Treatment method of waste bacterial liquid in glucurolactone preparation process by fermentation method

Abstract

The invention discloses a method for treating waste bacterial liquid in the process of preparing glucurolactone through a fermentation method, and relates to the technical field of glucurolactone production, the waste bacterial liquid concentrated through a ceramic membrane is taken, the waste bacterial liquid is collected, the volume concentration of escherichia coli in the waste bacterial liquid is 20-50%, and the total phosphorus content is 1500-2000 ppm; adding a flocculating agent into the filtrate, stirring, standing, then adding diatomite, and uniformly stirring to obtain a mixture, the flocculating agent comprising citric acid and chitosan; the mixture enters a diaphragm filter press, and a solid filter cake is obtained after filter pressing is finished. The problem of post-treatment of the waste bacterial liquid is solved, the bacterial liquid is high in protein content, easy to decay and stink, incapable of being placed for a long time, not easy to transport and incapable of being subjected to pollution discharge treatment, the bacterial liquid is prepared into a solid state through an effective flocculation method, the environment can be improved, filter cakes can be used for preparing organic fertilizer, and enterprise benefits are increased.

Description

Technical Field

[0001] The invention relates to the technical field of glucuron lactone production, and in particular to a method for treating waste bacterial liquid in the process of preparing glucuron lactone by fermentation. Background Art

[0002] The full name of glucuronolactone in Chinese is glucuronolactone, commonly known as liver taylor, with the molecular formula of C6H8O6, and its chemical composition is: D(+)-furanoglucuronic acid γ-lactone, English name: [D(+)-Glucofuranurono-6,3-lactone]. As a liver detoxifier and immune function regulator, glucuronolactone is a conventional liver protection medicine; glucuronolactone and its subsequent products are also the main additives of functional beverages and foods, weight loss drugs, cosmetics, etc., which have the effects of replenishing physical energy, improving hypoxia, nourishing skin, and delaying aging.

[0003] The main method for the current industrial production of glucuron lactone is the nitric acid oxidation method starting from starch. This method for preparing glucuron lactone has the disadvantages of low yield, many by-products, and difficult separation. In view of the above problems, the fermentation method for preparing glucuron lactone has become a research hotspot. Specific biological enzymes or strains are used to ferment specific substances that can form glucuronic acid or its precursors to prepare glucuronic acid, and glucuronic acid is then lactonized to form glucuron lactone. This method has the advantages of high efficiency, high yield, and low cost in preparing glucuron lactone. However, since the whole cell enzyme of Escherichia coli is required for conversion during the preparation process, the treatment of the bacterial liquid after the conversion becomes a problem. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in view of the deficiencies in the prior art, a method for treating waste bacterial liquid in the process of preparing glucuron-lactone by fermentation is provided, which is environmentally friendly and improves economic benefits.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A method for treating waste bacterial liquid in the process of preparing glucuron-lactone by fermentation, comprising the following steps:

[0007] A: taking the waste bacterial solution after the ceramic membrane concentration, collecting the waste bacterial solution, wherein the volume concentration of Escherichia coli in the waste bacterial solution is 20-50%, and the total phosphorus content is 1500-2000ppm;

[0008] B: adding a flocculant to the filtrate, stirring and then letting it stand, then adding diatomaceous earth, stirring evenly to obtain a mixture, wherein the flocculant includes citric acid and chitosan;

[0009] C: The mixed material enters the membrane filter press and a solid filter cake is obtained after the filtration is completed.

[0010] Preferably, the preparation method of the flocculant in step B is:

[0011] Firstly prepare 1-3%wt citric acid solution, heat it to 50-70°C after it is completely dissolved, then add 0.5-2%wt solid chitosan, stir and dissolve it completely, then cool it to room temperature to obtain a flocculant.

[0012] Preferably, the amount of flocculant added in step B accounts for 10-30% of the volume of the filtrate.

[0013] Preferably, after the flocculant is added in step B, the stirring speed is controlled to 10-20 rpm and the stirring is performed for 5-10 minutes.

[0014] Preferably, the standing time after adding the flocculant in step B is 10-20 minutes.

[0015] Preferably, the amount of diatomaceous earth added in step B accounts for 2-5% of the volume of the filtrate.

[0016] Preferably, calcium oxide is added to the filtrate before adding diatomaceous earth in step B to adjust the pH of the system to 8-9.

[0017] Preferably, in step C, the feed pressure of the membrane filter press is 0.1-0.4 MPa, and pressing begins after the feeding is completed. The pressing pressure is controlled at 0.8-1.0 MPa, and the pressing time is 10-30 min.

