Preparation and application of a composite material for removing ammonia nitrogen from fish ponds

Abstract

The present invention relates to the field of ammonia nitrogen adsorbents, and specifically to the preparation and application of a composite material for removing ammonia nitrogen for fish ponds. The composite material for removing ammonia nitrogen of the present invention is prepared by mixing a silicon-aluminum composite salt, peroxide, sodium citrate and a doped catalyst, wherein the silicon-aluminum composite salt is prepared by mixing a sodium aluminate solution and a sodium silicate solution, and the doped catalyst is a transition metal ternary catalyst. The composite material for removing ammonia nitrogen for fish ponds of the present invention has the advantages of simple manufacturing process, low cost, high efficiency, practicality and green environmental protection. It can be applied to dynamic aquaculture water bodies to efficiently remove ammonia nitrogen from water bodies, especially in aquaculture water bodies with low ammonia nitrogen concentrations. It has an efficient removal effect and is suitable for use in fish ponds for aquaculture where ammonia nitrogen concentrations are sensitively controlled.

Description

Technical Field

[0001] The invention relates to the field of ammonia nitrogen adsorbents, and in particular to the preparation and application of a composite material for removing ammonia nitrogen from fish ponds. Background Art

[0002] In aquaculture, ammonia nitrogen is a common pollutant in aquaculture water and a major cause of death for farmed organisms. It primarily originates from animal feces and food waste during the aquaculture process. As the number of fry in a pond increases, the amount of feed added also increases. However, due to low feed conversion rates, ammonia nitrogen is present in metabolic waste. Excessive ammonia nitrogen leads to delayed degradation by microorganisms in the water, resulting in elevated ammonia nitrogen levels that harm fish and lead to reduced production. Furthermore, it is difficult to reduce ammonia nitrogen levels through the nitrogen cycle.

[0003] When fish ponds are short on water and water changes are ineffective in reducing ammonia nitrogen levels in the aquaculture water, ammonia nitrogen removal agents are necessary. Based on the principle of removal, ammonia nitrogen removal agents for fish ponds can be categorized as chemical, biological, and physical. Chemical agents are quick to act, but due to the presence of numerous microorganisms in aquaculture water, the use of highly oxidizing agents can not only harm the fish but also affect the beneficial bacterial flora in the aquaculture water. Furthermore, chemical agents are prone to environmental pollution, so dosage must be strictly controlled. Biological agents are less likely to cause pollution, but currently reported effective agents, such as various nitrifying bacteria and Bacillus subtilis, have significant environmental impacts and are generally ineffective in practical applications. Physical adsorption is widely used due to its low cost and ease of operation. While most adsorbents are effective at high ammonia nitrogen concentrations, their application in fish ponds is less than ideal, as most fish are typically poisoned when ammonia nitrogen concentrations exceed 2 mg / L. Furthermore, most adsorbents are ineffective at ammonia nitrogen concentrations below 5 mg / L, and their effectiveness in complex pond waters is far inferior to that achieved in the laboratory. Practice has shown that floating matter and microorganisms in fish pond water will significantly reduce the performance of ammonia nitrogen removal composite materials. It is necessary to develop new and efficient ammonia nitrogen removal composite materials based on application scenarios. Summary of the Invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a composite material for removing ammonia nitrogen for fish ponds. The composite material has the advantages of simple manufacturing process, low cost, high efficiency and practicality. It can be used in dynamic aquaculture water bodies to efficiently remove ammonia nitrogen in water bodies, especially in aquaculture water bodies with low ammonia nitrogen concentration. It has an efficient removal effect and is suitable for use in fish ponds for aquaculture that are sensitive to the control of ammonia nitrogen concentration.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The invention provides a composite material for removing ammonia nitrogen from fish ponds. The composite material is composed of 55% to 75% of a silicon-aluminum composite salt, 15% to 30% of a peroxide, 1% to 3% of sodium citrate and 7% to 13% of a doping catalyst in percentage by mass. The doping catalyst is a transition metal ternary catalyst.

