Water conditioning preparation for aquaculture and preparation method thereof

Abstract

The invention discloses a water conditioning preparation for aquaculture and a preparation method thereof, and belongs to the technical field of fishery. Mixing the modified activated carbon, a compound bacteria solution and a laccase solution, and performing oscillation treatment to obtain a bacteria enzyme immobilized carbon material; mixing and stirring modified sodium alginate, glycosaminoglycan, the bacterial enzyme immobilized carbon material, chlorella powder, deionized water, L-sodium glutamate and glycerol, and then sequentially performing freeze thawing treatment, freeze drying, crushing and sieving to obtain the water conditioning preparation. According to the preparation method disclosed by the invention, a bacterium enzyme immobilized carbon material is obtained by loading microorganisms in a compound bacterium solution and laccase in a laccase solution with modified activated carbon, and the bacterium enzyme immobilized carbon material and chlorella powder are subjected to film coating and curing protection through cross-linking and curing of modified sodium alginate and glycosaminoglycan; furthermore, the purifying and regulating capability of the prepared water regulating preparation on the culture water body is improved.

Description

Technical Field

[0001] This invention belongs to the field of fishery technology, specifically relating to a water conditioning agent for aquaculture and its preparation method. Background Technology

[0002] Aquaculture, as a vital global fisheries industry, has seen its intensification increase in recent years due to sustained growth in market demand. Given limited fishery resources, sustainable growth in fisheries requires development in aquaculture, increasing stocking density, improving yield per unit area of ​​water, and appropriately expanding the available aquaculture area. However, existing traditional aquaculture techniques are no longer adequate to meet my country's aquaculture development requirements. Traditional methods are struggling to significantly increase yield per unit area, leading to declining profitability, decreased product quality, and a deteriorating aquaculture environment. Major farmed species are also experiencing severe and often explosive disease outbreaks. To address aquatic diseases and slow growth, farmers have increased stocking density. However, the water quality deterioration caused by high-density farming is becoming increasingly serious, directly impacting the health and yield of farmed organisms. In high-density aquaculture, problems such as improper use of aquatic drugs and additives, overcapacity farming, uneaten feed, and pollution from farmed organisms' excrement exist. These problems lead to increased organic matter and heavy metal ion content in the water. The increased organic matter results in persistently high chemical oxygen demand (COD). This increased COD not only causes microorganisms to consume large amounts of dissolved oxygen during decomposition and metabolism, leading to the death of fish and shrimp, but also causes eutrophication, microbial imbalance, and ultimately, ecosystem collapse. To address the negative impacts of current high-density aquaculture, water conditioners, as a key water quality control method in aquaculture, are widely used. Current forms of water conditioners include microbial water conditioners prepared through microorganisms, chemical water conditioners prepared through chemical products, and water conditioners produced through physical means. Microbial water conditioners primarily rely on the metabolic activity of microbial communities to purify water, making them environmentally friendly and effective. While chemical agents can utilize oxidation to decompose organic pollutants in water and have a rapid effect, the residue of oxidants can easily affect farmed organisms and damage microorganisms in the water, reducing the water's self-purification capacity. Physical methods mainly include using zeolites and other materials that can adsorb suspended substances through their porous structure, but because their function is relatively singular, their effect is poor.

[0003] Patent CN113213642A discloses a microecological preparation for water conditioning in the rearing of largemouth bass fry and its preparation method. The invention utilizes Bacillus, which can effectively degrade organophosphorus and organochlorine pesticides and can also be used as a flocculant to treat wastewater. Photosynthetic bacteria can effectively absorb and utilize harmful substances such as ammonia, nitrite, and hydrogen sulfide in the water and can also serve as initial feed for newly hatched fry, significantly improving their survival rate. Rhodococcus bacteria have a strong purification capacity for inorganic nitrogen and phosphorus in the water, maintaining a good ecological aquatic environment. Yeast can decompose and consume lipid residues in the water and, as a single-cell protein, is rich in nutrients and can enhance the immunity of largemouth bass fry. The preparation involves separately expanding the culture of these microorganisms to increase the number of microbial communities. Finally, the fermented broth from the expanded culture is dried and mixed to obtain the microecological preparation, used to solve water pollution problems in high-density aquaculture. However, microbial water conditioning preparations often have slow onset and poor efficacy due to the influence of water environment factors such as temperature and pH on the activity of the microorganisms.

[0004] Therefore, reducing the impact of the aquatic environment on microorganisms and thereby improving the purification and regulation capabilities of water conditioning agents prepared by microorganisms for aquaculture water is of great importance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a bacterial enzyme immobilized carbon material obtained by loading microorganisms from a composite bacterial solution and laccase from a laccase solution onto modified activated carbon. This material is then cross-linked and solidified into a film using modified sodium alginate and aminopolysaccharides, achieving a coating and solidification protection of the bacterial enzyme immobilized carbon material and Chlorella powder to obtain a water conditioning preparation. This solves the technical problems mentioned in the background art. Specifically, the technical solution of this invention includes the following: A method for preparing a water conditioning agent for aquaculture, the method comprising the following steps: Modified activated carbon, composite bacterial solution and laccase solution were mixed in a weight ratio of 1:15~20:30~40 and then treated with shaking at 100 r / min at 25℃ for 3h~4h to obtain bacterial enzyme immobilized carbon material. Modified sodium alginate, aminopolysaccharide, immobilized enzyme carbon material, chlorella powder, deionized water, L-glutamate sodium and glycerol were mixed and stirred in a weight ratio of 2~3:3~4:10~13:0.2~0.4:100~110:1:2, and then subjected to freeze-thaw treatment, freeze-drying at -20℃ for 24h and crushing through a 10-mesh sieve to obtain the water conditioning preparation.

[0006] Furthermore, the method for preparing the modified activated carbon includes the following steps: Coconut shell activated carbon and nitric acid solution are mixed in a weight ratio of 1:5~8 and heated to 40℃~50℃ for 60min~90min to obtain oxidized activated carbon; The modified activated carbon is obtained by dispersing oxidized activated carbon, crosslinking agent, graphene oxide and chloroform in a weight ratio of 1:2~3:0.1~0.2:40~50 and then heating to 60℃~70℃ for 2h~3h.

[0007] Furthermore, the coconut shell activated carbon has a mesh size of 40 mesh.

[0008] Furthermore, the molar concentration of the nitric acid solution is 2 mol / L to 3 mol / L.

