammonia nitrogen and phosphorus, because the adsorbent material provided by this invention does not adsorb heavy metals, it can become an additive for nitrogen and phosphorus in organic bio-fertilizers. After humification and fermentation, it generates bio-organic fertilizer for ecological restoration and saline-alkali soil improvement. Shenzhen has a large amount of reclaimed land exposed from the sea that requires a large amount of organic fertilizer for improvement and greening, representing a huge market. The nitrogen and phosphorus removal adsorbent material prepared by this invention is inexpensive, safe and environmentally friendly in its preparation, non-toxic and harmless, and can be recycled after treatment. The nitrogen and phosphorus removal adsorbent material prepared by this invention has a significant effect on removing ammonia nitrogen and phosphorus, and is easy to use. Application results demonstrate its good effectiveness. Attached Figure Description

[0020] Figure 1 The adsorption results are for the adsorbent material prepared in Example 1;

[0021] Figure 2 The adsorption results are for the adsorbent material prepared in Example 2;

[0022] Figure 3 The adsorption results are for the adsorbent material prepared in Example 3;

[0023] Figure 4 The adsorption results are for the adsorbent material prepared in Example 4;

[0024] Figure 5 The adsorption results are for the adsorbent material prepared in Example 5;

[0025] Figure 6 The adsorption results of the adsorbent material prepared in Example 1 after being exposed to air for 15 days;

[0026] Figure 7 The adsorption results are for the adsorbent material prepared in Comparative Example 1.

[0027] Figure 8 The adsorption results are for the adsorbent material prepared in Comparative Example 2;

[0028] Figure 9 The adsorption results are for the adsorption material prepared in Comparative Example 3;

[0029] Figure 10The adsorption results are for the adsorbent material prepared in Comparative Example 4.

[0030] Figure 11 The adsorption results of zeolite purchased from Tianjin Huaxun Medical Technology Co., Ltd.

[0031] Figure 12 The adsorption results of activated carbon purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. after being exposed to air for 15 days. Detailed Implementation

[0032] This invention provides a method for preparing a nitrogen and phosphorus removal adsorption material, comprising the following steps:

[0033] Zeolite material, ferrous sulfate and calcium fluoride are mixed and first activated to obtain a first activated product. The holding temperature of the first activation is 200-600℃.

[0034] The first activated product, iron oxide and borax are mixed and then subjected to a second activation to obtain a second activated product. The second activation includes sequentially performing a first stage of heat preservation activation and a second stage of heat preservation activation. The temperature of the first stage of heat preservation activation is 250-350℃, and the temperature of the second stage of heat preservation activation is 600-700℃.

[0035] The second activated product is subjected to ultrasonic vibration to obtain the nitrogen and phosphorus removal adsorption material.

[0036] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0037] In this invention, zeolite material, ferrous sulfate and calcium fluoride are mixed and activated to obtain a first activated product. The holding temperature for the first activation is 200-600℃.

[0038] In this invention, the zeolite material is preferably purchased from Tianjin Solomon Biotechnology Co., Ltd. The specific surface area of ​​the zeolite material is preferably 15-17 m². 2 / g, with an average pore size preferably of 12nm.

[0039] Prior to the first activation, the zeolite material is preferably pretreated, and the pretreatment preferably includes crushing and sieving in sequence, with grinding being a preferred embodiment of the crushing. The sieving is preferably performed through a 100-mesh sieve. The particle size of the zeolite material is preferably less than 150 micrometers.

[0040] The ferrous sulfate is preferably ferrous sulfate powder, and the particle size of the ferrous sulfate powder is preferably <150μm. The calcium fluoride is preferably calcium fluoride powder, and the particle size of the calcium fluoride powder is preferably <150μm.

[0041] In this invention, the preferred mass ratio of the zeolite material, ferrous sulfate and calcium fluoride is (3-10):(1-3):1, more preferably (3-6):(1-2):1, and in the embodiments it can be 5.56:1.67:1, 5:1.5:1, 3.5:1.75:1 or 10:3:1.

[0042] The present invention does not have any special requirements for the mixing method of the zeolite material, ferrous sulfate and calcium fluoride, as long as the above raw materials are mixed evenly.

[0043] In this invention, the preferred holding temperature for the first activation is 300–600°C, and in the embodiments, it can be 600°C, 400°C, or 300°C. The preferred holding time for the first activation is 5–7 hours, and in the embodiments, it can be 6 hours. The preferred heating rate from room temperature to the first activation temperature is 1–10°C / min, and in the embodiments, it can be 5°C / min. After the first activation is completed, the present invention preferably cools down to room temperature to obtain the first activated product.

[0044] After obtaining the first activated product, the present invention mixes the first activated product, iron oxide and borax, and performs a second activation to obtain a second activated product. The second activation includes performing a first stage of heat preservation activation and a second stage of heat preservation activation in sequence. The temperature of the first stage of heat preservation activation is 250-350°C, and the temperature of the second stage of heat preservation activation is 600-700°C.