[0007] Preferably, the silicon-aluminum composite salt is prepared by the following steps:

[0008] S1. dissolving aluminum oxide in an alkaline solution to prepare an aluminate solution;

[0009] S2, diatomaceous earth is treated with hydrochloric acid solution to obtain desalted silicon powder, and the desalted silicon powder is then mixed with sodium hydroxide and roasted to obtain sodium silicate clinker, and the sodium silicate clinker is dissolved in water to prepare a silicate solution;

[0010] S3. Mixing the aluminate solution and the silicate solution at a silicon-aluminum ratio of 1: (1-1.2), performing a hydrothermal reaction, and collecting the solid to obtain a silicon-aluminum composite salt.

[0011] More preferably, in step S2, the calcination is performed by heating from room temperature to 500°C to 600°C with a heating time of 150 min to 180 min, and calcining at this temperature for 4 to 6 hours.

[0012] Preferably, the doped catalyst is prepared by the following steps:

[0013] S1. Dissolve three soluble transition metal salts in water to obtain solution A; dissolve sodium hydroxide and sodium carbonate in water to obtain solution B;

[0014] S2. Add solution A and solution B dropwise to water at 80-100° C. and stir evenly. Keep the resulting solution at 100-140° C. for 30-36 hours, and collect the solid to obtain the doped catalyst.

[0015] More preferably, the transition metal is a combination of three of iron, cobalt, nickel, copper, zinc, silver and manganese.

[0016] Preferably, the peroxide is one or more of calcium peroxide, sodium percarbonate, potassium persulfate, and potassium monopersulfate complex salt.

[0017] The present invention also provides a method for preparing the above-mentioned composite material for removing ammonia nitrogen in fish ponds. The method comprises the following steps: firstly grinding and mixing a silicon-aluminum composite salt and sodium citrate, then grinding and mixing a peroxide and a doped catalyst, and then layering a certain amount of a mixture of the silicon-aluminum composite salt and sodium citrate, a mixture of the peroxide and the catalyst, and the remaining mixture of the silicon-aluminum composite salt and sodium citrate in order from bottom to top, and then pressing the layers into tablets to prepare a composite material sheet for removing ammonia nitrogen in fish ponds.

[0018] Preferably, 50% of the mixture of silicon-aluminum composite salt and sodium citrate, the mixture of peroxide and catalyst, and 50% of the mixture of silicon-aluminum composite salt and sodium citrate are layered in order from bottom to top and then pressed into tablets.

[0019] The present invention also provides the use of the above-mentioned ammonia nitrogen removal composite material for fish ponds in treating aquaculture water. The application method comprises: placing the composite preparation in an amount of 0.05 to 1 g / L in the aquaculture water for a treatment time of 6 to 48 hours. Ammonia (NH3) or ammonium ions (NH4 + ) is adsorbed, thereby reducing the ammonia nitrogen concentration in the water. At the same time, due to the presence of peroxide, ammonia nitrogen can be degraded to a certain extent, effectively improving the aquaculture water quality and increasing production. Sodium citrate plays a role in sterilization and disinfection.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The ammonia nitrogen removal composite material of the present invention is prepared by mixing silicon-aluminum composite salt, peroxide, sodium citrate and a doped catalyst, wherein the doped catalyst is a transition metal ternary catalyst. The ammonia nitrogen removal composite material for fish ponds of the present invention is tableted in a certain order during the preparation process, so that the adsorption material and the disinfectant are presented on the surface of the composite material, effectively adsorbing ammonia nitrogen in the aquaculture water body; the peroxide and the catalyst are placed inside the tablet, making it easier to store, while promoting the conversion of ammonia nitrogen adsorbed by the adsorption material, and improving the ammonia nitrogen removal ability. The ammonia nitrogen removal composite material for fish ponds of the present invention has the advantages of simple manufacturing process, low cost, high efficiency and practicality, and green environmental protection. It can be applied to dynamic aquaculture water bodies to efficiently remove ammonia nitrogen in water bodies, especially in aquaculture water bodies with low ammonia nitrogen concentrations. It has an efficient removal effect and is suitable for use in fish ponds for aquaculture that are sensitive to the control of ammonia nitrogen concentrations. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the ammonia nitrogen removal rate of the doped catalyst and PMS system;

