An ammonia-nitrogen adsorbing material for soil improvement, a preparation method and application thereof

Abstract

A method for preparing and applying an ammonia nitrogen adsorbent material for soil improvement is disclosed. First, straw fragments and zeolite powder are mixed to obtain a mixed raw material. Then, the mixed raw material is placed in a high-temperature tubular furnace for co-pyrolysis to obtain a composite co-pyrolysis product. Finally, the composite co-pyrolysis product is added to a NaOH solution, stirred evenly, shaken, and impregnated. After removal, it is repeatedly washed with deionized water until neutral, and then dried in a drying oven to obtain an alkali-modified product, i.e., the ammonia nitrogen adsorbent material. The application is to adsorb NH4+. + The -N material is added to the soil to improve soil properties, thereby promoting plant germination and growth; this invention prepares a material with high NH4 content through the co-pyrolysis of zeolite and straw. + Composite materials with -N adsorption capacity, adsorbing NH4 + The N-containing composite material can be recycled as a soil conditioner, and the addition of zeolite can enhance the biochar material's ability to absorb NH4. + Its -N adsorption capacity, along with its naturally loose and porous mineral properties, also make it feasible for soil improvement.

Description

Technical Field

[0001] This invention belongs to the field of environmental protection technology, and specifically relates to an ammonia nitrogen adsorption material that can be used for soil improvement, its preparation method, and its application. Background Technology

[0002] Adding biochar to soil can improve its physical, chemical, and biological properties, which is beneficial for soil improvement and remediation. Biochar can increase soil organic matter content, cation exchange capacity, permeability, and microbial activity, and increase the formation of soil aggregates. In particular, biochar has adsorption properties for soil nutrients such as nitrogen, phosphorus, and potassium, which can help alleviate the loss of soil nutrients, reduce agricultural nitrogen and phosphorus non-point source pollution, improve soil fertility, and promote crop growth. For example, rice straw char has good adsorption performance for nitrogen, phosphorus, and potassium, with adsorption capacities reaching (2.44±0.15) mg / g, (2.91±0.12) mg / g, and (4.97±0.22) mg / g, respectively, demonstrating outstanding carbon sequestration potential and farmland effects.

[0003] On the other hand, biochar is used for low concentrations of NH4 + The adsorption-based deep denitrification technology for -N wastewater has also been extensively studied. Similar to adsorption methods using biochar and activated carbon, it can remove NH4+ through ion exchange, chemical precipitation, and coordination via surface ions and chemical functional groups. + Adsorption of NH4 was achieved, resulting in good NH4 adsorption. + While biochar prepared from different materials exhibits varying adsorption capacities for different concentrations of ammonia nitrogen, studies have shown that *Ulva prolifera* biochar has a maximum adsorption capacity of 16.76 mg / g for treating water containing 10.00 mg / L ammonia nitrogen; rapeseed straw biochar has a maximum adsorption capacity of 12.51 mg / g for treating water containing 30.00 mg / L ammonia nitrogen; and *Chlorella vulgaris*-peanut shell co-pyrolysis biochar has a maximum adsorption capacity of 4.84 mg / g for treating water containing 5.00 mg / L ammonia nitrogen. Although adsorption methods are effective for low concentrations of NH4+... + -N has shown good results in wastewater treatment, but subsequent resource utilization and cost issues still need to be considered. In particular, large-scale wastewater treatment requires the consumption of a large amount of adsorption material and faces the problem of waste material treatment and disposal. Therefore, in practical applications, cost and the feasibility of its application still need to be comprehensively considered.

[0004] Zeolite is an aluminosilicate mineral containing calcium, sodium, and potassium (chemical formula: M). x / n [(AlO2) x (SiO2) y [·mH2O], where M represents metal cations such as sodium, calcium, and potassium, is a mineral material with ordered, uniformly interconnected channels and a large specific surface area, capable of cation exchange adsorption of NH4+.+ The potential of NH4+ in landfill leachate has been demonstrated by studies on the removal of NH4+ from zeolite adsorption methods. + The limiting adsorption capacity of -N can reach 15.5 mg NH4. + -N / g zeolite.

