Preparation method and application of biological flocculant

Abstract

The invention discloses a preparation method and application of a biological flocculant, white-rot fungi is used as a treatment strain, the white-rot fungi are subjected to enrichment culture and domestication to prepare a microbial liquid, the microbial liquid is compounded with a magnetic substance, and finally the compound is loaded on cellulose modified montmorillonite to prepare the flocculant. According to the flocculant disclosed by the invention, nutrient substances in the medicinal plant processing wastewater are converted into proteins by using the white-rot fungi, so that the medicinal plant processing wastewater is treated, and the COD (Chemical Oxygen Demand), the chromaticity and the pH (Potential of Hydrogen) of the wastewater are reduced, so that the wastewater reaches a discharge standard. The biological flocculant disclosed by the invention is loaded on cellulose modified montmorillonite, so that the pressure resistance of white-rot fungi to a growth environment is improved, high-concentration wastewater is prevented from inhibiting mycelial growth, and the wastewater treatment efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the field of sewage treatment, and particularly relates to a preparation method and application of a biological flocculant. Background Art

[0002] Medicinal plant processing wastewater is a kind of high-concentration organic wastewater that is very difficult to treat. At present, no domestic enterprise has been able to carry out thorough and effective treatment. Except for a few enterprises that treat it, most enterprises adopt the method of direct discharge. According to the survey, the wastewater treatment processes for medicinal plant processing that have been put into operation or under construction in the country are neutralization-anaerobic biological treatment (UASB)-aerobic biological treatment (SBR). The schemes of various plants are similar, and there are technical, cost and operation management problems to varying degrees. The treatment effect is not ideal. The production wastewater of most medicinal plant processing enterprises has not passed the acceptance of the environmental protection department and meets the discharge standards. For this reason, some scholars and scientific research institutions have conducted in-depth research on medicinal plant processing wastewater, mainly using comprehensive resource utilization, anaerobic, aerobic, physical and chemical and natural treatment technology to treat wastewater. These technologies can be divided into terminal treatment technology and front-end treatment technology for saponin wastewater.

[0003] Flocculation sedimentation is one of the important treatment methods in wastewater treatment. It is a treatment method that removes suspended matter by adding chemical reactants to mix and precipitate the suspended matter in the sewage and wastewater, achieve mud-water separation, and remove suspended matter. Flocculants are the key factor in determining the effect of flocculation treatment, and have an important impact on the operation of subsequent processes, the final effluent water quality and cost. Flocculants can be divided into two categories according to their chemical composition: inorganic flocculants and organic flocculants. Inorganic flocculants include inorganic coagulants and inorganic polymer flocculants; organic flocculants include synthetic organic polymer flocculants, natural organic polymer flocculants and microbial flocculants. Flocculants mainly neutralize some particles or particles in water with negative (positive) charges that are difficult to separate by groups with positive (negative) charges, reduce their potential, make them stable, and use their polymerization properties to concentrate these particles and separate them by physical or chemical methods.

[0004] The flocculation precipitation method has the disadvantages of slow reaction speed and high drug consumption, while high molecular weight flocculants such as basic polyaluminium chloride (PAC), polyaluminium sulfate, polyferric sulfate, etc., overcome the disadvantage of low molecular weight flocculants with low treatment efficiency, but their cost is high, and the treatment effect is poor at low temperature and low turbidity. Organic flocculants are generally high molecular weight polymers, such as polyamine flocculants and polyacrylamide flocculants, among which polyacrylamide has the advantages of small dosage, strong water clarification ability, fast flocculation speed, not easily affected by the pH value of water, and small amount of sludge generated, and has been widely used, but it has strong neurotoxicity and certain carcinogenicity. When a large amount of polyacrylamide is used to treat wastewater, it will produce high molecular weight residues, destroy the water biological chain, and then affect human health. Summary of the invention

[0005] In view of the above-mentioned deficiencies of the flocculant used when treating medicinal plant processing wastewater by flocculation sedimentation method, the present invention provides a method for preparing a biological flocculant, which avoids the use of high molecular weight flocculants and improves the treatment effect of medicinal plant processing wastewater.