[0009] Furthermore, the crosslinking agent includes glutaraldehyde.

[0010] Furthermore, the particle size of the graphene oxide is 10 μm to 20 μm.

[0011] Furthermore, the preparation method of the composite bacterial solution includes the following steps: The pretreated Bacillus subtilis bacterial solution, photosynthetic bacteria bacterial solution, and nitrifying bacteria bacterial solution were mixed in a weight ratio of 1:0.5~0.6:0.2~0.3 to obtain the composite bacterial solution.

[0012] Furthermore, the method for preparing the pretreated Bacillus subtilis bacterial solution includes the following steps: Bacillus subtilis was inoculated into LB agar medium and cultured at 25°C for 24 h to obtain activated Bacillus subtilis. Activated Bacillus subtilis was inoculated into broth liquid medium and cultured at 30°C for 20 h to obtain Bacillus subtilis seed culture. Bacillus subtilis seed culture and sterile physiological saline were mixed at a weight ratio of 1:9 and then irradiated with a UV light source at a distance of 25 cm from a distance of 20 W for 40 seconds to obtain a mutagenic bacterial culture. The mutagenic bacterial culture was inoculated into broth medium and cultured at 30°C until OD reached. 600 The pretreated Bacillus subtilis bacterial solution was obtained with a concentration of 0.6~0.8.

[0013] Furthermore, the photosynthetic bacteria culture includes OD. 600 The nitrifying bacteria solution contains 0.6-0.8% Rhodopseudomonas palustris bacterial solution, and the nitrifying bacteria solution includes OD... 600 The concentration of nitrifying bacteria in the solution is 0.6~0.8.

[0014] Furthermore, the mass concentration of the laccase solution is 3 g / mL to 4 g / mL.

[0015] Furthermore, the preparation of the modified sodium alginate includes the following steps: Sodium alginate, sodium periodate solution and deionized water are mixed in a weight ratio of 1:1:90~95, then treated in the dark, and then oxidized at 25℃ for 12h~14h to obtain oxidized sodium alginate. Ethylenediaminetetraacetic acid, ethylenediamine, EDC hydrochloride and N-hydroxysuccinimide were mixed in a weight ratio of 5:1:5:2 and reacted at 25°C for 15 h to obtain amino-modified ethylenediaminetetraacetic acid; The modified sodium alginate is obtained by mixing sodium oxidized alginate and amino-modified ethylenediaminetetraacetic acid in a weight ratio of 1:2~3 and reacting them at 25°C for 24 hours.

[0016] Furthermore, the molar concentration of the sodium periodate solution is 0.3 mol / L.

[0017] Furthermore, the aminopolysaccharide includes chitosan.

[0018] Furthermore, the freeze-thaw process consists of freezing at -20°C for 2 hours followed by thawing at 25°C for 2 hours as one freeze-thaw cycle, and the freeze-thaw process is repeated 3 times.

[0019] The second objective of this invention is to provide a water conditioning agent prepared by a method for preparing a water conditioning agent for aquaculture.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses a pretreated Bacillus subtilis, photosynthetic bacteria, and nitrifying bacteria as a composite bacterial solution in a water conditioning agent to perform purification functions. Bacillus subtilis, when added to the aquaculture environment, can rapidly multiply and produce a large number of highly active bacterial extracellular enzymes, such as proteases and amylases. These enzymes decompose and consume large-molecule organic pollutants such as uneaten feed and excrement in the pond, converting them into small-molecule organic acids and amino acids. These converted substances can serve as a nutrient source for photosynthetic bacteria, promoting nutrient cycling and reducing eutrophication. Ultraviolet irradiation induces mutations in Bacillus subtilis, resulting in highly active strains that enhance their ability to decompose organic matter. During their reproduction, photosynthetic bacteria utilize small-molecule organic matter and sulfides as carbon sources and ammonia and nitrite as nitrogen sources to synthesize their own bacterial proteins, thus purifying the water. Nitrifying bacteria gradually convert toxic ammonia nitrogen into low-toxicity nitrates, achieving water purification. Laccase, which decomposes organic pollutants, is used as an enzyme solution to further enhance the purification and degradation of organic pollutants in the aquaculture water, improving the utilization efficiency of organic pollutants by microorganisms in the composite bacterial solution. Coconut shell activated carbon was used as a carrier for adsorbing and immobilizing microorganisms and laccase. The activated carbon was oxidized to obtain oxygen-containing hydrophilic groups, resulting in oxidized activated carbon. Then, graphene oxide, with its good hydrophilicity and dispersibility, was chemically bonded to the surface of the oxidized activated carbon using a crosslinking agent to obtain modified activated carbon. This overcomes the shortcomings of activated carbon in water, such as poor dispersion and low adsorption capacity for microorganisms and laccase. The modified activated carbon was mixed with a composite bacterial solution and a laccase solution to obtain a microbial-enzyme immobilized carbon material loaded with microorganisms and laccase. The immobilization treatment improved the stability of the microorganisms and laccase, thereby increasing the efficiency of water purification. Next, amino-modified ethylenediaminetetraacetic acid (EDTA) is used to modify sodium alginate via imine bonds to obtain modified sodium alginate loaded with EDTA. Modified sodium alginate, aminopolysaccharides, immobilized microbial enzyme carbon material, and Chlorella powder are mixed and stirred, then subjected to freeze-thaw cycles, freeze-drying, and pulverization to obtain a water conditioning agent. Through the dual effects of hydrogen bonding and chemical cross-linking between modified sodium alginate and aminopolysaccharides, the cross-linked and solidified material forms a film on the surface of the immobilized microbial enzyme carbon material, thus obtaining the water conditioning agent. This not only further improves the stability of microorganisms and enzymes immobilized on the immobilized microbial enzyme carbon material through physical adsorption, but also introduces Chlorella, which has a high photosynthetic capacity, capable of producing large amounts of oxygen, increasing dissolved oxygen in the water, enhancing the metabolic activity of nitrifying bacteria, and degrading nitrates and nitrites in the water, reducing ammonia nitrogen levels, and decreasing the accumulation of toxic substances, thereby purifying the water quality. It also synergistically improves the purification efficiency of aquaculture water with microorganisms and laccase. Attached Figure Description

[0021] Figure 1 The image shows the surface SEM image of the water-conditioning preparation obtained in Example 1 of this invention. Figure 2The image shows the surface SEM image of the water-conditioning preparation obtained in Example 2 of this invention. Figure 3 The image shows the surface SEM image of the water-conditioning preparation obtained in Example 3 of this invention. Figure 4 This is a surface SEM image of the water-conditioning preparation obtained in Example 4 of the present invention; Figure 5 This is a surface SEM image of the water-conditioning formulation prepared in Comparative Example 1 of this invention; Figure 6 This is a surface SEM image of the water-conditioning formulation prepared in Comparative Example 2 of this invention; Figure 7 This is a surface SEM image of the water-conditioning formulation prepared in Comparative Example 5 of the present invention. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below 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 the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0024] Rhodopseudomonas palustris was purchased from the China Industrial Microbial Culture Collection Center. Bacillus subtilis and nitrifying bacteria were purchased from Jiangsu Lvke Biotechnology Co., Ltd. Chlorella powder was purchased from Shanghai Guangyu Biotechnology Co., Ltd.

