CN110937725B

CN110937725B - Method for restoring fermentation wastewater and preparing feed by utilizing mycoprotein

Info

Publication number: CN110937725B
Application number: CN201911332296.6A
Authority: CN
Inventors: 赵凤良; 季新利; 李德衡; 程士清; 尤学波; 张传松
Original assignee: Hulunbeier Northeast Fufeng Biotechnologies Co ltd
Current assignee: Hulunbeier Northeast Fufeng Biotechnologies Co ltd
Priority date: 2019-12-22
Filing date: 2019-12-22
Publication date: 2022-05-24
Anticipated expiration: 2039-12-22
Also published as: CN110937725A

Abstract

The invention belongs to the technical field of biological environmental protection, and discloses a method for restoring fermentation wastewater and preparing feed by utilizing mycoprotein, which comprises the following steps: step 1) collecting fermentation wastewater and mycoprotein generated by amino acid fermentation, step 2) restoring the fermentation wastewater, and step 3) preparing feed by using the mycoprotein. The process has short treatment time and good effect, and the treated wastewater can be applied to irrigation of gardens and farmlands, thereby greatly reducing the environmental protection pressure of enterprises. The invention repairs the fermentation wastewater and prepares the mycoprotein feed, thereby killing two birds with one stone, reducing the environmental protection pressure of enterprises and increasing the industrial added value.

Description

Method for restoring fermentation wastewater and preparing feed by utilizing mycoprotein

Technical Field

The invention belongs to the technical field of biological environmental protection, and particularly relates to a method for restoring fermentation wastewater and preparing feed by utilizing mycoprotein.

Background

At present, three methods of threonine production are mainly fermentation, protein hydrolysis and chemical synthesis, and the microbial fermentation method has become the mainstream method of threonine production. The fermentation process for producing threonine requires the technological operations of fermentation, membrane filtration, concentration and crystallization, centrifugal separation, drying, screening, packaging and the like, so that a large amount of organic wastewater is produced, the organic wastewater contains mycoprotein, which is a single-cell protein and contains abundant protein, and the analysis of the chemical components of the dried mycoprotein shows that the content of the protein in the threonine waste thallus is up to more than 80 percent, which is higher than the raw materials of bean pulp, yeast and the like commonly used by the conventional protein zymolyte. The amino acid variety and the proportion are complete, and the nutrient solution is rich in vitamins, nucleic acid, polysaccharide and other nutrient substances. And in addition, in the threonine fermentation process, the added carbohydrate and threonine are fermented together to generate isomaltose hypgather, maltose and the like. Mother liquor generated by threonine fermentation is filtered by an ultrafiltration membrane and then is desalted by bipolar membrane electrodialysis, and desalted waste water can be used for preparing fertilizers. The wastewater treatment does not reach the standard and is discharged, thereby not only seriously polluting the natural environment, but also restricting the development of the threonine industry. Although manufacturing enterprises, research institutions and related colleges and universities have conducted a great deal of research on governance. However, no mature complete technology is applied to production practice at home and abroad at present. The main problems are that one-time investment is too large, or daily operation cost is too high, most manufacturers cannot bear the cost, and the current situation of standard exceeding emission has to be maintained for a long time.

The prior patent technology of the applicant, namely 'a process for treating threonine high-concentration fermentation wastewater', prepares the fermentation wastewater into organic matters, can promote the growth of crops, and specifically comprises the following steps: heating threonine fermentation wastewater to 100 ℃, treating for 10min under the condition of heat preservation, cooling to room temperature, adding ammonia water to adjust the pH value to 6.5, then sequentially inoculating bacillus subtilis and trichoderma viride to perform fermentation treatment, wherein the inoculation amount is 5%, the fermentation temperature is 32 ℃, the fermentation time is 3 days, ending the fermentation, adding monopotassium phosphate, humic acid and urea into the fermentation liquor, stirring and mixing uniformly, filtering, and collecting filtrate to obtain the biological organic matter. The 'environment-friendly process for treating threonine fermentation wastewater by using biological agents' in the prior patent technology of the applicant adopts a microorganism adsorption carrier to treat wastewater, has a good effect and reaches the discharge standard, but has a long treatment period and more utilized microorganisms, so that once a certain microorganism is polluted or improperly stored, the whole process chain is stopped, and the potential risk is high. The applicant has continued research to obtain more ways to treat fermentation wastewater. Most of the adsorbents used for the waste water treatment are inorganic flocculants polyaluminium chloride, polyaluminium sulfate and compound flocculants, and due to the toxicity of the adsorbents, floc sediments are difficult to apply, and secondary pollution is easy to generate.