[0006] The present invention is achieved through the following technical solutions: A method for preparing a bioflocculant comprises the following steps: S1: Inoculate the white rot fungus onto the PDA medium slant under sterile conditions and culture at 28-30℃ for 2-3 days until the fungus moss covers the slant; The PDA medium contains 200 g potato juice, 20 g glucose and 15 g agar per liter, with a pH of 6.0; S2: In a sterile environment, take 2-3 loops of robust and uncontaminated slant cultures and inoculate them into sterilized PDA liquid enrichment medium. Cultivate them in a shaking incubator at 28-30°C and 120-150 rpm. Measure OD values ​​of three parallel cultures every day. 650 and pH value, and take their average value as the daily OD 650 and pH true value, up to OD 650 When the value is basically constant, the seed solution is obtained; The PDA liquid enrichment medium contains 200g potato juice, 20g glucose, 3g potassium dihydrogen phosphate, 1.5g magnesium sulfate and trace VB1 per liter, and the pH is 5.0-6.0; S3: diluting the medicinal plant processing wastewater by 2-6 times, then compounding the dilution with the PDA liquid enrichment medium at a volume fraction of 30%-100%, and adjusting the pH to 4.0-6.0 with sodium hydroxide to obtain an acclimation solution; S4: Inoculate 80-120 mL of seed solution per liter of acclimatization solution, and culture in a shaking incubator at 28-30°C and 120-150 r / min; measure 3 parallel CODcr and OD every day. 650 and pH value, and take their average values ​​as the daily CODcr, OD 650 and the true value of pH until the three values ​​are basically constant, and the microbial culture liquid is obtained; S5: According to the ratio of ferric chloride: ferrous sulfate: ultrapure water = (3-5): (2-4): 50, ferric chloride and ferrous sulfate are dissolved in ultrapure water to obtain a mixed solution, and then 10% ammonia water by mass of ultrapure water is quickly added to the mixed solution, heated to 90°C and stirred continuously for 30 minutes, cooled to room temperature, filtered, washed, dried, and then black precipitates are collected to obtain magnetic particles; S6: ultrasonically dispersing the magnetic particles in ultrapure water at a solid-liquid ratio of 1:1000, then adding microbial culture liquid and sodium persulfate, stirring for 5 hours to mix evenly, to obtain a mixed agent; S7: Mix the cellulose-modified montmorillonite and the mixed reagent in a mass ratio of (1-2):1 to obtain a bioflocculant.

[0007] The present invention uses white rot fungi as the treated strain, prepares a microbial liquid through enrichment culture and domestication, and then compounds with magnetic substances and finally loads the liquid on cellulose modified montmorillonite to prepare a flocculant. The flocculant can utilize nutrients in the wastewater of medicinal plants for growth, thereby reducing COD and chromaticity in the wastewater of medicinal plants, so that various pollutant indicators of the treated wastewater are greatly reduced. The magnetic load material can improve the separation efficiency in the later separation of mycelium. The mycelium loaded on the cellulose modified montmorillonite can avoid the inhibitory effect of high-concentration wastewater on mycelium growth, thereby improving the growth efficiency of the mycelium, and further improving the mycelium to convert pollutants in the wastewater into proteins, thereby achieving purification of the wastewater. The dry material of the white rot fungi after growth is rich in protein and non-toxic, and can be used for the preparation of other products, thereby maximizing the utilization of resources.

[0008] Preferably, the mass ratio of the magnetic particles, the microbial culture liquid and the sodium persulfate used in step S6 is 1:1:0.1.

[0009] Preferably, the method for preparing the cellulose-modified montmorillonite comprises the following steps: A1: Bamboo fiber and deionized water were mixed at a ratio of 1 g:100 mL to obtain a mixed solution. Based on the volume of 100 mL of the mixed solution, 0.3-0.5 g of 2,2,6,6-tetramethylpiperidine and 37-40 mL of sodium hypochlorite were added at the same time. During the mixing reaction, the pH was adjusted to 9-11 with hydrochloric acid or sodium hydroxide. The mixture was reacted for 10-12 h to obtain a suspension. The suspension was then treated with ultrasound at 0.5-1 MHz and 300-400 W for 1 h. Finally, the suspension was freeze-dried to obtain nanofibers. A2: Dissolve montmorillonite in water to obtain a 5-10wt% montmorillonite suspension, then centrifuge at 1000r / min for 2-5min to remove large particles in the montmorillonite suspension, and finally treat with 0.5-1MHz, 300-400W ultrasound for 15-20min, and then dry at 60°C to constant weight to obtain nano-montmorillonite; A3: Nanofibers and nano-montmorillonite were dispersed in deionized water in a mass ratio of 1:1, and ultrasonically treated at 2-3 MHz and 300-400 W for 30-45 min. Polyethyleneimine was then added to produce a hydrogel. The hydrogel was then pre-frozen at -20°C for 2-3 h, and finally freeze-dried at -50°C for 72 h to obtain cellulose-modified montmorillonite.