[0005] Currently, there are technologies that use modified biochar or zeolite to prepare nitrogen and phosphorus adsorbents and apply them to the soil as soil conditioners ([1] Duan Qinglong. Adsorption effect of modified biochar on ammonia nitrogen and total phosphorus in simulated wastewater and simulation analysis [D]. Northeast Agricultural University, 2022. DOI:10.27010 / d.cnki.gdbnu.2022.000788; [2] Macravey. Application of zeolite in environmental protection [D]. Guangxi Normal University, 2019), but it has disadvantages in terms of effect and cost when used as a single material to prepare adsorbents. Currently, there are also technologies that use a mixture of biochar and zeolite as a composite matrix for artificial wetlands to adsorb NH4. + -N([3]Xu Jianling, Zou Li, Wang Xinyu, et al. An artificial wetland with plants and composite substrate under low temperature intermittent aeration[P]. Hainan Province: CN202410841669.7, 2024-10-25), but there are no reports in literature or patents on the use of zeolite and biochar or activated carbon in soil improvement. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention aims to provide an ammonia nitrogen adsorbent material that can be used for soil improvement, its preparation method, and its application. This material is prepared by co-pyrolysis of zeolite and waste agricultural straw, and possesses high NH4 content. + The composite material with -N adsorption capacity enables efficient denitrification of low-concentration domestic sewage and adsorption of NH4+. + The composite material after adding -N can be further reused as a soil conditioner, and the addition of zeolite is expected to improve the NH4+ responsiveness of biochar materials. + Its -N adsorption capacity, along with its naturally loose and porous mineral properties, also make it feasible for soil improvement.

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

[0008] A nitrogen adsorbent material for soil improvement, the raw materials of which include straw fragments and zeolite powder in a mass ratio of 7:3-9:1.

[0009] The straw fragments are made from corn stalks, which are collected, air-dried and stored at room temperature. Before preparing biochar, they are dried overnight, crushed and passed through an 80-120 mesh sieve to obtain straw fragments.

[0010] The zeolite used is natural clinoptilolite, which is ground and passed through a 170-230 mesh sieve to obtain zeolite powder.

[0011] A method for preparing an ammonia nitrogen adsorbent material that can be used for soil amendment includes the following steps:

[0012] S1. Mix straw fragments and zeolite powder evenly to obtain mixed raw materials. The mass ratio of straw fragments to zeolite powder is 7:3-9:1.

[0013] S2. The mixed raw materials obtained in step S1 are placed in a high-temperature tubular furnace for co-pyrolysis at 10℃·min. -1 The heating gradient raises the furnace temperature to 500-750℃ and holds it for 1-2 hours, during which nitrogen is introduced as a protective gas to isolate oxygen; during the pyrolysis process, zeolite and corn stalks undergo a co-pyrolysis reaction to obtain a composite co-pyrolysis product.

[0014] S3. Add the composite co-pyrolysis product obtained in step S2 at 0.1-0.3% to a 1 mol / L NaOH solution, stir until homogeneous, and heat at 20-25°C and 100-140 r·min. -1 After being shaken and soaked for 22-26 hours under the conditions, the product is taken out, repeatedly washed with deionized water until neutral, and then dried in a drying oven to obtain the alkali-modified product, namely the ammonia nitrogen adsorption material.

[0015] The composite co-pyrolysis product is produced at 20–25°C and 100–140 r·min. -1 Under these conditions, 22–26 h for 20 mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 16.84–17.22 mg / g.

[0016] The alkali-modified product is tested at 20–25°C and 100–140 r·min. -1 Under these conditions, 22–26 h for 20 mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 17.89-19.08 mg / g.

[0017] The aforementioned application of an ammonia nitrogen adsorbent material for soil improvement involves adsorbing NH4. + The -N material is added to the soil to improve soil properties, thereby promoting plant germination and growth.