Montmorillonite is aluminosilicate with a two-dimensional plane layered structure, and is formed by alternate arrangement of tetrahedral sheets (T) and octahedral sheets (o) which respectively consist of silicon-oxygen tetrahedron and aluminum oxygen (hydroxyl) octahedron, and the most main structural units of montmorillonite are 2: 1 layer, i.e. a T-O-T layer consisting of two tetrahedral sheets sandwiching an octahedral sheet. The silicon-oxygen tetrahedral sheet is a silicon-oxygen sheet formed by three vertex oxygens of silicon-oxygen tetrahedrons in the same plane and sharing with adjacent silicon-oxygen tetrahedrons to form a series of approximate hexagonal ring grids. The aluminum oxy (hydroxyl) octahedron is a hexa-coordinated aluminum oxy (hydroxyl) octahedron which is composed of two hydroxyl groups which take aluminum as central atoms and are positioned in the same plane with four vertex oxygens of a tetrahedron opposite to each other, and the octahedron is coordinated with the central atoms of adjacent octahedrons by O. (OH) to form an octahedron sheet. Montmorillonite has excellent characteristics such as electronegativity and ion exchange, and is applied to many fields. Has received considerable attention in the fields of water purification and wastewater treatment, and the research and application efforts are gradually increasing. Because the silica structure on the surface of the montmorillonite has extremely strong hydrophilicity, can adsorb polar water molecules and hydrolyze interlayer cations, so that the surface of the montmorillonite is usually coated with a thin water film, the unmodified bentonite has poorer capability of adsorbing organic matters, but the modified bentonite is obviously improved in the effect of treating wastewater.

Disclosure of Invention

The invention aims to provide a method for restoring fermentation wastewater and preparing feed by utilizing mycoprotein, aiming at the defects of the prior art.

In order to achieve the purpose of the invention, the following technical scheme is adopted.

A method for restoring fermentation wastewater and preparing feed by utilizing mycoprotein comprises the following steps: step 1) collecting fermentation wastewater and mycoprotein generated by amino acid fermentation, step 2) restoring the fermentation wastewater, and step 3) preparing feed by using the mycoprotein.

Further, the method comprises the steps of:

step 1) collecting fermentation wastewater and mycoprotein generated by preparing amino acid through microbial fermentation;

step 2) repairing fermentation wastewater:

the fermentation wastewater enters a sedimentation tank, natural sedimentation solid-liquid separation is carried out to obtain sediment and supernatant, the supernatant is discharged into a treatment tank, the pH value is adjusted to 6.5-7.0, 0.05-0.2% of adsorbent is added for treatment for 12-36h, and the supernatant is discharged for irrigation of gardens and agriculture;

step 3) preparing feed by utilizing mycoprotein:

Drying the mycoprotein precipitate, crushing the mycoprotein precipitate into powder by a crusher, then placing the powder into a reaction kettle, adding 1-2 times of hydrochloric acid by weight, carrying out ultrasonic treatment for 3-5min, then stirring and hydrolyzing at the temperature of 70-80 ℃ for 10-20 h at the stirring speed of 100-300rpm, and finally adding sodium hydroxide to adjust the pH value of the solution to 7, thus obtaining an amino acid solution;

mixing rice chaff, vinasse and sorghum, crushing by using a crusher, and sieving by using a 50-mesh sieve to obtain main materials; adding amino acid solution into the main materials with the same weight, stirring and heating, stopping heating until the water content is 30-40%, granulating with a granulator, drying, and packaging.

Preferably, the adsorbent is prepared according to the following steps: the montmorillonite is acidized by citric acid, then is subjected to complex reaction with nano active carbon, and finally is dried to obtain the nano active carbon.