[0010] Waste bamboo fiber paper and montmorillonite are used as raw materials for adsorption materials. The raw materials are widely available, green and pollution-free, and are in line with the national economic cycle and waste recycling development guidelines. By modifying nanocellulose and montmorillonite, the adsorption performance of pollutants is improved. At the same time, bamboo fiber modified montmorillonite has a good porous structure, which can provide sufficient channels to load white rot fungi, thereby improving the growth environment of the fungus in wastewater and reducing the inhibitory effect of high-concentration wastewater on the growth of fungi. At the same time, the porous structure has a good adsorption capacity for ionic pollutants in wastewater, which can purify wastewater while providing more biomass to be converted to white rot fungi, further promoting the growth of white rot fungi to improve the biological conversion efficiency of white rot fungi.

[0011] The application of the bioflocculant in wastewater from medicinal plant processing comprises the following steps: B1: Inoculate the bioflocculant in the medicinal plant processing wastewater at a rate of 50-150 mL / L of the medicinal plant processing wastewater, and at the same time, add urea and potassium dihydrogen phosphate to the medicinal plant processing wastewater at a mass ratio of m(COD)∶m(N)∶m(P)=200∶5∶(0.5-5), adjust the initial pH to 4.0-6.0, and obtain a reaction mixture; B2: The reaction mixture is reacted at 28°C and 200-220r / min for 4-6 days to complete the treatment of the medicinal plant processing wastewater; B3: The treated medicinal plant processing wastewater is separated from the white rot fungi, and the white rot fungi located deep in the water and difficult to salvage are adsorbed and removed by magnets.

[0012] Preferably, the medicinal plant processing wastewater in step B1 is diluted 4-6 times before inoculating the bioflocculant.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention adopts white rot fungi as the main material to prepare bioflocculants, and utilizes white rot fungi to convert nutrients in the wastewater from medicinal plant processing into proteins, thereby achieving the treatment of the wastewater from medicinal plant processing, reducing the COD, chromaticity and pH of the wastewater, and thus making the wastewater meet the discharge standards.

[0014] 2. The present invention adds magnetic material to the flocculant, which facilitates the subsequent separation of mycelium without affecting the growth of mycelium. In particular, mycelium located deep in the water and difficult to fish out can be separated by magnetic means.

[0015] 3. The bioflocculant of the present invention is loaded on cellulose-modified montmorillonite, which improves the pressure resistance of white rot fungi to the growth environment, avoids high-concentration wastewater from inhibiting mycelium growth, and thus improves wastewater treatment efficiency. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the embodiments. Unless otherwise specified, the techniques used in the embodiments are all conventional techniques known in the art.

[0017] The white rot fungi used in the following examples ( Phanerochaete chrysosporium ) were purchased from the Culture Collection Center of the Chinese Academy of Sciences.

[0018] Embodiment 1: A method for preparing a bioflocculant, comprising the following steps: S1: Inoculate the white rot fungus onto the PDA medium slant under sterile conditions and culture at 28°C for 3 days until the fungus moss covers the slant; The PDA medium contains 200 g potato juice, 20 g glucose and 15 g agar per liter, with a pH of 6.0; S2: In a sterile environment, take 2 loops of robust and uncontaminated slant cultures and inoculate them into sterilized PDA liquid enrichment medium. Cultivate them in a shaking incubator at 28°C and 120 rpm. Measure OD values ​​of 3 replicates every day. 650 and pH value, and take their average value as the daily OD 650 and pH true value, up to OD 650 When the value is basically constant, the seed solution is obtained; The PDA liquid enrichment medium contains 200g potato juice, 20g glucose, 3g potassium dihydrogen phosphate, 1.5g magnesium sulfate and trace amounts of VB1 per liter, with a pH of 5.0; S3: diluting the medicinal plant processing wastewater by 6 times, then compounding the dilution with the PDA liquid enrichment medium at a volume fraction of 100%, and adjusting the pH to 4.0 with sodium hydroxide to obtain an acclimation solution; S4: Inoculate 80 mL of seed solution in each liter of acclimatization solution and culture in a shaking incubator at 28°C and 120 r / min; measure CODcr and OD in three parallel conditions every day. 650 and pH value, and take their average values ​​as the daily CODcr, OD 650 and the true value of pH until the three values ​​are basically constant, and the microbial culture liquid is obtained; S5: According to the ratio of ferric chloride: ferrous sulfate: ultrapure water = 3:2:50, ferric chloride and ferrous sulfate are dissolved in ultrapure water to obtain a mixed solution, and then 10% ammonia water by mass of ultrapure water is quickly added to the mixed solution, heated to 90°C and stirred continuously for 30 minutes, cooled to room temperature, filtered, washed, dried, and then black precipitates are collected to obtain magnetic particles; S6: ultrasonically dispersing the magnetic particles in ultrapure water at a solid-liquid ratio of 1:1000, then adding microbial culture liquid and sodium persulfate, stirring for 5 hours to mix evenly, to obtain a mixed agent; the mass ratio of the magnetic particles, microbial culture liquid and sodium persulfate is 1:1:0.1; S7: Mix the cellulose-modified montmorillonite and the mixed agent in a mass ratio of 2:1 to obtain a bioflocculant.