[0045] In this invention, the iron(III) oxide is preferably iron(III) oxide powder, and the particle size of the iron(III) oxide powder is preferably <150 μm. The borax is preferably borax powder, and the particle size of the borax powder is preferably <150 μm.

[0046] In this invention, the preferred mass ratio of the first activated product, iron oxide and borax is 10:1:(4-4.5), and in the embodiments it can be 10:1:4 or 10:1:4.29.

[0047] The present invention does not have any special requirements for the mixing method of the first activated product, iron oxide and borax, as long as the above raw materials are mixed evenly.

[0048] In this invention, the second activation preferably includes: raising the temperature from room temperature to the temperature of the first-stage heat preservation activation for a first-stage heat preservation activation, and then raising the temperature from the first-stage heat preservation activation temperature to the temperature of the first-stage heat preservation activation for a second-stage heat preservation activation. The temperature of the first-stage heat preservation activation is preferably 300–350°C, and in the embodiments, it can be 300°C or 350°C. The heat preservation time of the first-stage heat preservation activation is preferably 1–3 hours, and in the embodiments, it can be 2 hours. The heating rate from room temperature to the temperature of the first-stage heat preservation activation is preferably 1–10°C / min, and in the embodiments, it can be 10°C / min. The temperature of the second-stage heat preservation activation is preferably 620–680°C. The heat preservation time of the second-stage heat preservation activation is preferably 2–4 hours, and in the embodiments, it can be 3.5 hours. The heating rate from the temperature of the first-stage heat preservation activation to the temperature of the second-stage heat preservation activation is preferably 1–5°C / min, and in the embodiments, it can be 5°C / min.

[0049] After obtaining the second activated product, the present invention subjectes the second activated product to ultrasonic vibration treatment to obtain the denitrification and phosphorus removal adsorption material.

[0050] In this invention, the ultrasonic oscillation treatment is preferably performed in an ultrasonic oscillator. The temperature of the ultrasonic oscillation treatment is preferably 50–65°C, and in the embodiment, it can be 65°C. The duration of the ultrasonic oscillation treatment is preferably 1–3 hours, and in the embodiment, it can be 2 hours.

[0051] The present invention provides a denitrification and phosphorus removal adsorption material prepared by the preparation method described in the above technical solution.

[0052] This invention provides the application of the nitrogen and phosphorus removal adsorption material described in the above technical solution in nitrogen and phosphorus removal in water bodies.

[0053] In this invention, the concentration of ammonia nitrogen (as ammonium salt mass concentration) in the water body can be 30–5000 mg / L, and in the examples, it can be 30 mg / L, 36 mg / L, 100 mg / L, 1000 mg / L, or 5000 mg / L. The total phosphorus concentration in the water body can be 8–10 mg / L.

[0054] In this invention, the preferred application scenarios for the nitrogen and phosphorus removal adsorption material include: prevention and control of eutrophic algal blooms in lakes and reservoirs, treatment of various enterprises discharging ammonia nitrogen and phosphorus wastewater, treatment of aquaculture wastewater, treatment of wastewater from small rural and urban sewage treatment plants that have long failed to meet ammonia nitrogen and phosphorus standards, and pre-treatment and post-treatment of wastewater from urban sewage treatment plants.

[0055] The nitrogen and phosphorus removal adsorption material provided by this invention can improve the removal efficiency of ammonia nitrogen and phosphorus, change the long process of multi-stage nitrification and denitrification in sewage treatment plants into a short AA / O process, significantly reduce energy consumption and treatment costs, and ensure stable compliance with total nitrogen and total phosphorus standards.

[0056] Currently, common activated carbon adsorbents and artificial zeolite adsorbents are generally expensive, can only adsorb ammonia nitrogen and phosphorus, cannot simultaneously adsorb and remove ammonia nitrogen and phosphorus, have low efficiency, are not suitable for large-scale application, and are difficult to recycle after use. However, the denitrification and phosphorus removal adsorbent material provided by this invention is inexpensive, green and harmless, and can be recycled for resource utilization after use. The denitrification and phosphorus removal adsorbent material provided by this invention has the following advantages: (1) It can achieve simultaneous targeted denitrification and phosphorus removal, with an ammonia nitrogen adsorption efficiency of 80-85% and a phosphorus adsorption rate of 60-70%; (2) The denitrification and phosphorus removal adsorbent material does not cause secondary pollution, is environmentally friendly, non-toxic and harmless, and can be recycled; (3) The adsorbent production process has low cost and can be widely used.

[0057] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0058] The zeolite materials used in the following examples and comparative examples were purchased from Tianjin Solomon Biotechnology Co., Ltd., and the specific surface area of ​​the zeolite materials was 15-17 m². 2 / g, with an average pore size of 12nm.