[0023] Figure 2 This is a trend chart showing the change of ammonia nitrogen content in aquaculture water over time after adding different ammonia nitrogen removal composite materials;

[0024] Figure 3 This is a trend chart of the change of ammonia nitrogen content in aquaculture water of ammonia nitrogen removal composite materials under different tableting methods over time;

[0025] Figure 4 This is a trend chart of the change of ammonia nitrogen content in aquaculture water over time when the ammonia nitrogen removal composite material is continuously used in the water body. DETAILED DESCRIPTION

[0026] The following is a further description of specific embodiments of the present invention. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0027] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0028] The ammonia nitrogen concentration in the following examples was determined using HJ 535-2009 "Determination of ammonia nitrogen in water", and the calculation formula for the removal rate η was: η=(C0-C i ) / C0*100%, where: C0 is the ammonia nitrogen concentration of the original water (mg / L); C i It is the ammonia nitrogen concentration in the treated water (mg / L).

[0029] Example 1 Preparation of silicon-aluminum composite salt and determination of pores and potential

[0030] 1. Preparation of silicon-aluminum composite salt

[0031] S1. Weigh aluminum oxide and sodium hydroxide in a mass ratio of 1:2, add them to pure water at a solid-liquid ratio of 1 g:5 mL, and magnetically stir at 300 r / min at 65°C for 1 h to prepare a sodium aluminate solution;

[0032] S2. Dissolve diatomaceous earth in 5 mol / L hydrochloric acid solution at a solid-liquid ratio of 1 g:10 mL, stir magnetically at 300 r / min at 30°C for 3 h, collect the solid by filtration, wash with water until the filtrate is neutral, and dry in an oven at 80°C for 6 h to obtain desalted silicon powder;

[0033] S3, desalted silicon powder and sodium hydroxide are weighed in a mass ratio of 1:2 and placed in a crucible, placed in a muffle furnace, heated from 30°C to 550°C with a heating time of 3h, and roasted at this temperature for 4h to obtain sodium silicate clinker after roasting;

[0034] S4, adding the sodium silicate clinker of S3 into pure water at a solid-liquid ratio of 1 g:4 mL, and magnetically stirring at 65°C and 300 r / min for 1 h to prepare a sodium silicate solution;

[0035] S5. Mix the sodium aluminate solution of S1 with the sodium silicate solution of S4, adjust the silicon-aluminum ratio to 1:1, add 0.1 g of NaCl per 10 mL to adjust the sodium content, place in a hydrothermal reactor and keep warm at 100° C. for 15 h, filter and dry the solid product to obtain a silicon-aluminum composite salt.

[0036] 2. Performance characterization of silicon-aluminum composite salt

[0037] 4A molecular sieve was selected as a comparison because its main components are similar to those of the silicon-aluminum composite salt. The SiO2:Al2O3 ratio of the silicon-aluminum composite salt and the 4A molecular sieve is close to 1:1, and they also have the same adsorption capacity. Table 1 is a comparison of the pore and potential data of the silicon-aluminum composite salt and the 4A molecular sieve:

[0038] Table 1 Pore and potential of silicon-aluminum composite salt and 4A molecular sieve

[0039]

[0040] According to the size of BET, it can be known that the specific surface area of ​​the silicon-aluminum composite salt is larger than that of the 4A molecular sieve, which is more conducive to its adsorption process and can provide more effective adsorption area, thereby improving the adsorption capacity.

[0041] According to the positive and negative Zeta potential, it can be judged that the surface potential of silicon-aluminum composite salt and molecular sieve are both negative, which is beneficial for the adsorption of NH4 + Positive ions have a promoting effect; judging by the absolute value of the electric potential, silicon-aluminum composite salts have a stronger adsorption effect on positive ions, and can be better dispersed in the water body, so that they can come into more sufficient contact with ammonia nitrogen in the water, and ultimately improve the adsorption capacity.