Preferably, the adsorbent is prepared according to the following steps: the montmorillonite is acidized by citric acid, then is subjected to complex reaction with nano active carbon, is mixed with the composite microbial inoculum, and is finally dried to obtain the montmorillonite.

Preferably, the adsorbent is prepared as follows:

crushing montmorillonite powder, sieving with a 50-100 mesh sieve, collecting undersize, drying and dehydrating at 90-100 ℃ for 30min, taking out the montmorillonite powder, and mixing the montmorillonite powder with the rest raw materials in a proportion of 1 g: adding 10-15% citric acid aqueous solution into 1-3ml of the adsorbent, soaking and acidifying at 50-70 deg.C for 60-90min, adding 30-50% montmorillonite powder nano activated carbon, heating to 70-80 deg.C for 60-90min, centrifuging at 400-500rpm for 3-5min, collecting precipitate, and oven drying at low temperature to obtain the adsorbent.

Preferably, the adsorbent is prepared according to the following steps:

crushing montmorillonite powder, sieving with a 50-100 mesh sieve, collecting undersize, drying and dehydrating at 90-100 ℃ for 30min, taking out the montmorillonite powder, and mixing the montmorillonite powder with the rest raw materials in a proportion of 1 g: adding 10-15% citric acid aqueous solution into 1-3ml of the mixture, soaking and acidifying at 50-70 deg.C for 60-90min, adding 30-50% montmorillonite powder nano activated carbon, heating to 70-80 deg.C for 60-90min, centrifuging at 400-500rpm for 3-5min, collecting precipitate, and oven drying at low temperature to obtain adsorption carrier;

stirring and mixing the composite microbial inoculum and an adsorption carrier according to the mass ratio of 1:1-3, then drying at the drying temperature of 20-25 ℃, and packaging to obtain the adsorbent, wherein the water content of the dried mixture is 15-25%.

Preferably, the preparation method of the complex microbial inoculum comprises the following steps: respectively culturing thiobacillus denitrificans and nitrosomonas to obtain bacterial liquids, and uniformly mixing the two bacterial liquids to obtain the composite bacterial agent.

Preferably, the concentration of the hydrochloric acid is 2-5 mol/L.

Preferably, the frequency of the ultrasound is 20-30 kHz.

Preferably, the rice chaff, the vinasse and the sorghum are mixed according to a mass ratio of 1-2:1-2: 2-3.

Compared with the prior art, the invention mainly has the following advantages that:

montmorillonite has strong cation exchange capacity, during the acidification process of montmorillonite, hydrogen ions firstly displace metal cations in interlaminar regions, the special performance of the hydrogen ions can adsorb organic matters, the montmorillonite is negatively charged and mutually exclusive along with the partial outflow of the metal cations, so that the specific surface area is increased, and a large number of broken bonds are formed due to the removal of partial hydroxyl groups, so that the activity is enhanced; compared with sulfuric acid, the citric acid treatment condition is mild, and can not cause great damage to active groups on montmorillonite, so that the original structure of montmorillonite is changed; the interlayer spacing of the montmorillonite is improved by citric acid modified acidification treatment.

Under the condition of citric acid and a certain temperature, metal cations on the montmorillonite can generate copolymerization and complexation reaction with inorganic anions on the nano activated carbon, such as carboxyl and other groups, so that a deposition effect is formed, and the nano activated carbon is deposited on the surface of the montmorillonite to form a flocculating constituent; the nano activated carbon is attached to the surface of montmorillonite, has good adsorption performance, and can also enrich microorganisms to be used as an attachment carrier of the microorganisms.

The nano activated carbon and the montmorillonite are skillfully complexed together to prepare the modified montmorillonite, and different adsorption mechanisms are adopted, so that the nano activated carbon and the montmorillonite can be mutually cooperated to efficiently remove pollutants, the treatment time is shortened, and the sewage treatment efficiency is improved.

The poultry feed is prepared by hydrolyzing the mycoprotein, the feeding efficiency is improved, and the death rate is reduced; realizes waste utilization and brings certain profit for enterprises.

