Fulvic acid extract based on marigold fermentation waste liquid and extraction method and application thereof

Abstract

The invention relates to the technical field of fulvic acid extraction, and is a fulvic acid extract based on marigold fermentation waste liquid, an extraction method and an application thereof. The former is prepared by the following method: the first step is to place weathered coal with a particle size of 40 to 180 microns in an extraction tank, add softened water and stir evenly, activate the weathered coal with ultrasound, filter and dry, and obtain the activated weathered coal; the second step is to add the activated weathered coal to marigold fermentation waste liquid, add a required amount of methanol, and after ultrasonic treatment, leaching at a required temperature, filter the leached marigold fermentation waste liquid, and the filtrate is a fulvic acid extract based on marigold fermentation waste liquid. The invention is based on the acidity of marigold fermentation waste liquid, is used to extract fulvic acid from weathered coal, expands a new method for the extraction of fulvic acid, and extracts thiophene substances in marigold fermentation waste liquid into fulvic acid extract by methanol, giving the fulvic acid extract insecticide and antibacterial functions.

Description

Technical Field

[0001] The invention relates to the technical field of fulvic acid extraction, and is a fulvic acid extract based on marigold fermentation waste liquid, an extraction method and an application thereof. Background Art

[0002] Marigold, also known as stinking hibiscus, mainly contains compounds such as thiophenes, flavonoids, volatile oils, and other nutrients such as amino acids and carotenoids. In industry, marigold is used as a raw material to extract compounds and nutrients in marigold. After industrial extraction and treatment, marigold fermentation waste liquid still contains a certain amount of thiophenes, flavonoids, lutein and other ingredients. If it is directly discarded, it will cause a waste of resources without effective utilization. Lutein, as an antioxidant, can not only react with free radicals to generate non-toxic products, but also interrupt the free radical chain reaction, prevent cells from being destroyed, and protect the body. The thiophene component in marigold fermentation waste liquid has the advantages of contact killing and high mortality rate, and is often used for pest control. In addition, it has a certain inhibitory effect on fungi, bacteria, algae and other microorganisms. Flavonoids can be used as a primary antioxidant, and have many effects in the body, such as anti-cancer, anti-aging, anti-inflammatory and anti-allergic, hemostasis and analgesia, and prevention of cardiovascular diseases.

[0003] Humic acid contains a large number of oxygen-containing functional groups, including hydroxyl, carboxyl, carbonyl, methoxy and phenolic hydroxyl groups. These functional groups make humic acid have excellent properties such as adsorption, ion exchange and weak acid properties. Humic acid can increase the yield of agricultural products by increasing the activity of certain enzymes in plants and stimulating the synthesis of carrier proteins in plants. Humic acid can also complex with heavy metal ions to remove heavy metal ions in wastewater. Humic acid can also be used as a concrete additive to adjust the setting rate of concrete and reduce the consumption of concrete. The main methods for extracting humic acid are alkali dissolution and acid precipitation, oxidation, acid extraction, microbial degradation, etc. Haider et al. (Haider R, ghaurim A, Akhtar K. Isolation of coal degrading fungus from drilled core coal sample and effect of prior fungal pretreatment on chemical attributes of extracted humic acid [J]. Geomicrobiology Journal, 2015, 32, 944-953) used isolated MWI fungi to pretreat coal samples and then extracted humic acid. After elemental and spectral analysis of humic acid, it was found that the oxygen content of humic acid was relatively high. Fong et al. (Fong SS, Seng L, Chong Wn, et al. Characterization of the coal-derived humic acids from mukah, Sarawak as soil conditioner [J]. Journal of the Brazilian Chemical Society, 2006, 17 (3): 582-587) used potassium hydroxide and sodium hydroxide solutions of different concentrations as extractants of humic acid, and extracted humic acid from lignite at a ratio of 1:1045 between the mass of the coal sample and the volume of the alkali solution, and characterized the humic acid. However, the method is complicated in operation. The Chinese patent document with publication number CN112812323A discloses a method for extracting humic acid from a mineral source, which uses a low eutectic solvent to extract humic acid. The method has the advantages of simple and rapid preparation method, and the solvent is environmentally friendly, but the extraction cost is relatively high. A Chinese patent document with publication number CN113683647A discloses a process for extracting humic acid, in which coal is acidified and then humic acid is extracted with a higher alcohol. The process has the characteristics of simple extraction process, solvent recyclability, and high extraction rate, but the application field of the extracted humic acid is limited.The Chinese patent document with publication number CN112980748A discloses a Bacillus brevis, its use and a method for converting lignite to produce humic acid, which provides a method for producing humic acid by microorganisms, and has the function of efficiently degrading lignite to produce humic acid. However, due to the harsh preservation conditions of microorganisms and the complex process conditions of biochemical reactions, the production cost of humic acid is indirectly increased. Huculak-. Huculak- Hoffmann J, Hoffmann K. Evaluation of the possibilities of using humic acids obtained from lignite in the production of commercial fertilizers [J]. Journal of Soils & Sediments, 2018 (4): 1-13) Sodium hydroxide, sodium pyrophosphate and potassium hydroxide solutions of different concentrations were used to extract humic acid from lignite, and six types of humic acids were analyzed and compared using thermal analysis, UV-visible spectrophotometry, nuclear magnetic resonance, molecular fluorescence and other methods. The results showed that the humic acid extracted by sodium pyrophosphate solution contained more carboxyl groups. When sodium hydroxide solution was used as the extractant, the humic acid extraction rate could reach 50%. The condensation degree of humic acid extracted by sodium hydroxide and potassium hydroxide solutions was lower than that of humic acid extracted by sodium pyrophosphate solution. However, the humic acid extraction cost of this method was higher.

