A method and system for resource utilization of carbon dioxide in wine based on microalgae culture

Abstract

The present invention discloses a method and system for resource utilization of carbon dioxide in wine based on microalgae cultivation. The method comprises the following steps: inoculating microalgae into an algae pond, turning on a lighting device, then introducing the carbon dioxide generated by fermentation in a fermentation tank into the algae pond, and introducing a culture solution into the algae pond. After the microalgae grow for a period of time, the high-density microalgae biomass attached to the packing is filtered through a filter screen, and made into algal fertilizer and returned to the vineyard. The low-concentration algae-containing water is introduced into an artificial wetland and discharged after purification. Through the coupling of the fermentation tank, the algae pond and the artificial wetland, on the one hand, the microalgae are used to fix carbon dioxide to produce algal fertilizer products and return them to the vineyard. On the other hand, the microalgae can also preliminarily treat the wastewater from wine brewing, and the wastewater from microalgae cultivation is deeply treated by the artificial wetland, ultimately achieving low emissions or even zero emissions of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide resource utilization, and particularly relates to a method and system for carbon dioxide resource utilization of wine based on microalgae culture. Background Art

[0002] Alcohol fermentation is the core link in wine brewing. A large amount of high-purity carbon dioxide gas is generated during fermentation, and only a small part will dissolve in the wine. If the carbon dioxide generated during fermentation is not discharged in time, the pomace cap in the fermentation tank will be pressed and rise continuously, which is not only unfavorable for the extraction of characteristic substances such as pigments, phenols and aromas in the pericarp, but also may cause the phenomenon of overflowing the tank, resulting in a decline in the quality and yield of wine. If the carbon dioxide is directly discharged from the fermentation tank, the carbon dioxide concentration in the production workshop will continue to increase. Under normal circumstances, the carbon dioxide content in the air is 0.04%. When the carbon dioxide content in the environment where people are located rapidly increases and exceeds 5%, symptoms such as increased blood pressure, palpitations, dizziness and shortness of breath will occur; when the carbon dioxide content > 10%, there will be a risk of asphyxiation; when the carbon dioxide content is 17-20%, flash death will occur within a few seconds. Most of the reasons for the death of workers in fermentation enterprises due to improper operation and entering fermentation equipment containing high-concentration carbon dioxide are of this kind. Therefore, the fermentation workshop needs to be ventilated to reduce the carbon dioxide concentration in the production workshop and ensure production safety. However, most of the carbon dioxide discharged from the fermentation tank will ultimately enter the atmosphere, resulting in an exacerbation of the greenhouse effect.

[0003] Currently, the commonly used carbon dioxide recovery methods in industry include absorption methods (chemical absorption, physical absorption, physical-chemical absorption), adsorption methods (pressure swing adsorption, temperature swing adsorption), distillation methods (adsorptive distillation, cryogenic distillation), and membrane separation methods, etc. There are differences in the purity and composition of the raw gas in different types of factories. The cost of recovering one ton of carbon dioxide is about 140 - 780 yuan. Generally, the carbon dioxide recovery costs in the ethanol production, synthetic ammonia, and natural gas processing industries that produce high-purity carbon dioxide are significantly lower than those in other industries, and the average cost of recovering one ton of carbon dioxide can be reduced by about 199 yuan compared with other industries. Generally, the solvent absorption method is suitable for enriching and recovering low-concentration carbon dioxide, and is not very suitable for recovering high-concentration carbon dioxide gas generated by alcohol fermentation. The pressure swing adsorption method, adsorptive distillation method, and cryogenic distillation method can all recover the carbon dioxide generated during the alcohol fermentation process, and the recovery purity can reach food grade. Among them, the adsorptive distillation method combines the characteristics of low energy consumption of the adsorption method and the high separation efficiency of the distillation method, can adjust the carbon dioxide product to industrial grade or food grade during production, and has a relatively low recovery cost, which is a relatively economical and effective carbon dioxide recovery method. The membrane separation method can also recover and process high-concentration carbon dioxide gas, but the membrane material has a short lifespan and needs to be replaced frequently. When different industries select carbon dioxide recovery methods, they need to comprehensively consider aspects such as the purity and composition of the raw gas, the purity of the required carbon dioxide product, and the production cost. They can choose a single carbon dioxide recovery method or combine several methods. During the wine brewing process, by classifying and recovering alcohol, aroma, and carbon dioxide in the fermentation gas, the membrane separation method and the adsorptive distillation method can be combined. The membrane separation method is used to concentrate and enrich alcohol and aroma substances, and the adsorptive distillation method is used to purify carbon dioxide, which can not only recover alcohol and aroma substances, but also produce food-grade carbon dioxide products, reducing the waste of fermentation gas resources during the brewing process.

