Production method and system of modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment

Abstract

The invention relates to the technical field of wastewater treatment, and discloses a production method and system of a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment. The modified glycerol carbon source comprises a product glyceraldehyde obtained by a catalytic oxidation process of crude glycerol; the catalytic oxidation process comprises a photocatalytic reaction using a photocatalyst; the photocatalyst comprises tin dioxide compounded with zinc oxide. The method comprises the following steps: pretreating crude glycerol, and carrying out catalytic oxidation under the action of a photocatalyst to generate glyceraldehyde; and determining the concentration of glyceraldehyde in the product through ultraviolet spectrophotometry, and filtering after the concentration reaches the standard to obtain the modified glycerol carbon source. The production system comprises a photocatalyst production area, a photocatalytic reaction and product detection area and a product separation and collection area. The preparation process of the modified glycerol carbon source is simple and environment-friendly, the sewage treatment effect is obvious, the production system is intelligent and efficient, and the modified glycerol carbon source can also be used for producing biomanufactured carbon sources and has wide market prospects.

Description

Technical Field

[0001] The invention relates to the field of sewage treatment, and in particular to a production method and system of a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment. Background Art

[0002] With the continuous development of my country's national economy, the process of industrialization and urbanization continues to advance, and a large number of rural populations have migrated to cities and towns, which has led to an increase in the comprehensive water consumption in cities and towns, and the discharge of industrial wastewater and domestic sewage has also continued to grow year by year. Due to the relatively backward infrastructure construction in some cities, the imperfect sewage pipe network facilities, low treatment capacity, and unbalanced development in various regions, only a part of the large amount of industrial and domestic sewage can enter the sewage treatment plant, while the other part is directly discharged into rivers, lakes and other water bodies without treatment, causing serious water pollution problems, causing ecosystem degradation, and exacerbating water resource tensions.

[0003] In urban sewage, nitrogen pollution caused by nitrogen-containing compounds is the most serious problem. Adjusting the carbon-nitrogen ratio of influent water through low-cost external carbon sources has become an important method to improve sewage treatment efficiency. In recent years, with the continuous development of the biodiesel industry, the application research of its byproduct crude glycerol has attracted widespread attention. Modifying crude glycerol to obtain modified glycerol carbon source for urban sewage treatment is an important direction of crude glycerol application research.

[0004] The Chinese patent application with publication number CN 116969592 A discloses a composite carbon source and its preparation method and application. The preparation method of the composite carbon source is as follows: 1) adding acid to crude glycerol for acidification to obtain a first acidified oil and a first glycerol liquid; 2) adding an alkaline solution to the first glycerol liquid and adjusting the pH, standing for stratification, removing the precipitate, and obtaining a second glycerol liquid; 3) performing vacuum distillation on the first acidified oil and heating to obtain a third glycerol liquid and a first residue; 4) adding water to the first residue, centrifugation, evaporation and condensation to obtain a fourth glycerol liquid and a second residue; 5) mixing the second glycerol liquid and the fourth glycerol liquid, and adding sugars, alcohols, acids and a denitrification promoter to obtain the composite carbon source. The composite carbon source has higher utilization and selectivity. By combining with other carbon sources, microbial growth and metabolism can be promoted.

[0005] However, the preparation conditions of the composite carbon source are harsh, not environmentally friendly, and the preparation process is not simple enough. Summary of the invention

[0006] In summary, the present invention aims to provide a method and system for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment. By using an environmentally friendly photocatalyst and a relatively simple process, crude glycerol is modified to obtain a modified glycerol carbon source, which is used in the field of sewage treatment to improve the biochemical efficiency and rate of sewage treatment. Moreover, the preparation process of the modified glycerol carbon source is simple and environmentally friendly, the sewage treatment effect is obvious, the production system is intelligent and efficient, and it can also be used to produce a carbon source for biological manufacturing.

[0007] In order to achieve the above objectives, this application adopts the following technical solutions:

[0008] In the first aspect, the present application provides a method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment. The method for producing the modified glycerol carbon source comprises: preparing a photocatalyst, a photocatalytic reaction of a crude glycerol dilution, and detecting, separating and collecting the modified glycerol carbon source product; the photocatalyst comprises tin dioxide composited with zinc oxide; the photocatalytic reaction of the crude glycerol dilution comprises: the crude glycerol dilution undergoes a catalytic oxidation process to obtain glyceraldehyde; the photocatalytic reaction reacts at room temperature in a weak acid environment of pH 4 to 5; the detection of the modified glycerol carbon source product comprises: using ultraviolet spectrophotometry to measure in real time the concentration of glyceraldehyde in the crude glycerol dilution after photocatalysis.

[0009] A method for producing a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment comprises the following steps:

[0010] The crude glycerol is diluted with distilled water, and an organic acid is added to obtain a crude glycerol dilution after filtration, and the pH of the crude glycerol dilution is adjusted to 4-5;

[0011] Then add tin dioxide compounded with zinc oxide to the crude glycerol dilution, and irradiate under ultraviolet light for a set time T1 at room temperature while stirring;

[0012] Then, the concentration M of glyceraldehyde in the crude glycerol dilution after photocatalysis is measured in real time by ultraviolet spectrophotometry. When the concentration M of glyceraldehyde reaches the index range, stirring is stopped, and the crude glycerol dilution is filtered to obtain a filtrate, i.e., a modified glycerol carbon source.

[0013] The method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment also includes preparing tin dioxide for composite zinc oxide, comprising the following steps:

[0014] Add tin dioxide to distilled water, and perform ultrasonic dispersion under stirring for a set time T2, then add a mixture of zinc acetate dihydrate and ethanol to the distilled water and continue ultrasonic dispersion for a set time T3;

[0015] Then the ultrasound is terminated, the product is collected by centrifugation, and the product is dried at a set temperature R1. Finally, the product is calcined at a set temperature R2 for a set time T4, and the product is cooled to room temperature and discharged to obtain tin dioxide of composite zinc oxide.