[0004] The pH value of the waste liquid produced by marigold flowers after fermentation is 4. It not only contains a large amount of lactic acid, amino acids, etc., but also has a high COD content. Direct discharge will cause serious pollution to the environment. Therefore, the comprehensive resource utilization of marigold fermentation waste liquid can solve the environmental pollution problem of waste liquid on the one hand, and make full use of the nutrients in the waste liquid for comprehensive development on the other hand to achieve the purpose of improving economic benefits. Chen Baosun et al. (Chen Baosun, Xie Weiming, Li Tianping, et al. Key technology and process for resource utilization of marigold fermentation and squeezing waste liquid. Yunnan Province, Qujing Kangzhuang Fertilizer Co., Ltd., 2012-12-14) mixed biological bacteria with marigold flower fermentation liquid and water-absorbing substances, which not only harmlessly solved the problem of high BOD and COD, but also the organic fertilizer obtained after the reaction also has the characteristics of good use effect. The preparation method is simple and easy to operate, but the components such as lutein and thiophene in marigold fermentation and squeezing waste liquid have not been effectively utilized. The Chinese patent document with publication number CN111285725A discloses a marigold production waste liquid recycling process, which separates the waste liquid in the marigold production process to obtain flower mud and clear liquid, adjusts the pH of the clear liquid to add bacteria and urea fermentation to obtain organic liquid fertilizer, which can be reused in marigold planting farmland. This method has certain economic value and social benefits, but its preparation time is long and the production cost is high. The Chinese patent document with publication number CN110386839A discloses a marigold flower wastewater utilization method, which ferments organic carbon liquid, potassium hydroxide, glucose, urea, peat, potassium dihydrogen sulfate, etc. with marigold waste liquid, and takes out the supernatant after precipitation to add rooting water and organic calcium fertilizer, which not only achieves the purpose of turning waste into treasure, but also solves the problem of drought and water shortage, but its reaction ratio and operation are complicated and costly. The Chinese patent document with publication number CN109020698A discloses a method for utilizing marigold fermentation dehydration waste liquid as fertilizer, which neutralizes the marigold fermentation dehydration waste liquid with quicklime and adjusts the pH to neutral, and after standing for 3 days, adds manganese sulfate, sodium molybdate, sodium tetraborate, etc. and stirs them evenly to obtain a fertilizer nutrient solution, which can be used for fertilizing crops such as corn and marigold, but its preparation process is cumbersome and limited to preparing fertilizer nutrient solution. The Chinese patent document with publication number CN107311726A discloses a method for treating marigold flower fermentation waste liquid, which mixes organic carbon bacterial liquid, marigold flower fermentation liquid, coagulant bacillus bacterial agent and potassium hydroxide, passes air for treatment for five to ten days, and then separates the solid and liquid to obtain an organic carbon nutrient solution that is not only harmless, but also can increase the yield and improve the quality of crops, but the preparation cycle of the nutrient solution is long and the process is complicated. Li Junhe et al. (Li Junhe, Ye Luzhou, Bao Fugang, et al. Research and Application of Technology of Raw Material Recovery Device in Waste Liquid during Marigold Processing. Yunnan Province, Chenguang Biotechnology Group Tengchong Co., Ltd., 2021-08-31.) developed a raw material recovery device for waste liquid in the processing of marigold, which turned the waste liquid into liquid fertilizer to achieve resource recycling, but the process is complicated. Summary of the invention