[0018] The application method includes the following steps:

[0019] Step 1: The ammonia nitrogen adsorbent material prepared above is subjected to an environment of 20–25°C and 100–140 r·min. -1 Under these conditions, 22–26 h for 20 mg·L-1 NH4 + NH4 in -N solution + After adsorption of -N, the soil amendment material is obtained by centrifugation and drying in an oven.

[0020] Step 2: Mix the soil amendment material with the soil at a ratio of 1‰ to 2‰ to obtain the amended soil.

[0021] Step 3: Soak the seeds in deionized water to promote germination, and then plant the germinated seeds in the improved soil as described above.

[0022] Step 4: Water thoroughly for the first time, place in a well-lit area at room temperature, add water every two days in equal amounts, record the germination and growth of the seeds, and measure the soil pH and water holding capacity after the process is complete.

[0023] The final improvement results showed that the germination rate of seeds in soil with 1‰ to 2‰ soil amendment material was 60% to 70%, the average plant height was 7.0 to 9.0 cm after one week, the soil pH was 7.46 to 7.92 after planting, and the water holding capacity was 22.82% to 24.37%.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention uses corn stalks and zeolite as raw materials to prepare a product with excellent ammonia nitrogen (NH4+) through co-pyrolysis and NaOH modification. + Supported zeolite biochar materials with NH4+ adsorption properties can be used for low concentrations of NH4+. + Deep denitrification treatment of -N wastewater, adsorption of NH4 + The -N-containing material can be further used as a soil conditioner to improve the physical and chemical properties of the soil, thereby promoting plant germination and growth. Significant advantages and technical effects are as follows: ① Using agricultural waste as raw material, supplemented with inexpensive and readily available zeolite materials, a highly efficient deep denitrification adsorption material for low-concentration ammonia nitrogen wastewater has been developed, achieving the technical effect of treating pollution with waste; ② Through technical parameter control, a composite functional material combining low-concentration ammonia nitrogen wastewater adsorption and purification with soil improvement has been prepared. This not only provides an effective technical means for denitrification treatment in sewage treatment plants, but also allows the nitrogen-adsorbed material to be returned to the field for soil improvement, achieving the beneficial technical effect of wastewater treatment and soil improvement through waste reuse; ③ Soil physical and chemical analysis revealed that adding 1-2‰ loaded zeolite biochar material can improve the soil environment for spinach growth, reduce soil acidity, balance soil water retention capacity, and help promote spinach germination and growth. Attached Figure Description

[0026] Figure 1 This is a SEM image of the microstructure of Z@C-OH8:2 in Example 1 of the present invention. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] Example 1: An ammonia nitrogen adsorbent material that can be used for soil improvement, the raw materials of which include straw fragments and zeolite powder in a mass ratio of 8:2.

[0029] The straw fragments used are corn stalks, collected in Qinghai Province, air-dried after collection and stored at room temperature; dried overnight before biochar preparation, then crushed and passed through a 100-mesh sieve to obtain straw fragments;

[0030] The zeolite used is natural clinoptilolite, which is ground and passed through a 200-mesh sieve to obtain zeolite powder.

[0031] A method for preparing an ammonia nitrogen adsorbent material that can be used for soil amendment includes the following steps:

[0032] S1. Mix straw fragments and zeolite powder evenly to obtain mixed raw materials. The mass ratio of straw fragments to zeolite powder is 8:2.

[0033] S2. The mixed raw materials obtained in step S1 are placed in a high-temperature tubular furnace for co-pyrolysis at 10℃·min. -1 The temperature gradient was used to raise the furnace temperature to 500℃ and hold it for 1 hour. During this time, nitrogen was introduced as a protective gas to isolate oxygen. During the pyrolysis process, zeolite and corn stalks underwent a co-pyrolysis reaction to obtain a composite co-pyrolysis product, named Z@C 8:2.

[0034] The composite co-pyrolysis product Z@C 8:2 was processed at 22℃ and 120 r·min. -1 Under these conditions, 24h for 20 mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 17.22 mg / g;

[0035] S3. Add 0.2% of the composite co-pyrolysis product obtained in step S2 to a 1 mol / L NaOH solution, stir until homogeneous, and incubate at 23°C and 120 r·min. -1 After being shaken and soaked for 24 hours under the conditions, the product was taken out, repeatedly washed with deionized water until neutral, and then dried in a drying oven to obtain the alkali-modified product, namely the ammonia nitrogen adsorbent material, named Z@C-OH 8:2.