[0042] Example 2 Preparation of doped catalyst and analysis of different preparation conditions

[0043] 1. Preparation of doped catalyst

[0044] S1. Weigh 0.5820 g of cobalt nitrate hexahydrate, 0.8080 g of ferric nitrate nonahydrate, and 0.0.3788 g of copper sulfate pentahydrate and dissolve them in 100 mL of water (the molar ratio of the three is 1:1:1) to obtain solution A; weigh 2 g of sodium hydroxide and 6 g of sodium carbonate and dissolve them in 50 mL of water to obtain solution B;

[0045] S2. Place 25 mL of water in an 80°C water bath, set the speed to 300 r / min, and slowly add the above two solutions dropwise until both solution A and solution B are added. Continue stirring for 60 minutes after the addition is complete.

[0046] S3. The obtained solution was added to a hydrothermal reactor and kept warm at 120° C. for 24 h. The filtered material was then washed until the effluent was neutral. Finally, the mixture was dried at 80° C. to obtain a cobalt-copper-iron ternary catalyst (doped catalyst).

[0047] 2. Performance characterization of doped catalysts

[0048] Three groups of experiments were set up, namely 0.05g doped catalyst, 0.05g potassium monopersulfate (PMS), and 0.05g doped catalyst mixed with 0.05g PMS. The experimental water body was 50mL of ammonia nitrogen water with an initial concentration of 5mg / L. After standing for 6 hours, the ammonia nitrogen content C of the water body was measured. i , calculate the clearance rate η, the ammonia nitrogen clearance rate of the doped catalyst and PMS system is as follows Figure 1 The specific results are shown in Table 2:

[0049] Table 2 Ammonia nitrogen removal rate of doped catalyst and PMS system

[0050]

[0051] It can be seen that the iron-copper-cobalt ternary catalyst itself has almost no ammonia nitrogen removal ability, but has a good ability to catalyze the degradation of ammonia nitrogen by PMS.

[0052] 3. Catalytic effect of different proportions of doped catalysts on PMS

[0053] According to the preparation steps of the doped catalyst, the ratio of iron, copper and cobalt was changed to prepare catalysts with different ratios. 50 mL of water containing ammonia nitrogen with an initial concentration of 5 mg / L was transferred to a 100 mL conical flask. 0.05 g of the doped catalysts with different ratios and 0.05 g of PMS were weighed and added to the ammonia nitrogen-containing water. After standing for 6 hours, the ammonia nitrogen content of the water was measured. i , calculate the clearance rate η, the results are shown in Table 3:

[0054] Table 3 Ammonia nitrogen removal rate of different ratios of doped catalyst and PMS system

[0055]

[0056]

[0057] It can be found from the table that the ternary catalysts prepared with iron, copper and cobalt as raw materials all have certain catalytic capabilities, but the optimal ratio is 1:1:1. When the copper content increases, copper will precipitate first during the preparation process, thereby affecting the co-precipitation effect of the entire catalyst, so no better effect is achieved.

[0058] 4. Catalysis of PMS by ternary catalysts of different transition metals

[0059] According to the preparation steps of the doped catalyst described above, different transition metal nitrates or sulfates were used, and different transition metal doped catalysts were prepared according to a molar ratio of 1:1:1. 50 mL of water containing ammonia nitrogen with an initial concentration of 5 mg / L was transferred to a 100 mL conical flask. 0.05 g of the doped catalysts with different proportions and 0.05 g of PMS were weighed and added to the ammonia nitrogen-containing water. After standing for 6 hours, the ammonia nitrogen content of the water was measured. i , calculate the clearance rate η, the results are shown in Table 4:

[0060] Table 4 Ammonia nitrogen removal rate of different doped catalysts and PMS system

[0061]

[0062]

[0063] It can be seen from the table that the doped catalysts prepared by using different transition metals all have good ability to catalyze the degradation of ammonia nitrogen by PMS, among which the iron-cobalt-zinc ternary catalyst has the best ammonia nitrogen removal effect.