[0005] The present invention provides a fulvic acid extract based on marigold fermentation waste liquid, an extraction method and an application thereof, which overcome the deficiencies of the above-mentioned prior art, can efficiently extract fulvic acid from weathered coal, and can effectively solve the environmental pollution and resource waste problems of the existing marigold fermentation waste liquid.

[0006] One of the technical solutions of the present invention is achieved through the following measures: a fulvic acid extract based on marigold fermentation waste liquid is obtained according to the following preparation method: the first step is to place weathered coal with a particle size of 40 microns to 180 microns in an extraction tank, add softened water and stir evenly, activate the weathered coal with ultrasound, and filter and dry to obtain the activated weathered coal; the second step is to add the activated weathered coal to marigold fermentation waste liquid, and add a required amount of methanol, after ultrasonic treatment, leaching at a required temperature, filtering the leached marigold fermentation waste liquid, and the filtrate is the fulvic acid extract based on marigold fermentation waste liquid.

[0007] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions:

[0008] The above preparation method also includes a third step of removing methanol from the fulvic acid extract based on marigold fermentation waste liquid. The specific operation is: removing and recovering the methanol in the fulvic acid extract based on marigold fermentation waste liquid through a rotary distiller at a temperature of 70 degrees Celsius to 85 degrees Celsius and a time of 25 minutes to 60 minutes, and repeatedly using the recovered methanol in the preparation of the fulvic acid extract.

[0009] In the first step, the mass ratio of softened water to weathered coal is 2:1 to 36:1; or / and, the set power of the ultrasonic wave is 200 watts to 800 watts.

[0010] In the first step, the activation time of the weathered coal is 10 minutes to 80 minutes; or / and the activation temperature is 20 degrees Celsius to 90 degrees Celsius.

[0011] In the first step, the drying temperature of the activated weathered coal is 70 degrees Celsius to 100 degrees Celsius.

[0012] In the second step, 10 ml to 150 ml of marigold fermentation waste liquid is added to each gram of activated weathered coal.

[0013] In the second step, the volume ratio of marigold fermentation waste liquid to methanol is 1:1 to 1:10; or / and, the ultrasonic treatment time is 20 minutes to 40 minutes.

[0014] In the above second step, the leaching time is 12 hours to 48 hours; or / and, the leaching temperature is 15 degrees Celsius to 100 degrees Celsius.

[0015] The second technical solution of the present invention is achieved through the following measures: a method for extracting fulvic acid based on marigold fermentation waste liquid, which is carried out according to the following steps: the first step is to place weathered coal with a particle size of 40 microns to 180 microns in an extraction tank, add softened water and stir evenly, activate the weathered coal with ultrasound, and filter and dry to obtain the activated weathered coal; the second step is to add the activated weathered coal to marigold fermentation waste liquid, and add the required amount of methanol, after ultrasonic treatment, leaching at the required temperature, filtering the leached marigold fermentation waste liquid, and the filtrate is the fulvic acid extract based on marigold fermentation waste liquid.