[0018] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0019] 1. Solved the post-treatment problem of waste bacterial liquid. The bacterial liquid has a high protein content, is easy to corrupt and stink, cannot be left for a long time, is difficult to transport, and cannot be discharged into sewage. It is prepared into a solid state through an effective flocculation method, which can not only improve the environment, but the filter cake can also be used to prepare organic fertilizer to increase corporate benefits.

[0020] 2. A small amount of flocculant can achieve the purpose of flocculation, with low processing cost, which is suitable for industrial treatment of waste bacterial liquid.

[0021] 3. Adding calcium oxide during the treatment process can effectively remove the phosphorus content in the waste liquid, reducing the total phosphorus content to below 5ppm, reducing the cost of sewage treatment. Moreover, calcium oxide can react with phosphorus to form calcium phosphate precipitate, which can play a filtering aid role in the filtration process and speed up the filtration speed of the filtrate. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the embodiments.

[0023] Example 1

[0024] A method for treating waste bacterial liquid in the process of preparing glucuron-lactone by fermentation, comprising the following steps:

[0025] A: Take 100L of glucuronic acid conversion liquid, concentrate it through ceramic membrane, collect 12L of waste bacterial liquid, and collect 88L of filtrate. The filtrate is the glucuronic acid product, in which the volume concentration of Escherichia coli in the waste bacterial liquid is 30% and the total phosphorus content is 1800ppm;

[0026] B: First prepare 2%wt citric acid solution, heat it to 60°C after it is completely dissolved, then add 1.5%wt solid chitosan, and after it is completely dissolved, cool it to room temperature to obtain a flocculant. Then add 20% of the volume of the waste bacterial solution to the flocculant, stir at 15rpm for 8min, let it stand for 15min after stirring, add calcium oxide to the waste bacterial solution, adjust the pH of the system to 8, then add 3% of the volume of the waste bacterial solution to diatomaceous earth, stir evenly to obtain a mixture;

[0027] C: The mixed material enters the membrane filter press, and after the filtration, 1010g of solid filter cake is obtained, which is used to prepare organic fertilizer. 15L of clarified filtrate is collected, and the total phosphorus content is 3ppm. The feed pressure of the membrane filter press is 0.2MPa, and the pressing begins after the feeding is completed. The pressing pressure is controlled at 0.9MPa, and the pressing time is 10min.

[0028] Example 2

[0029] A method for treating waste bacterial liquid in the process of preparing glucuron-lactone by fermentation, comprising the following steps:

[0030] A: Take 100L of glucuronic acid conversion liquid, concentrate it through ceramic membrane, collect 18L of waste bacterial liquid, and collect 82L of filtrate. The filtrate is the glucuronic acid product, in which the volume concentration of Escherichia coli in the waste bacterial liquid is 20%, and the total phosphorus content is 1500ppm;

[0031] B: First prepare 1%wt citric acid solution, heat it to 50°C after it is completely dissolved, then add 0.5%wt solid chitosan, and after it is completely dissolved, cool it to room temperature to obtain a flocculant. Then add 10% of the volume of the waste bacterial solution to the flocculant, stir at 10rpm for 5min, let it stand for 10min after stirring, add calcium oxide to the waste bacterial solution, adjust the pH of the system to 9, then add 2% of the volume of the waste bacterial solution to diatomaceous earth, stir evenly to obtain a mixture;

[0032] C: The mixed material enters the membrane filter press, and after the filtration, 940g of solid filter cake is obtained, which is used to prepare organic fertilizer. 20L of filtrate is collected, and the total phosphorus content is 2ppm. The feed pressure of the membrane filter press is 0.1MPa, and the pressing begins after the feeding is completed. The pressing pressure is controlled at 0.8MPa, and the pressing time is 10min.

[0033] Example 3

[0034] A method for treating waste bacterial liquid in the process of preparing glucuron-lactone by fermentation, comprising the following steps:

[0035] A: Take 100L of glucuronic acid conversion liquid, concentrate it through ceramic membrane, collect 8L of waste bacterial liquid, and collect 92L of filtrate. The filtrate is the glucuronic acid product, in which the volume concentration of Escherichia coli in the waste bacterial liquid is 50% and the total phosphorus content is 2000ppm;

[0036] B: First prepare 3%wt citric acid solution, heat it to 70℃ after it is completely dissolved, then add 2%wt solid chitosan, and after it is completely dissolved, cool it to room temperature to get a flocculant. Then add 30% flocculant by volume to the waste bacterial solution, stir at 20rpm for 10min, let it stand for 20min after stirring, add calcium oxide to the waste bacterial solution, adjust the pH of the system to 8, then add 5% diatomaceous earth by volume to the waste bacterial solution, stir evenly to get a mixture;

[0037] C: The mixed material enters the membrane filter press, and after the filtration, 1180g of solid filter cake is obtained, which is used to prepare organic fertilizer. 11L of filtrate is collected, and the total phosphorus content is 4ppm. The feed pressure of the membrane filter press is 0.4MPa, and the pressing begins after the feeding is completed. The pressing pressure is controlled at 1.0MPa, and the pressing time is 30min.

