Compound microbial agent for efficiently purifying water body and preparation method of compound microbial agent

Abstract

The invention relates to a compound microbial agent for efficiently purifying a water body and a preparation method thereof, and belongs to the field of water body purification. The preparation method comprises the following steps: by taking diatomite, polyaluminum chloride, ammonium sulfate, glucose, nano calcium carbonate, bacterial strains and self-made modified chitosan as raw materials, preparing a compound microbial agent for efficiently purifying a water body. And adding bacterial strains, nano calcium carbonate, ammonium sulfate and modified chitosan into the dried product, and mixing to obtain the compound microbial agent for efficiently purifying the water body. The compound microbial agent for efficiently purifying the water body has a good flocculation effect, has a good treatment effect on suspended particles, COD (Chemical Oxygen Demand), insoluble organic matters and heavy metal ions in sewage, is good in stability and can be widely applied to the field of water body purification.

Description

Technical Field

[0001] The present invention belongs to the field of water purification, and in particular, relates to a composite microbial agent for efficiently purifying water and a preparation method thereof. Background Art

[0002] Microbial water purification technology utilizes the metabolic activities of microorganisms to convert organic matter, nitrogen, phosphorus and other pollutants in water into harmless substances, thereby achieving water purification. These microorganisms used to purify water can take insoluble organic matter and soluble low-molecular compounds from sewage as nutrient sources, convert them into harmless substances such as carbon dioxide, water, nitrogen and so on through catabolism and anabolism, and treat suspended particles in sewage through flocculation. Microbial water purification technology can quickly degrade organic pollutants in sewage, and will not produce new pollutants during the treatment process, which has important environmental significance. However, for urban sewage and industrial sewage contaminated by heavy metal ions, the water purification effect of microorganisms will be greatly affected. Heavy metal ions such as cadmium ions, lead ions, mercury ions, etc. have toxic effects on microorganisms and can inhibit the growth and reproduction of microorganisms. When these heavy metal ions exist in water, they will combine with enzymes and proteins in microbial cells, interfere with the normal metabolic activities of microorganisms, thereby causing a sharp decrease in the number of microorganisms and a significant decrease in water purification capacity. Based on this, the present invention provides a high-efficiency water purification composite microbial agent and a preparation method thereof. Summary of the invention

[0003] The object of the present invention is to provide a highly efficient composite microbial agent for purifying water and a preparation method thereof, so as to solve the problems mentioned in the above background technology.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A highly efficient composite microbial agent for purifying water, comprising the following raw materials in parts by weight: 24-30 parts of diatomaceous earth, 16-20 parts of polyaluminium chloride, 4-5 parts of ammonium sulfate, 8-12 parts of glucose, 10-12 parts of nano-calcium carbonate, 10-12 parts of nitrifying bacteria, 2-4 parts of bacillus, 8-10 parts of yeast, 4-6 parts of photosynthetic bacteria, 6-8 parts of lactic acid bacteria, and 2.4-3 parts of modified chitosan; A method for preparing a composite microbial agent for efficiently purifying water comprises the following steps: The first step is to weigh the raw materials according to the mass proportions: 24-30 parts of diatomaceous earth, 16-20 parts of polyaluminium chloride, 4-5 parts of ammonium sulfate, 8-12 parts of glucose, 10-12 parts of nano-calcium carbonate, 10-12 parts of nitrifying bacteria, 2-4 parts of bacillus, 8-10 parts of yeast, 4-6 parts of photosynthetic bacteria, 6-8 parts of lactic acid bacteria, and 2.4-3 parts of modified chitosan; Step 2: adding diatomaceous earth, polyaluminium chloride and glucose into deionized water, and mixing by ultrasonic dispersion at room temperature to obtain a suspension; The third step is to dry the suspension obtained in the second step to constant weight, add nitrifying bacteria, Bacillus, yeast, photosynthetic bacteria, lactic acid bacteria, nano-calcium carbonate, ammonium sulfate and modified chitosan to the dry product, and mix by ultrasonic oscillation at room temperature to obtain a highly efficient composite microbial agent for purifying water.