[0016] The third technical solution of the present invention is achieved through the following measures: an application of a fulvic acid extract based on marigold fermentation waste liquid in the fields of soil remediation, agriculture and aquaculture.

[0017] The invention is based on the acidic characteristics of marigold fermentation waste liquid and is used to extract fulvic acid from weathered coal, thereby expanding a new method for the extraction of fulvic acid. Thiophene substances are extracted into the fulvic acid extract by methanol, thereby giving the fulvic acid extract liquid insecticidal and antibacterial functions, thereby effectively solving the problems of environmental pollution and resource waste caused by direct discharge of marigold fermentation waste liquid without full utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Attached Figure 1 This is the infrared spectrum of fulvic acid in the fulvic acid extract based on marigold fermentation waste liquid in Example 13. DETAILED DESCRIPTION

[0019] The present invention is not limited by the following embodiments, and the specific implementation method can be determined according to the technical scheme of the present invention and the actual situation. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all known and commonly used chemical reagents and chemicals in the prior art; unless otherwise specified, the percentages in the present invention are all mass percentages; the normal temperature and room temperature in the present invention generally refer to a temperature of 15 degrees Celsius to 25 degrees Celsius, and are generally defined as 25 degrees Celsius.

[0020] The present invention will be further described below in conjunction with embodiments:

[0021] Example 1: The fulvic acid extract based on marigold fermentation waste liquid is prepared according to the following method:

[0022] The first step is to place weathered coal with a particle size of 40 microns to 180 microns in an extraction tank, add softened water and stir evenly, activate the weathered coal with ultrasound, and filter and dry to obtain the activated weathered coal; the second step is to add the activated weathered coal to marigold fermentation waste liquid, and add the required amount of methanol, after ultrasonic treatment, leaching at the required temperature, and filtering the leached marigold fermentation waste liquid. The filtrate is the fulvic acid extract based on the marigold fermentation waste liquid.

[0023] The present invention adds weathered coal to marigold fermentation waste liquid. The mechanism is that the marigold fermentation waste liquid used is acidic. The large amount of H+ contained in it can effectively destroy the binding state of metal ions and carboxyl groups in the fulvic acid salt in the weathered coal to generate free fulvic acid, and the fulvic acid is extracted from the solution according to the characteristic that the fulvic acid is easily soluble in water. Since the marigold fermentation waste liquid activates the weathered coal, the chemical bonds of the fulvic acid can be weakened, the "active center" is opened, and the extraction rate of the fulvic acid is improved. The present invention can turn waste into treasure, and the fulvic acid in the weathered coal is extracted by using the waste liquid after marigold processing and production. The extraction method is simple, relatively safe, and has obvious effects. In addition, the α-terthiophene in the marigold fermentation waste liquid can be leached into the fulvic acid extract by methanol extraction, which gives the fulvic acid the insecticidal and antibacterial functions.

[0024] The fulvic acid in the present invention refers to the water-soluble organic carboxylic acid in humic acid, which has a wide range of uses in agriculture, industry, medicine, etc. Fulvic acid can be obtained from mineral resources such as peat, lignite, weathered coal, or other biomass resources. The present invention does not require high pressure conditions, and the extraction temperature does not exceed 100 degrees Celsius. The raw material source is abundant and the price is low. Compared with the traditional fulvic acid extraction process, it does not need to use reagents and raw materials such as sulfuric acid, nitric acid, acetone, etc., and the extraction method is green and safe.

[0025] Example 2: As an optimization of the above example, the above preparation method also includes a third step of removing methanol from the fulvic acid extract based on marigold fermentation waste liquid. The specific operation is: removing and recovering the methanol in the fulvic acid extract based on marigold fermentation waste liquid through a rotary distiller at a temperature of 70 degrees Celsius to 85 degrees Celsius and a time of 25 minutes to 60 minutes, and repeatedly using the recovered methanol in the preparation of the fulvic acid extract.

[0026] Embodiment 3: As an optimization of the above embodiment, in the first step, the mass ratio of softened water to weathered coal is 2:1 to 36:1; or / and, the set power of the ultrasonic wave is 200 watts to 800 watts.