[0059] Example 1:

[0060] The purchased zeolite material was ground and pulverized and passed through a 100-mesh sieve to obtain zeolite material powder (particle size <150μm).

[0061] Step 1: Mix 50g of zeolite material powder with 15g of ferrous sulfate powder and 9g of calcium fluoride powder evenly, then heat in a furnace at a rate of 5℃ / min and maintain at 600℃ for 6h. After cooling to room temperature, collect the solid block powder 1.

[0062] Step 2: Add 5g of iron oxide powder and 20g of borax powder to 50g of block powder 1, mix well, then heat in a furnace at a rate of 10℃ / min and maintain at 300℃ for 2h, then heat at a rate of 5℃ / min and maintain at 600℃ for 3.5h. After cooling to room temperature, collect the solid block powder 2.

[0063] Step 3: Place 50g of block powder 2 in an ultrasonic oscillator and oscillate at 60℃ for 2 hours to obtain the finished material.

[0064] Example 2:

[0065] The purchased zeolite material was ground and pulverized and passed through a 100-mesh sieve to obtain zeolite material powder (particle size <150μm).

[0066] Step 1: Mix 100g of zeolite material powder with 30g of ferrous sulfate powder and 20g of calcium fluoride powder evenly, then heat in a furnace at a rate of 5℃ / min and maintain at 400℃ for 6 hours. After cooling to room temperature, collect the solid block powder 1.

[0067] Step 2: Add 10g of iron oxide powder and 40g of borax powder to 100g of block powder 1, mix well, then heat in a furnace at a rate of 10℃ / min and maintain at 350℃ for 2h, then heat at a rate of 5℃ / min and maintain at 700℃ for 3.5h. After cooling to room temperature, collect the block powder 2 solid.

[0068] Step 3: Place 100g of block powder 2 in an ultrasonic oscillator and oscillate at 60℃ for 2 hours to obtain the finished material.

[0069] Example 3:

[0070] The purchased zeolite material was ground and pulverized and passed through a 100-mesh sieve to obtain zeolite material powder (particle size <150μm).

[0071] Step 1: Mix 500g of zeolite material powder with 150g of ferrous sulfate powder and 100g of calcium fluoride powder evenly, then heat in a furnace at a rate of 5℃ / min and maintain at 300℃ for 6 hours. After cooling to room temperature, collect the blocky powder 1 solid.

[0072] Step 2: Add 50g of iron oxide powder and 200g of borax powder to 500g of block powder 1 and mix evenly. Then heat in a heating furnace at a rate of 10℃ / min and maintain at 350℃ for 2h. Then heat at a rate of 5℃ / min and maintain at 600℃ for 3.5h. After cooling to room temperature, collect the solid block powder 2.

[0073] Step 3: Place 500g of block powder 2 in an ultrasonic oscillator and oscillate at 60℃ for 2 hours to obtain the finished material.

[0074] Example 4:

[0075] The purchased zeolite material was ground and pulverized and passed through a 100-mesh sieve to obtain zeolite material powder (particle size <150μm).

[0076] Step 1: Mix 70g of zeolite material powder, 35g of ferrous sulfate powder, and 20g of calcium fluoride powder evenly, then heat in a furnace at a rate of 5℃ / min and maintain at 600℃ for 6 hours. After cooling to room temperature, collect the solid block powder 1.

[0077] Step 2: Add 7g of iron oxide powder and 30g of borax powder to 70g of block powder 1 and mix evenly. Then heat in a furnace at a rate of 10℃ / min and maintain at 350℃ for 2h. Then heat at a rate of 5℃ / min and maintain at 600℃ for 3.5h. After cooling to room temperature, collect the solid block powder 2.

[0078] Step 3: Place 70g of block powder 2 in an ultrasonic oscillator and oscillate at 60℃ for 2 hours to obtain the finished material.

[0079] Example 5:

[0080] The purchased zeolite material was ground and pulverized and passed through a 100-mesh sieve to obtain zeolite material powder (particle size <150μm).

[0081] Step 1: Mix 5g of zeolite material powder with 1.5g of ferrous sulfate powder and 1g of calcium fluoride powder evenly, then heat in a furnace at a rate of 5℃ / min and maintain at 600℃ for 6h. After cooling to room temperature, collect the blocky powder 1 solid.

[0082] Step 2: Add 0.5g of iron oxide powder and 2g of borax powder to 5g of block powder 1 and mix evenly. Then heat in a heating furnace at a rate of 10℃ / min and maintain at 350℃ for 2h. Then heat at a rate of 5℃ / min and maintain at 650℃ for 3.5h. After cooling to room temperature, collect the block powder 2 solid.

[0083] Step 3: Place 5g of block powder 2 in an ultrasonic oscillator and oscillate at 60℃ for 2 hours to obtain the finished material.