[0025] Preparation Example 1 The preparation of pretreated Bacillus subtilis bacterial suspension includes the following steps: After the inoculation loop was sterilized by high temperature, Bacillus subtilis was dipped into the loop and streaked back and forth on a sterilized LB agar medium. The streaked LB agar medium plates were then placed in a constant temperature incubator at 25℃ for 24 hours to obtain activated Bacillus subtilis. 10g of peptone, 3g of beef extract powder, and 5g of sodium chloride were weighed using an electronic balance and placed in an Erlenmeyer flask. 500mL of purified water was added, and the mixture was heated and stirred until the powder was completely dissolved. Purified water was then added to bring the volume to 1L. The flask was then placed in a high temperature sterilizer and sterilized at 121℃ for 30 minutes. After cooling to room temperature, a broth liquid medium was obtained. Three loops of the sterilized inoculation loop were inoculated into the broth liquid medium and placed in a constant temperature shaking incubator at 30℃. The mixture was shaken at 100r / min for 20 hours to obtain Bacillus subtilis seed culture. Mix 10 mL of Bacillus subtilis seed culture with 90 mL of sterilized physiological saline, then pour the mixture into a sterilized Petri dish. Place the dish on a clean bench and position a 20W UV lamp 25 cm directly above the dish for 40 seconds of UV irradiation. After UV treatment, use a sterile loop to collect three loops of the UV-treated Bacillus subtilis colonies and add them to 1 L of broth. Incubate the dish in a 30°C shaking incubator at 50 rpm until the OD reaches the target value. 600 The pretreated Bacillus subtilis bacterial solution was obtained after the concentration was set to 0.6.

[0026] Preparation Example 2 The preparation of pretreated Bacillus subtilis bacterial suspension includes the following steps: The preparation process was consistent with that of Preparation Example 1, and the culture was eventually carried out until the OD reached 100%. 600 The pretreated Bacillus subtilis bacterial solution was obtained after the concentration was set to 0.8.

[0027] Preparation Example 3 The preparation of pretreated Bacillus subtilis bacterial suspension includes the following steps: The preparation process was consistent with that of Preparation Example 1, and the culture was eventually carried out until the OD reached the target value. 600 The pretreated Bacillus subtilis bacterial solution was obtained after the process was completed to version 1.0.

[0028] Preparation Example 4 The preparation of the compound bacterial solution specifically includes the following processes: Weigh 1 part by weight of the pretreated Bacillus subtilis bacterial solution obtained in Example 1, and 0.5 parts by weight of OD 600 The concentration of Rhodopseudomonas palustris bacterial suspension was 0.6% and the concentration of OD was 0.2%. 600 A composite bacterial solution was prepared by mixing 0.6% nitrifying bacteria solution and stored at 10℃ for later use.

[0029] Preparation Example 5 The preparation of the compound bacterial solution specifically includes the following processes: Weigh 1 part by weight of the pretreated Bacillus subtilis bacterial solution obtained in Example 1, and 0.55 parts by weight of OD 600 The concentration of *Rhodopseudomonas palustris* bacterial suspension was 0.6% and the OD concentration was 0.25 parts by weight. 600 A composite bacterial solution was prepared by mixing 0.6% nitrifying bacteria solution and stored at 10℃ for later use.

[0030] Preparation Example 6 The preparation of the compound bacterial solution specifically includes the following processes: Weigh 1 part by weight of the pretreated Bacillus subtilis bacterial solution obtained in Preparation Example 2, and 0.6 parts by weight of OD 600 The concentration of Rhodopseudomonas palustris bacterial suspension was 0.6% and the concentration of OD was 0.3%. 600A composite bacterial solution was prepared by mixing 0.6% nitrifying bacteria solution and stored at 10℃ for later use.

[0031] Preparation Example 7 The preparation of the compound bacterial solution specifically includes the following processes: Weigh 1 part by weight of the pretreated Bacillus subtilis bacterial solution obtained in Preparation Example 2, and 0.6 parts by weight of OD 600 The concentration of Rhodopseudomonas palustris bacterial suspension was 0.8 and the concentration of OD was 0.3 parts by weight. 600 A composite bacterial solution was prepared by mixing nitrifying bacteria solution with a concentration of 0.8 and stored at 10°C for later use.

[0032] Preparation Example 8 The preparation of the compound bacterial solution specifically includes the following processes: Weigh 1 part by weight of the Bacillus subtilis seed solution obtained in Example 1, and 0.6 parts by weight of OD 600 The concentration of Rhodopseudomonas palustris bacterial suspension was 0.8 and the concentration of OD was 0.3 parts by weight. 600 A composite bacterial solution was prepared by mixing nitrifying bacteria solution with a concentration of 0.8 and stored at 10°C for later use.

[0033] Preparation Example 9 The preparation of the compound bacterial solution specifically includes the following processes: Weigh 1 part by weight of the pretreated Bacillus subtilis bacterial solution obtained in Preparation Example 3, and 0.6 parts by weight of OD 600 The concentration of Rhodopseudomonas palustris bacterial suspension was 0.8 and the concentration of OD was 0.3 parts by weight. 600 A composite bacterial solution was prepared by mixing nitrifying bacteria solution with a concentration of 0.8 and stored at 10°C for later use.