[0005] Furthermore, the time condition of ultrasonic dispersion in the second step is 20-30 min.

[0006] Furthermore, the time condition of ultrasonic oscillation in the third step is 60-90 min.

[0007] Furthermore, the modified chitosan is prepared by the following steps: Step 1, methyl pyrazine-2-acetate, N-bromosuccinimide, p-toluenesulfonic acid and acetonitrile are mixed in a three-necked flask, a condenser and a thermometer are installed, magnetic stirring is turned on, the system temperature is raised to 60-70°C, and the reaction is carried out at a temperature of 60-70°C for 2h. After the reaction is completed, ether is added to the three-necked flask, and then washed with a saturated sodium carbonate solution and a saturated sodium chloride solution in sequence, and then the organic layer is separated with a separatory funnel, the organic layer is rotary evaporated to remove the solvent, and then subjected to silica gel column chromatography to obtain intermediate 1; Step 2, 2-pyrazinylethanethiol, potassium carbonate and anhydrous ethanol were mixed in a three-necked flask under ice-water bath conditions, magnetic stirring was turned on, and then anhydrous ethanol solution of intermediate 1 was added dropwise to the three-necked flask for 0.5 h. After the addition was completed, the ice-water bath was removed, and the reaction was carried out at room temperature for 3 h. After the reaction was completed, the reaction solution was evaporated to remove the solvent and then subjected to silica gel column chromatography to obtain intermediate 2; Step 3, intermediate 2, ethanol solution and sodium hydroxide were mixed in a three-necked flask, magnetic stirring was turned on, and the mixture was reacted at room temperature for 3 h. After the reaction was completed, dilute hydrochloric acid was added dropwise to the three-necked flask to adjust the pH to 3-4, and then ethyl acetate was added to the three-necked flask for extraction, and the organic layer was separated by a separatory funnel, and the organic layer was rotary evaporated to obtain intermediate 3; Step 4: Mix the intermediate 3, chitosan, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide and dilute hydrochloric acid in a three-necked flask, start magnetic stirring, and react at room temperature for 48 hours. After the reaction is completed, the reaction solution is rotary evaporated and poured into anhydrous ethanol for precipitation, followed by vacuum filtration. The obtained solid is dried to obtain the chitosan.

[0008] Furthermore, the amount ratio of pyrazine-2-acetic acid methyl ester, N-bromosuccinimide, p-toluenesulfonic acid and acetonitrile used in step 1 is 0.1 mol: 0.08-0.1 mol: 0.02 mol: 60-80 mL.

[0009] Furthermore, the anhydrous ethanol solution of intermediate 1 used in step 2 is prepared from 0.06 mol of intermediate 1 and 40 mL of anhydrous ethanol.

[0010] Furthermore, the amount ratio of 2-pyrazinylethanethiol, potassium carbonate, anhydrous ethanol, and anhydrous ethanol solution of intermediate 1 used in step 2 is 0.06 mol: 0.1-0.12 mol: 60-80 mL: 45.46 g.

[0011] Furthermore, the ethanol solution used in step 3 is an ethanol aqueous solution with a volume fraction of 75%.

[0012] Furthermore, the usage ratio of the intermediate 2, ethanol solution and sodium hydroxide used in step 3 is 0.04 mol: 50-60 mL: 0.06-0.08 mol.

[0013] Furthermore, the dilute hydrochloric acid used in step 4 is dilute hydrochloric acid with a pH value of 4.5.

[0014] Furthermore, the amount ratio of intermediate 3, chitosan, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide, and dilute hydrochloric acid used in step 4 is 0.02 mol: 10 g: 6-7 g: 3-3.5 g: 120 mL.

[0015] Furthermore, the mass ratio of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide used in step 4 is 2:1.