[0064] Example 3 Preparation of Ammonia Nitrogen Removal Composite Material A

[0065] Ammonia nitrogen scavenging composite material A was prepared according to the following mass fractions:

[0066]

[0067] First, the silicon-aluminum composite salt and sodium citrate are ground and mixed, and evenly divided into two equal parts. Then, the potassium monopersulfate composite salt and the iron-cobalt-zinc ternary catalyst are ground and mixed. 50% of the silicon-aluminum composite salt and sodium citrate mixture, the potassium monopersulfate composite salt and catalyst mixture, and 50% of the silicon-aluminum composite salt and sodium citrate mixture are layered in order from bottom to top. The mixture is pressed at 30Kpa for 3 minutes in a tablet press to prepare 0.2g ammonia nitrogen scavenging composite material tablets with a thickness of 3mm and a diameter of 1.5cm.

[0068] Example 4 Preparation of Ammonia Nitrogen Removal Composite Material B

[0069] Ammonia nitrogen scavenging composite material B was prepared according to the following mass fractions:

[0070]

[0071]

[0072] First, the silicon-aluminum composite salt and sodium citrate are ground and mixed, and evenly divided into two equal parts. Then, the potassium monopersulfate composite salt and the iron-cobalt-zinc ternary catalyst are ground and mixed. 50% of the silicon-aluminum composite salt and sodium citrate mixture, the potassium monopersulfate composite salt and catalyst mixture, and 50% of the silicon-aluminum composite salt and sodium citrate mixture are layered in order from bottom to top. The mixture is pressed at 30Kpa for 3 minutes in a tablet press to prepare 0.2g ammonia nitrogen scavenging composite material tablets with a thickness of 3mm and a diameter of 1.5cm.

[0073] Comparative Example 1 Preparation of Ammonia Nitrogen Removal Composite Material C

[0074] The preparation method is the same as that of Example 3, except that 4A molecular sieve is used instead of silicon-aluminum composite salt, and other components remain unchanged. Ammonia nitrogen scavenging composite material C is prepared according to the proportion of ammonia nitrogen scavenging composite material A.

[0075] Comparative Example 2 Preparation of Ammonia Nitrogen Removal Composite Material D

[0076] The preparation method is the same as that of Example 4, except that 4A molecular sieve is used instead of silicon-aluminum composite salt, and other components remain unchanged. Ammonia nitrogen scavenging composite material D is prepared according to the proportion of ammonia nitrogen scavenging composite material B.

[0077] Comparative Example 3 Preparation of Ammonia Nitrogen Removal Composite Material A1

[0078] Ammonia nitrogen scavenging composite material A1 was prepared according to the proportions and ingredients of the ammonia nitrogen scavenging composite material A in Example 3, and the tableting process was changed, that is, all the components were mixed together and ground and mixed using a ball mill, and then tableted at 30 Kpa in a tablet press for 3 minutes to prepare 0.2 g ammonia nitrogen scavenging composite material tablets with a thickness of 3 mm and a diameter of 1.5 cm.

[0079] Experimental Example 1 Performance Characterization of Ammonia Nitrogen Removal Composite Materials

[0080] 1. Performance characterization of different ammonia nitrogen removal composite materials

[0081] Aquaculture water was prepared with NH4Cl at a concentration of 5 mg / L as the solution to be treated. 1 L was transferred to a beaker. The treatment time was 72 hours. The experiment was divided into 5 groups. The specific treatment conditions are as follows:

[0082] In group 1, three tablets of ammonia nitrogen scavenging composite material A were added, and the ammonia nitrogen content changed over time from the initial 5 mg / L to 1.95 mg / L after 72 h;

[0083] In group 2, three tablets of ammonia nitrogen scavenging composite material B were added. As time went by, the ammonia nitrogen content decreased from the initial 5 mg / L to 2.32 mg / L after 72 hours.

[0084] In group 3, three tablets of ammonia nitrogen scavenging composite material C were added, and the ammonia nitrogen content changed over time from the initial 5 mg / L to 3.67 mg / L after 72 h;

[0085] In group 4, three tablets of ammonia nitrogen scavenging composite material D were added, and the ammonia nitrogen content changed over time from the initial 5 mg / L to 3.74 mg / L after 72 h;

[0086] According to the instructions, Group 5 was dosed with the same mass of Dijian No. 3 (Hunan Kunyuan Biotechnology Co., Ltd.) as the ammonia nitrogen removal composite material. Its ammonia nitrogen content changed over time from the initial 5 mg / L and decreased to 3.26 mg / L in 72 hours. Its removal ability was not as good as that of ammonia nitrogen removal composite materials A and B.