[0004] CN 201620202184.4 discloses a carbon dioxide recovery and reuse system for a fermentation tank, including a fermentation tank. The top of the fermentation tank is provided with a top cover, and a first gas pipe is connected to the top cover. The end of the first gas pipe is connected to the first valve port of a three-way valve. The second valve port of the three-way valve is connected to a second gas pipe, and the end of the second gas pipe passes through the top cover of the target tank and extends into the tank. The third valve port of the three-way valve is connected to a third gas pipe, and a stop valve is provided in the third gas pipe. The end of the third gas pipe leads to a carbon dioxide collection bag. This utility model has a simple structure and is economical and applicable, recovering a large amount of carbon dioxide generated during the fermentation process; however, this system only stores carbon dioxide and does not carry out resource utilization.

[0005] Chinese Patent Document CN201810149103.2 discloses a method for treating winery wastewater using an artificial wetland and a method for preparing the artificial wetland. The winery wastewater treatment method includes the following steps: S10, pre-treating the sewage; S20, connecting the pre-treated sewage to a UASB reactor through a pipeline; S30, connecting the UASB reactor to a secondary sedimentation tank through a pipeline; S40, connecting the secondary sedimentation tank to an SBR tank; S50, connecting the SBR tank to a flotation decolorization system, and the flotation decolorization system releases charged microbubbles with a diameter of micrometers in the wastewater through a flotation device; S60, connecting the flotation decolorization system to the artificial wetland; this system treats the brewing wastewater using the artificial wetland, but does not resourcefully utilize the wastewater. Summary of the Invention

[0006] In order to solve the deficiencies of the prior art, the purpose of the present invention is to provide a method and system for resource utilization of carbon dioxide in wine based on microalgae cultivation. Through the coupling of a fermentation tank, an algae pond, and an artificial wetland, on the one hand, microalgae are used to fix carbon dioxide to produce an algal fertilizer product and return it to the vineyard. In addition, the microalgae can also preliminarily treat the wine brewing wastewater, and the microalgae cultivation wastewater is deeply treated using the artificial wetland, ultimately achieving low emissions or even zero emissions of the system.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions:

[0008] A system for resource utilization of carbon dioxide in wine based on microalgae cultivation, including a fermentation tank, an algae pond, and an artificial wetland. The fermentation tank and the algae pond are interconnected. The algae pond is filled with packing materials and a culture solution; the algae pond and the artificial wetland are interconnected, and a modified substrate is laid in the artificial wetland.

[0009] Preferably, the microalgae are one or more of Chlamydomonas reinhardtii, Chlorella vulgaris, Microcystis aeruginosa, Tetradesmus obliquus, Scenedesmus, Synechocystis, Spirulina, Haematococcus pluvialis, Botryococcus braunii, Dunaliella salina, Euglena gracilis, Nostoc sphaeroides, Nannochloropsis, Aphanizomenon flos-aquae, and Tribonema aequale.