[0016] Beneficial effects of the present invention: 1) The present invention uses diatomaceous earth, polyaluminium chloride, ammonium sulfate, glucose, nano-calcium carbonate, bacterial strains and homemade modified chitosan as raw materials to prepare a highly efficient composite microbial agent for purifying water. The present invention prepares a highly efficient composite microbial agent for purifying water by first preparing diatomaceous earth, polyaluminium chloride and glucose into a suspension, uniformly mixing and then drying, and then adding bacterial strains, nano-calcium carbonate, ammonium sulfate and modified chitosan to the dried product to mix. The preparation method of the present invention is simple and easy to scale up. The prepared composite microbial agent has good flocculation effect, can effectively absorb fine suspended particles in water, and has good stability.

[0017] 2) The present invention uses pyrazine-2-acetic acid methyl ester as a raw material and N-bromosuccinimide as a brominating agent, and a halogenation reaction is carried out with the α-hydrogen atom of pyrazine-2-acetic acid methyl ester under the catalytic condition of p-toluenesulfonic acid to obtain intermediate 1, and then uses intermediate 1 and 2-pyrazinylethanethiol as raw materials, utilizes the bromine atom of intermediate 1 and 2-pyrazinylethanethiol to undergo a nucleophilic substitution reaction to obtain intermediate 2, and then hydrolyzes the ester group of intermediate 2 under a strong alkaline environment to obtain intermediate 3 containing a carboxyl group, and finally the carboxyl group of intermediate 3 reacts with the amino group of chitosan under the carbonization of 1-ethyl-3-(3-dimethylaminopropyl) Under the catalytic action of diimide hydrochloride and N-hydroxysuccinimide, an amidation reaction is carried out and the chitosan is grafted onto the chitosan to obtain a modified chitosan; the chitosan has a good flocculation effect. The present invention modifies the chitosan and grafts an intermediate 3 with good coordination ability onto the chitosan. The intermediate 3 has multiple nitrogen atom coordination sites and sulfur atom coordination sites, and can play a good coordination and adsorption role on heavy metal ions such as lead ions, mercury ions, and cadmium ions in water. The modified chitosan has a good flocculation effect and a good heavy metal ion adsorption capacity, which can greatly improve the purification effect on the water body.

[0018] 3) The high-efficiency composite microbial agent for purifying water bodies of the present invention has a good flocculation effect, and has a good treatment effect on suspended particles, COD, insoluble organic matter, and heavy metal ions in sewage, and has good stability, and can be widely used in the field of water purification. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Embodiment 1, a kind of modified chitosan is prepared by the following steps: Step 1, 0.1 mol of pyrazine-2-acetic acid methyl ester, 0.08 mol of N-bromosuccinimide, 0.02 mol of p-toluenesulfonic acid and 60 mL of acetonitrile were mixed in a three-necked flask, a condenser and a thermometer were installed, magnetic stirring was turned on, the system temperature was raised to 60°C, and the reaction was carried out at 60°C for 2 hours. After the reaction was completed, ether was added to the three-necked flask, and then washed with saturated sodium carbonate solution and saturated sodium chloride solution in sequence, and then the organic layer was separated with a separatory funnel, the organic layer was evaporated to remove the solvent, and then the intermediate 1 was obtained by silica gel column chromatography; Step 2, under ice-water bath conditions, 0.06 mol 2-pyrazinylethanethiol, 0.1 mol potassium carbonate, and 60 mL of anhydrous ethanol were mixed in a three-necked flask, and magnetic stirring was turned on. Then, 45.46 g of a solution prepared by 0.06 mol of intermediate 1 and 40 mL of anhydrous ethanol was added dropwise to the three-necked flask for 0.5 h. After the addition was completed, the ice-water bath was removed, and the reaction was carried out at room temperature for 3 h. After the reaction was completed, the reaction solution was evaporated to remove the solvent and then subjected to silica gel column chromatography to obtain intermediate 2; Step 3, 0.04 mol of intermediate 2, 50 mL of 75% ethanol aqueous solution and 0.06 mol of sodium hydroxide were mixed in a three-necked flask, magnetic stirring was turned on, and the reaction was carried out at room temperature for 3 hours. After the reaction was completed, dilute hydrochloric acid was added dropwise to the three-necked flask to adjust the pH to 3, and then ethyl acetate was added to the three-necked flask for extraction, and the organic layer was separated by a separatory funnel, and the organic layer was rotary evaporated to obtain intermediate 3; Step 4, 0.02 mol of intermediate 3, 10 g of chitosan, 6 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, 3 g of N-hydroxysuccinimide, and 120 mL of dilute hydrochloric acid with a pH value of 4.5 were mixed in a three-necked flask, magnetic stirring was turned on, and the reaction was carried out at room temperature for 48 hours. After the reaction was completed, the reaction solution was rotary evaporated and poured into anhydrous ethanol for precipitation, and then vacuum filtered. The obtained solid was dried to obtain the chitosan.