[0034] Preparation Example 10 The preparation of modified sodium alginate specifically includes the following processes: One part by weight of sodium alginate and one part by weight of sodium periodate solution with a molar concentration of 0.3 mol / L were added to 90 parts by weight of deionized water and stirred until evenly dispersed. The mixture was then protected from light and placed in a 25°C environment for oxidative treatment with stirring for 12 hours. After the oxidation treatment, two parts by weight of ethylene glycol were added to quench the oxidation reaction to obtain a reaction mixture. The reaction mixture was then poured into a dialysis bag with a molecular weight cutoff of 1 kDa and dialyzed with deionized water for 2 days. After dialysis, the liquid in the bag was removed, dried, and dehydrated to obtain oxidized sodium alginate. Five parts by weight of ethylenediaminetetraacetic acid (EDTA) and one part by weight of ethylenediamine were weighed and added to 40 parts by weight of anhydrous acetone and stirred until evenly dispersed. Then, five parts by weight of EDC hydrochloride and two parts by weight of N-hydroxysuccinimide were added and stirred. The temperature was then controlled at 25°C and the reaction was timed for 15 hours. After the reaction was completed, the acetone was removed by vacuum evaporation to obtain the reaction solution. Then, an equal volume of phosphate buffer solution with pH 6.8 and ethyl acetate were added to the reaction solution and stirred until homogeneous. The organic phase was extracted and separated. After vacuum drying, amino-modified ethylenediaminetetraacetic acid was obtained. One part by weight of oxidized sodium alginate and two parts by weight of amino-modified ethylenediaminetetraacetic acid were added to 20 parts by weight of deionized water. The mixture was stirred and dispersed evenly using an ultrasonic power of 300W, and then stirred at 200 rpm for 24 hours at 25°C. After the reaction was completed, the mixture was dialyzed with deionized water for 2 days through a dialysis bag with a molecular weight cutoff of 1 kDa, and then dried to remove water to obtain modified sodium alginate.

[0035] Preparation Example 11 The preparation of modified sodium alginate specifically includes the following processes: One part by weight of sodium alginate and one part by weight of sodium periodate solution with a molar concentration of 0.3 mol / L were added to 95 parts by weight of deionized water and stirred until evenly dispersed. The mixture was then protected from light and placed in a 25°C environment for oxidative treatment with stirring for 14 hours. After the oxidation treatment, two parts by weight of ethylene glycol were added to quench the oxidation reaction to obtain a reaction mixture. The reaction mixture was then poured into a dialysis bag with a molecular weight cutoff of 1 kDa and dialyzed with deionized water for 2 days. After dialysis, the liquid in the bag was removed, dried, and dehydrated to obtain oxidized sodium alginate. Five parts by weight of ethylenediaminetetraacetic acid (EDTA) and one part by weight of ethylenediamine were weighed and added to 40 parts by weight of anhydrous acetone and stirred until evenly dispersed. Then, five parts by weight of EDC hydrochloride and two parts by weight of N-hydroxysuccinimide were added and stirred. The temperature was then controlled at 25°C and the reaction was timed for 15 hours. After the reaction was completed, the acetone was removed by vacuum evaporation to obtain the reaction solution. Then, an equal volume of phosphate buffer solution with pH 6.8 and ethyl acetate were added to the reaction solution and stirred until homogeneous. The organic phase was extracted and separated. After vacuum drying, amino-modified ethylenediaminetetraacetic acid was obtained. One part by weight of oxidized sodium alginate and three parts by weight of amino-modified ethylenediaminetetraacetic acid were added to 20 parts by weight of deionized water. The mixture was stirred and dispersed evenly using an ultrasonic power of 300W, and then stirred at 200 rpm for 24 hours at 25°C. After the reaction was completed, the mixture was dialyzed with deionized water for 2 days through a dialysis bag with a molecular weight cutoff of 1 kDa, and then dried to remove water to obtain modified sodium alginate.

[0036] Preparation Example 12 The preparation of modified sodium alginate specifically includes the following processes: One part by weight of sodium alginate and 1.5 parts by weight of sodium periodate solution with a molar concentration of 0.3 mol / L were weighed and added to 95 parts by weight of deionized water. The mixture was stirred until evenly dispersed, then protected from light and placed in a 25°C environment for oxidative treatment with stirring for 16 hours. After the oxidation treatment, 2 parts by weight of ethylene glycol were added to quench the oxidation reaction to obtain a reaction mixture. The reaction mixture was poured into a dialysis bag with a molecular weight cutoff of 1 kDa and dialyzed with deionized water for 2 days. After dialysis, the liquid in the bag was removed and dried to obtain oxidized sodium alginate. The remaining preparation process was consistent with that in Preparation Example 11.

[0037] Preparation Example 13 The preparation of modified sodium alginate specifically includes the following processes: One part by weight of sodium alginate and one part by weight of a 0.3 mol / L sodium periodate solution were added to 95 parts by weight of deionized water and stirred until evenly dispersed. The mixture was then protected from light and placed in a 25°C environment for oxidative treatment with stirring for 14 hours. After oxidation, two parts by weight of ethylene glycol were added to quench the oxidation reaction, resulting in a reaction mixture. This mixture was then poured into a dialysis bag with a molecular weight cutoff of 1 kDa and dialyzed with deionized water for two days. After dialysis, the liquid in the bag was removed, dried, and dehydrated to obtain oxidized sodium alginate, which was used as modified sodium alginate.

[0038] Preparation Example 14 The preparation of modified activated carbon specifically includes the following processes: One part by weight of coconut shell activated carbon passing through a 40-mesh sieve was added to five parts by weight of a 2 mol / L nitric acid solution and mixed thoroughly. The mixture was then heated to 40°C and reacted for 60 minutes. After the reaction, the solid particles were collected by filtration and repeatedly washed with deionized water until the pH of the rinsing waste liquid was neutral. The solid particles were then dried in a vacuum drying oven at 60°C to remove water, yielding oxidized activated carbon. One part by weight of oxidized activated carbon, two parts by weight of glutaraldehyde, and 0.1 parts by weight of graphene oxide with a particle size of 10 μm were weighed and added to 40 parts by weight of chloroform. The mixture was dispersed evenly using an ultrasonic power of 300 W, and then heated to 60°C and reacted at 200 r / min for 2 hours. After the reaction, the particles were filtered and dried under reduced pressure to constant weight to obtain modified activated carbon.