[0036] The alkali-modified product Z@C-OH 8:2 was tested at 22℃ and 120 r·min. -1 Under these conditions, 24h for 20 mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 19.08 mg / g.

[0037] The microstructure of the Z@C-OH8:2 material in this embodiment is shown below. Figure 1 It can be seen that the material surface is smooth, and the interior contains slits and mesopores, exhibiting NH4+. + -N has favorable attachment sites, and there is no obvious attachment of other microparticles. Zeolite particles have been attached to the surface of biochar or embedded in the pores of biochar.

[0038] Example 2: An ammonia nitrogen adsorbent material that can be used for soil improvement, the raw materials of which include straw fragments and zeolite powder in a mass ratio of 7:3.

[0039] The straw fragments used are corn stalks, collected in Qinghai Province, air-dried and stored at room temperature after collection; dried overnight before biochar preparation, then crushed and passed through an 80-mesh sieve to obtain straw fragments;

[0040] The zeolite used is natural clinoptilolite, which is ground and passed through a 170-mesh sieve to obtain zeolite powder.

[0041] A method for preparing an ammonia nitrogen adsorbent material that can be used for soil amendment includes the following steps:

[0042] S1. Mix straw fragments and zeolite powder evenly to obtain mixed raw materials. The mass ratio of straw fragments to zeolite powder is 7:3.

[0043] S2. The mixed raw materials obtained in step S1 are placed in a high-temperature tubular furnace for co-pyrolysis at 10℃·min. -1 The temperature gradient was used to raise the furnace temperature to 750℃ and hold it for 2 hours. During this time, nitrogen was introduced as a protective gas to isolate oxygen. During the pyrolysis process, zeolite and corn stalks underwent a co-pyrolysis reaction to obtain a composite co-pyrolysis product, named Z@C 7:3.

[0044] The composite co-pyrolysis product Z@C 7:3 was processed at 20℃ and 120 r·min. -1 Under these conditions, 22h for 20mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 17.08 mg / g;

[0045] S3. Add 0.3% of the composite co-pyrolysis product obtained in step S2 to a 1 mol / L NaOH solution, stir until homogeneous, and incubate at 25°C and 100 rpm. -1 After being shaken and soaked for 26 hours under the conditions, the product was taken out, repeatedly washed with deionized water until neutral, and then dried in a drying oven to obtain the alkali-modified product, namely the ammonia nitrogen adsorbent material, named Z@C-OH 7:3.

[0046] The alkali-modified product Z@C-OH 7:3 was tested at 20℃ and 100 r·min. -1 Under these conditions, 20 mg·L⁻¹ for 26 h -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 18.93 mg / g.

[0047] Example 3: An ammonia nitrogen adsorbent material that can be used for soil improvement, the raw materials of which include straw fragments and zeolite powder in a mass ratio of 9:1.

[0048] The straw fragments used are corn stalks, collected in Qinghai Province, air-dried and stored at room temperature after collection; dried overnight before biochar preparation, then crushed and passed through a 120-mesh sieve to obtain straw fragments;

[0049] The zeolite used is natural clinoptilolite, which is ground and passed through a 230-mesh sieve to obtain zeolite powder.

[0050] A method for preparing an ammonia nitrogen adsorbent material that can be used for soil amendment includes the following steps:

[0051] S1. Mix straw fragments and zeolite powder evenly to obtain mixed raw materials. The mass ratio of straw fragments to zeolite powder is 9:1.

[0052] S2. The mixed raw materials obtained in step S1 are placed in a high-temperature tubular furnace for co-pyrolysis at 10℃·min. -1 The temperature gradient raised the furnace temperature to 600℃ and held it for 1.5 hours, during which nitrogen was introduced as a protective gas to isolate oxygen. During the pyrolysis process, zeolite and corn stalks underwent a co-pyrolysis reaction to obtain a composite co-pyrolysis product, named Z@C 9:1.