[0087] The trend of ammonia nitrogen content in aquaculture water changing over time after adding different ammonia nitrogen removal composite materials is as follows: Figure 2 As shown, ammonia-nitrogen scavenging composite materials A and B maintain excellent ammonia-nitrogen removal capabilities, maintaining high efficiency and sustained performance. The iron-cobalt-zinc-doped catalysts catalyze PMS to purify aquaculture water, effectively improving water quality. They demonstrate diverse functionality and excellent results. Furthermore, the performance of the silicon-aluminum composite adsorption material is significantly superior to that of the 4A molecular sieve.

[0088] 2. Influence of tableting process

[0089] Aquaculture water was prepared with NH4Cl at a concentration of 5 mg / L as the solution to be treated. 1 L was transferred to a beaker and the treatment time was 72 h. The experiment was divided into two groups. The specific treatment conditions are as follows:

[0090] In group 1, three tablets of ammonia nitrogen scavenging composite material A were added, and the ammonia nitrogen content changed over time from the initial 5 mg / L to 1.95 mg / L after 72 h;

[0091] Three tablets of ammonia nitrogen scavenging composite material A1 were added to group 2. As time went by, the ammonia nitrogen content changed from the initial 5 mg / L to 2.54 mg / L after 72 h.

[0092] The trend of ammonia nitrogen content in aquaculture water of ammonia nitrogen removal composite materials under different tableting methods over time is as follows Figure 3 As shown, it can be found that the ammonia nitrogen removal composite material needs to be added in a certain order to maximize its effectiveness. Placing the adsorbent and disinfectant on the surface of the composite material effectively adsorbs ammonia nitrogen from the aquaculture water. Placing the peroxide and catalyst inside the tablet makes it easier to store and promotes the conversion of ammonia nitrogen adsorbed by the adsorbent, improving its ammonia nitrogen removal capacity. Direct tableting after uniform mixing does not achieve this effect.

[0093] 3. Ammonia nitrogen removal and ammonia nitrogen regulation ability of composite material A

[0094] Prepare aquaculture water with a concentration of 5 mg / L using NH4Cl as the solution to be treated. Transfer 1L to a beaker and add 3 tablets of ammonia nitrogen scavenging composite material A. Take out 10mL of aquaculture water every 72 hours to measure the ammonia nitrogen content. After the measurement, add 10mL of lake water containing NH4Cl to increase the ammonia nitrogen content to 5 mg / L. Repeat this operation for 5 consecutive measurements.

[0095] The trend of ammonia nitrogen content in aquaculture water with continuous use of ammonia nitrogen removal composite materials over time is as follows Figure 4 As shown, measurements show that during the first removal process, Composite Material A reduced the initial ammonia nitrogen concentration in the aquaculture water from 5 mg / L to 1.83 mg / L. After increasing the ammonia nitrogen concentration again, it was reduced to 1.91 mg / L. After five consecutive removals, it was reduced to 3.92 mg / L. This demonstrates Composite Material A's ability to continuously remove ammonia nitrogen. During the aquaculture process, the water environment is in a constant state of flux, and ammonia nitrogen increases with fish metabolism. The Composite Material maintains a long-lasting effect in the water, regulating ammonia nitrogen concentrations to maintain a low level without harming fish growth and development.

[0096] In summary, the ammonia nitrogen removal composite material for fish ponds of the present invention can continuously and efficiently remove ammonia nitrogen, wherein the iron, cobalt and zinc doped catalyst can catalyze PMS to purify aquaculture water bodies and effectively improve water quality; the silicon-aluminum composite salt has a stronger adsorption effect on positive ions and can be better dispersed in the water body, so that it can be in more sufficient contact with the ammonia nitrogen in the water quality, thereby improving the adsorption capacity. In addition, the present invention presents the adsorbent material and the disinfectant on the surface of the composite material, effectively adsorbing ammonia nitrogen from the aquaculture water body; the peroxide and the catalyst are placed inside the tablet, making it easier to store, while promoting the conversion of ammonia nitrogen adsorbed by the adsorbent material, improving the ammonia nitrogen removal ability, and maximizing the effect of the ammonia nitrogen removal composite material.

