A method for treating winery wastewater

Abstract

The present application discloses a method for treating winery wastewater, wherein the method uses a hydrophobic low eutectic solvent to separate fusel alcohols, phosphates and ammonia nitrogen substances in the winery wastewater; the hydrophobic low eutectic solvent includes a hydrogen bond acceptor and a hydrogen bond donor; the hydrogen bond acceptor is composed of menthol and tetrabutylammonium chloride; and the hydrogen bond donor is lauric acid. The solvent has unique hydrophobicity and selectivity, and realizes the effective separation and recovery of fusel alcohols, phosphates and ammonia nitrogen in the winery wastewater. This technology has solved the problems of high cost, complex operation and low separation efficiency in traditional wastewater treatment methods in a breakthrough way, which not only simplifies the operation process and reduces the treatment cost, but also significantly improves the safety and stability of the treatment process, thereby achieving a win-win situation between environmental protection and economic benefits.

Description

Technical Field

[0001] The present application relates to the technical field of wastewater treatment, and in particular to a method for treating winery wastewater. Background Art

[0002] Winery wastewater is generated in many links of the brewing process, including but not limited to soaking grains, equipment cleaning, filtration and processing of lees. These wastewaters contain a large amount of alcohols, ammonia nitrogen produced by protein decomposition, and impurities such as phosphates, which cause its chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) to exceed the standard, and cannot be directly used for reuse or discharge. Existing wastewater treatment methods mainly include removing large suspended particles in wastewater by sedimentation, flotation and other methods; then using biochemical treatment to degrade organic pollutants in wastewater to reduce COD values; and finally deep treatment, using membrane separation, advanced oxidation and other advanced technologies to further remove difficult-to-degrade organic substances. Although these methods are simple to operate and the technology is mature and reliable, they also have the problems of long treatment processes and high operating costs, and fail to effectively recover fusel alcohols with potential economic value in wastewater. Therefore, exploring and developing efficient wastewater treatment technologies is not only helpful for wineries to protect the environment, but also to reduce production costs to a certain extent.

[0003] Therefore, there is an urgent need for a new method that is not only low-cost, simple to operate, safe, and stable, but also able to efficiently separate fusel alcohols, phosphates, and ammonia nitrogen substances from winery wastewater. Summary of the invention

[0004] In view of this, the present application provides a method for treating winery wastewater. The treatment method provided in the present application is low in cost, simple to operate, safe, stable, and can efficiently separate fusel alcohols, phosphates and ammonia nitrogen substances from winery wastewater.

[0005] In a first aspect, the present application provides a method for treating winery wastewater, the method comprising: extracting and separating fusel alcohols, phosphates and ammonia nitrogen substances in the winery wastewater using a hydrophobic low eutectic solvent; the hydrophobic low eutectic solvent comprises a hydrogen bond acceptor and a hydrogen bond donor;

[0006] The hydrogen bond acceptor consists of menthol and tetrabutylammonium chloride;

[0007] The hydrogen bond donor is lauric acid.

[0008] By adopting the above technical scheme, this application proposes an innovative method for treating winery wastewater using a hydrophobic low eutectic solvent. The solvent is composed of menthol and tetrabutylammonium chloride as hydrogen bond acceptors and lauric acid as a hydrogen bond donor. With its unique physical and chemical properties, it realizes the effective separation and recovery of fusel alcohols, phosphates and ammonia nitrogen in winery wastewater. This technology has solved the problems of high cost, complex operation and low separation efficiency in traditional wastewater treatment methods in a breakthrough way. It not only simplifies the operation process and reduces the treatment cost, but also significantly improves the safety and stability of the treatment process, thereby achieving a win-win situation between environmental protection and economic benefits. In addition, with its economy, excellent separation effect and stable operating characteristics, under specific operating conditions, this technical solution can reduce the chemical oxygen demand (COD) of wastewater after low eutectic solvent extraction treatment to no more than 500 mg / L, control the total nitrogen (TN) content within 50 mg / L, and limit the total phosphorus (TP) content to less than 10 mg / L, which fully complies with the requirements of GB 3544-2008 "Beer Industry Pollutant Emission Standards", ensuring that the treated wastewater can meet the discharge standards, thereby promoting the sustainable use of water resources and the protection of the ecological environment.

[0009] Optionally, the molar mass ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:(1.2-1.5).

[0010] By adopting the above technical scheme, the method proposed in this application can more accurately control the composition ratio of the low eutectic solvent to optimize its separation and recovery performance of fusel alcohols, phosphates and ammonia nitrogen substances in brewery wastewater. This precisely proportioned low eutectic solvent can not only effectively improve the extraction efficiency of the target substance, but also ensure that the quality of the treated wastewater meets the requirements of GB 3544-2008 "Beer Industry Pollutant Emission Standard", that is, the chemical oxygen demand (COD) does not exceed 500 mg / L, the total nitrogen (TN) content does not exceed 50 mg / L, and the total phosphorus (TP) content does not exceed 10 mg / L, thereby ensuring environmental quality while achieving maximum resource utilization and promoting the harmonious development of economy and environment.