[0053] The aforementioned composite co-pyrolysis product Z@C 9:1 was processed at 25℃ and 140 r·min. -1 Under these conditions, 22h for 20mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 16.81 mg / g;

[0054] S3. Add 0.1% of the composite co-pyrolysis product obtained in step S2 to a 1 mol / L NaOH solution, stir until homogeneous, and heat at 20°C and 140 r·min. -1 After being shaken and soaked for 22 hours under the specified conditions, the product was removed, repeatedly washed with deionized water until neutral, and then dried in a drying oven to obtain an alkali-modified product, namely an ammonia nitrogen adsorbent material, named Z@C-OH 9:1.

[0055] The alkali-modified product Z@C-OH 9:1 was tested at 25℃ and 140 r·min. -1 Under these conditions, 22h for 20mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 17.89 mg / g.

[0056] Comparative Example 1: An ammonia nitrogen adsorption material, the raw materials of which include straw fragments and zeolite powder in a mass ratio of 1:1.

[0057] The straw fragments used are corn stalks, collected in Qinghai Province, air-dried after collection and stored at room temperature; dried overnight before biochar preparation, then crushed and passed through a 100-mesh sieve to obtain straw fragments;

[0058] The zeolite used is natural clinoptilolite, which is ground and passed through a 200-mesh sieve to obtain zeolite powder.

[0059] A method for preparing an ammonia nitrogen adsorption material includes the following steps:

[0060] S1. Mix straw fragments and zeolite powder evenly to obtain mixed raw materials, with a mass ratio of straw fragments to zeolite powder of 1:1.

[0061] S2. The mixed raw materials obtained in step S1 are placed in a high-temperature tubular furnace for co-pyrolysis at 10℃·min. -1 The temperature gradient was used to raise the furnace temperature to 500℃ and hold it for 1 hour. During this time, nitrogen was introduced as a protective gas to isolate oxygen. During the pyrolysis process, zeolite and corn stalks underwent a co-pyrolysis reaction to obtain a composite co-pyrolysis product, named Z@C1:1.

[0062] The composite co-pyrolysis product Z@C1:1 was subjected to a reaction at 22°C and 120 r·min. -1 Under these conditions, 24h for 20 mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 7.59 mg / g;

[0063] S3. Add 0.2% of the composite co-pyrolysis product obtained in step S2 to a 1 mol / L NaOH solution, stir until homogeneous, and incubate at 25°C and 120 r·min. -1 After being shaken and soaked for 24 hours under the conditions, the product was taken out, repeatedly washed with deionized water until neutral, and then dried in a drying oven to obtain the alkali-modified product, namely the ammonia nitrogen adsorbent material, named Z@C-OH 1:1.

[0064] The alkali-modified product Z@C-OH 1:1 was tested at 22℃ and 120 r·min. -1 Under these conditions, 24h for 20 mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 8.21 mg / g.

[0065] Comparative Example 2, an ammonia nitrogen adsorption material, the raw materials of which include straw fragments and zeolite powder in a mass ratio of 3:7;

[0066] The straw fragments used are corn stalks, collected in Qinghai Province, air-dried after collection and stored at room temperature; dried overnight before biochar preparation, then crushed and passed through a 100-mesh sieve to obtain straw fragments;

[0067] The zeolite used is natural clinoptilolite, which is ground and passed through a 200-mesh sieve to obtain zeolite powder.

[0068] A method for preparing an ammonia nitrogen adsorption material includes the following steps:

[0069] S1. Mix straw fragments and zeolite powder evenly to obtain mixed raw materials, with a mass ratio of straw fragments to zeolite powder of 3:7.

[0070] S2. The mixed raw materials obtained in step S1 are placed in a high-temperature tubular furnace for co-pyrolysis at 10℃·min. -1 The temperature gradient was used to raise the furnace temperature to 500℃ and hold it for 1 hour, during which nitrogen was introduced as a protective gas to isolate oxygen. During the pyrolysis process, zeolite and corn stalks underwent a co-pyrolysis reaction to obtain a composite co-pyrolysis product, named Z@C3:7.