[0021] Embodiment 2, a kind of modified chitosan is prepared by the following steps: Step 1, 0.1 mol of pyrazine-2-acetic acid methyl ester, 0.09 mol of N-bromosuccinimide, 0.02 mol of p-toluenesulfonic acid, and 70 mL of acetonitrile were mixed in a three-necked flask, a condenser and a thermometer were installed, magnetic stirring was turned on, the system temperature was raised to 65°C, and the reaction was carried out at 65°C for 2 hours. After the reaction was completed, ether was added to the three-necked flask, and then washed with saturated sodium carbonate solution and saturated sodium chloride solution in sequence, and then the organic layer was separated with a separatory funnel, the organic layer was rotary evaporated to remove the solvent, and then subjected to silica gel column chromatography to obtain intermediate 1; Step 2, under ice-water bath conditions, 0.06 mol 2-pyrazinylethanethiol, 0.11 mol potassium carbonate, and 70 mL of anhydrous ethanol were mixed in a three-necked flask, and magnetic stirring was turned on. Then, 45.46 g of a solution prepared by 0.06 mol of intermediate 1 and 40 mL of anhydrous ethanol was added dropwise to the three-necked flask for 0.5 h. After the addition was completed, the ice-water bath was removed, and the reaction was carried out at room temperature for 3 h. After the reaction was completed, the reaction solution was evaporated to remove the solvent and then subjected to silica gel column chromatography to obtain intermediate 2; Step 3, 0.04 mol of intermediate 2, 55 mL of 75% ethanol aqueous solution and 0.07 mol of sodium hydroxide were mixed in a three-necked flask, magnetic stirring was turned on, and the reaction was carried out at room temperature for 3 h. After the reaction was completed, dilute hydrochloric acid was added dropwise to the three-necked flask to adjust the pH to 3.5, and then ethyl acetate was added to the three-necked flask for extraction, and the organic layer was separated by a separatory funnel, and the organic layer was rotary evaporated to obtain intermediate 3; Step 4, 0.02 mol of intermediate 3, 10 g of chitosan, 6.5 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, 3.25 g of N-hydroxysuccinimide, and 120 mL of dilute hydrochloric acid with a pH value of 4.5 were mixed in a three-necked flask, magnetic stirring was turned on, and the reaction was carried out at room temperature for 48 hours. After the reaction was completed, the reaction solution was rotary evaporated and poured into anhydrous ethanol for precipitation, and then vacuum filtered. The obtained solid was dried to obtain the chitosan.