[0011] Optionally, the molar mass ratio of menthol to tetrabutylammonium chloride is 1:(1-2.4).

[0012] By adopting the above technical scheme, the method proposed in this application can more finely adjust the proportion of the internal components of the low eutectic solvent to adapt to the specific conditions of different winery wastewaters and optimize its separation and recovery efficiency of fusel alcohols, phosphates and ammonia nitrogen substances in the wastewater.

[0013] Optionally, the molar mass ratio of menthol to tetrabutylammonium chloride is 1:(1.8-2.4).

[0014] Optionally, the preparation method of the hydrophobic low eutectic solvent is as follows: the hydrogen bond acceptor and the hydrogen bond donor are mixed according to a ratio and stirred at a temperature of 60-80° C. for 2-4 hours to form a transparent and uniform liquid, thereby obtaining the hydrophobic low eutectic solvent.

[0015] Optionally, the stirring speed is 150-250 rpm / min.

[0016] Optionally, the treatment method comprises the following steps: mixing a hydrophobic low eutectic solvent with winery wastewater, and then performing extraction and separation.

[0017] By adopting the above technical scheme, the method proposed in this application can effectively utilize a specific ratio of low eutectic solvent to mix with wastewater, and utilize its unique hydrophobicity and selectivity to specifically separate harmful substances such as fusel alcohols, phosphates and ammonia nitrogen in winery wastewater. This process not only simplifies the process flow of wastewater treatment and reduces the treatment cost, but also due to the special properties of the low eutectic solvent, makes the treatment process safer, more stable, and has better treatment effect, which can significantly reduce the chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) content in the wastewater.

[0018] Optionally, the temperature of the extraction separation is 10-30°C.

[0019] Optionally, the mass ratio of the mixture of the hydrophobic low eutectic solvent and the winery wastewater is 1:(1-10).

[0020] Optionally, the extraction process is countercurrent extraction, and the extraction stages are 1-5.

[0021] By adopting the above technical scheme, the method proposed in this application can significantly improve the extraction efficiency of hydrophobic low eutectic solvents for substances such as fusel alcohols, phosphates and ammonia nitrogen in brewery wastewater through multiple contacts and separations during multi-stage countercurrent extraction. Countercurrent extraction can ensure that there is a maximum contact area and the most sufficient mass transfer opportunity between the solvent and the wastewater, so that the target pollutants can be separated more thoroughly. The multi-stage setting can adjust the number of extractions according to actual needs to achieve the best treatment effect, ensuring that the final treated wastewater can meet the emission requirements in GB 3544-2008 "Beer Industry Pollutant Emission Standards", that is, the chemical oxygen demand (COD) does not exceed 500 mg / L, the total nitrogen (TN) does not exceed 50 mg / L, and the total phosphorus (TP) does not exceed 10 mg / L, thereby achieving effective protection of the environment and improvement of economic benefits.

[0022] In summary, the present invention includes at least the following beneficial technical effects:

[0023] 1. This application proposes an innovative method for treating winery wastewater using a hydrophobic low eutectic solvent. The solvent is composed of menthol and tetrabutylammonium chloride as hydrogen bond acceptors and lauric acid as a hydrogen bond donor. With its unique physical and chemical properties, it can effectively separate and recover fusel alcohols, phosphates and ammonia nitrogen in winery wastewater. This technology has solved the problems of high cost, complex operation and low separation efficiency in traditional wastewater treatment methods in a breakthrough way. It not only simplifies the operation process and reduces the treatment cost, but also significantly improves the safety and stability of the treatment process, thereby achieving a win-win situation between environmental protection and economic benefits. In addition, with its economy, excellent separation effect and stable operating characteristics, under specific operating conditions, this technical solution can reduce the chemical oxygen demand (COD) of wastewater after low eutectic solvent extraction treatment to no more than 500 mg / L, control the total nitrogen (TN) content within 50 mg / L, and limit the total phosphorus (TP) content to less than 10 mg / L, which fully complies with the requirements of GB 3544-2008 "Beer Industry Pollutant Emission Standards", ensuring that the treated wastewater can meet the discharge standards, thereby promoting the sustainable use of water resources and the protection of the ecological environment.