[0084] Test Example 1

[0085] A 30 mg / L ammonium chloride solution and a 10 mg / L sodium dihydrogen phosphate solution were prepared to test the adsorption effect of the adsorption material. The concentrations of ammonia nitrogen and phosphate in the solutions before and after adsorption were measured using a Barrington spectrophotometer. The amount of adsorption material prepared in Example 1 was 1 g / L (test solution), and six parallel experiments (1A–1F) were conducted.

[0086] Ammonia nitrogen adsorption: Weigh 6 portions of 0.1g of the adsorbent material prepared in Example 1 and transfer them to 150mL clean beakers respectively. Add 100mL of the 30mg / L ammonium chloride solution prepared above to each beaker. Adsorb at a stirring rate of 120rpm / min on a magnetic stirrer at room temperature for 12h. After the adsorption is completed, filter the mixture with medium-speed filter paper, take the filtrate, and use a Barrington spectrophotometer to detect the ammonia nitrogen concentration in the filtrate.

[0087] Ammonia nitrogen adsorption rate:

[0088]

[0089] In equation (1), η is the adsorption rate (%), C0, C e The concentrations of ammonia nitrogen in the solution (mg / L) are shown in the initial and equilibrium states, respectively.

[0090] Total phosphorus adsorption: Weigh 6 portions of 0.1g of the activated adsorption material prepared in Example 1 and transfer them to 150mL clean beakers respectively. Add 100mL of the 10mg / L sodium dihydrogen phosphate solution prepared above to each beaker. Adsorb at 120rpm / min on a magnetic stirrer at room temperature for 12h. After adsorption is complete, filter the mixture with medium-speed filter paper, take the filtrate, and use a Barrington spectrophotometer to detect the total phosphorus concentration in the filtrate.

[0091] Total phosphorus adsorption rate:

[0092]

[0093] In equation (2), η is the adsorption rate (%), C0, C e The total phosphorus concentration (mg / L) in the solution is shown in the initial and equilibrium states, respectively.

[0094] The adsorption results of experiments 1A to 1F are shown in Table 1 and Figure 1 As shown:

[0095] Table 1 Adsorption results of experiments 1A to 1F

[0096]

[0097] As shown in Table 1, the ammonia nitrogen adsorption capacity of the adsorbent material prepared in Example 1 was 25.08–25.71 mg, and the ammonia nitrogen adsorption rate was 83.6–85.7%; the total phosphorus adsorption capacity was 7.30–7.37 mg, and the total phosphorus adsorption rate was 73.08–73.73%, indicating that the adsorbent material had excellent adsorption performance.

[0098] Test Example 2

[0099] In the laboratory, a mixed solution of 30 mg / L ammonium chloride and 10 mg / L sodium dihydrogen phosphate was prepared to activate the adsorbent material and test its adsorption effect on ammonia nitrogen and phosphate ions. The amount of adsorbent material prepared in Example 2 was 1 g / L (test solution), and six parallel experiments 2A to 2F were conducted.

[0100] Ammonia nitrogen adsorption and total phosphorus adsorption: Weigh 0.1 g of the activated adsorption material prepared in Example 2 and transfer it to a 150 mL clean beaker. Add 100 mL of the above-prepared mixed solution to the beaker, and then adsorb at room temperature on a magnetic stirrer at a stirring rate of 120 r / min for 12 h. After adsorption is complete, filter the mixture using medium-speed filter paper, collect the filtrate, and use a Barrington spectrophotometer to detect the remaining ammonia nitrogen concentration. Use a Barrington spectrophotometer to detect the remaining total phosphorus concentration.

[0101] Ammonia nitrogen adsorption efficiency: The ammonia nitrogen removal rate was calculated according to formula (1). Total phosphorus adsorption efficiency: The phosphorus removal rate was calculated according to formula (2). The results are shown in Table 2 and... Figure 2 As shown:

[0102] Table 2 Adsorption results of experiments 2A to 2F

[0103]

[0104]

[0105] As shown in Table 2, the ammonia nitrogen adsorption capacity of the adsorbent material prepared in Example 2 was 24.81–25.42 mg, and the ammonia nitrogen adsorption rate was 82.70–84.73%; the total phosphorus adsorption capacity was 7.26–7.30 mg, and the total phosphorus adsorption rate was 72.61–73.06%, indicating that the adsorbent material had excellent adsorption performance.

[0106] Test Example 3

[0107] The main indicators prepared in the laboratory were: COD: 300 mg / L (using glucose as the carbon source), ammonia nitrogen: 30 mg / L, TP: 10 mg / L. The effect of activating the adsorbent material to adsorb ammonia nitrogen and phosphate ions simultaneously was tested by simulating wastewater. The amount of adsorbent material prepared in Example 3 was 1 g / L (test solution), and six parallel experiments 3A to 3F were conducted.