[0022] Embodiment 3, a kind of modified chitosan is prepared by the following steps: Step 1, 0.1 mol of pyrazine-2-acetic acid methyl ester, 0.1 mol of N-bromosuccinimide, 0.02 mol of p-toluenesulfonic acid, and 80 mL of acetonitrile were mixed in a three-necked flask, a condenser and a thermometer were installed, magnetic stirring was turned on, the system temperature was raised to 70°C, and the reaction was carried out at 70°C for 2 hours. After the reaction was completed, ether was added to the three-necked flask, and then washed with saturated sodium carbonate solution and saturated sodium chloride solution in sequence, and then the organic layer was separated with a separatory funnel, the organic layer was evaporated to remove the solvent, and then the intermediate 1 was obtained by silica gel column chromatography; Step 2, under ice-water bath conditions, 0.06 mol 2-pyrazinylethanethiol, 0.12 mol potassium carbonate, and 80 mL of anhydrous ethanol were mixed in a three-necked flask, and magnetic stirring was turned on. Then, 45.46 g of a solution prepared by 0.06 mol of intermediate 1 and 40 mL of anhydrous ethanol was added dropwise to the three-necked flask for 0.5 h. After the addition was completed, the ice-water bath was removed, and the reaction was carried out at room temperature for 3 h. After the reaction was completed, the reaction solution was evaporated to remove the solvent and then subjected to silica gel column chromatography to obtain intermediate 2; Step 3, 0.04 mol of intermediate 2, 60 mL of 75% ethanol aqueous solution and 0.08 mol of sodium hydroxide were mixed in a three-necked flask, magnetic stirring was turned on, and the reaction was carried out at room temperature for 3 h. After the reaction was completed, dilute hydrochloric acid was added dropwise to the three-necked flask to adjust the pH to 4, and then ethyl acetate was added to the three-necked flask for extraction, and the organic layer was separated by a separatory funnel, and the organic layer was rotary evaporated to obtain intermediate 3; Step 4, 0.02 mol of intermediate 3, 10 g of chitosan, 7 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, 3.5 g of N-hydroxysuccinimide, and 120 mL of dilute hydrochloric acid with a pH value of 4.5 were mixed in a three-necked flask, magnetic stirring was turned on, and the reaction was carried out at room temperature for 48 hours. After the reaction was completed, the reaction solution was rotary evaporated and poured into anhydrous ethanol for precipitation, and then vacuum filtered. The obtained solid was dried to obtain the chitosan.

[0023] Comparative Example 1: This comparative example is unmodified chitosan.

[0024] The modified chitosan and unmodified chitosan obtained in Examples 1-3 were tested for their metal ion adsorption capacity. The modified chitosan and chitosan were weighed in the same mass and placed in a cadmium ion (Cd 2+ ) wastewater, the adsorption capacity was tested, where the wastewater pH value was 6, the cadmium ion concentration was 40 mg / L, and the adsorption time was 120 min. The test results are shown in Table 1: Table 1

[0025] It can be seen from Table 1 that the modified chitosan of the present invention in Examples 1-3 has a much better adsorption effect on cadmium ions than the unmodified chitosan, which indicates that the modified chitosan of the present invention has a good adsorption effect on heavy metal ions.

[0026] Example 4, a highly efficient composite microbial agent for purifying water, comprising the following raw materials in parts by weight: 24 parts of diatomaceous earth, 16 parts of polyaluminium chloride, 4 parts of ammonium sulfate, 8 parts of glucose, 10 parts of nano-calcium carbonate, 10 parts of nitrifying bacteria, 2 parts of Bacillus, 8 parts of yeast, 4 parts of photosynthetic bacteria, 6 parts of lactic acid bacteria, and 2.4 parts of modified chitosan obtained in Example 1; A method for preparing a composite microbial agent for efficiently purifying water comprises the following steps: The first step is to weigh the raw materials by mass: 24 parts of diatomaceous earth, 16 parts of polyaluminium chloride, 4 parts of ammonium sulfate, 8 parts of glucose, 10 parts of nano-calcium carbonate, 10 parts of nitrifying bacteria, 2 parts of Bacillus, 8 parts of yeast, 4 parts of photosynthetic bacteria, 6 parts of lactic acid bacteria, and 2.4 parts of modified chitosan obtained in Example 1; Step 2: Add diatomaceous earth, polyaluminium chloride and glucose into deionized water, and mix them by ultrasonic dispersion for 20 minutes at room temperature to obtain a suspension; Step 3: Dry the suspension obtained in the second step to constant weight, add nitrifying bacteria, Bacillus, yeast, photosynthetic bacteria, lactic acid bacteria, nano-calcium carbonate, ammonium sulfate and the modified chitosan obtained in Example 1 to the dry product, and mix by ultrasonic oscillation at room temperature for 60 minutes to obtain a highly efficient composite microbial agent for purifying water.