[0024] 2. The method proposed in this application can significantly improve the extraction efficiency of hydrophobic low eutectic solvents for substances such as fusel alcohols, phosphates and ammonia nitrogen in brewery wastewater through multiple contacts and separations during multi-stage countercurrent extraction. Countercurrent extraction can ensure that there is a maximum contact area and the most sufficient mass transfer opportunity between the solvent and the wastewater, so that the target pollutants can be separated more thoroughly. The multi-stage setting can adjust the number of extractions according to actual needs to achieve the best treatment effect, ensuring that the final treated wastewater can meet the emission requirements in GB 3544-2008 "Beer Industry Pollutant Emission Standards", that is, the chemical oxygen demand (COD) does not exceed 500 mg / L, the total nitrogen (TN) does not exceed 50 mg / L, and the total phosphorus (TP) does not exceed 10 mg / L, thereby achieving effective protection of the environment and improvement of economic benefits. DETAILED DESCRIPTION

[0025] The present application is further described in detail below with reference to the embodiments.

[0026] The scheme of the present application is described below in conjunction with the following specific examples. Unless otherwise specified, the raw materials used in the following examples are all from common commercial products, and the devices or equipment used are all purchased from conventional market sales channels. Specific embodiments

[0028] Example 1-42

[0029] Example 1

[0030] This embodiment provides a method for treating winery wastewater. The wastewater (wastewater sample) generated by a winery in Guizhou is used as the object, and a hydrophobic low eutectic solvent is prepared as an extractant to extract and remove fusel alcohols and nitrogen and phosphorus impurities in the wastewater.

[0031] The wastewater sample information is as follows: the chemical oxygen demand of the wastewater is 13872 mg / L, the total phosphorus content is 58 mg / L, the total nitrogen content is 279 mg / L, and the pH is 6.0.

[0032] The hydrophobic low eutectic solvent in this embodiment is prepared by the following method: a hydrogen bond acceptor and a hydrogen bond donor are mixed and stirred at 60° C. for 2 h at a stirring speed of 150 rpm / min to form a transparent and uniform liquid, thereby obtaining a hydrophobic low eutectic solvent.

[0033] The hydrogen bond acceptor in this embodiment is composed of menthol and tetrabutylammonium chloride in a molar mass ratio of 1:1.

[0034] The hydrogen bond donor in this example is lauric acid.

[0035] The molar mass ratio of the hydrogen bond acceptor to the hydrogen bond donor in this embodiment is 1:1.2.

[0036] The method for treating winery wastewater in this embodiment includes the following steps: mixing a hydrophobic low eutectic solvent and winery wastewater in a mass ratio of 1:1, and extracting and removing impurities under the conditions of an extraction temperature of 10° C. and an extraction level of 1. After the impurity removal is completed, the COD content, total nitrogen content, and total phosphorus content in the water phase are detected.

[0037] Pollutant Emission Standards for Brewing Industry: Wastewater must meet the emission requirements of GB 3544-2008 Pollutant Emission Standards for Brewing Industry, that is, the chemical oxygen demand (COD) shall not exceed 500 mg / L, the total nitrogen (TN) shall not exceed 50 mg / L, and the total phosphorus (TP) shall not exceed 10 mg / L.

[0038] If the COD, total nitrogen and total phosphorus content in the wastewater meet the "Beer Industry Pollutant Emission Standards" after the wastewater is treated by the treatment method provided in this application, it is recorded as qualified in this embodiment. If any one of them does not meet the standard, it is recorded as unqualified. The experiment corresponding to each embodiment is repeated three times, and the average value is taken as the final experimental test result.

[0039] The differences between Example 2-42 and Example 1 are shown in Table 1.

[0040] Table 1 - Differences between Example 2-42 and Example 1

[0041]

[0042]

[0043]

[0044] Result analysis: The difference between Example 2-3 and Example 1 is that the extraction stages are different. Combined with the experimental detection structure, it can be seen that as the extraction stages increase, the treatment method of the present application has a better effect on removing impurities from wastewater.

[0045] The difference between Example 4-42 and Example 1 is that when treating the wastewater in the brewery, the selection of some parameters is different. Combined with the test data provided in Table 1, it can be seen that after the wastewater in the brewery is treated by the treatment method of Example 1-42, the COD value, total nitrogen and total phosphorus content in the wastewater meet the "Beer Industry Pollutant Emission Standard".

[0046] Comparative Examples 1-5

[0047] Comparative Example 1

[0048] The difference between this comparative example and Example 3 is that the hydrogen bond acceptor in this comparative example is menthol. The other parts are consistent with Example 3.

[0049] Comparative Example 2

[0050] The difference between this comparative example and Example 3 is that the hydrogen bond acceptor in this comparative example is tetrabutylammonium chloride. The other parts are consistent with Example 3.

[0051] Comparative Example 3

[0052] The difference between this comparative example and Example 3 is that the hydrogen bond donor in this comparative example is nonanoic acid. The other parts are consistent with Example 3.

[0053] Comparative Example 4

[0054] The difference between this comparative example and Example 3 is that the hydrogen bond acceptor in this comparative example is composed of menthol and tetrabutylammonium bromide in a molar mass ratio of 1:1. The other parts are consistent with Example 3.