[0019] The preparation method of the cellulose-modified montmorillonite comprises the following steps: A1: Bamboo fiber and deionized water were mixed at a ratio of 1 g:100 mL to obtain a mixed solution. Based on the volume of 100 mL of the mixed solution, 0.3 g of 2,2,6,6-tetramethylpiperidine and 37 mL of sodium hypochlorite were added at the same time. During the mixing reaction, the pH was adjusted to 9 with hydrochloric acid or sodium hydroxide. The mixture was reacted for 10 h to obtain a suspension. The suspension was then treated with ultrasound at 0.5 MHz and 400 W for 1 h, and finally freeze-dried to obtain nanofibers. A2: Montmorillonite was dissolved in water to obtain a 5wt% montmorillonite suspension, and then centrifuged at 1000r / min for 2min to remove large particles in the montmorillonite suspension, and finally treated with 1MHz, 300W ultrasound for 15min, and then dried at 60°C to constant weight to obtain nano-montmorillonite; A3: Nanofibers and nano-montmorillonite were dispersed in deionized water in a mass ratio of 1:1, and ultrasonically treated at 2 MHz and 400 W for 30 min. Polyethyleneimine was then added to produce a hydrogel. The hydrogel was then pre-frozen at -20 °C for 2 h and finally freeze-dried at -50 °C for 72 h to obtain cellulose-modified montmorillonite.

[0020] The application of the bioflocculant in wastewater from medicinal plant processing comprises the following steps: B1: Inoculate the bioflocculant in the medicinal plant processing wastewater at a rate of 50 mL / L of the medicinal plant processing wastewater, and at the same time, add urea and potassium dihydrogen phosphate to the medicinal plant processing wastewater at a mass ratio of m(COD):m(N):m(P)=200:5:0.5, adjust the initial pH to 4.0, and obtain a reaction mixture; the medicinal plant processing wastewater is diluted 6 times; B2: The reaction mixture was reacted at 28°C and 200 r / min for 4 days to complete the treatment of the medicinal plant processing wastewater; B3: The treated medicinal plant processing wastewater is separated from the white rot fungi, and the white rot fungi located deep in the water and difficult to salvage are adsorbed and removed by magnets.

[0021] The COD removal rate of the medicinal plant processing wastewater treated in this example was 87.90%, the chromaticity was reduced by 20%, and the cell dry weight reached 29.8 g / L.

[0022] Example 2: A method for preparing a bioflocculant, comprising the following steps: S1: Inoculate the white rot fungus onto the PDA medium slant under sterile conditions and culture at 30°C for 2 days until the fungus moss covers the slant; The PDA medium contains 200 g potato juice, 20 g glucose and 15 g agar per liter, with a pH of 6.0; S2: In a sterile environment, take 3 loops of healthy and uncontaminated slant strains and inoculate them into sterilized PDA liquid enrichment medium, and culture them in a shaking incubator at 30°C and 150 rpm. Measure OD of 3 parallel strains every day. 650 and pH value, and take their average value as the daily OD 650 and pH true value, up to OD 650 When the value is basically constant, the seed solution is obtained; The PDA liquid enrichment medium contains 200g potato juice, 20g glucose, 3g potassium dihydrogen phosphate, 1.5g magnesium sulfate and trace amounts of VB1 per liter, with a pH of 6.0; S3: diluting the medicinal plant processing wastewater by 2 times, then compounding the dilution with the PDA liquid enrichment medium at a volume fraction of 30%, and adjusting the pH to 6.0 with sodium hydroxide to obtain an acclimation solution; S4: Inoculate 120 mL of seed solution in each liter of acclimatization solution, and culture in a shaking incubator at 30°C and 150 r / min; measure CODcr and OD in three parallel conditions every day. 650 and pH value, and take their average values ​​as the daily CODcr, OD 650 and the true value of pH until the three values ​​are basically constant, and the microbial culture liquid is obtained; S5: Dissolve ferric chloride and ferrous sulfate in ultrapure water according to the ratio of ferric chloride: ferrous sulfate: ultrapure water = 5:4:50 to obtain a mixed solution, quickly add ammonia water with a mass percentage of 10% of the ultrapure water to the mixed solution, heat to 90°C and stir continuously for 30 minutes, cool to room temperature, filter, wash, dry and collect the black precipitate to obtain magnetic particles; S6: ultrasonically dispersing the magnetic particles in ultrapure water at a solid-liquid ratio of 1:1000, then adding microbial culture liquid and sodium persulfate, stirring for 5 hours to mix evenly, to obtain a mixed agent; the mass ratio of the magnetic particles, microbial culture liquid and sodium persulfate is 1:1:0.1; S7: Mix the cellulose-modified montmorillonite and the mixed agent in a mass ratio of 1:1 to obtain a bioflocculant.