[0027] Example 5, a highly efficient composite microbial agent for purifying water, comprising the following raw materials in parts by weight: 27 parts of diatomaceous earth, 18 parts of polyaluminium chloride, 4.5 parts of ammonium sulfate, 10 parts of glucose, 11 parts of nano-calcium carbonate, 11 parts of nitrifying bacteria, 3 parts of Bacillus, 9 parts of yeast, 5 parts of photosynthetic bacteria, 7 parts of lactic acid bacteria, and 2.7 parts of modified chitosan obtained in Example 2; A method for preparing a composite microbial agent for efficiently purifying water comprises the following steps: The first step is to weigh the raw materials by mass: 27 parts of diatomaceous earth, 18 parts of polyaluminium chloride, 4.5 parts of ammonium sulfate, 10 parts of glucose, 11 parts of nano-calcium carbonate, 11 parts of nitrifying bacteria, 3 parts of Bacillus, 9 parts of yeast, 5 parts of photosynthetic bacteria, 7 parts of lactic acid bacteria, and 2.7 parts of modified chitosan obtained in Example 2; Step 2: Add diatomaceous earth, polyaluminium chloride and glucose into deionized water, and mix them by ultrasonic dispersion for 25 minutes at room temperature to obtain a suspension; Step 3: Dry the suspension obtained in the second step to constant weight, add nitrifying bacteria, Bacillus, yeast, photosynthetic bacteria, lactic acid bacteria, nano-calcium carbonate, ammonium sulfate and the modified chitosan obtained in Example 2 to the dry product, and mix by ultrasonic oscillation at room temperature for 75 minutes to obtain a highly efficient composite microbial agent for purifying water.

[0028] Example 6, a highly efficient composite microbial agent for purifying water, comprising the following raw materials in parts by weight: 30 parts of diatomaceous earth, 20 parts of polyaluminium chloride, 5 parts of ammonium sulfate, 12 parts of glucose, 12 parts of nano-calcium carbonate, 12 parts of nitrifying bacteria, 4 parts of Bacillus, 10 parts of yeast, 6 parts of photosynthetic bacteria, 8 parts of lactic acid bacteria, and 3 parts of modified chitosan obtained in Example 3; A method for preparing a composite microbial agent for efficiently purifying water comprises the following steps: The first step is to weigh the raw materials by mass: 30 parts of diatomaceous earth, 20 parts of polyaluminium chloride, 5 parts of ammonium sulfate, 12 parts of glucose, 12 parts of nano-calcium carbonate, 12 parts of nitrifying bacteria, 4 parts of Bacillus, 10 parts of yeast, 6 parts of photosynthetic bacteria, 8 parts of lactic acid bacteria, and 3 parts of modified chitosan obtained in Example 3; Step 2: Add diatomaceous earth, polyaluminium chloride and glucose into deionized water, and mix them by ultrasonic dispersion for 30 minutes at room temperature to obtain a suspension; Step 3: Dry the suspension obtained in the second step to constant weight, add nitrifying bacteria, Bacillus, yeast, photosynthetic bacteria, lactic acid bacteria, nano-calcium carbonate, ammonium sulfate and the modified chitosan obtained in Example 3 to the dry product, and mix by ultrasonic oscillation at room temperature for 90 minutes to obtain a highly efficient composite microbial agent for purifying water.