[0010] Preferably, the packing materials are one or more of grape branches, flannel, loofah sponge, corn cob, zeolite, gravel, ceramsite, biochar, sawdust, and ultra-fine fibers; the culture solution is wine brewing wastewater; a lighting device is also provided above the algae pond.

[0011] Preferably, the culture solution is wine brewing wastewater.

[0012] Preferably, a lighting device is also provided above the algae pond.

[0013] Preferably, a soil layer is also laid in the constructed wetland. The soil layer is laid above the modified substrate, and aquatic plants are planted in the soil layer.

[0014] Preferably, the preparation method of the modified substrate for the wine carbon dioxide resource utilization system based on microalgae culture comprises the following steps:

[0015] A. Dissolve chitosan in an acetic acid aqueous solution, then dropwise add an ethanol solution of formaldehyde, stir and react, adjust the pH of the system to precipitate the product, filter the product, wash it with ethanol, and dry it to obtain Schiff base chitosan; the reaction process is shown in the following figure:

[0016]

[0017] B. Add Schiff base chitosan to a NaOH ethanol solution to swell it, then dropwise add a p-vinylbenzenesulfonyl chloride ethanol solution, stir and react, filter by suction, wash it with acetone, and dry it to obtain sulfonylated chitosan; the reaction process is shown in the following figure:

[0018]

[0019] C. Disperse the modified biochar in DMF, then add sulfonylated chitosan, acrylamide, and azobisisobutyronitrile, continuously introduce N2, stir and react, distill off the solvent under reduced pressure, and dry it under vacuum to obtain a biochar / chitosan composite material;

[0020] D. Immerse the biochar / chitosan composite material in an acetic acid aqueous solution, stir and react, filter, wash, and dry the product to obtain the modified substrate.

[0021] Preferably, in step A, the concentration of the acetic acid aqueous solution is 1-10 wt%; the weight ratio of chitosan to the acetic acid aqueous solution is 1:30-60; the concentration of the ethanol solution of formaldehyde is 2.5-15 wt%, the pH of the system is adjusted with a 10-20 wt% NaOH solution, and the weight ratio of the ethanol solution of formaldehyde to the acetic acid aqueous solution is 1-2:1; the stirring reaction conditions are stirring at 30-60 °C for 3-5 h.

[0022] Preferably, in step B, the concentration of the NaOH ethanol solution is 10-20 wt%, the swelling time is 2-4 h, and the concentration of the p-vinylbenzenesulfonyl chloride ethanol solution is 5-15 wt%; the weight ratio of Schiff base chitosan to the p-vinylbenzenesulfonyl chloride ethanol solution is 1:10-100; the p-vinylbenzenesulfonyl chloride ethanol solution is added dropwise within 30-90 min; the stirring reaction conditions are stirring at 40-80 °C for 4-7 h.

[0023] Preferably, in step C, the weight ratio of the modified biochar, sulfonated and esterified chitosan, acrylamide, and azodiisobutyronitrile is 1:1.4 - 2.3:0.6 - 1.5:0.01 - 0.03; the stirring reaction conditions are stirring reaction at 60 - 70 °C for 2 - 3 h.

[0024] Preferably, in step C, the preparation method of the modified biochar includes the following steps: dispersing the biochar into a KH570 ethanol solution, with the weight ratio of biochar, KH570, and ethanol being 10:1 - 3:60 - 80, stirring and reacting at 60 - 80 °C for 4 - 6 h, filtering, washing, and drying the product to obtain the modified biochar.

[0025] Preferably, in step D, the concentration of the acetic acid aqueous solution is 5 - 15 wt%, and the weight ratio of the biochar / chitosan composite material to the acetic acid aqueous solution is 1:10 - 30; the stirring reaction conditions are stirring reaction at 20 - 50 °C for 12 - 24 h, washing 3 - 5 times with absolute ethanol, and the drying conditions are vacuum drying at 60 - 80 °C.