[0023] The preparation method of the cellulose-modified montmorillonite comprises the following steps: A1: Bamboo fiber and deionized water were mixed at a ratio of 1 g:100 mL to obtain a mixed solution. Based on the volume of 100 mL of the mixed solution, 0.5 g of 2,2,6,6-tetramethylpiperidine and 40 mL of sodium hypochlorite were added at the same time. During the mixing reaction, the pH was adjusted to 11 with hydrochloric acid or sodium hydroxide. The suspension was reacted for 12 h to obtain a suspension. The suspension was then treated with 1 MHz, 300 W ultrasound for 1 h, and finally freeze-dried to obtain nanofibers. A2: Montmorillonite was dissolved in water to obtain a 10wt% montmorillonite suspension, and then centrifuged at 1000r / min for 5min to remove large particles in the montmorillonite suspension, and finally treated with 1MHz, 300W ultrasound for 20min, and then dried at 60°C to constant weight to obtain nano-montmorillonite; A3: Nanofibers and nano-montmorillonite were dispersed in deionized water in a mass ratio of 1:1, and ultrasonically treated at 3MHz, 300W for 45min. Polyethyleneimine was then added to produce a hydrogel. The hydrogel was then pre-frozen at -20°C for 3h and finally freeze-dried at -50°C for 72h to obtain cellulose-modified montmorillonite.

[0024] The application of the bioflocculant in wastewater from medicinal plant processing comprises the following steps: B1: Inoculate the bioflocculant in the medicinal plant processing wastewater at a rate of 150 mL / L of the medicinal plant processing wastewater, and at the same time, add urea and potassium dihydrogen phosphate to the medicinal plant processing wastewater at a mass ratio of m(COD):m(N):m(P)=200:5:5, and adjust the initial pH to 4.0-6.0 to obtain a reaction mixture; the medicinal plant processing wastewater is diluted 4 times; B2: The reaction mixture was reacted at 28°C and 220r / min for 4 days to complete the treatment of the medicinal plant processing wastewater; B3: The treated medicinal plant processing wastewater is separated from the white rot fungi, and the white rot fungi located deep in the water and difficult to salvage are adsorbed and removed by magnets.

[0025] The COD removal rate of the medicinal plant processing wastewater treated in this example was 91.70%, the chromaticity was reduced by 20%, and the cell dry weight reached 35.6 g / L.