[0108] Ammonia nitrogen adsorption and total phosphorus adsorption: Weigh 0.1 g of the activated adsorption material prepared in Example 3 and transfer it to a 150 mL clean beaker. Add 100 mL of the simulated wastewater prepared above to the beaker, and then adsorb at room temperature on a magnetic stirrer at a stirring rate of 120 r / min for 12 h. After adsorption is complete, filter the mixture using medium-speed filter paper, take the filtrate, and use a Barrington spectrophotometer to detect the remaining ammonia nitrogen concentration. Use a Barrington spectrophotometer to detect the remaining total phosphorus concentration.

[0109] Ammonia nitrogen adsorption efficiency: The ammonia nitrogen removal rate was calculated according to formula (1). Total phosphorus adsorption efficiency: The phosphorus removal rate was calculated according to formula (2). The results are shown in Table 3 and... Figure 3 As shown:

[0110] Table 3 Adsorption results of experiments 3A-3F

[0111]

[0112]

[0113] As shown in Table 3, the ammonia nitrogen adsorption capacity of the adsorbent material prepared in Example 3 was 24.45–25.04 mg, and the ammonia nitrogen adsorption rate was 81.51–83.47%; the total phosphorus adsorption capacity was 7.16–7.27 mg, and the total phosphorus adsorption rate was 71.61–72.75%, indicating that the adsorbent material has excellent adsorption performance.

[0114] Test Example 4

[0115] Wastewater samples from the aeration tank of a wastewater treatment plant were taken to test the effect of activated adsorption material on the simultaneous adsorption of ammonia nitrogen and phosphate ions. The amount of adsorption material used was 1 g / L (test solution), and six parallel experiments (4A-4F) were conducted.

[0116] The raw wastewater in the aeration tank of the wastewater treatment plant had an ammonia nitrogen concentration of 36 mg / L and a total phosphorus concentration of 8 mg / L. Ammonia nitrogen adsorption: 0.1 g of the activated adsorption material prepared in Example 4 was weighed and transferred to a 150 mL clean beaker. 100 mL of the above wastewater sample was added to the beaker, and adsorption was carried out at room temperature on a magnetic stirrer at a stirring rate of 120 r / min for 12 h. After adsorption, the mixture was filtered using medium-speed filter paper. The filtrate was collected, and the remaining ammonia nitrogen concentration was detected using a Barrington spectrophotometer. The remaining total phosphorus concentration was also detected using a Barrington spectrophotometer.

[0117] Ammonia nitrogen adsorption efficiency: The ammonia nitrogen removal rate was calculated according to formula (1). Total phosphorus adsorption efficiency: The phosphorus removal rate was calculated according to formula (2). The results are shown in Table 4 and... Figure 4 As shown:

[0118] Table 4 Adsorption results of experiments 4A-4F

[0119]

[0120] As shown in Table 4, the ammonia nitrogen adsorption capacity of the adsorbent material prepared in Example 4 was 28.08–28.59 mg, and the ammonia nitrogen adsorption rate was 80.22–81.37%; the total phosphorus adsorption capacity was 5.48–5.63 mg, and the total phosphorus adsorption rate was 68.52–70.39%, indicating that the adsorbent material had excellent adsorption performance.

[0121] Test Example 5

[0122] Wastewater samples from the aeration tank of a wastewater treatment plant were taken to test the effect of activated adsorption material on the simultaneous adsorption of ammonia nitrogen and phosphate ions. The amount of adsorption material used was 1 g / L (test solution), and six parallel experiments were conducted from 5A to 5F.

[0123] The raw wastewater in the aeration tank of the wastewater treatment plant had an ammonia nitrogen concentration of 36 mg / L and a total phosphorus concentration of 8 mg / L. Ammonia nitrogen adsorption: 0.1 g of the activated adsorption material prepared in Example 5 was weighed and transferred to a 150 mL clean beaker. 100 mL of the above wastewater sample was added to the beaker, and adsorption was carried out at room temperature on a magnetic stirrer at a stirring rate of 120 r / min for 12 h. After adsorption was complete, the mixture was filtered using medium-speed filter paper. The filtrate was collected, and the remaining ammonia nitrogen concentration was detected using a Barrington spectrophotometer. The remaining total phosphorus concentration was also detected using a Barrington spectrophotometer.

[0124] Ammonia nitrogen adsorption efficiency: The ammonia nitrogen removal rate was calculated according to formula (1). Total phosphorus adsorption efficiency: The phosphorus removal rate was calculated according to formula (2). The results are shown in Table 5 and... Figure 5 As shown:

[0125] Table 5 Adsorption results of experiments 5A-5F

[0126]

[0127] As shown in Table 5, the ammonia nitrogen adsorption capacity of the adsorbent material prepared in Example 5 was 23.74–24.30 mg, and the ammonia nitrogen adsorption rate was 79.25–80.98%; the total phosphorus adsorption capacity was 6.85–7.01 mg, and the total phosphorus adsorption rate was 68.49–70.09%, indicating that the adsorbent material had excellent adsorption performance.