[0026] The present invention also claims to protect a method for resource utilization of carbon dioxide in wine, including the following steps: inoculating microalgae into the algal pond, turning on the lighting device, then introducing the carbon dioxide generated by fermentation in the fermentation tank into the algal pond, and introducing the culture solution into the algal pond. After the microalgae grow for a period of time, filtering the microalgae biomass through a filter screen, making the filler into algal fertilizer and returning it to the vineyard, and introducing the algae-containing water into the constructed wetland for purification and then discharging it.

[0027] Preferably, the rate of carbon dioxide introduction is 0.001 - 10 vvm.

[0028] Preferably, the light intensity is 1000 - 20000 lx, the light-dark cycle is 8 h:16 h - 24 h:0 h, and the temperature in the algal pond is 20 - 40 °C.

[0029] Preferably, the culture time of the microalgae in the algal pond is 3 - 5 d, and the residence time of the algae-containing water in the constructed wetland is 1 - 3 d.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1) The present invention provides a method and system for resource utilization of carbon dioxide in wine based on microalgae culture. Through the coupling of the fermentation tank, algal pond, and constructed wetland, the carbon dioxide generated during wine brewing is effectively recovered by microalgae, and the wastewater generated during the brewing process is also consumed during the microalgae culture process. Finally, the microalgae biomass is filtered, and the filler with high-concentration microalgae grown on it is returned to the vineyard as algal fertilizer, realizing the reuse of biological resources, while the remaining low-concentration algae-containing water is treated by the constructed wetland, achieving low emissions or even zero emissions of the system.

[0032] 2) The present invention provides a modified substrate for constructed wetland. First, the amino group is protected by the Schiff base reaction of formaldehyde and the 2-NH2 group of chitosan. Then, through the substitution reaction of vinylbenzenesulfonyl chloride and the 6-OH group of chitosan, vinyl and sulfonyl groups are introduced into chitosan under alkaline conditions to obtain sulfonylated chitosan. The sulfonyl group can improve the dispersibility of chitosan in water and simultaneously enhance its performance in removing COD and BOD. The introduced vinyl group prepares for subsequent reactions. KH570 is used to modify biochar. On the one hand, it can improve the dispersibility of biochar, and on the other hand, introduce unsaturated double bonds onto the biochar surface. Then, under the action of an initiator, acrylamide and sulfonylated chitosan containing unsaturated double bonds undergo addition polymerization on the biochar surface to obtain a biochar / chitosan composite material. Finally, a deprotection reaction is carried out on its 2-NH2 to obtain the modified substrate. The modified substrate is rich in -NH2, and -NH2 can coordinate with heavy metal ions by providing electron pairs to improve the adsorption capacity of the modified substrate for heavy metal ions. The chitosan molecular chain can form a precipitate after adsorbing pollutants to settle the pollutants. Grafting the organic polymer flocculant polyacrylamide onto the biochar surface and copolymerizing it with sulfonylated chitosan can synergistically improve the adsorption and chelation effects of the modified substrate, increase the electro-neutralization, bridging adsorption, sweeping and net-trapping effects of the modified substrate on organic molecule, facilitate the generation of more and larger flocculation sedimentation bodies, enhance the decolorization and waste removal effects, and significantly improve the removal effect of pollutants in wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some schematic diagrams of the embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is a process flow diagram of the carbon dioxide resource utilization of wine based on microalgae cultivation provided by the present invention.

[0035] In the figure, 1, fermentation tank; 2, algal pond; 3, packing; 4, culture solution; 5, constructed wetland; 6, modified substrate; 7, lighting device; 8, soil layer; 9, filter screen; 10, vineyard. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following embodiments are used to further elaborate on the present invention in detail. Of course, the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0037] Unless otherwise specified, the chemical reagents and materials in the present invention are all purchased through market channels or synthesized from raw materials purchased through market channels.