[0055] Comparative Example 5

[0056] The difference between this comparative example and Example 3 is that the hydrogen bond acceptor in this comparative example is composed of menthol and tetrapentyl ammonium chloride in a molar mass ratio of 1:1.

[0057] The chemical oxygen demand in the raw wastewater was 13872 mg / L, the total nitrogen content was 279 mg / L, the total phosphorus content was 58 mg / L, and the pH was 6.0.

[0058] The experimental test structures of Comparative Examples 1-5 are shown in Table 2.

[0059] Table 2 - Experimental test structure table of comparative examples 1-5

[0060]

[0061] Result analysis: According to the experimental test results, the main difference between Comparative Example 1 and Example 3 is that the hydrogen bond acceptors in Comparative Example 1 are all menthol, while Example 3 uses a combination of menthol and tetrabutylammonium chloride; the main difference between Comparative Example 2 and Example 1 is that the hydrogen bond acceptors in Comparative Example 2 are all tetrabutylammonium chloride. The experimental results show that when the hydrogen bond acceptors are all menthol or tetrabutylammonium chloride, the hydrophobic low eutectic solvent has an incomplete impurity removal effect on the wastewater, resulting in the treated wastewater failing to meet the requirements of the "Beer Industry Pollutant Emission Standard". The main difference between Comparative Example 3 and Example 3 is that nonanoic acid is used as one of the hydrogen bond donors in Comparative Example 3, while lauric acid is used in Example 3. Experimental data show that the type of hydrogen bond donor also affects the impurity removal effect of the hydrophobic low eutectic solvent on the wastewater, resulting in the treated wastewater failing to meet the emission standards. The difference between Comparative Example 4 and Example 3 is that the hydrogen bond acceptors in this comparative example are composed of menthol and tetrabutylammonium bromide with a molar mass ratio of 1:1. The difference between Comparative Example 5 and Example 3 is that in this comparative example, the hydrogen bond acceptor is composed of menthol and tetrapentyl ammonium chloride in a molar mass ratio of 1:1. Combined with the experimental test results in Table 2, it can be seen that when preparing a hydrophobic deep eutectic solvent, changing any component thereof will affect the extraction and separation effect of the prepared hydrophobic deep eutectic solvent on wastewater.

[0062] Based on the above experimental results, the method for treating winery wastewater using a hydrophobic low eutectic solvent of a specific composition provided in this application can effectively remove pollutants such as fusel alcohols, phosphates and ammonia nitrogen in the wastewater, so that the treated wastewater meets the discharge standards. Therefore, it is expected to become a key technical solution in the field of wastewater treatment.

[0063] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for treating winery wastewater, characterized in that: The treatment method comprises: using a hydrophobic low eutectic solvent to extract and separate fusel alcohols, phosphates and ammonia nitrogen substances in winery wastewater; the hydrophobic low eutectic solvent comprises a hydrogen bond acceptor and a hydrogen bond donor; The hydrogen bond acceptor consists of menthol and tetrabutylammonium chloride; The hydrogen bond donor is lauric acid.

2. The method for treating winery wastewater according to claim 1, characterized in that: The molar mass ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:(1.2-1.5).

3. The method for treating winery wastewater according to claim 1, characterized in that: The molar mass ratio of the menthol to tetrabutylammonium chloride is 1:(1-2.4).

4. The method for treating winery wastewater according to claim 1, characterized in that: The molar mass ratio of the menthol to tetrabutylammonium chloride is 1:(1.8-2.4).

5. The method for treating winery wastewater according to claim 1, characterized in that: The preparation method of the hydrophobic low eutectic solvent is as follows: the hydrogen bond acceptor and the hydrogen bond donor are mixed according to a ratio and stirred at a temperature of 60-80° C. for 2-4 hours to obtain the hydrophobic low eutectic solvent.

6. The method for treating winery wastewater according to claim 1, characterized in that: The treatment method comprises the following steps: mixing a hydrophobic low eutectic solvent with winery wastewater, and then performing extraction separation.

7. The method for treating winery wastewater according to claim 6, characterized in that: The temperature of the extraction separation is 10-30°C.

8. The method for treating winery wastewater according to claim 6, characterized in that: The volume ratio of the mixture of the hydrophobic low eutectic solvent and the winery wastewater is 1:(1-10).

9. The method for treating winery wastewater according to claim 6, characterized in that: The extraction process is countercurrent extraction, and the extraction stages are 1-5.

10. The method for treating winery wastewater according to claim 1, characterized in that: The winery wastewater meets the following conditions: chemical oxygen demand 10000-15000 mg / L, total phosphorus 40-60 mg / L, total nitrogen 200-300 mg / L, and pH 5-7.

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