[0026] Embodiment 3: A method for preparing a bioflocculant, comprising the following steps: S1: Inoculate the white rot fungus onto the PDA medium slant under sterile conditions and culture at 29°C for 2-3 days until the fungus moss covers the slant; The PDA medium contains 200 g potato juice, 20 g glucose and 15 g agar per liter, with a pH of 6.0; S2: In a sterile environment, take 2-3 loops of robust and uncontaminated slant cultures and inoculate them into sterilized PDA liquid enrichment medium. Cultivate them in a shaking incubator at 29°C and 130 rpm. Measure OD values ​​of three parallel cultures every day. 650 and pH value, and take their average value as the daily OD 650 and pH true value, up to OD 650 When the value is basically constant, the seed solution is obtained; The PDA liquid enrichment medium contains 200g potato juice, 20g glucose, 3g potassium dihydrogen phosphate, 1.5g magnesium sulfate and trace amounts of VB1 per liter, with a pH of 5.0; S3: diluting the medicinal plant processing wastewater by 4 times, then compounding the dilution with the PDA liquid enrichment medium at a volume fraction of 50%, and adjusting the pH to 5.0 with sodium hydroxide to obtain an acclimation solution; S4: Inoculate 100 mL of seed solution in each liter of acclimation solution, and culture in a shaking table at 29°C and 140 r / min; measure 3 parallel CODcr, OD650 and pH values ​​every day, and take the average value as the actual value of CODcr, OD650 and pH every day until the three values ​​are basically constant, and obtain the microbial culture solution; S5: According to the ratio of ferric chloride: ferrous sulfate: ultrapure water = 3:4:50, ferric chloride and ferrous sulfate are dissolved in ultrapure water to obtain a mixed solution, and then 10% ammonia water by mass of ultrapure water is quickly added to the mixed solution, heated to 90°C and stirred continuously for 30 minutes, cooled to room temperature, filtered, washed, dried, and then black precipitates are collected to obtain magnetic particles; S6: ultrasonically dispersing the magnetic particles in ultrapure water at a solid-liquid ratio of 1:1000, then adding microbial culture liquid and sodium persulfate, stirring for 5 hours to mix evenly, to obtain a mixed agent; the mass ratio of the magnetic particles, microbial culture liquid and sodium persulfate is 1:1:0.1; S7: Mix the cellulose-modified montmorillonite and the mixed agent in a mass ratio of 1.25:1 to obtain a bioflocculant.

[0027] The preparation method of the cellulose-modified montmorillonite comprises the following steps: A1: Bamboo fiber and deionized water were mixed at a ratio of 1 g:100 mL to obtain a mixed solution. Based on the volume of 100 mL of the mixed solution, 0.35 g of 2,2,6,6-tetramethylpiperidine and 38 mL of sodium hypochlorite were added at the same time. During the mixing reaction, the pH was adjusted to 10 with hydrochloric acid or sodium hydroxide. The suspension was reacted for 11 h to obtain a suspension. The suspension was then treated with ultrasound at 0.8 MHz and 350 W for 1 h, and finally freeze-dried to obtain nanofibers. A2: Montmorillonite was dissolved in water to obtain an 8 wt% montmorillonite suspension, and then centrifuged at 1000 r / min for 3 min to remove large particles in the montmorillonite suspension, and finally treated with 0.7 MHz, 320 W ultrasound for 18 min, and then dried at 60°C to constant weight to obtain nano-montmorillonite; A3: Nanofibers and nano-montmorillonite were dispersed in deionized water in a mass ratio of 1:1, and ultrasonically treated at 2 MHz and 350 W for 40 min. Polyethyleneimine was then added to produce a hydrogel. The hydrogel was then pre-frozen at -20 °C for 3 h and finally freeze-dried at -50 °C for 72 h to obtain cellulose-modified montmorillonite.

[0028] The application of the bioflocculant in wastewater from medicinal plant processing comprises the following steps: B1: Inoculate the bioflocculant in the medicinal plant processing wastewater at an amount of 100 mL / L of the medicinal plant processing wastewater, and at the same time, add urea and potassium dihydrogen phosphate to the medicinal plant processing wastewater according to the mass ratio of m(COD):m(N):m(P)=200:5:1, adjust the initial pH to 5.0, and obtain a reaction mixture; the medicinal plant processing wastewater is diluted 5 times; B2: The reaction mixture was reacted at 28°C and 210r / min for 5 days to complete the treatment of the medicinal plant processing wastewater; B3: The treated medicinal plant processing wastewater is separated from the white rot fungi, and the white rot fungi located deep in the water and difficult to salvage are adsorbed and removed by magnets.

[0029] The COD removal rate of the medicinal plant processing wastewater treated in this example was 87.00%, the chroma was reduced by 20%, and the cell dry weight reached 33.1 g / L.