[0038] Chitosan was purchased from Sinopharm Chemical Reagent Co., Ltd., and its product number is 69047438;

[0039] Biochar was purchased from Gongyi Pengxing Water Purification Materials Co., Ltd., coconut shell activated carbon, with a mesh number of 100 - 200 meshes.

[0040] The following is a further description of the present invention through specific examples.

[0041] Example 1

[0042] A preparation method of a modified matrix in a wine carbon dioxide resource utilization system based on microalgae culture includes the following steps:

[0043] A. Dissolve 1 g of chitosan in 60 g of 10 wt% acetic acid aqueous solution, then drop in 60 g of 15 wt% formaldehyde ethanol solution, stir and react at 60 °C for 5 h, adjust the pH of the system with 20 wt% NaOH solution to precipitate the product, filter the product, wash it with ethanol, and dry it to obtain Schiff base chitosan;

[0044] B. Add 1 g of Schiff base chitosan to 20 wt% NaOH ethanol solution to swell for 4 h, then dropwise add 100 g of 15 wt% p - vinylbenzenesulfonyl chloride ethanol solution, finish dropping in 90 min, stir and react at 80 °C for 7 h, carry out suction filtration, wash with acetone, and dry to obtain sulfonated chitosan;

[0045] C. Disperse biochar into KH570 ethanol solution, the weight ratio of biochar, KH570, and ethanol is 10:3:80, stir and react at 80 °C for 6 h, filter, wash, and dry the product to obtain modified biochar;

[0046] D. Disperse 1 g of modified biochar in 30 g of DMF, then add 2.3 g of sulfonated chitosan, 1.5 g of acrylamide, and 0.03 g of azobisisobutyronitrile, continuously introduce N2, stir and react at 70 °C for 3 h, remove the solvent by reduced pressure distillation, and dry in vacuum to obtain a biochar / chitosan composite material;

[0047] E. Immerse 1 g of the biochar / chitosan composite material in 30 g of 15 wt% acetic acid aqueous solution, stir and react at 50 °C for 24 h, filter the product, wash it 5 times with absolute ethanol, and dry it in vacuum at 80 °C to obtain the modified matrix.

[0048] Example 2

[0049] A preparation method of a modified matrix in a wine carbon dioxide resource utilization system based on microalgae culture, comprising the following steps:

[0050] A. Dissolve 1 g of chitosan in 50 g of 5 wt% acetic acid aqueous solution, then dropwise add 40 g of 10 wt% formaldehyde ethanol solution, stir and react at 45 °C for 4 h, adjust the pH of the system with 15 wt% NaOH solution to precipitate the product, filter the product, wash it with ethanol, and dry it to obtain Schiff base chitosan;

[0051] B. Add 1 g of Schiff base chitosan to 15 wt% NaOH ethanol solution to swell for 3 h, then dropwise add 60 g of 10 wt% p-vinylbenzenesulfonyl chloride ethanol solution, finish dropping in 60 min, stir and react at 60 °C for 6 h, carry out suction filtration, wash with acetone, and dry to obtain sulfonated chitosan;

[0052] C. Disperse biochar into KH570 ethanol solution, the weight ratio of biochar, KH570, and ethanol is 10:2:70, stir and react at 70 °C for 5 h, filter, wash, and dry the product to obtain modified biochar;

[0053] D. Disperse 1 g of modified biochar in 30 g of DMF, then add 1.8 g of sulfonated chitosan, 1.1 g of acrylamide, and 0.02 g of azobisisobutyronitrile, continuously introduce N2, stir and react at 65 °C for 2.5 h, remove the solvent by reduced pressure distillation, and dry in vacuum to obtain a biochar / chitosan composite material;

[0054] E. Immerse 1 g of biochar / chitosan composite material in 20 g of 10 wt% acetic acid aqueous solution, stir and react at 35 °C for 18 h, filter the product, wash it 4 times with absolute ethanol, and dry it in vacuum at 70 °C to obtain the modified matrix.