[0038] Example 4

[0039] A method for treating waste bacterial liquid in the process of preparing glucuron-lactone by fermentation, comprising the following steps:

[0040] A: Take 100L of glucuronic acid conversion liquid, concentrate it through ceramic membrane, collect 10L of waste bacterial liquid, and collect 90L of filtrate. The filtrate is the glucuronic acid product, in which the volume concentration of Escherichia coli in the waste bacterial liquid is 40% and the total phosphorus content is 1700ppm;

[0041] B: First prepare 2.5%wt citric acid solution, heat it to 55°C after it is completely dissolved, then add 1.5%wt solid chitosan, and after it is completely dissolved, cool it to room temperature to obtain a flocculant. Then add 25% of the volume of the waste bacterial solution to the flocculant, stir at 15rpm for 10min, let it stand for 10min after stirring, add calcium oxide to the waste bacterial solution, adjust the pH of the system to 8, then add 3.5% of the volume of the waste bacterial solution to diatomaceous earth, stir evenly, and obtain a mixture;

[0042] C: The mixed material enters the membrane filter press, and after the filtration, 960g of solid filter cake is obtained, which is used to prepare organic fertilizer. 12.5L of filtrate is collected, and the total phosphorus content is 3ppm. The feed pressure of the membrane filter press is 0.2MPa, and the pressing begins after the feeding is completed. The pressing pressure is controlled at 0.9MPa, and the pressing time is 25min.

[0043] It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

Claims

1. A method for treating waste bacterial liquid in the process of preparing glucuron-lactone by fermentation, characterized in that The following steps are involved: A: taking the waste bacterial solution after the ceramic membrane concentration, collecting the waste bacterial solution, wherein the volume concentration of Escherichia coli in the waste bacterial solution is 20-50%, and the total phosphorus content is 1500-2000ppm; B: adding a flocculant to the filtrate, stirring and then letting it stand, then adding diatomaceous earth, stirring evenly to obtain a mixture, wherein the flocculant includes citric acid and chitosan; C: The mixed material enters the membrane filter press and a solid filter cake is obtained after the filtration is completed.

2. The method for treating waste bacterial liquid in the process of preparing glucuronolactone by fermentation as claimed in claim 1, characterized in that: The preparation method of the flocculant in step B is: Firstly prepare 1-3%wt citric acid solution, heat it to 50-70°C after it is completely dissolved, then add 0.5-2%wt solid chitosan, stir and dissolve it completely, then cool it to room temperature to obtain a flocculant.

3. The method for treating waste bacterial liquid in the process of preparing glucuronolactone by fermentation as claimed in claim 1, characterized in that: The amount of flocculant added in step B accounts for 10-30% of the volume of the filtrate.

4. The method for treating waste bacterial liquid in the process of preparing glucuronolactone by fermentation as claimed in claim 1, characterized in that: After the flocculant is added in step B, the stirring speed is controlled to 10-20 rpm and the stirring is performed for 5-10 minutes.

5. The method for treating waste bacterial liquid in the process of preparing glucuronolactone by fermentation as claimed in claim 1, characterized in that: The standing time after adding the flocculant in step B is 10-20 minutes.

6. The method for treating waste bacterial liquid in the process of preparing glucuronolactone by fermentation as claimed in claim 1, characterized in that: The amount of diatomaceous earth added in step B is 2-5% of the volume of the filtrate.

7. The method for treating waste bacterial liquid in the process of preparing glucuronolactone by fermentation as claimed in claim 1, characterized in that: In step B, before adding diatomaceous earth, calcium oxide is added to the filtrate to adjust the pH of the system to 8-9.

8. The method for treating waste bacterial liquid in the process of preparing glucuronolactone by fermentation as claimed in claim 1, characterized in that: In step C, the feed pressure of the membrane filter press is 0.1-0.4 MPa. After the feeding is completed, the pressing begins. The pressing pressure is controlled at 0.8-1.0 MPa, and the pressing time is 10-30 min.