[0039] Preparation Example 15 The preparation of modified activated carbon specifically includes the following processes: One part by weight of coconut shell activated carbon passing through a 40-mesh sieve was added to six parts by weight of a 2 mol / L nitric acid solution and mixed thoroughly. The mixture was then heated to 45°C and reacted for 70 min. After the reaction, the solid particles were collected by filtration and repeatedly washed with deionized water until the pH of the waste liquid was neutral. The solid particles were then dried in a vacuum drying oven at 60°C to remove water, thus obtaining oxidized activated carbon. One part by weight of oxidized activated carbon, 2.5 parts by weight of glutaraldehyde, and 0.1 parts by weight of graphene oxide with a particle size of 10 μm were weighed and added to 40 parts by weight of chloroform. The mixture was dispersed evenly using an ultrasonic power of 300 W, and then heated to 60°C and reacted at a speed of 200 r / min for 2.5 h. After the reaction, the particles were obtained by filtration and dried under reduced pressure to constant weight to obtain modified activated carbon.

[0040] Preparation Example 16 The preparation of modified activated carbon specifically includes the following processes: One part by weight of coconut shell activated carbon passing through a 40-mesh sieve was added to seven parts by weight of a 3 mol / L nitric acid solution and mixed thoroughly. The mixture was then heated to 50°C and reacted for 80 minutes. After the reaction, the solid particles were collected by filtration and repeatedly washed with deionized water until the pH of the waste liquid was neutral. The solid particles were then dried in a vacuum drying oven at 60°C to remove water and obtain oxidized activated carbon. One part by weight of oxidized activated carbon, three parts by weight of glutaraldehyde, and 0.15 parts by weight of graphene oxide with a particle size of 20 μm were weighed and added to 50 parts by weight of chloroform. The mixture was dispersed evenly using an ultrasonic power of 300 W, and then heated to 70°C and reacted at a speed of 200 r / min for 2.5 hours. After the reaction, the particles were obtained by filtration and dried under reduced pressure to constant weight to obtain modified activated carbon.

[0041] Preparation Example 17 The preparation of modified activated carbon specifically includes the following processes: One part by weight of coconut shell activated carbon passing through a 40-mesh sieve was added to eight parts by weight of a 3 mol / L nitric acid solution and mixed thoroughly. The mixture was then heated to 50°C and reacted for 90 minutes. After the reaction, the solid particles were collected by filtration and repeatedly washed with deionized water until the pH of the rinsing waste liquid was neutral. The solid particles were then dried in a vacuum drying oven at 60°C to remove water, yielding oxidized activated carbon. One part by weight of oxidized activated carbon, three parts by weight of glutaraldehyde, and 0.2 parts by weight of graphene oxide with a particle size of 20 μm were weighed and added to 50 parts by weight of chloroform. The mixture was dispersed evenly using an ultrasonic power of 300 W, and then heated to 70°C and reacted at 200 r / min for 3 hours. After the reaction, the particles were obtained by filtration and dried under reduced pressure to constant weight to obtain modified activated carbon.

[0042] Preparation Example 18 The preparation of modified activated carbon specifically includes the following processes: One part by weight of coconut shell activated carbon passing through a 40-mesh sieve was added to eight parts by weight of a 4 mol / L nitric acid solution and mixed thoroughly. The mixture was then heated to 60°C and reacted for 100 min. After the reaction, the solid particles were collected by filtration and repeatedly washed with deionized water until the pH of the waste liquid was neutral. The solid particles were then dried in a vacuum drying oven at 60°C to remove water and obtain oxidized activated carbon. One part by weight of oxidized activated carbon, three parts by weight of glutaraldehyde, and 0.2 parts by weight of graphene oxide with a particle size of 20 μm were weighed and added to 50 parts by weight of chloroform. The mixture was dispersed evenly using an ultrasonic power of 300 W, and then heated to 70°C and reacted at a speed of 200 r / min for 3 h. After the reaction, the particles were obtained by filtration and dried under reduced pressure to constant weight to obtain modified activated carbon.

[0043] Preparation Example 19 The preparation of modified activated carbon specifically includes the following processes: One part by weight of coconut shell activated carbon passed through a 40-mesh sieve was added to eight parts by weight of a 3 mol / L nitric acid solution and mixed thoroughly. The mixture was then heated to 50°C and reacted for 90 min. After the reaction, the solid particles were collected by filtration and repeatedly washed with deionized water until the pH of the waste liquid was neutral. The solid particles were then dried in a vacuum drying oven at 60°C to remove water and obtain oxidized activated carbon. One part by weight of oxidized activated carbon, three parts by weight of glutaraldehyde, and 0.2 parts by weight of graphene oxide with a particle size of 40 μm were weighed and added to 50 parts by weight of chloroform. The mixture was dispersed evenly using an ultrasonic power of 300 W, and then heated to 70°C and reacted at a speed of 200 r / min for 3 h. After the reaction, the particles were obtained by filtration and dried under reduced pressure to constant weight to obtain modified activated carbon.

[0044] Preparation Example 20 The preparation of oxidizing activated carbon specifically includes the following processes: One part by weight of coconut shell activated carbon that has passed through a 40-mesh sieve was added to eight parts by weight of a 3 mol / L nitric acid solution and mixed thoroughly. The mixture was then heated to 50°C and reacted for 90 minutes. After the reaction was completed, the solid particles were collected by filtration. The solid particles were repeatedly washed with deionized water until the pH of the waste liquid was neutral. The waste liquid was then dried in a vacuum drying oven at 60°C to remove water and obtain oxidized activated carbon.

[0045] Example 1 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: Weigh 1 part by weight of the modified activated carbon obtained in Preparation Example 14, 15 parts by weight of the composite bacterial solution obtained in Preparation Example 4, and 30 parts by weight of a laccase solution with a mass concentration of 3 g / mL, mix them together, and then treat them at 25°C with a shaking speed of 100 r / min for 3 h. After filtration, the bacterial enzyme immobilized carbon material is obtained. Weigh 2 parts by weight of the modified sodium alginate obtained in Preparation Example 10, 3 parts by weight of chitosan, 100 parts by weight of deionized water, 1 part by weight of L-glutamate sodium, and 2 parts by weight of glycerol, mix them together, and then treat them at 30°C with a shaking speed of 100 r / min for 3 h. The mixture was dispersed evenly using 0W ultrasonic power, then 10 parts by weight of immobilized bacterial enzyme carbon material and 0.2 parts by weight of Chlorella powder were added and stirred until evenly dispersed. The mixture was then poured into a mold and placed at 25℃ for 12 hours, followed by freezing at -20℃ for 2 hours. This freeze-thaw cycle was repeated three times, and finally, the mixture was freeze-dried at -20℃ for 24 hours. After drying, the mixture was crushed and passed through a 10-mesh sieve to obtain the water-conditioning formulation. The surface-cured cross-linked structure of the water-conditioning formulation was observed using a scanning electron microscope. The results are as follows: Figure 1 As shown in the figure, the cross-linked and solidified encapsulation structure was successfully constructed with well-developed pores, which facilitates contact with water and thus plays a role in purification and degradation.