[0027] Example 4: As an optimization of the above example, in the first step, the activation time of the weathered coal is 10 minutes to 80 minutes; or / and, the activation temperature is 20 degrees Celsius to 90 degrees Celsius.

[0028] Example 5: As an optimization of the above example, in the first step, the drying temperature of the activated weathered coal is 70 degrees Celsius to 100 degrees Celsius.

[0029] Example 6: As an optimization of the above example, in the second step, 10 ml to 150 ml of marigold fermentation waste liquid is added to each gram of activated weathered coal.

[0030] Example 7: As an optimization of the above example, in the second step, the volume ratio of marigold fermentation waste liquid to methanol is 1:1 to 1:10; or / and, the ultrasonic treatment time is 20 minutes to 40 minutes.

[0031] Embodiment 8: As an optimization of the above embodiment, in the second step, the leaching time is 12 hours to 48 hours; or / and, the leaching temperature is 15 degrees Celsius to 100 degrees Celsius.

[0032] Example 9: Application of the fulvic acid extract based on marigold fermentation waste liquid in the fields of soil remediation, agriculture and aquaculture.

[0033] The fulvic acid extract based on marigold fermentation waste liquid of the present invention can loosen the soil in the field of soil remediation, open the salt water elution channel, and reduce the salt content in the topsoil; it has a buffering effect on the soil pH, effectively complexes, chelates, fixes or adsorbs and fixes heavy metal ions in the soil, reduces the biological effectiveness of heavy metals, reduces the absorption of heavy metal ions in plants, protects the ecological environment, and maintains a green soil environment; in the field of breeding, it can be used as a feed additive to improve feed utilization and the immunity of livestock and poultry, improve the reproductive capacity of livestock and poultry, and reduce breeding costs; in the field of agriculture, it can be used as a slow-release agent and stabilizer for nitrogen fertilizer, a synergist for phosphate fertilizer, and a protective agent for potassium fertilizer, and is made into various organic and inorganic compound fertilizers with nitrogen fertilizer, phosphate fertilizer, and potassium fertilizer.

[0034] Example 10: The fulvic acid extract based on marigold fermentation waste liquid is prepared according to the following method:

[0035] In the first step, 15 grams of weathered coal are placed in an extraction tank, softened water is added according to the mass ratio of softened water to weathered coal (5:1), and after stirring evenly, it is placed in an ultrasonic treatment pool, the ultrasonic power is set to 350 watts, the activation time is 30 minutes, the temperature is 40 degrees Celsius, and after filtering, it is dried at 80 degrees Celsius to obtain activated weathered coal.

[0036] In the second step, 1 gram of activated weathered coal and 15 milliliters of marigold fermentation waste liquid were added to the extraction tank, and humic acid was extracted after 25 minutes of ultrasonic treatment. The extraction time was 12 hours at a temperature of 45 degrees Celsius. After standing and stratification, the supernatant was taken to determine its absorbance and fluorescence intensity.

[0037] Example 11: The fulvic acid extract based on marigold fermentation waste liquid is prepared according to the following method:

[0038] In the first step, 15 grams of weathered coal are placed in an extraction tank, softened water is added according to the mass ratio of softened water to weathered coal (5:1), and after stirring evenly, it is placed in an ultrasonic treatment pool, the ultrasonic power is set to 350 watts, the activation time is 30 minutes, the temperature is 40 degrees Celsius, and after filtering, it is dried at 80 degrees Celsius to obtain activated weathered coal.

[0039] In the second step, 1 gram of activated weathered coal and 20 milliliters of marigold fermentation waste liquid were added to the extraction tank, and methanol was added at a volume ratio of 1:2. After 20 minutes of ultrasonic treatment, humic acid was extracted. The leaching time was 16 hours and the leaching temperature was 50 degrees Celsius. The marigold fermentation waste liquid after leaching was filtered, and the filtrate was the humic acid extract based on marigold fermentation waste liquid.