[0097] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations of these embodiments may be made without departing from the principles and spirit of the present invention, and the changes still fall within the scope of protection of the present invention.

Claims

1. A composite material for removing ammonia nitrogen from fish ponds, characterized in that: The catalyst is composed of 55% to 75% of a silicon-aluminum composite salt, 15% to 30% of a peroxide, 1% to 3% of sodium citrate, and 7% to 13% of a doping catalyst by mass percentage; wherein the doping catalyst is a transition metal ternary catalyst; The silicon-aluminum composite salt is prepared by the following steps: S1. dissolving aluminum oxide in an alkaline solution to prepare an aluminate solution; S2, diatomaceous earth is treated with hydrochloric acid solution to obtain desalted silicon powder, and the desalted silicon powder is then mixed with sodium hydroxide and roasted to obtain sodium silicate clinker, and the sodium silicate clinker is dissolved in water to prepare a silicate solution; S3, mixing the aluminate solution and the silicate solution at a silicon-aluminum ratio of 1: (1 to 1.2), then performing a hydrothermal reaction, and collecting the solid to obtain a silicon-aluminum composite salt; The preparation method of the ammonia nitrogen removal composite material comprises the following steps: first grinding and mixing a silicon-aluminum composite salt and sodium citrate, then grinding and mixing a peroxide and a doped catalyst, and then layering a certain amount of a silicon-aluminum composite salt and sodium citrate mixture, a peroxide and catalyst mixture, and the remaining silicon-aluminum composite salt and sodium citrate mixture in order from bottom to top, and then pressing the layers into tablets to prepare ammonia nitrogen removal composite material tablets for fish ponds.

2. The composite material for removing ammonia nitrogen from fish ponds according to claim 1, characterized in that: In step S2, the calcination is performed by heating from room temperature to 500°C to 600°C with a heating time of 150 min to 180 min, and calcining at the temperature for 4 to 6 hours.

3. The composite material for removing ammonia nitrogen from fish ponds according to claim 1, characterized in that: The doped catalyst is prepared by the following steps: S1. Dissolve three soluble transition metal salts in water to obtain solution A; dissolve sodium hydroxide and sodium carbonate in water to obtain solution B; S2. Add solution A and solution B dropwise to water at 80-100° C. and stir evenly. Keep the resulting solution at 100-140° C. for 30-36 hours, and collect the solid to obtain the doped catalyst.

4. The composite material for removing ammonia nitrogen from fish ponds according to claim 3, characterized in that: The transition metal is a combination of three of iron, cobalt, nickel, copper, zinc, silver and manganese.

5. The composite material for removing ammonia nitrogen from fish ponds according to claim 1, characterized in that: The peroxide is one or more of calcium peroxide, sodium percarbonate, potassium persulfate, and potassium monopersulfate composite salt.

6. The method for preparing the composite material for removing ammonia nitrogen from fish ponds according to any one of claims 1 to 5, characterized in that: First, the silicon-aluminum composite salt and sodium citrate are ground and mixed, and then the peroxide and the doped catalyst are ground and mixed. A certain amount of the silicon-aluminum composite salt and sodium citrate mixture, the peroxide and catalyst mixture, and the remaining silicon-aluminum composite salt and sodium citrate mixture are layered in order from bottom to top and pressed into sheets to obtain ammonia nitrogen removal composite material sheets for fish ponds.

7. The method for preparing the composite material for removing ammonia nitrogen from fish ponds according to claim 6, wherein: A mixture of 50% of the silicon-aluminum composite salt and sodium citrate, a mixture of peroxide and catalyst, and a mixture of 50% of the silicon-aluminum composite salt and sodium citrate are layered in order from bottom to top and then pressed into tablets.

Images