[0128] Test Example 6

[0129] Test Example 6 is the same as Test Example 1, except that the test object is replaced with the adsorbent material prepared in Example 1 after being exposed to air for 15 days. Six parallel experiments I to VI were conducted, and the results are shown in Table 6. Figure 6 As shown:

[0130] Table 6 Adsorption results of experiments I to VI

[0131]

[0132] As shown in Table 6, after 15 days of exposure to air, the ammonia nitrogen adsorption capacity of the adsorbent material prepared in Example 1 was 24.88–25.63 mg, with an ammonia nitrogen adsorption rate of 82.93–85.45%; the total phosphorus adsorption capacity was 7.21–7.36 mg, with a total phosphorus adsorption rate of 72.14–73.60%, indicating excellent adsorption performance. This demonstrates that the adsorbent material prepared by this invention has stable activity, is not easily deteriorated, and its adsorption performance is even better than that of the adsorbent material before exposure.

[0133] Test Example 7

[0134] Test Example 7 uses the same materials as Test Example 1 to test the material's adsorption capacity for heavy metals. Six parallel tests were conducted using 1 mol / L potassium dichromate, 1 mol / L cadmium chloride, and 1 mol / L copper sulfate solutions. The results are shown in Table 7.

[0135] Table 7 Adsorption results of experiments I to VI

[0136] Experiment number Potassium dichromate adsorption rate Cadmium chloride adsorption rate Copper sulfate adsorption rate Experiment I 3.4％ 5.6％ 3.6％ Experiment II 4.6％ 5.7％ 4.8％ Experiment III 0.9％ 6.3％ 4.2％ Experiment IV 2.5％ 5.9％ 3.4％ Experiment V 2.4％ 5.3％ 3.5％ Experiment VI 1.1％ 5.4％ 2.8％

[0137] As can be seen from Table 7, the adsorbent material prepared in Example 1 has no adsorption effect on common heavy metals. Therefore, the adsorbent material prepared in this invention has no risk of heavy metal pollution, is non-toxic and harmless, and is healthy and safe.

[0138] Comparative Example 1: (Compared to Example 1)

[0139] The purchased zeolite material was ground and pulverized and passed through a 100-mesh sieve to obtain zeolite material powder (particle size <150μm).

[0140] Step 1: Mix 50g of sample powder with 15g of ferrous sulfate powder and 9g of calcium fluoride powder evenly, then heat in a furnace at a rate of 5℃ / min and maintain at 600℃ for 6h. After cooling to room temperature, collect the solid block powder 1.

[0141] Step 2: Add 5g of iron oxide powder and 20g of borax powder to 50g of block powder 1. Mix well, then heat in a furnace at a rate of 10℃ / min for 2 hours at 350℃, then heat at a rate of 5℃ / min for 3.5 hours at 600℃. After cooling to room temperature, collect the block powder solid to obtain the adsorbent material.

[0142] Comparative Example 2: (Compared to Example 3)

[0143] The purchased zeolite material was ground and pulverized and passed through a 100-mesh sieve to obtain zeolite material powder (particle size <150μm).

[0144] Step 1: Mix 500g of sample powder with 150g of ferrous sulfate powder and 100g of calcium fluoride powder evenly, then heat in a furnace at a rate of 5℃ / min and maintain at 600℃ for 6h. After cooling to room temperature, collect the solid block powder 1.

[0145] Step 2: Place 500g of block powder 1 in an ultrasonic oscillator and oscillate at 60℃ for 2 hours to obtain the finished material.

[0146] Comparative Example 3: (Compared to Example 1)

[0147] The only difference between Comparative Example 3 and Example 1 is that the activation temperature in the first step of the preparation method is 200°C, and the second step is heated at a rate of 5°C / min, with an activation temperature of 200°C and a holding time of 5.5h. The rest is the same as Example 1.

[0148] Comparative Example 4: (Compared to Example 1)

[0149] The only difference between Comparative Example 4 and Example 1 is that the activation temperature in the first step of the preparation method is 100°C, and the second step is heated at a rate of 5°C / min, with the activation temperature at 100°C and the holding time being 5.5h. The rest is the same as Example 1.