Drawings

FIG. 1: the influence of montmorillonite with different modification modes on the removal rate of ammonia nitrogen;

FIG. 2: the influence of montmorillonite in different modification modes on the removal rate of SS.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the present application will be clearly and completely described below with reference to specific embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A method for restoring fermentation wastewater and preparing feed by utilizing mycoprotein comprises the following steps:

taking threonine fermentation wastewater as an example, the threonine fermentation wastewater is wastewater generated in the process of preparing threonine by using a microbial fermentation technology, and the generation mode is as follows: separating mycoprotein in the threonine fermentation liquor by using a high-speed disc separator, recovering mycoprotein precipitate for preparing mycoprotein feed, and collecting supernatant; performing membrane filtration, concentration and isoelectric precipitation on the supernatant to extract threonine, wherein the generated wastewater is threonine fermentation wastewater;

repairing fermentation wastewater:

crushing montmorillonite powder, sieving with a 50-mesh sieve, collecting undersize, placing in a drying container at 100 ℃ for drying and dehydrating for 30min, taking out the montmorillonite powder, and mixing the montmorillonite powder with the rest raw materials in a weight ratio of 1 g: adding 10% citric acid aqueous solution into 2ml of the mixture, carrying out soaking modification treatment, controlling the temperature at 60 ℃, keeping the temperature for 60min, then adding 30% by mass of montmorillonite powder of nano activated carbon, raising the reaction temperature to 70 ℃, keeping the temperature for 60min, centrifuging at 500rpm for 3min, collecting precipitate, and drying at low temperature to obtain modified montmorillonite used as an adsorbent;

Feeding threonine fermentation wastewater into a sedimentation tank, naturally settling, performing solid-liquid separation to obtain sediment and supernatant, discharging the supernatant into a treatment tank, adjusting the pH to 6.5, adding 0.1% of adsorbent, treating for 24h, and discharging for garden and agricultural irrigation;

preparing feed by utilizing mycoprotein:

drying the mycoprotein precipitate, crushing the mycoprotein precipitate into powder by a crusher, then placing the powder into a reaction kettle, adding hydrochloric acid with the concentration of 3mol/L, the concentration of which is two times of the weight of the hydrochloric acid, carrying out ultrasonic treatment for 3min at the ultrasonic frequency of 25kHz, then stirring and hydrolyzing for 18 hours at the temperature of 75 ℃, wherein the stirring speed is 200rpm, and finally adding sodium hydroxide to adjust the pH value of the solution to 7, thus obtaining an amino acid solution;

mixing rice chaff, vinasse and sorghum according to the mass ratio of 1:1:2, crushing by using a crusher, and sieving by using a 50-mesh sieve to obtain a main material; adding the amino acid solution into the main materials with the same weight, stirring and heating the mixture, stopping heating when the water content is 35% (w/w), granulating the mixture by using a granulator, drying and packaging the granules to obtain the amino acid water-soluble organic fertilizer.

Example 2

1) repairing fermentation wastewater:

crushing montmorillonite powder, sieving with a 50-mesh sieve, collecting undersize, placing in a drying container at 95 ℃ for drying and dehydrating for 40min, taking out the montmorillonite powder, and mixing the montmorillonite powder with the rest raw materials in a weight ratio of 1 g: adding 12% citric acid aqueous solution into 1ml of the mixture, soaking and modifying at 60 deg.C for 70min under heat preservation, adding 40% montmorillonite powder nano activated carbon, raising reaction temperature to 70 deg.C, treating at 80min under heat preservation, centrifuging at 500rpm for 4min, collecting precipitate, and oven drying at low temperature to obtain modified montmorillonite;

Respectively culturing Thiobacillus denitrificans ATCC 25259 and nitrosomonas ATCC 19718 according to conventional culture method to obtain the culture medium with concentration of 2 × 10⁹cfu/ml bacterial liquid, and uniformly mixing the two bacterial liquids to obtain the composite bacterial agent;

and (2) stirring and mixing the composite microbial inoculum and the modified montmorillonite according to the mass ratio of 1:2, then drying at the drying temperature of 20 ℃, and packaging to obtain the adsorbent, wherein the water content of the dried adsorbent is 15%.