[0040] Example 12: The fulvic acid extract based on marigold fermentation waste liquid is prepared according to the following method:

[0041] In the first step, 15 grams of weathered coal are placed in an extraction tank, softened water is added according to the mass ratio of softened water to weathered coal (10:1), and after stirring evenly, it is placed in an ultrasonic treatment pool, and the ultrasonic power is set to 350 watts, the activation time is 30 minutes, the temperature is 40 degrees Celsius, and after filtering, it is dried at 80 degrees Celsius to obtain activated weathered coal.

[0042] In the second step, 1 gram of activated weathered coal and 40 milliliters of marigold fermentation waste liquid were added into the extraction tank, and methanol was added at a volume ratio of 1:4 between the material and the liquid. Fulvic acid was extracted after 25 minutes of ultrasonic treatment. The extraction time was 20 hours and the extraction temperature was 55 degrees Celsius. The extracted marigold fermentation waste liquid was filtered and the filtrate was the fulvic acid extract based on the marigold fermentation waste liquid.

[0043] Example 13: The fulvic acid extract based on marigold fermentation waste liquid is prepared according to the following method:

[0044] In the first step, 15 grams of weathered coal are placed in an extraction tank, softened water is added according to the mass ratio of softened water to weathered coal (10:1), and after stirring evenly, it is placed in an ultrasonic treatment pool, and the ultrasonic power is set to 350 watts, the activation time is 30 minutes, the temperature is 40 degrees Celsius, and after filtering, it is dried at 80 degrees Celsius to obtain activated weathered coal.

[0045] In the second step, 1 gram of activated weathered coal and 60 milliliters of marigold fermentation waste liquid were added into the extraction tank, and methanol was added at a material-liquid volume ratio of 1:5. Fulvic acid was extracted after ultrasonic treatment for 30 minutes. The extraction time was 24 hours and the extraction temperature was 60 degrees Celsius. The extracted marigold fermentation waste liquid was filtered and the filtrate was the fulvic acid extract based on marigold fermentation waste liquid.

[0046] Example 14: The fulvic acid extract based on marigold fermentation waste liquid is prepared according to the following method:

[0047] In the first step, 15 grams of weathered coal are placed in an extraction tank, softened water is added according to the mass ratio of softened water to weathered coal (15:1), and after stirring evenly, it is placed in an ultrasonic treatment pool, the ultrasonic power is set to 350 watts, the activation time is 30 minutes, the temperature is 40 degrees Celsius, and after filtering, it is dried at 80 degrees Celsius to obtain activated weathered coal.

[0048] In the second step, 1 gram of activated weathered coal and 80 milliliters of marigold fermentation waste liquid were added into the extraction tank, and methanol was added at a material-liquid volume ratio of 1:6. Fulvic acid was extracted after ultrasonic treatment for 35 minutes. The extraction time was 28 hours and the extraction temperature was 65 degrees Celsius. The extracted marigold fermentation waste liquid was filtered and the filtrate was the fulvic acid extract based on marigold fermentation waste liquid.

[0049] Example 15: The fulvic acid extract based on marigold fermentation waste liquid is prepared according to the following method:

[0050] In the first step, 15 grams of weathered coal are placed in an extraction tank, softened water is added according to the mass ratio of softened water to weathered coal (15:1), and after stirring evenly, it is placed in an ultrasonic treatment pool, the ultrasonic power is set to 350 watts, the activation time is 30 minutes, the temperature is 40 degrees Celsius, and after filtering, it is dried at 80 degrees Celsius to obtain activated weathered coal.

[0051] In the second step, 1 gram of activated weathered coal and 100 milliliters of marigold fermentation waste liquid were added into the extraction tank, and methanol was added at a volume ratio of 1:8 between the material and the liquid. Fulvic acid was extracted after 40 minutes of ultrasonic treatment. The extraction time was 32 hours and the extraction temperature was 70 degrees Celsius. The extracted marigold fermentation waste liquid was filtered and the filtrate was the fulvic acid extract based on the marigold fermentation waste liquid.