[0029] Comparative Example 2, a highly efficient composite microbial agent for purifying water, comprising the following raw materials in parts by weight: 30 parts of diatomaceous earth, 20 parts of polyaluminium chloride, 5 parts of ammonium sulfate, 12 parts of glucose, 12 parts of nano-calcium carbonate, 12 parts of nitrifying bacteria, 4 parts of Bacillus, 10 parts of yeast, 6 parts of photosynthetic bacteria, 8 parts of lactic acid bacteria, and 3 parts of chitosan; A method for preparing a composite microbial agent for efficiently purifying water comprises the following steps: The first step is to weigh the raw materials according to the mass fraction: 30 parts of diatomaceous earth, 20 parts of polyaluminium chloride, 5 parts of ammonium sulfate, 12 parts of glucose, 12 parts of nano-calcium carbonate, 12 parts of nitrifying bacteria, 4 parts of Bacillus, 10 parts of yeast, 6 parts of photosynthetic bacteria, 8 parts of lactic acid bacteria and 3 parts of chitosan; Step 2: Add diatomaceous earth, polyaluminium chloride and glucose into deionized water, and mix them by ultrasonic dispersion for 30 minutes at room temperature to obtain a suspension; The third step is to dry the suspension obtained in the second step to constant weight, add nitrifying bacteria, Bacillus, yeast, photosynthetic bacteria, lactic acid bacteria, nano-calcium carbonate, ammonium sulfate and chitosan to the dry product, and mix by ultrasonic oscillation at room temperature for 90 minutes to obtain a highly efficient composite microbial agent for purifying water.

[0030] Comparative Example 3: This comparative example is a commercially available microbial carrier adsorption water purifier.

[0031] The performance tests were performed on a high-efficiency composite microbial agent for purifying water in Examples 4-6 and Comparative Example 2 and a commercially available microbial carrier adsorption water purifier in Comparative Example 3. Equal amounts of the water purifiers were placed in urban domestic sewage contaminated by heavy metals, and the COD removal rate in the water was determined with reference to the national standard HJ 828-2017 "Determination of Chemical Oxygen Demand in Water Quality - Dichromate Method", the suspended solids removal rate in the water was determined with reference to the national standard GB / T11901-1989 "Determination of Suspended Solids in Water Quality - Gravimetric Method", and the ammonia nitrogen removal rate in the water was determined with reference to the national standard HJ536-2009 "Determination of Ammonia Nitrogen in Water Quality - Salicylic Acid Spectrophotometric Method". The test results are shown in Table 2: Table 2

[0032] It can be seen from Table 2 that the high-efficiency composite microbial agent for purifying water bodies in Examples 4-6 of the present invention has a much better purification effect on sewage contaminated by heavy metals than the commercially available microbial carrier adsorption water purifier in Comparative Example 3. Comparative Example 2 conducted a control experiment on the modified chitosan used in the present invention. Failure to use the modified chitosan of the present invention will lead to a decrease in the purification effect on water bodies contaminated by heavy metals. The reason is that the heavy metal ions in the water have a toxic effect on microorganisms. In summary, the high-efficiency composite microbial agent for purifying water bodies of the present invention has a good purification effect on sewage and can be widely used in the field of water purification.

[0033] The above is a detailed introduction to a highly efficient composite microbial agent for purifying water provided by the present invention and a method for preparing the same. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including manufacturing and using any device or system, and implementing any combination method. It should be pointed out that for ordinary technicians in the technical field, the present invention can also be improved and modified without departing from the principles of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed in the present invention can be used in combination with each other in any way. The fact that these combinations are not exhaustively described in this specification is only for the purpose of omitting space and saving resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A highly efficient composite microbial agent for purifying water, characterized in that: The invention comprises the following raw materials in parts by weight: 24-30 parts of diatomaceous earth, 16-20 parts of polyaluminium chloride, 4-5 parts of ammonium sulfate, 8-12 parts of glucose, 10-12 parts of nano-calcium carbonate, 10-12 parts of nitrifying bacteria, 2-4 parts of bacillus, 8-10 parts of yeast, 4-6 parts of photosynthetic bacteria, 6-8 parts of lactic acid bacteria and 2.4-3 parts of modified chitosan; Wherein, the modified chitosan is prepared by the following steps: Step 1, methyl pyrazine-2-acetate, N-bromosuccinimide, p-toluenesulfonic acid and acetonitrile are mixed in a container, stirred evenly, the system temperature is raised to 60-70° C., and reacted at 60-70° C. for 2 h to obtain intermediate 1; Step 2, 2-pyrazinylethanethiol, potassium carbonate and anhydrous ethanol were mixed in a container under ice-water bath conditions, and after stirring, anhydrous ethanol solution of intermediate 1 was added dropwise to the container for 0.5 h. After the addition was completed, the ice-water bath was removed, and the reaction was carried out at room temperature for 3 h to obtain intermediate 2; Step 3, intermediate 2, ethanol solution and sodium hydroxide are mixed in a container, stirred evenly, and reacted at room temperature for 3 hours. After the reaction is completed, dilute hydrochloric acid is added dropwise to a three-necked flask to adjust the pH to 3-4 to obtain intermediate 3; Step 4: Mix the intermediate 3, chitosan, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide and dilute hydrochloric acid in a container, stir evenly, and react at room temperature for 48 hours to obtain the chitosan.