[0030] Embodiment 4: A method for preparing a bioflocculant, comprising the following steps: S1: Inoculate the white rot fungus onto the PDA medium slant under sterile conditions and culture at 29°C for 3 days until the fungus moss covers the slant; The PDA medium contains 200 g potato juice, 20 g glucose and 15 g agar per liter, with a pH of 6.0; S2: In a sterile environment, take 3 loops of healthy and uncontaminated slant strains and inoculate them into sterilized PDA liquid enrichment medium, and culture them in a shaking incubator at 29°C and 130 rpm. Measure OD of 3 parallel strains every day. 650 and pH value, and take their average value as the daily OD 650 and pH true value, up to OD 650 When the value is basically constant, the seed solution is obtained; The PDA liquid enrichment medium contains 200g potato juice, 20g glucose, 3g potassium dihydrogen phosphate, 1.5g magnesium sulfate and trace VB1 per liter, and the pH is 5.2; S3: diluting the medicinal plant processing wastewater by 5 times, then compounding the dilution with the PDA liquid enrichment medium at a volume fraction of 60%, and adjusting the pH to 5.2 with sodium hydroxide to obtain an acclimation solution; S4: Inoculate 100 mL of seed solution in each liter of acclimation solution, and culture in a shaking table at 29°C and 130 r / min; measure 3 parallel CODcr, OD650 and pH values ​​every day, and take the average value as the actual value of CODcr, OD650 and pH every day until the three values ​​are basically constant, and obtain the microbial culture solution; S5: According to the ratio of ferric chloride: ferrous sulfate: ultrapure water = 4:3:50, ferric chloride and ferrous sulfate are dissolved in ultrapure water to obtain a mixed solution, and then 10% ammonia water by mass of ultrapure water is quickly added to the mixed solution, heated to 90°C and stirred continuously for 30 minutes, cooled to room temperature, filtered, washed, dried, and then black precipitates are collected to obtain magnetic particles; S6: ultrasonically dispersing the magnetic particles in ultrapure water at a solid-liquid ratio of 1:1000, then adding microbial culture liquid and sodium persulfate, stirring for 5 hours to mix evenly, to obtain a mixed agent; the mass ratio of the magnetic particles, microbial culture liquid and sodium persulfate is 1:1:0.1; S7: Mix the cellulose-modified montmorillonite and the mixed agent in a mass ratio of 1.5:1 to obtain a bioflocculant.

[0031] The preparation method of the cellulose-modified montmorillonite comprises the following steps: A1: Bamboo fiber and deionized water were mixed at a ratio of 1 g:100 mL to obtain a mixed solution. Based on the volume of 100 mL of the mixed solution, 0.4 g of 2,2,6,6-tetramethylpiperidine and 38 mL of sodium hypochlorite were added at the same time. During the mixing reaction, the pH was adjusted to 9-11 with hydrochloric acid or sodium hydroxide. The mixture was reacted for 10-12 h to obtain a suspension. The suspension was then treated with ultrasound at 0.6 MHz and 380 W for 1 h, and finally freeze-dried to obtain nanofibers. A2: Montmorillonite was dissolved in water to obtain a 6 wt% montmorillonite suspension, and then centrifuged at 1000 r / min for 4 min to remove large particles in the montmorillonite suspension, and finally treated with 0.8 MHz, 350 W ultrasound for 18 min, and then dried at 60°C to constant weight to obtain nano-montmorillonite; A3: Nanofibers and nano-montmorillonite were dispersed in deionized water in a mass ratio of 1:1, and ultrasonically treated at 3 MHz and 300 W for 30 min. Polyethyleneimine was then added to produce a hydrogel. The hydrogel was then pre-frozen at -20 °C for 3 h and finally freeze-dried at -50 °C for 72 h to obtain cellulose-modified montmorillonite.

[0032] The application of the bioflocculant in wastewater from medicinal plant processing comprises the following steps: B1: Inoculate the bioflocculant in the medicinal plant processing wastewater at a rate of 120 mL / L of the medicinal plant processing wastewater, and at the same time, add urea and potassium dihydrogen phosphate to the medicinal plant processing wastewater at a mass ratio of m(COD):m(N):m(P)=200:5:3, adjust the initial pH to 5.2, and obtain a reaction mixture; the medicinal plant processing wastewater is diluted 4 times; B2: The reaction mixture was reacted at 28°C and 210r / min for 5 days to complete the treatment of the medicinal plant processing wastewater; B3: The treated medicinal plant processing wastewater is separated from the white rot fungi, and the white rot fungi located deep in the water and difficult to salvage are adsorbed and removed by magnets.

[0033] The COD removal rate of the medicinal plant processing wastewater treated in this example was 82.64%, the chroma was reduced by 20%, and the cell dry weight reached 30.6 g / L.