[0150] Comparative Test Case 1

[0151] Comparative Test Example 1 is the same as Test Example 1, except that the test object is replaced with the adsorbent material prepared in Comparative Example 1. Six sets of parallel experiments 1a to 1f were performed, and the results are shown in Table 8. Figure 7 As shown:

[0152] Table 8 Adsorption results of experiments 1a-1f

[0153]

[0154] As shown in Table 8, the ammonia nitrogen adsorption capacity of the adsorbent material prepared in Comparative Example 1 was 12.81–13.17 mg, and the ammonia nitrogen adsorption rate was 42.70–43.89%; the total phosphorus adsorption capacity was 4.42–4.54 mg, and the total phosphorus adsorption rate was 44.24–44.81%. The adsorption performance of the adsorbent material prepared in Comparative Example 1 was significantly worse than that of the adsorbent material provided by this invention. This indicates that high-temperature loading activation alone is not effective, but the combined effect of high-temperature loading activation and ultrasound can effectively improve the adsorption performance.

[0155] Comparative Test Example 2

[0156] Comparative Test Example 2 is the same as Test Example 1, except that the test object is replaced with the adsorbent material prepared in Comparative Example 2. Six parallel experiments 2a to 2f were conducted, and the results are shown in Table 9. Figure 8 As shown:

[0157] Table 9 Adsorption results of experiments 2a-2f

[0158]

[0159] As shown in Table 9, the ammonia nitrogen adsorption capacity of the adsorbent material prepared in Comparative Example 2 was 21.47–21.62 mg, and the ammonia nitrogen adsorption rate was 71.56–72.05%; the total phosphorus adsorption capacity was 5.92–6.05 mg, and the total phosphorus adsorption rate was 59.17–60.50%. The adsorption performance of the adsorbent material prepared in Comparative Example 2 was significantly worse than that of the adsorbent material provided by this invention. This indicates that modifying inorganic polymer materials with ferrous sulfate and calcium fluoride alone cannot effectively improve the adsorption performance of the materials.

[0160] Comparative Test Case 3

[0161] Comparative Test Example 3 was the same as Test Example 1, except that the test object was replaced with the adsorbent material prepared in Comparative Example 3. Six parallel experiments 3a–3f were conducted, and the results are shown in Table 10. Figure 9 As shown:

[0162] Table 10 Adsorption results of experiments 3a-3f

[0163]

[0164] As shown in Table 10, the ammonia nitrogen adsorption capacity of the adsorbent material prepared in Comparative Example 3 was 19.94–20.23 mg, and the ammonia nitrogen adsorption rate was 66.47–67.45%; the total phosphorus adsorption capacity was 5.04–5.17 mg, and the total phosphorus adsorption rate was 50.45–51.73%. The adsorption performance of the adsorbent material prepared in Comparative Example 3 was significantly worse than that of the adsorbent material provided by this invention. This indicates that the activation temperature significantly affects the adsorption performance of the material. Lowering the activation temperature cannot effectively activate inorganic polymers, thus leading to a decrease in adsorption capacity and adsorption rate.

[0165] Comparative Test Case 4

[0166] Comparative Test Example 4 is the same as Test Example 1, except that the test object is replaced with the adsorbent material prepared in Comparative Example 4. Six parallel experiments 4a–4f were conducted, and the results are shown in Table 11. Figure 10 As shown:

[0167] Table 11 Adsorption results of experiments 4a-4f

[0168]

[0169] As shown in Table 11, the ammonia nitrogen adsorption capacity of the adsorbent material prepared in Comparative Example 4 was 21.18–21.53 mg, and the ammonia nitrogen adsorption rate was 70.61–71.77%; the total phosphorus adsorption capacity was 5.79–5.98 mg, and the total phosphorus adsorption rate was 57.91–59.77%. The adsorption performance of the adsorbent material prepared in Comparative Example 4 was significantly worse than that of the adsorbent material provided by this invention. This also indicates that the activation temperature significantly affects the adsorption performance of the material. Lowering the activation temperature cannot effectively activate inorganic polymers, thus leading to a decrease in adsorption capacity and adsorption rate.

[0170] Comparative Test Example 5

[0171] Comparative Test Example 5 is the same as Test Example 1, except that the test object was replaced with zeolite purchased from Tianjin Huaxun Medical Technology Co., Ltd. The zeolite was pulverized and passed through a 200-mesh sieve before testing. Six parallel experiments (5a-5f) were conducted, and the results are shown in Table 12. Figure 11 As shown:

[0172] Table 12 Adsorption results of experiments 5a-5f

[0173]

[0174] As shown in Table 12, the ammonia nitrogen adsorption capacity of zeolite is 19.88–20.21 mg, and the ammonia nitrogen adsorption rate is 66.26–67.37%; the total phosphorus adsorption capacity is 5.71–5.86 mg, and the total phosphorus adsorption rate is 57.05–58.63%. Therefore, it can be seen that the adsorption performance of the present invention is superior to that of zeolite, thus solving the problem of low adsorption performance of commonly used zeolite adsorbents.