[0052] Test part:

[0053] The fulvic acid in the fulvic acid extract based on marigold fermentation waste liquid obtained in Example 13 was tested by infrared spectroscopy. The infrared spectrum of the fulvic acid extracted in Example 13 is shown in FIG. Figure 1 .from Figure 1 It can be seen that at 3423cm -1 Hydrogen bonded hydroxyl group at 1617 cm -1 There are stretching vibration peaks of aromatic ring conjugation and carbonyl conjugation C=C and carbonyl C=0 at 1384cm -1 There is an in-plane bending vibration peak of CH at 1111cm -1 and 1032cm -1 There is a stretching vibration peak of CO at . The extracted product contains carboxyl, carbonyl, hydroxyl and aromatic ring structures, which are consistent with the structural characteristics of fulvic acid.

[0054] The contents of α-terthiophene and fulvic acid in the fulvic acid extract based on marigold fermentation waste liquid obtained in Examples 10 to 15 were tested:

[0055] α-terthiophene standard curve drawing: weigh 0.012 g of α-terthiophene standard sample, prepare a series of standard solutions, use blank as reference sample, draw a standard curve at the best excitation wavelength, emission wavelength of 428 nm, excitation light of 352 nm, the standard curve equation is y = 25.605 + 1079.151x (R 2 =0.997).

[0056] Drawing of the standard curve of fulvic acid: accurately weigh 0.2 g of fulvic acid standard sample, dissolve it in softened water and dilute to 100 ml, prepare a series of standard solutions in sequence, measure its absorbance at a wavelength of 665 nm, draw a standard curve, and the equation of the standard curve is y=3.950x+0.0827(R 2 =0.9960).

[0057] The results of the determination of α-terthiophene and fulvic acid contents in the fulvic acid extracts based on marigold fermentation waste liquid obtained in Examples 10 to 15 are shown in Table 1. In addition, the biochemical fulvic acid in the raw material marigold fermentation waste liquid was determined, and the content of biochemical fulvic acid in the marigold fermentation waste liquid was 0.034 g / L.

[0058] Determination of antibacterial activity of fulvic acid extract from marigold fermentation wastewater:

[0059] Phosphorus content standard curve establishment: First, prepare 1 μg / ml phosphorus standard sample, then take 0.05 ml to 5.00 ml of standard sample (volume increment is 0.05 ml) and add it to a 10 ml colorimetric tube, dilute to the scale line, add 0.2 ml of ascorbic acid and 0.4 ml of ammonium molybdate solution respectively, after color development at room temperature, measure the absorbance at 700 nm wavelength, and draw a standard curve. Then take 1 ml of fulvic acid extract and add it to a test tube containing 2 ml of test water sample, dilute with distilled water, add 0.45 ml of ammonium molybdate, mix thoroughly, and measure the absorbance at 700 nm wavelength after color development. The sterilization rate is calculated according to the following formula, and the results are listed in Table 1.

[0060]

[0061] Wherein, ρ is the sterilization rate, %; W0 is the lipid phosphorus content in the blank sample; W1 is the lipid phosphorus content in the test sample.

[0062] The above measurement results show that the extraction of fulvic acid from weathered coal is achieved by using marigold fermentation waste liquid. Based on the acidic characteristics of marigold fermentation waste liquid, H+ destroys the binding state of metal ions and carboxyl groups in fulvic acid salts to generate free fulvic acid, and organic solvents such as methanol can further synergistically enhance the extraction effect of marigold fermentation waste liquid in extracting fulvic acid from weathered coal. In addition, ultrasonic treatment can accelerate the release and diffusion of weakly polar α-terthiophene, increase the extraction amount of α-terthiophene by polar solvent methanol, and the methanol in the extract can be removed and recycled by a rotary distiller. The fulvic acid extract based on marigold fermentation waste liquid of the present invention not only has abundant raw material sources, low prices, and mild reaction conditions, but also avoids the large-scale use of sulfuric acid, nitric acid, acetone, etc. compared to the traditional fulvic acid extraction process, and will not cause pollution to the environment. The fulvic acid extract can also play an important role in insecticide and antibacterial, and is a multifunctional extract.