[0034] The above embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims

1. A method for preparing a bioflocculant, characterized in that: The following steps are involved: S1: Inoculate the white rot fungus onto the PDA medium slant under sterile conditions and culture at 28-30℃ for 2-3 days until the fungus moss covers the slant; The PDA medium contains 200 g potato juice, 20 g glucose and 15 g agar per liter, with a pH of 6.0; S2: In a sterile environment, take 2-3 loops of robust and uncontaminated slant cultures and inoculate them into sterilized PDA liquid enrichment medium. Cultivate them in a shaking incubator at 28-30°C and 120-150 rpm. Measure OD of 3 replicates every day. 650 and pH value, and take their average value as the daily OD 650 and pH true value, up to OD 650 When the value is basically constant, the seed solution is obtained; The PDA liquid enrichment medium contains 200g potato juice, 20g glucose, 3g potassium dihydrogen phosphate, 1.5g magnesium sulfate and trace VB1 per liter, and the pH is 5.0-6.0; S3: diluting the medicinal plant processing wastewater by 2-6 times, then compounding the dilution with the PDA liquid enrichment medium at a volume fraction of 30%-100%, and adjusting the pH to 4.0-6.0 with sodium hydroxide to obtain an acclimation solution; S4: Inoculate 80-120 mL of seed solution per liter of acclimatization solution, and culture in a shaking incubator at 28-30°C and 120-150 r / min; measure 3 parallel CODcr and OD every day. 650 and pH value, and take their average values ​​as the daily CODcr, OD 650 and the true value of pH until the three values ​​are basically constant, and the microbial culture liquid is obtained; S5: According to the ratio of ferric chloride: ferrous sulfate: ultrapure water = (3-5): (2-4): 50, ferric chloride and ferrous sulfate are dissolved in ultrapure water to obtain a mixed solution, and then 10% ammonia water by mass of ultrapure water is quickly added to the mixed solution, heated to 90°C and stirred continuously for 30 minutes, cooled to room temperature, filtered, washed, dried, and then black precipitates are collected to obtain magnetic particles; S6: ultrasonically dispersing the magnetic particles in ultrapure water at a solid-liquid ratio of 1:1000, then adding microbial culture liquid and sodium persulfate, stirring for 5 hours to mix evenly, to obtain a mixed agent; S7: Mix the cellulose-modified montmorillonite and the mixed reagent in a mass ratio of (1-2):1 to obtain a bioflocculant.

2. The method for preparing a bioflocculant according to claim 1, characterized in that: The mass ratio of the magnetic particles, the microbial culture liquid and the sodium persulfate used in step S6 is 1:1:0.

1.

3. The method for preparing the bioflocculant according to claim 1, characterized in that: The preparation method of the cellulose-modified montmorillonite comprises the following steps: A1: Bamboo fiber and deionized water were mixed at a ratio of 1 g:100 mL to obtain a mixed solution. Based on the volume of 100 mL of the mixed solution, 0.3-0.5 g of 2,2,6,6-tetramethylpiperidine and 37-40 mL of sodium hypochlorite were added at the same time. During the mixing reaction, the pH was adjusted to 9-11 with hydrochloric acid or sodium hydroxide. The mixture was reacted for 10-12 h to obtain a suspension. The suspension was then treated with ultrasound at 0.5-1 MHz and 300-400 W for 1 h. Finally, the suspension was freeze-dried to obtain nanofibers. A2: Dissolve montmorillonite in water to obtain a 5-10wt% montmorillonite suspension, then centrifuge at 1000r / min for 2-5min to remove large particles in the montmorillonite suspension, and finally treat with 0.5-1MHz, 300-400W ultrasound for 15-20min, and then dry at 60°C to constant weight to obtain nano-montmorillonite; A3: Nanofibers and nano-montmorillonite were dispersed in deionized water in a mass ratio of 1:1, and ultrasonically treated at 2-3 MHz and 300-400 W for 30-45 min. Polyethyleneimine was then added to produce a hydrogel. The hydrogel was then pre-frozen at -20°C for 2-3 h, and finally freeze-dried at -50°C for 72 h to obtain cellulose-modified montmorillonite.

4. The use of the bioflocculant obtained by the preparation method according to any one of claims 1 to 3 in wastewater from medicinal plant processing, characterized in that: The following steps are involved: B1: Inoculate the bioflocculant in the medicinal plant processing wastewater at a rate of 50-150 mL / L of the medicinal plant processing wastewater, and at the same time, add urea and potassium dihydrogen phosphate to the medicinal plant processing wastewater at a mass ratio of m(COD)∶m(N)∶m(P)=200∶5∶(0.5-5), adjust the initial pH to 4.0-6.0, and obtain a reaction mixture; B2: The reaction mixture is reacted at 28°C and 200-220r / min for 4-6 days to complete the treatment of the medicinal plant processing wastewater; B3: The treated medicinal plant processing wastewater is separated from the white rot fungi, and the white rot fungi located deep in the water and difficult to salvage are adsorbed and removed by magnets.

5. The use according to claim 4, characterized in that: The medicinal plant processing wastewater in step B1 is diluted 4-6 times before inoculation with the bioflocculant.