[0046] Example 2 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: Weigh 1 part by weight of the modified activated carbon obtained in Preparation Example 15, 17 parts by weight of the composite bacterial solution obtained in Preparation Example 5, and 34 parts by weight of a laccase solution with a mass concentration of 3 g / mL, mix them together, and then treat them at 25°C with shaking at 100 r / min for 3 h. After filtration, the bacterial enzyme immobilized carbon material is obtained. Weigh 2.5 parts by weight of the modified sodium alginate obtained in Preparation Example 10, 3.5 parts by weight of chitosan, 105 parts by weight of deionized water, 1 part by weight of L-glutamate sodium, and 2 parts by weight of glycerol, mix them together, and then... The mixture was dispersed evenly using 300W ultrasonic power, then 11 parts by weight of immobilized bacterial enzyme carbon material and 0.3 parts by weight of Chlorella powder were added and stirred until evenly dispersed. The mixture was then poured into a mold and placed at 25℃ for 12 hours, followed by freezing at -20℃ for 2 hours. This freeze-thaw cycle was repeated three times, and finally, the mixture was freeze-dried at -20℃ for 24 hours. After drying, the mixture was crushed and passed through a 10-mesh sieve to obtain the water-conditioning formulation. The surface-cured cross-linked structure of the water-conditioning formulation was observed using a scanning electron microscope. The results are as follows: Figure 2 As shown in the figure, the cross-linked and solidified encapsulation structure was successfully constructed with well-developed pores, which facilitates contact with water and thus plays a role in purification and degradation.

[0047] Example 3 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: Weigh 1 part by weight of the modified activated carbon obtained in Preparation Example 16, 19 parts by weight of the composite bacterial solution obtained in Preparation Example 6, and 38 parts by weight of a laccase solution with a mass concentration of 4 g / mL, mix them together, and then treat them at 25°C with shaking at 100 r / min for 3.5 h. After filtration, the bacterial enzyme immobilized carbon material is obtained. Weigh 2.5 parts by weight of the modified sodium alginate obtained in Preparation Example 11, 3.5 parts by weight of chitosan, 105 parts by weight of deionized water, 1 part by weight of L-glutamate sodium, and 2 parts by weight of glycerol, mix them together, and... The mixture was dispersed evenly using an ultrasonic power of 300W, then 12 parts by weight of immobilized charcoal material and 0.4 parts by weight of Chlorella powder were added and stirred until evenly dispersed. The mixture was then poured into a mold and placed at 25℃ for 12 hours, followed by freezing at -20℃ for 2 hours. This freeze-thaw cycle was repeated three times, and finally, the mixture was freeze-dried at -20℃ for 24 hours. After drying, the mixture was crushed and passed through a 10-mesh sieve to obtain the water-conditioning formulation. The surface-cured cross-linked structure of the water-conditioning formulation was observed using a scanning electron microscope. The results are as follows: Figure 3 As shown in the figure, the cross-linked and solidified encapsulation structure was successfully constructed with well-developed pores, which facilitates contact with water and thus plays a role in purification and degradation.

[0048] Example 4 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: Weigh 1 part by weight of the modified activated carbon obtained in Preparation Example 17, 20 parts by weight of the composite bacterial solution obtained in Preparation Example 7, and 40 parts by weight of a laccase solution with a mass concentration of 4 g / mL, mix them together, and then treat them at 25°C with shaking at 100 r / min for 4 h. After filtration, the bacterial enzyme immobilized carbon material is obtained. Weigh 3 parts by weight of the modified sodium alginate obtained in Preparation Example 11, 4 parts by weight of chitosan, 110 parts by weight of deionized water, 1 part by weight of L-glutamate sodium, and 2 parts by weight of glycerol, mix them together, and then mix them with 30 The mixture was dispersed evenly using 0W ultrasonic power, then 13 parts by weight of immobilized bacterial enzyme carbon material and 0.4 parts by weight of Chlorella powder were added and stirred until evenly dispersed. The mixture was then poured into a mold and placed at 25℃ for 12 hours, followed by freezing at -20℃ for 2 hours. This freeze-thaw cycle was repeated three times, and finally, the mixture was freeze-dried at -20℃ for 24 hours. After drying, the mixture was crushed and passed through a 10-mesh sieve to obtain the water-conditioning formulation. The surface-cured cross-linked structure of the water-conditioning formulation was observed using a scanning electron microscope. The results are as follows: Figure 4 As shown in the figure, the cross-linked and solidified encapsulation structure was successfully constructed with well-developed pores, which facilitates contact with water and thus plays a role in purification and degradation.

[0049] Comparative Example 1 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: The modified sodium alginate and chitosan obtained in Preparation Example 11 (3 parts by weight) in Example 4 were increased to 5 parts by weight and 6 parts by weight, respectively. The rest of the preparation process remained the same as in Example 4. The surface-cured cross-linked structure of the water conditioning preparation was observed by scanning electron microscopy. The results are as follows: Figure 5 As shown in the figure, although the cross-linked and cured encapsulation structure was successfully constructed, the cross-linking was too tight, making it almost impossible to form a porous structure.

[0050] Comparative Example 2 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: One part by weight of the modified activated carbon obtained in Preparation Example 17, 20 parts by weight of the composite bacterial solution obtained in Preparation Example 7, and 40 parts by weight of laccase solution with a mass concentration of 4 g / mL were weighed and mixed together. The mixture was then treated with shaking at 100 r / min for 4 h at 25 °C, and then filtered to obtain the bacterial enzyme immobilized carbon material. Three parts by weight of the modified sodium alginate obtained in Preparation Example 11, 4 parts by weight of chitosan, 110 parts by weight of deionized water, 1 part by weight of L-glutamate sodium, and 2 parts by weight of glycerol were weighed and mixed, and dispersed evenly with ultrasonic power of 300 W. Then, 13 parts by weight of the bacterial enzyme immobilized carbon material, 0.4 parts by weight of Chlorella powder, and 2 parts by weight of 1% calcium chloride solution were added and stirred until evenly dispersed. The mixture was then poured into a mold and placed at 25 °C for 12 h, and finally freeze-dried at -20 °C for 24 h. After drying, the mixture was removed, crushed, and passed through a 10-mesh sieve to obtain the water-conditioning preparation. The surface solidification cross-linking structure of the water-conditioning preparation was observed using a scanning electron microscope, and the results are as follows: Figure 6 As shown in the figure, although the cross-linked and cured encapsulation structure was successfully constructed, the cross-linking was too tight, making it almost impossible to form a porous structure.