[0063] In summary, the present invention provides a fulvic acid extract based on marigold fermentation waste liquid, an extraction method and an application thereof. Based on the acidic characteristic of marigold fermentation waste liquid, the extract is used to extract fulvic acid from weathered coal. On the one hand, the recycling of marigold fermentation waste liquid is realized, and the pollution problem of direct discharge of marigold fermentation waste liquid to the environment is effectively solved; on the other hand, fulvic acid in weathered coal is extracted by marigold fermentation waste liquid, which provides an effective new method for the extraction of fulvic acid and expands the application scope of fulvic acid, which is of great significance to the extraction process of fulvic acid and the comprehensive utilization of marigold fermentation waste liquid.

[0064] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

[0065] Table 1

[0066]

Claims

1. A fulvic acid extract based on marigold fermentation waste liquid, characterized in that Obtained by the following preparation method: In the first step, weathered coal with a particle size of 40 microns to 180 microns is placed in an extraction tank, softened water is added and stirred evenly, the weathered coal is activated by ultrasonic wave, and filtered and dried to obtain activated weathered coal; The second step is to add the activated weathered coal to the marigold fermentation waste liquid, and add a required amount of methanol, and after ultrasonic treatment, leaching is carried out at a required temperature, and the leached marigold fermentation waste liquid is filtered, and the filtrate is the fulvic acid extract based on the marigold fermentation waste liquid; Wherein, in the first step, the mass ratio of softened water to weathered coal is 2:1 to 36:1, the set power of the ultrasonic wave is 200 watts to 800 watts, the activation time of the weathered coal is 10 minutes to 80 minutes, and the activation temperature is 20 degrees Celsius to 90 degrees Celsius; In the second step, 10 ml to 150 ml of marigold fermentation waste liquid is added to each gram of activated weathered coal, the volume ratio of marigold fermentation waste liquid to methanol is 1:1 to 1:10, and the ultrasonic treatment time is 20 minutes to 40 minutes.

2. The fulvic acid extract based on marigold fermentation waste liquid according to claim 1, characterized in that The preparation method also includes a third step of removing methanol from the fulvic acid extract based on marigold fermentation waste liquid. The specific operation is: removing and recovering the methanol in the fulvic acid extract based on marigold fermentation waste liquid through a rotary distiller at a temperature of 70 degrees Celsius to 85 degrees Celsius and a time of 25 minutes to 60 minutes, and repeatedly using the recovered methanol in the preparation of the fulvic acid extract.

3. The fulvic acid extract based on marigold fermentation waste liquid according to claim 1 or 2, characterized in that In the first step, the activated weathered coal is dried at a temperature of 70 to 100 degrees Celsius.

4. The fulvic acid extract based on marigold fermentation waste liquid according to claim 3, characterized in that In the second step, the leaching time is 12 hours to 48 hours; or / and, the leaching temperature is 15 degrees Celsius to 100 degrees Celsius.

5. A method for extracting fulvic acid from marigold fermentation waste liquid according to any one of claims 1 to 4, characterized in that Follow these steps: In the first step, weathered coal with a particle size of 40 microns to 180 microns is placed in an extraction tank, softened water is added and stirred evenly, the weathered coal is activated by ultrasonic wave, and filtered and dried to obtain activated weathered coal; The second step is to add the activated weathered coal to the marigold fermentation waste liquid, and add a required amount of methanol, and after ultrasonic treatment, leaching is carried out at a required temperature, and the leached marigold fermentation waste liquid is filtered, and the filtrate is the fulvic acid extract based on the marigold fermentation waste liquid; Wherein, in the first step, the mass ratio of softened water to weathered coal is 2:1 to 36:1, the set power of the ultrasonic wave is 200 watts to 800 watts, the activation time of the weathered coal is 10 minutes to 80 minutes, and the activation temperature is 20 degrees Celsius to 90 degrees Celsius; In the second step, 10 ml to 150 ml of marigold fermentation waste liquid is added to each gram of activated weathered coal, the volume ratio of marigold fermentation waste liquid to methanol is 1:1 to 1:10, and the ultrasonic treatment time is 20 minutes to 40 minutes.

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