[0055] Example 3

[0056] A preparation method of a modified matrix in a wine carbon dioxide resource utilization system based on microalgae culture, comprising the following steps:

[0057] A. Dissolve 1 g of chitosan in 30 g of 1 wt% acetic acid aqueous solution, then dropwise add 30 g of 2.5 wt% formaldehyde ethanol solution, stir and react at 30 °C for 3 h, adjust the pH of the system with 10 wt% NaOH solution to precipitate the product, filter the product, wash it with ethanol, and dry it to obtain Schiff base chitosan;

[0058] B. Add 1 g of Schiff base chitosan to 10 wt% NaOH ethanol solution to swell for 2 h, then dropwise add 10 g of 5 wt% p-vinylbenzenesulfonyl chloride ethanol solution, finish dropping in 30 min, stir and react at 40 °C for 4 h, carry out suction filtration, wash with acetone, and dry to obtain sulfonated chitosan;

[0059] C. Disperse the biochar into the KH570 ethanol solution. The weight ratio of biochar, KH570, and ethanol is 10:1:60. Stir and react at 60 °C for 4 h. Filter, wash, and dry the product to obtain the modified biochar.

[0060] D. Disperse 1 g of the modified biochar in 30 g of DMF, then add 1.4 g of sulfonated chitosan, 0.6 g of acrylamide, and 0.01 g of azobisisobutyronitrile. Continuously introduce N2 and stir and react at 60 °C for 2 h. Remove the solvent by vacuum distillation and dry in vacuum to obtain the biochar / chitosan composite.

[0061] E. Immerse 1 g of the biochar / chitosan composite in 10 g of 5 wt% acetic acid aqueous solution and stir and react at 20 °C for 12 h. Filter the product, wash it 3 times with absolute ethanol, and dry it in vacuum at 60 °C to obtain the modified matrix.

[0062] Example 4

[0063] As Figure 1 described, the present invention provides a wine carbon dioxide resource utilization system based on microalgae culture, including a fermentation tank 1, an algae pond 2, and an artificial wetland 5. The fermentation tank 1 is interconnected with the algae pond 2. The algae pond 2 is filled with a filler 3 and a culture solution 4. The filler 3 is grape branches, and the culture solution 4 is wine brewing wastewater. A lighting device 7 is also provided above the algae pond 2. The algae pond 2 is interconnected with the artificial wetland 5. The artificial wetland 5 is paved with a modified matrix 6 and a soil layer 8, and aquatic plants are planted.

[0064] The present invention also provides a method for wine carbon dioxide resource utilization using the above system, including the following steps: inoculate Chlorella into the algae pond 2, turn on the lighting device 7, with a light intensity of 10000 lx and a light-dark cycle of 8 h:16 h, and the temperature in the algae pond is 25 °C. Then introduce the carbon dioxide generated by fermentation in the fermentation tank 1 into the algae pond 2 at a rate of 1 vvm, and introduce the culture solution 4 into the algae pond 2. The microalgae are cultured in the algae pond 2 for 4 d. Filter the microalgae biomass through a filter screen 9, make the filler 3 into algal fertilizer and return it to the vineyard 10, and introduce the algae-containing water into the artificial wetland 5 to stay for 1 d and then discharge it after purification.

[0065] Comparative Example 1

[0066] A preparation method of a modified matrix for a wine carbon dioxide resource utilization system based on microalgae culture includes the following steps:

[0067] A. Dissolve 1 g of chitosan in 60 g of 10 wt% acetic acid aqueous solution, then dropwise add 60 g of 15 wt% formaldehyde ethanol solution, stir and react at 60 °C for 5 h, adjust the pH of the system with 20 wt% NaOH solution to precipitate the product, filter the product, wash it with ethanol, and dry it to obtain Schiff-base chitosan;