[0071] The composite co-pyrolysis product Z@C3:7 was subjected to a reaction at 22°C and 120 r·min. -1 Under these conditions, 24h for 20 mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 8.91 mg / g;

[0072] S3. Add 0.2% of the composite co-pyrolysis product obtained in step S2 to a 1 mol / L NaOH solution, stir until homogeneous, and incubate at 25°C and 120 r·min. -1 After being shaken and soaked for 24 hours under the conditions, the product was taken out, repeatedly washed with deionized water until neutral, and then dried in a drying oven to obtain the alkali-modified product, namely the ammonia nitrogen adsorbent material, named Z@C-OH 3:7.

[0073] The alkali-modified product Z@C-OH 3:7 was tested at 22℃ and 120 r·min. -1 Under these conditions, 24h for 20 mg·L -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 9.43 mg / g.

[0074] Table 1 compares the maximum ammonia nitrogen adsorption capacity of Examples 1-3 with that of Comparative Examples 1-2. It can be seen that under the conditions of Example 1, the adsorption capacity of Z@C 8:2 before alkali modification and Z@C-OH 8:2 after alkali modification, compared with other straw-zeolite materials of different ratios, significantly increased the adsorption capacity of NH4+. + -N has the best adsorption effect.

[0075] Table 1

[0076]

[0077] Application Example 1: The application of the ammonia nitrogen adsorbent material described in Example 1, which can be used for soil improvement, adsorbs NH4+. + The material after -N is added in appropriate amounts to the soil to improve soil properties, thereby promoting plant germination and growth; the application method includes the following steps:

[0078] Step 1: The ammonia nitrogen adsorbent material Z@C-OH 8:2 prepared above is subjected to an incubation period of 22℃ and 120 r·min. -1 Under these conditions, 24h for 20 mg·L -1 NH4 + NH4 in -N solution + After adsorption of -N, the soil amendment material is obtained by centrifugation and drying in an oven.

[0079] Step 2: Mix the soil amendment material with the soil at a ratio of 1‰ to obtain the amended soil.

[0080] Step 3: Soak spinach seeds in deionized water to promote germination, and then plant the germinated spinach seeds in the improved soil.

[0081] Step 4: Water thoroughly for the first time, place in a well-lit area at room temperature, add water every two days in equal amounts, record the germination and growth of the seeds, and measure the soil pH and water holding capacity after the process is complete.

[0082] The final improvement results were that the germination rate of seeds in the soil with 1‰ soil amendment was 70%, the average plant height was 9.0cm after one week, the soil pH was 7.46 and the water holding capacity was 22.82%.

[0083] Application Example 2: The ammonia nitrogen adsorbent Z@C-OH 8:2 prepared in Example 1 was subjected to an induction heating process at 20°C and 100 rpm. -1 Under these conditions, 20 mg·L⁻¹ for 26 h -1 NH4 + NH4 in -N solution + After adsorption of -N, the soil amendment material is obtained by centrifugation and drying in an oven. The soil amendment material is then mixed with soil at a ratio of 2‰, and the rest is the same as in Application Example 1.

[0084] The final improvement results were as follows: the germination rate of seeds in the soil with 2‰ soil amendment was 60%; the average plant height was 7.0 cm after one week; the soil pH was 7.92 and the water holding capacity was 24.37% after planting.

[0085] Application Example 3: The ammonia nitrogen adsorbent Z@C-OH 8:2 prepared in Example 1 was subjected to an induction heating process at 25°C and 140 rpm. -1 Under these conditions, 22h for 20mg·L -1 NH4 + NH4 in -N solution + After adsorption of -N, the soil amendment material is obtained by centrifugation and drying in an oven. The soil amendment material is then mixed with soil at a ratio of 1.5‰, and the rest is the same as in Application Example 1.

[0086] The final improvement results were as follows: the germination rate of seeds in the soil with 1.5‰ soil amendment was 62.5%, the average plant height was 7.6 cm after one week, the soil pH was 7.62 and the water holding capacity was 23.58% after planting.