[0051] Comparative Example 3 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: The composite bacterial solution in Example 4 was replaced with the composite bacterial solution obtained in Preparation Example 8, and the rest of the preparation process was the same as in Example 4.

[0052] Comparative Example 4 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: The composite bacterial solution in Example 4 was replaced with the composite bacterial solution obtained in Preparation Example 9, and the rest of the preparation process was the same as in Example 4.

[0053] Comparative Example 5 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: The modified sodium alginate in Example 4 was replaced with the modified sodium alginate obtained in Preparation Example 12, while the rest of the preparation process remained the same as in Example 4. The surface-cured cross-linked structure of the water conditioning agent was observed using a scanning electron microscope, and the results are as follows: Figure 7 As shown in the figure, although the cross-linked and cured encapsulation structure was successfully constructed, the cross-linking was too tight, making it almost impossible to form a porous structure.

[0054] Comparative Example 6 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: The modified sodium alginate in Example 4 was replaced with the modified sodium alginate obtained in Preparation Example 13, and the rest of the preparation process was the same as in Example 4.

[0055] Comparative Example 7 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: The modified activated carbon in Example 4 was replaced with the modified activated carbon obtained in Preparation Example 18, and the rest of the preparation process was the same as in Example 4.

[0056] Comparative Example 8 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: The modified activated carbon in Example 4 was replaced with the modified activated carbon obtained in Preparation Example 19, and the rest of the preparation process was the same as in Example 4.

[0057] Comparative Example 9 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: The modified activated carbon in Example 4 was replaced with the modified activated carbon obtained in Preparation Example 20, and the rest of the preparation process was the same as in Example 4.

[0058] Comparative Example 10 A method for preparing a water conditioning agent for aquaculture specifically includes the following steps: The Chlorella powder in Example 4 was removed and not added, while the rest of the preparation process remained the same as in Example 4.

[0059] The water conditioning agents obtained in Examples 1-4 and Comparative Examples 1-10 were added once a day at a dosage of 20g per square meter of water for 7 consecutive days. Then, on the 20th day, the changes in COD, dissolved oxygen and nitrite in the aquaculture water were tested and compared with the aquaculture water before addition (blank group). The results are shown in Table 1 below.

[0060] Table 1. Water Purification Status in Aquaculture Source of materials COD (mg / L) Dissolved oxygen (mg / L) Nitrite (mg / L) Blank group 33.02 4.17 0.38 Example 1 10.18 5.08 0.11 Example 2 8.55 5.47 0.08 Example 3 7.24 5.72 0.06 Example 4 6.05 5.85 0.05 Comparative Example 1 24.08 4.32 0.31 Comparative Example 2 25.21 4.25 0.32 Comparative Example 3 13.77 4.66 0.22 Comparative Example 4 14.06 4.65 0.23 Comparative Example 5 23.74 4.36 0.29 Comparative Example 6 13.01 4.72 0.18 Comparative Example 7 14.69 4.65 0.23 Comparative Example 8 15.14 4.59 0.26 Comparative Example 9 13.52 4.71 0.19 Comparative Example 10 13.47 3.24 0.35 Based on the results in Table 1 above, the following conclusions can be drawn: (1) As can be seen from Examples 1 to 4, the water conditioning agent prepared by the present invention has a good effect on water purification.

[0061] (2) Comparative Example 1 shows that the cross-linking is too tight because the amount of modified sodium alginate and chitosan exceeds a certain range, which is not conducive to the formation of pores after cross-linking and curing, and thus not conducive to the purification and degradation effect in contact with water.

[0062] (3) Comparative Example 2 shows that although the use of calcium chloride crosslinking can save the freeze-thaw treatment, on the one hand, it may make the crosslinking too tight, which is not conducive to the formation of pores after crosslinking and curing. On the other hand, calcium chloride may be chelated by ethylenediaminetetraacetic acid, which makes it difficult to effectively chelate and fix heavy metal ions in the water, reducing the auxiliary catalytic degradation efficiency of laccase, and thus not conducive to the purification and degradation effect of contacting the water.

[0063] (4) Comparative Example 3 shows that the water conditioning agent prepared has poor water purification performance. This may be because in this system, conventionally cultured Bacillus subtilis is difficult to work synergistically with photosynthetic bacteria, nitrifying bacteria, Chlorella and immobilized encapsulation system to achieve good water purification effect through the preparation method of this system.

[0064] (5) Comparative Example 4 shows that when the OD600 of the pretreated Bacillus subtilis bacterial solution is 1.0, the purification efficiency of the water conditioning agent is reduced. This may be due to the excessive OD600 caused by over-cultivation. Although it will help increase the number of bacteria, too many bacteria will lead to excessive consumption of nutrients, which may cause Bacillus subtilis to enter the death phase prematurely. The activity of the bacteria may be weakened, thus affecting the purification effect on the water.

[0065] (6) Comparative Example 5 shows that the water purification effect of the prepared water conditioning agent is poor. This may be because the amount of sodium periodate used in the preparation of sodium alginate oxidation process is too large, the oxidation time is too long, and the overall oxidation intensity is too strong. This may cause sodium alginate to produce too many aldehyde groups due to excessive oxidation, resulting in too tight cross-linking with chitosan, which leads to poor final water purification effect.

[0066] (7) Comparative Example 6 shows that the water purification effect of the prepared water conditioning agent is poor. This may be because the heavy metal ions in the aquaculture water will affect the activity of laccase, lose the chelating and fixing effect of heavy metal ions by ethylenediaminetetraacetic acid, and be not conducive to the auxiliary function of laccase.