The threonine fermentation wastewater enters a sedimentation tank, natural sedimentation solid-liquid separation is carried out to obtain sediment and supernatant, the supernatant is discharged into a treatment tank, the pH value is adjusted to 6.8, 0.08 percent (mass-to-volume ratio) of adsorption treatment agent is added for treatment for 36 hours, and the treated supernatant is discharged for irrigation of gardens and agriculture;

preparing feed by utilizing mycoprotein:

drying the mycoprotein precipitate, crushing the mycoprotein precipitate into powder by a crusher, then placing the powder into a reaction kettle, adding 1.5 times of hydrochloric acid with the weight concentration of 4mol/L, carrying out ultrasonic treatment for 4min at the ultrasonic frequency of 20kHz, then stirring and hydrolyzing for 16 hours at the temperature of 80 ℃, wherein the stirring speed is 200rpm, and finally adding sodium hydroxide to adjust the pH value of the solution to 7, thus obtaining an amino acid solution;

mixing rice chaff, vinasse and sorghum according to the mass ratio of 2:2:3, crushing by a crusher, and sieving by a 50-mesh sieve to obtain a main material; adding the amino acid solution into the main materials with the same weight, stirring and heating the mixture, stopping heating when the water content is 30% (w/w), granulating the mixture by using a granulator, drying the granules and packaging the granules to obtain the amino acid liquid.

Example 3

The treatment effect of different adsorbents on the wastewater.

The indexes of pollutants in the wastewater subjected to the sedimentation treatment in the sedimentation tank are as follows: COD is 3145mg/L, ammonia nitrogen is 417mg/L, SS is 316mg/L, and organophosphorus is 179 mg/L; the treatment time of the adsorbent is 36h, the effluent index is monitored, and the pollutant removal rate is calculated, which is shown in table 1 specifically;

type of adsorbent:

group 1: modified montmorillonite prepared according to example 2;

group 2: the adsorbent of example 2;

group 3: an unmodified montmorillonite;

group 4: activated carbon.

TABLE 1

	COD removal rate%	The ammonia nitrogen removal rate%	SS removal Rate%	Organic phosphorusRemoval rate%
					Group 1	90.3	91.5	89.7	85.4
Group 2	98.9	99.2	98.1	99.7
					Group 3	71.3	63.7	59.4	64.8
Group 4	62.1	57.8	40.3	39.5

As can be seen from table 1 above, group 2 prepares the adsorbent by mixing the modified montmorillonite and the complex microbial inoculum, and has the best treatment effect on various pollutants in wastewater, wherein the nano activated carbon is a better thallus attachment, and thallus can be enriched, so that the pollutants on the adsorbent are subjected to biological oxidation treatment, and the pollutants are thoroughly removed; the modified montmorillonite has the next lower treatment capacity on pollutants, the montmorillonite is activated by acid, the interlayer spacing is increased under the action of acid, the interlayer spacing is increased by more than 1nm compared with that of the unmodified montmorillonite, and the nano activated carbon is deposited on the surface of the montmorillonite through complexation; the effects of unmodified montmorillonite and a conventional activated carbon adsorbent are not ideal, the spacing between layers of the unmodified montmorillonite is relatively small, and a water film is contained, so that the adsorption of pollutants is not facilitated; the activated carbon is prematurely in a saturated adsorption state and has relatively poor adsorption capacity for pollutants.

Example 4

The influence of different modification modes on the adsorption property of the montmorillonite.

Mode 1: the process is carried out by using 10% sulfuric acid for acidification modification, and the rest is the same as example 1;

mode 2: only 10% sulfuric acid is adopted for acidification treatment, and no nano active carbon is added;

mode 3: only 10% of citric acid is adopted for acidification treatment, and no nano active carbon is added;

mode 4: the adsorbent of example 1.