[0087] In Comparative Example 1, the soil amendment material was mixed with the soil at a ratio of 0‰, and the rest was the same as in Application Example 1.

[0088] The final results showed a soil seed germination rate of 40%, an average plant height of 6.5 cm after one week, a soil pH of 6.82, and a water holding capacity of 26.09%.

[0089] In Comparative Example 2, the soil amendment material was mixed evenly with the soil at a ratio of 0.5‰, and the rest was the same as in Application Example 1.

[0090] The final improvement results showed a seed germination rate of 30% in the soil with 0.5‰ soil conditioner added. One week later, the average plant height was 6.0 cm. The soil pH after planting was 7.15, and the water holding capacity was 26.03%.

[0091] In Comparative Example 3, the soil amendment material was mixed with the soil at a ratio of 3‰, and the rest was the same as in Application Example 1.

[0092] The final improvement results showed a seed germination rate of 35% in the soil with added 3‰ soil conditioner. One week later, the average plant height was 6.0 cm. The soil pH after planting was 8.01, and the water holding capacity was 29.67%.

[0093] Table 2 shows a comparison of the soil improvement effects of Application Examples 1-3 and Application Comparative Examples 1-3. From the aspects of soil seed germination rate, average plant height, soil pH and water holding capacity, it can be seen that Application Example 1, which added 1‰ soil amendment material, had the best soil improvement effect compared with other application examples.

[0094] Table 2

[0095]

[0096] The application effects of Embodiments 2 and 3 of the present invention are similar to those of Embodiment 1.

Claims

1. An application of an ammonia nitrogen adsorbent material that can be used for soil improvement, characterized in that, Adsorb NH4 + The material after -N is added to the soil to improve soil properties, thereby promoting plant germination and growth. The soil improvement material is mixed with the soil at a ratio of 1‰ to 2‰ to obtain the improved soil. The raw materials include straw fragments and zeolite powder in a mass ratio of 7:3 to 9:

1. The straw scraps are made from corn stalks. After collection, the stalks are air-dried and stored at room temperature. Before preparing biochar, the stalks are dried overnight, crushed, and passed through an 80-120 mesh sieve to obtain straw scraps. The zeolite used is natural clinoptilolite, which is ground and passed through a 170-230 mesh sieve to obtain zeolite powder. The method for preparing an ammonia nitrogen adsorbent material that can be used for soil improvement includes the following steps: S1. Mix straw fragments and zeolite powder evenly to obtain mixed raw materials. The mass ratio of straw fragments to zeolite powder is 7:3-9:

1. S2. The mixed raw materials obtained in step S1 are placed in a high-temperature tubular furnace for co-pyrolysis at 10℃·min. -1 The heating gradient raises the furnace temperature to 500~750℃ and holds it for 1~2 hours, during which nitrogen is introduced as a protective gas to isolate oxygen; during the pyrolysis process, zeolite and corn stalks undergo a co-pyrolysis reaction to obtain a composite co-pyrolysis product. S3. Add the composite co-pyrolysis product obtained in step S2 at 0.1~0.3% to a NaOH solution containing 1 mol / L, stir until homogeneous, and heat at 20~25℃ and 100~140 r·min. -1 After being shaken and soaked for 22-26 hours under the conditions, the product is taken out, repeatedly washed with deionized water until neutral, and then dried in a drying oven to obtain the alkali-modified product, namely ammonia nitrogen adsorption material. The aforementioned composite co-pyrolysis product is produced at 20-25℃ and 100-140 r·min. -1 Under these conditions, 20 mg·L⁻¹ for 22–26 h -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 16.84~17.22 mg / g; The alkali-modified product is tested at 20-25℃ and 100-140 r·min. -1 Under these conditions, 20 mg·L⁻¹ for 22–26 h -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 17.89-19.08 mg / g.