[0068] B. Add 1 g of Schiff-base chitosan to 20 wt% NaOH ethanol solution to swell for 4 h, then dropwise add 100 g of 15 wt% p-vinylbenzenesulfonyl chloride ethanol solution, finish dropping in 90 min, stir and react at 80 °C for 7 h, carry out suction filtration, wash with acetone, and dry to obtain sulfonated chitosan;

[0069] C. Immerse 1 g of sulfonated chitosan in 30 g of 15 wt% acetic acid aqueous solution, stir and react at 50 °C for 24 h, filter the product, wash it 5 times with absolute ethanol, and vacuum dry at 80 °C to obtain the modified matrix.

[0070] Comparative Example 2

[0071] A preparation method of a modified matrix for a wine carbon dioxide resource utilization system based on microalgae culture, comprising the following steps:

[0072] A. Disperse biochar into KH570 ethanol solution, the weight ratio of biochar, KH570, and ethanol is 10:3:80, stir and react at 80 °C for 6 h, filter, wash, and dry the product to obtain modified biochar;

[0073] B. Disperse 1 g of modified biochar in 30 g of DMF, then add 1.5 g of acrylamide and 0.03 g of azobisisobutyronitrile, continuously introduce N2, stir and react at 70 °C for 3 h, distill off the solvent under reduced pressure, and vacuum dry to obtain the modified matrix.

[0074] Collect the brewing wastewater from a winery, the wastewater quality: COD is 982.3 mg / L, BOD is 1104.7 mg / L, SS is 231.5 mg / L. Use the modified matrices prepared in Examples 1-3 and Comparative Examples 1-2 to treat it. In addition, use the modified matrix to treat the simulated wastewater added with lead nitrate (200 mg / L) and copper nitrate (200 mg / L). The wastewater is evenly divided into 5 portions, each portion is 1 m 3 , the dosage of the modified matrix is 0.1 g / L, the treatment time is 5 h, and the content data of each pollutant in the treated wastewater are shown in Table 1.

[0075] Table 1 Treatment effect of the modified matrix on wastewater (mg / L)

[0076] COD BOD SS Lead ion Copper ion Example 1 17.4 29.7 52.1 24.3 10.9 Example 2 21.3 32.8 59.6 25.9 14.3 Example 3 22.5 36.2 67.3 28.4 15.8 Comparative Example 1 243.6 297.3 121.4 69.5 53.2 Comparative Example 2 157.1 184.6 96.7 52.8 47.5

[0077] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A wine carbon dioxide resource utilization system based on microalgae cultivation, comprising a fermentation tank, an algal pond and a constructed wetland, characterized in that, The fermenter is interconnected with the algae pond, and the algae pond is filled with packing materials and a culture solution; the algae pond is interconnected with the constructed wetland, and a modified substrate is laid in the constructed wetland; The preparation method of the modified substrate is characterized by comprising the following steps: A. Dissolve chitosan in an acetic acid aqueous solution, then dropwise add an ethanol solution of formaldehyde, stir and react, adjust the pH of the system to precipitate the product, filter the product, wash it with ethanol, and dry it to obtain Schiff base chitosan; B. Add Schiff base chitosan to an NaOH ethanol solution for swelling, then dropwise add an ethanol solution of p-vinylbenzenesulfonyl chloride, stir and react, carry out suction filtration, wash with acetone, and dry to obtain sulfonated chitosan; C. Modify biochar with KH570, disperse the modified biochar in DMF, then add sulfonated chitosan, acrylamide, and azobisisobutyronitrile, continuously introduce N2, stir and react, distill off the solvent under reduced pressure, and dry in vacuum to obtain a biochar / chitosan composite material; D. Immerse the biochar / chitosan composite material in an acetic acid aqueous solution, stir and react, filter, wash, and dry the product to obtain the modified substrate.