[0175] Comparative Test Case 6

[0176] Comparative Test Example 6 is the same as Test Example 1, except that the test subject is replaced with activated carbon purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. The activated carbon was exposed to air for 15 days before testing. Six parallel experiments (6a-6f) were conducted, and the results are shown in Table 13. Figure 12 As shown:

[0177] Table 13 Adsorption results of experiments 6a-6f

[0178]

[0179] As shown in Table 13, the ammonia nitrogen adsorption capacity of activated carbon exposed to air for 15 days was 10.27–10.55 mg, with an ammonia nitrogen adsorption rate of 34.24–35.17%; the total phosphorus adsorption capacity was 2.03–2.16 mg, with a total phosphorus adsorption rate of 20.30–21.62%. This indicates that the adsorption performance of activated carbon exposed to air for 15 days was significantly lower than that of the adsorption material of this invention after the same 15-day exposure, further demonstrating that the activated carbon provided by this invention possesses stable activity and is not easily deteriorated.

[0180] In summary, the adsorption material provided by this invention has excellent adsorption performance, stable activity, and is not easily deteriorated.

[0181] As can be seen from the above embodiments, the adsorbent material obtained by the preparation method provided by the present invention has an average mesopore diameter of 22.40 nm and a BET specific surface area of ​​182.76 m². 2 / g. Both the raw materials and the finished product are free of toxic and harmful substances. The preparation method is safe and environmentally friendly, low in cost, and easy to scale up.

[0182] The adsorbent material prepared by this invention forms various types of activation sites and microporous / mesoporous structures, achieving both physical absorption and chemical fixation functions. Specifically, the adsorbent material forms active sites such as hydroxyl groups, which can undergo ion exchange with ammonium and phosphate ions for chemical adsorption. Furthermore, the material itself contains aluminum and calcium ions (NH4+). +1 It can also adsorb phosphate ions (PO4). -3 Experiments have demonstrated that this material exhibits simultaneous and specific absorption and removal performance for ammonia nitrogen ions and phosphorus; the absorption efficiency for ammonia nitrogen is 80-85%, and for total phosphorus, it is over 65-70%. Under the conditions of Test Example 1, the adsorbent material prepared in Example 1, at a solution concentration of 1 g / L, achieved an ammonia nitrogen adsorption capacity of 988 mg / g under high ammonia nitrogen concentrations. Specific test data are as follows: at a solution concentration of 1 g / L, the adsorbent material prepared in Example 1 had an ammonia nitrogen adsorption capacity of 84.8 mg / g at 100 mg / L; an initial concentration of 1000 mg / L; and an ammonia nitrogen adsorption capacity of 307 mg / g at 5000 mg / L. Furthermore, the adsorbent material prepared in this invention has been experimentally verified to be a targeted specific adsorbent material, adsorbing only ammonia nitrogen and phosphorus, and not heavy metals. Therefore, it will not generate hazardous waste.

[0183] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a nitrogen and phosphorus removal adsorption material, characterized in that, Includes the following steps: Zeolite material, ferrous sulfate and calcium fluoride are mixed and first activated to obtain a first activated product. The holding temperature of the first activation is 200-600℃. The first activated product, iron oxide and borax are mixed and then subjected to a second activation to obtain a second activated product. The second activation includes sequentially performing a first stage of heat preservation activation and a second stage of heat preservation activation. The temperature of the first stage of heat preservation activation is 250-350℃, and the temperature of the second stage of heat preservation activation is 600-700℃. The second activated product is subjected to ultrasonic vibration to obtain the nitrogen and phosphorus removal adsorption material.

2. The preparation method according to claim 1, characterized in that, The first activation temperature is 300-600℃.

3. The preparation method according to claim 1 or 2, characterized in that, The holding time for the first activation is 5 to 7 hours, and the heating rate from room temperature to the first activation is 1 to 10 °C / min.

4. The preparation method according to claim 1, characterized in that, The mass ratio of the zeolite material, ferrous sulfate and calcium fluoride is (3-10):(1-3):

1.

5. The preparation method according to claim 1, characterized in that, The temperature for the first stage of heat preservation and activation is 300-350℃, the heat preservation and activation time for the first stage is 1-3 hours, and the heating rate from room temperature to the temperature of the first stage of heat preservation and activation is 1-10℃ / min.

6. The preparation method according to claim 1 or 5, characterized in that, The holding time for the second stage of heat preservation activation is 2 to 4 hours, and the heating rate from the temperature of the first stage of heat preservation activation to the temperature of the second stage of heat preservation activation is 1 to 5 °C / min.

7. The preparation method according to claim 1, characterized in that, The mass ratio of the first activated product, iron oxide, and borax is 10:1:(4-4.5).

8. The preparation method according to claim 1, characterized in that, The ultrasonic vibration treatment is performed at a temperature of 50–65°C for 1–3 hours.

9. The denitrification and phosphorus removal adsorption material prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the denitrification and phosphorus removal adsorption material according to claim 9 in denitrification and phosphorus removal in water bodies.

Images