[0067] (8) Comparative Example 7 shows that the water purification effect of the prepared water conditioning agent is poor. This may be because when coconut shell activated carbon increases the active hydrophilic oxygen groups through oxidation, the nitric acid concentration is too high and the oxidation time is too long, which may cause its own structure to collapse, weakening the adsorption and fixation of bacterial enzymes. This may result in a smaller number of bacterial enzymes on the final prepared water conditioning agent, thus showing a poor water purification effect.

[0068] (9) Comparative Example 8 shows that the water purification effect of the prepared water conditioning agent is poor. This may be because although graphene oxide has good hydrophilic dispersibility and can improve the dispersibility of coconut shell activated carbon in water, thereby improving the adsorption and fixation of bacterial enzymes, if the particle size of the graphene oxide used in the preparation method of this system is too large, it may not be able to be effectively loaded on the surface of coconut shell activated carbon, resulting in poor improvement of hydrophilic dispersibility and inability to effectively contact the composite bacterial solution and laccase solution. On the other hand, the particle size may be too large, which may block the pore size of coconut shell activated carbon to a certain extent, weakening the adsorption and fixation of bacterial enzymes, which may result in a small number of bacterial enzymes on the final prepared water conditioning agent, thus showing a poor water purification effect.

[0069] (10) Comparative Example 9 shows that the water purification effect of the prepared water conditioning agent is poor. This may be because although nitric acid oxidation can increase the hydrophilic oxygen-containing groups on the surface of coconut shell activated carbon, which helps to improve the water dispersibility of coconut shell activated carbon, it may rely heavily on nitric acid oxidation modification in this system, which has a poor effect and is not conducive to loading bacterial enzymes, ultimately resulting in poor water purification performance.

[0070] (11) Comparative Example 10 shows that the water purification effect of the prepared water conditioning agent is poor. This may be due to the lack of Chlorella, which can increase dissolved oxygen, which is not conducive to improving the metabolic activity of microorganisms, thus weakening the effect of purifying water.

[0071] The embodiments and accompanying drawings described above have provided a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for preparing a water conditioning agent for aquaculture, characterized in that, The preparation method includes the following steps: Modified activated carbon, composite bacterial solution and laccase solution were mixed in a weight ratio of 1:15~20:30~40 and then treated with shaking at 100 r / min at 25℃ for 3h~4h to obtain bacterial enzyme immobilized carbon material. Modified sodium alginate, aminopolysaccharide, immobilized enzyme carbon material, chlorella powder, deionized water, L-glutamate sodium and glycerol were mixed and stirred in a weight ratio of 2~3:3~4:10~13:0.2~0.4:100~110:1:2, and then subjected to freeze-thaw treatment, freeze-drying at -20℃ for 24h and crushing through a 10-mesh sieve to obtain the water conditioning preparation.

2. The method for preparing a water conditioning agent for aquaculture according to claim 1, characterized in that, The method for preparing the modified activated carbon includes the following steps: Coconut shell activated carbon and nitric acid solution are mixed in a weight ratio of 1:5~8 and heated to 40℃~50℃ for 60min~90min to obtain oxidized activated carbon; The modified activated carbon is obtained by dispersing oxidized activated carbon, crosslinking agent, graphene oxide and chloroform in a weight ratio of 1:2~3:0.1~0.2:40~50 and then heating to 60℃~70℃ for 2h~3h.

3. The method for preparing a water conditioning agent for aquaculture according to claim 2, characterized in that, The crosslinking agent includes glutaraldehyde.

4. The method for preparing a water conditioning agent for aquaculture according to claim 1, characterized in that, The preparation method of the compound bacterial solution includes the following steps: The pretreated Bacillus subtilis bacterial solution, photosynthetic bacteria bacterial solution, and nitrifying bacteria bacterial solution were mixed in a weight ratio of 1:0.5~0.6:0.2~0.3 to obtain the composite bacterial solution.

5. The method for preparing a water conditioning agent for aquaculture according to claim 4, characterized in that, The method for preparing the pretreated Bacillus subtilis bacterial solution includes the following steps: Bacillus subtilis was inoculated into LB agar medium and cultured at 25°C for 24 h to obtain activated Bacillus subtilis. Activated Bacillus subtilis was inoculated into broth liquid medium and cultured at 30°C for 20 h to obtain Bacillus subtilis seed culture. Bacillus subtilis seed culture and sterile physiological saline were mixed at a weight ratio of 1:9 and then irradiated with a 20W UV lamp at a distance of 25 cm directly below the sample for 40 seconds to obtain a mutagenic bacterial culture. The mutagenic bacterial culture was then inoculated into broth medium and cultured at 30°C until the OD reached its maximum. 600 The pretreated Bacillus subtilis bacterial solution was obtained with a concentration of 0.6~0.

8.

6. The method for preparing a water conditioning agent for aquaculture according to claim 4, characterized in that, The photosynthetic bacteria culture includes OD 600 The nitrifying bacteria solution contains 0.6-0.8% Rhodopseudomonas palustris bacterial solution, and the nitrifying bacteria solution includes OD... 600 The concentration of nitrifying bacteria in the solution is 0.6~0.

8.

7. The method for preparing a water conditioning agent for aquaculture according to claim 1, characterized in that, The preparation of the modified sodium alginate includes the following steps: Sodium alginate, sodium periodate solution and deionized water are mixed in a weight ratio of 1:1:90~95, then treated in the dark, and then oxidized at 25℃ for 12h~14h to obtain oxidized sodium alginate. Ethylenediaminetetraacetic acid, ethylenediamine, EDC hydrochloride and N-hydroxysuccinimide were mixed in a weight ratio of 5:1:5:2 and reacted at 25°C for 15 h to obtain amino-modified ethylenediaminetetraacetic acid; The modified sodium alginate is obtained by mixing sodium oxidized alginate and amino-modified ethylenediaminetetraacetic acid in a weight ratio of 1:2~3 and reacting them at 25°C for 24 hours.

8. The method for preparing a water conditioning agent for aquaculture according to claim 1, characterized in that, The aminopolysaccharide includes chitosan.

9. The method for preparing a water conditioning agent for aquaculture according to claim 1, characterized in that, The freeze-thaw process consists of freezing at -20°C for 2 hours and then thawing at 25°C for 2 hours as one freeze-thaw cycle, and the freeze-thaw process is repeated 3 times.

10. A water conditioning agent for aquaculture, characterized in that, The water conditioning agent is prepared by the method described in any one of claims 1 to 9 for preparing a water conditioning agent for aquaculture.

Images