2. The system according to claim 1, characterized in that, Microalgae are cultured in the algae pond, and the microalgae are one or more of Chlamydomonas reinhardtii, Chlorella vulgaris, Microcystis aeruginosa, Tetradesmus obliquus, Scenedesmus, Synechocystis, Spirulina, Haematococcus pluvialis, Botryococcus braunii, Dunaliella salina, Euglena gracilis, Nostoc sphaeroides, Nannochloropsis oculata, Aphanizomenon flos-aquae, and Audouinella aurantiaca; the packing materials are one or more of grape branches, flannel, loofah sponges, corn cobs, zeolites, gravels, ceramsites, biochar, sawdust, and ultrafine fibers; the culture solution is wine brewing wastewater; a lighting device is also arranged above the algae pond.

3. The system according to claim 1, characterized in that, A soil layer is also laid in the constructed wetland, the soil layer is laid above the modified substrate, and aquatic plants are planted in the soil layer.

4. The system according to claim 1, characterized in that, In step A, the concentration of the acetic acid aqueous solution is 1-10 wt%; the weight ratio of chitosan to the acetic acid aqueous solution is 1:30-60; the concentration of the ethanol solution of formaldehyde is 2.5-15 wt%, the pH of the system is adjusted with a 10-20 wt% NaOH solution, and the weight ratio of the ethanol solution of formaldehyde to the acetic acid aqueous solution is 1-2:1; the stirring reaction conditions are stirring at 30-60 °C for 3-5 h.

5. The system according to claim 1, characterized in that, In step B, the concentration of the NaOH ethanol solution is 10-20 wt%, the swelling time is 2-4 h, and the concentration of the ethanol solution of p-vinylbenzenesulfonyl chloride is 5-15 wt%; the weight ratio of Schiff base chitosan to the ethanol solution of p-vinylbenzenesulfonyl chloride is 1:10-100; the ethanol solution of p-vinylbenzenesulfonyl chloride is added dropwise within 30-90 min; the stirring reaction conditions are stirring at 40-80 °C for 4-7 h.

6. The system according to claim 1, wherein In step C, the weight ratio of the modified biochar, sulfonated chitosan, acrylamide, and azobisisobutyronitrile is 1:1.4-2.3:0.6-1.5:0.01-0.03; the stirring reaction conditions are stirring at 60-70 °C for 2-3 h.

7. The system according to claim 1, characterized in that, In step C, the preparation method of the modified biochar comprises the following steps: dispersing biochar into a KH570 ethanol solution, with the weight ratio of biochar, KH570, and ethanol being 10:1 - 3:60 - 80, stirring and reacting at 60 - 80 °C for 4 - 6 h, filtering, washing, and drying the product to obtain the modified biochar.

8. The system according to claim 1, characterized in that, In step D, the concentration of the acetic acid aqueous solution is 5 - 15 wt%, and the weight ratio of the biochar / chitosan composite material to the acetic acid aqueous solution is 1:10 - 30; the stirring reaction conditions are stirring and reacting at 20 - 50 °C for 12 - 24 h, washing 3 - 5 times with absolute ethanol, and the drying conditions are vacuum drying at 60 - 80 °C.

9. A method for resource utilization of carbon dioxide in wine using the system according to any one of claims 1 to 8, characterized in that, It comprises the following steps: inoculating microalgae into the algae pond, turning on the lighting device, then introducing the carbon dioxide generated by fermentation in the fermentation tank into the algae pond, and introducing the culture solution into the algae pond. After the microalgae have grown for a period of time, filtering the high-density microalgae biomass attached to the packing through a filter screen, and making it into algal fertilizer to be returned to the vineyard, and introducing the low-concentration algae-containing water into the constructed wetland for purification and then discharging it; the rate of introducing carbon dioxide into the algae pond is 0.001 - 10 vvm; the light intensity in the algae pond is 1000 - 20000 lx, the light-dark cycle is 8 h:16 h - 24 h:0 h, and the temperature in the algae pond is 20 - 40 °C.

Images