2. The application according to claim 1, characterized in that, Includes the following steps: Step 1: The ammonia nitrogen adsorbent material prepared above is subjected to an environment of 20-25℃ and 100-140 r·min. -1 Under these conditions, 20 mg·L⁻¹ for 22–26 h -1 NH4 + NH4 in -N solution + After adsorption of -N, the soil amendment material is obtained by centrifugation and drying in an oven. Step 2: Mix the soil amendment material with the soil at a ratio of 1‰ to 2‰ to obtain the amended soil. Step 3: Soak the seeds in deionized water to promote germination, and then plant the germinated seeds in the improved soil as described above. Step 4: Water thoroughly for the first time, place in a warm, well-lit area, add water every two days, record the germination and growth of the seeds, and measure the soil pH and water holding capacity after the process is complete. The final improvement results showed that the germination rate of seeds in soil with 1‰~2‰ soil amendment material was 60%~70%, the average plant height was 7.0~9.0cm after one week, the soil pH was 7.46~7.92 after planting, and the water holding capacity was 22.82%~24.37%.

3. The application according to claim 1 or 2, characterized in that: Its raw materials include straw fragments and zeolite powder in a mass ratio of 8:2; The straw fragments used are corn stalks, collected in Qinghai Province, air-dried after collection and stored at room temperature; dried overnight before biochar preparation, then crushed and passed through a 100-mesh sieve to obtain straw fragments; The zeolite used is natural clinoptilolite, which is ground and passed through a 200-mesh sieve to obtain zeolite powder.

4. The application according to claim 3, characterized in that, A method for preparing an ammonia nitrogen adsorbent material that can be used for soil amendment includes the following steps: S1. Mix straw fragments and zeolite powder evenly to obtain mixed raw materials. The mass ratio of straw fragments to zeolite powder is 8:

2. S2. The mixed raw materials obtained in step S1 are placed in a high-temperature tubular furnace for co-pyrolysis at 10℃·min. -1 The temperature gradient was used to raise the furnace temperature to 500℃ and hold it for 1 hour. During this time, nitrogen was introduced as a protective gas to isolate oxygen. During the pyrolysis process, zeolite and corn stalks underwent a co-pyrolysis reaction to obtain a composite co-pyrolysis product, named Z@C 8:

2. The composite co-pyrolysis product Z@C 8:2 was subjected to a reaction at 22°C and 120 r·min. -1 Under these conditions, 20 mg·L⁻¹ for 24 hours -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 17.22 mg / g; S3. Add 0.2% of the composite co-pyrolysis product obtained in step S2 to a 1 mol / L NaOH solution, stir until homogeneous, and incubate at 23°C and 120 r·min. -1 After being shaken and soaked for 24 hours under the conditions, the product was taken out, repeatedly washed with deionized water until neutral, and dried in a drying oven to obtain the alkali-modified product, namely the ammonia nitrogen adsorption material, named Z@C-OH 8:

2. The alkali-modified product Z@C-OH 8:2 was tested at 22℃ and 120 r·min. -1 Under these conditions, 20 mg·L⁻¹ for 24 hours -1 NH4 + NH4+ in -N solution + The maximum adsorption capacity of -N is 19.08 mg / g.

5. The application according to claim 4, characterized in that: Adsorb NH4 + The -N-treated material is added to the soil in appropriate amounts to improve soil properties, thereby promoting plant germination and growth. The application method includes the following steps: Step 1: The ammonia nitrogen adsorbent material Z@C-OH 8:2 prepared above is subjected to an incubation period of 22℃ and 120 r·min. -1 Under these conditions, 24 h of 20 mg·L -1 NH4 + NH4 in -N solution + After adsorption of -N, the soil amendment material is obtained by centrifugation and drying in an oven. Step 2: Mix the soil amendment material with the soil at a ratio of 1‰ to obtain the amended soil. Step 3: Soak spinach seeds in deionized water to promote germination, and then plant the germinated spinach seeds in the improved soil. Step 4: Water thoroughly for the first time, place in a warm, well-lit area, add water every two days, record the germination and growth of the seeds, and measure the soil pH and water holding capacity after the process is complete. The final improvement results were as follows: the germination rate of seeds in the soil with 1‰ soil amendment was 70%; the average plant height was 9.0cm after one week; the soil pH was 7.46 and the water holding capacity was 22.82% after planting.

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