2. The highly efficient composite microbial agent for purifying water according to claim 1, characterized in that: The amount ratio of pyrazine-2-acetic acid methyl ester, N-bromosuccinimide, p-toluenesulfonic acid and acetonitrile used in step 1 is 0.1 mol: 0.08-0.1 mol: 0.02 mol: 60-80 mL.

3. The highly efficient composite microbial agent for purifying water according to claim 1, characterized in that: The anhydrous ethanol solution of intermediate 1 used in step 2 is prepared from 0.06 mol of intermediate 1 and 40 mL of anhydrous ethanol.

4. The highly efficient composite microbial agent for purifying water according to claim 1, characterized in that: The amount ratio of 2-pyrazinylethanethiol, potassium carbonate, anhydrous ethanol, and anhydrous ethanol solution of intermediate 1 used in step 2 is 0.06 mol: 0.1-0.12 mol: 60-80 mL: 45.46 g.

5. The highly efficient composite microbial agent for purifying water according to claim 1, characterized in that: The ethanol solution used in step 3 is an ethanol aqueous solution with a volume fraction of 75%, and the amount ratio of the intermediate 2, the ethanol solution, and the sodium hydroxide used is 0.04 mol: 50-60 mL: 0.06-0.08 mol.

6. The highly efficient composite microbial agent for purifying water according to claim 1, characterized in that: The dilute hydrochloric acid used in step 4 is a dilute hydrochloric acid with a pH value of 4.5, and the amount ratio of the intermediate 3, chitosan, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide, and dilute hydrochloric acid used is 0.02 mol: 10 g: 6-7 g: 3-3.5 g: 120 mL.

7. The highly efficient composite microbial agent for purifying water according to claim 1, characterized in that: The mass ratio of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide used in step 4 is 2:

1.

8. The method for preparing a highly efficient composite microbial agent for purifying water according to any one of claims 1 to 7, characterized in that: The following steps are involved: The first step is to weigh the raw materials according to the mass proportions: 24-30 parts of diatomaceous earth, 16-20 parts of polyaluminium chloride, 4-5 parts of ammonium sulfate, 8-12 parts of glucose, 10-12 parts of nano-calcium carbonate, 10-12 parts of nitrifying bacteria, 2-4 parts of bacillus, 8-10 parts of yeast, 4-6 parts of photosynthetic bacteria, 6-8 parts of lactic acid bacteria, and 2.4-3 parts of modified chitosan; Step 2: adding diatomaceous earth, polyaluminium chloride and glucose into deionized water, and mixing by ultrasonic dispersion at room temperature to obtain a suspension; The third step is to dry the suspension obtained in the second step to constant weight, add nitrifying bacteria, Bacillus, yeast, photosynthetic bacteria, lactic acid bacteria, nano-calcium carbonate, ammonium sulfate and modified chitosan to the dry product, and mix by ultrasonic oscillation at room temperature to obtain a highly efficient composite microbial agent for purifying water.

9. The method for preparing a highly efficient composite microbial agent for purifying water according to claim 8, characterized in that: The time condition of ultrasonic dispersion in the second step is 20-30min.

10. The method for preparing a highly efficient composite microbial agent for purifying water according to claim 8, characterized in that: The time condition of ultrasonic oscillation in the third step is 60-90 minutes.

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