The fermentation wastewater is treated by adopting four ways of adsorbents, and the process is the same as that of the example 1; detecting the removal rate conditions of ammonia nitrogen and SS at different time points, as shown in fig. 1-2, horizontal data show that the first 12h and the modes 1-4 have obvious removal effects on pollutants, the first 6h and the differences of various modes are not large, which shows that the four adsorbents at the moment have large volume and strong adsorption capacity, are not in a saturated state, the adsorption capacity is gradually reduced along with the increase of the treatment time, and the modes 2 and 3 are basically close to the maximum removal rate when the treatment time is 12 h; while the maximum removal rates of the mode 1 and the mode 4 are relatively lagged, the adsorbent in the mode 1 shows a removal rate with higher efficiency in about 18h, and the mode 4 reaches a peak value in 24 h; longitudinal data observation shows that the treatment capacity of the mode 4 for two main pollutants, namely ammonia nitrogen and SS, is obviously superior to that of the mode 2 and the mode 3, and is also superior to that of the mode 1, probably because when the montmorillonite is treated by strong acid acidification, certain damage can be caused to the composition structure of the montmorillonite, the acidity of the citric acid is relatively weak, the structure composition cannot be greatly influenced, and the citric acid and the sulfuric acid are the same, and metal cations can be replaced by hydrogen ions, so that the adsorption capacity of the montmorillonite is improved; the nano activated carbon is a microporous structure with narrow distribution and single pore diameter, the specific surface area is more than 1000 square meters per gram, metal cations on the montmorillonite can generate copolymerization and complexation with groups such as inorganic anion carboxyl and the like on the nano activated carbon, so that a deposition effect is formed, the nano activated carbon is deposited on the surface of the montmorillonite to form floccules, the nano activated carbon and the montmorillonite adopt different adsorption mechanisms and are ingeniously complexed together, and the nano activated carbon and the montmorillonite can be mutually cooperated to efficiently remove pollutants together.

Example 5

The feed disclosed by the invention is used for poultry feeding experiments.

Selecting poultry animals: selecting 80 chicks from the Aijia Yijia broiler variety, and feeding for 1-30 days;

the feed is randomly divided into 2 groups of 40 feed, and the feed environment and the feed mode are completely the same and are comparable.

Common feed (corn 56.7%, soybean meal 30%, fishbone meal 7.5%, calcium bicarbonate 1.3%, stone powder 1.2%, salt 0.3%, oil 3%) is used as a control group;

the bacterial protein feed prepared in the embodiment 1 of the invention is selected as an experimental group.

The average body weight and the number of deaths of the chickens in the experimental group and the control group are shown in table 2:

TABLE 2

Group of	Body weight g	Number of dead
			Experimental group	1458.5±146.6	3
Control group	1270.3±174.1	5

As shown in table 2 above, the body weight of the experimental group was significantly increased compared to the control group, and the number of deaths was 3, which was also lower than that of the control group.

Although the present invention has been described in detail with respect to the general description and the specific embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made based on the present invention. Accordingly, it is intended that all such modifications and variations as fall within the true spirit of this invention be included within the scope thereof.

Claims

1. A method for restoring fermentation wastewater and preparing feed by utilizing mycoprotein comprises the following steps:

step 2) repairing fermentation wastewater:

step 3) preparing feed by utilizing mycoprotein:

mixing rice chaff, vinasse and sorghum, crushing by a crusher, and sieving by a 50-mesh sieve to obtain a main material; adding amino acid solution into the main materials with the same weight, stirring and heating, stopping heating when the water content is 30-40%, granulating by a granulator, drying, and packaging to obtain the product;

the adsorbent is prepared according to the following steps:

Stirring and mixing the composite microbial inoculum and the adsorption carrier according to the mass ratio of 1:1-3, then drying at the temperature of 20-25 ℃, and packaging after drying, wherein the water content is 15-25%;

the preparation method of the composite microbial inoculum comprises the following steps: respectively culturing thiobacillus denitrificans and nitrosomonas to obtain bacterial liquids, and uniformly mixing the two bacterial liquids to obtain the composite bacterial agent.

2. The method of claim 1, wherein the hydrochloric acid has a concentration of 2 to 5 mol/L.

3. The method of claim 1, wherein the ultrasound has a frequency of 20-30 kHz.

4. The method according to claim 1, wherein the rice chaff, the distiller's grains and the sorghum are mixed in a mass ratio of 1-2:1-2: 2-3.