[0016] In a second aspect, the present application provides a production system of a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment, the production system comprising a photocatalyst production area, a photocatalytic reaction and product detection area, and a product separation and collection area connected in sequence.

[0017] Beneficial technical effects

[0018] The present application is different from the conventional method of preparing glyceraldehyde by catalytic oxidation of crude glycerol. Instead, it adopts the form of photocatalysis, which can selectively increase the proportion of glyceraldehyde generated by catalytic oxidation of crude glycerol under milder conditions in a more environmentally friendly manner.

[0019] The photocatalyst used in this application is tin dioxide of composite zinc oxide. Through the sol-gel method, the zinc oxide generated by the reaction of zinc acetate dihydrate is composited on the tin dioxide micro-nano particles in the same solution system, and then the two are more firmly combined by high-temperature calcination. An S-type heterojunction is formed in the tin dioxide of the composite zinc oxide, and a special charge transfer process occurs. In a weakly acidic catalytic environment, when irradiated with ultraviolet light, the relatively useless electrons on the conduction band of tin dioxide are combined with the relatively useless holes on the valence band of zinc oxide, and the electrons with strong reducing ability on the conduction band of zinc oxide and the holes with strong oxidizing ability on the valence band of tin dioxide are retained, thereby realizing the separation of photogenerated electron-hole pairs with strong redox ability at the heterojunction interface, thereby significantly improving the catalytic efficiency and selectivity, and realizing the selective increase of the proportion of glyceraldehyde generated by catalytic oxidation of crude glycerol under mild conditions.

[0020] The present application also provides a modified glycerol carbon source production system that combines catalyst production, photocatalytic reaction, and product separation and collection, and uses ultraviolet spectrophotometry to measure in real time the concentration of glyceraldehyde produced after catalytic oxidation of crude glycerol, thereby achieving intelligent control of the photocatalytic reaction and obtaining qualified modified glycerol carbon sources more intelligently and accurately.

[0021] The overall production process of the modified glycerol carbon source only requires adding a photocatalyst to a weakly acidic glycerol dilution solution, and then stirring under ultraviolet light irradiation at room temperature. The reaction conditions are mild, and no additional heating or addition of strong acids or alkalis is required. It is low-carbon and environmentally friendly, and the process is simple. At the same time, the modified glycerol carbon source ensures that the concentration of glyceraldehyde is within a certain range through real-time detection, and can be intelligently regulated as needed. Therefore, it can significantly improve the biochemical efficiency and rate in sewage treatment, and can also be used to produce carbon sources for biomanufacturing, and has broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the production process of the modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment.

[0023] Figure 2 It is a schematic diagram of the composition of the production system of the modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment.

[0024] The meaning of the accompanying symbols: 1. Photocatalyst production area; 2. Photocatalytic reaction and product detection area; 3. Product separation and collection area; 4. Catalyst pretreatment room; 5. Calcination laboratory; 6. Heat dissipation port; 7. Treatment room; 8. Ultraviolet spectrophotometer detection device; 9. Sample transfer channel; 10. Liquid delivery pipeline. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application is further described in detail below in conjunction with the embodiments. However, this should not be understood as the scope of the present application being limited to the following examples. Without departing from the above-mentioned method ideas of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] In this application, the terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit the application.

[0027] The terms “first” and “second”, if used, are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0028] In addition, as used in this application and the appended claims, the singular forms "for," "or," "an," "any," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0029] In the first aspect, the present application provides a method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment, the method for producing the modified glycerol carbon source comprising: preparing a photocatalyst, a photocatalytic reaction of a crude glycerol dilution, and detecting, separating and collecting the modified glycerol carbon source product; the photocatalyst comprises tin dioxide composited with zinc oxide; the photocatalytic reaction of the crude glycerol dilution comprises: obtaining glyceraldehyde through a catalytic oxidation process of the crude glycerol dilution; the photocatalytic reaction reacts at room temperature under a weak acid environment of pH 4 to 5; the detection of the modified glycerol carbon source product comprises: using ultraviolet spectrophotometry to measure in real time the concentration of glyceraldehyde in the crude glycerol dilution after photocatalysis.

[0030] A method for producing a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment, comprising:

[0031] The crude glycerol is diluted with distilled water, and an organic acid is added to obtain a crude glycerol dilution after filtration, and the pH of the crude glycerol dilution is adjusted to 4-5;

[0032] Then add tin dioxide compounded with zinc oxide to the crude glycerol dilution, and irradiate under ultraviolet light for a set time T1 at room temperature while stirring;

[0033] Then, the concentration M of glyceraldehyde in the crude glycerol dilution after photocatalysis is measured in real time by ultraviolet spectrophotometry. When the concentration M of glyceraldehyde reaches the index range, stirring is stopped, and the crude glycerol dilution is filtered to obtain a filtrate, i.e., a modified glycerol carbon source.

[0034] Preferably, the organic acid is one or more of formic acid, acetic acid, and oxalic acid; the mass ratio of the crude glycerol, distilled water, organic acid, and tin dioxide of the composite zinc oxide is (50-60): (30-45): (5-10): (5-10).

[0035] Preferably, the method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment further comprises preparing tin dioxide of composite zinc oxide, comprising the following steps:

[0036] Add tin dioxide to distilled water, and perform ultrasonic dispersion under stirring for a set time T2, then add a mixture of zinc acetate dihydrate and ethanol to the distilled water and continue ultrasonic dispersion for a set time T3;

[0037] Then the ultrasound is terminated, the product is collected by centrifugation, and the product is dried at a set temperature R1. Finally, the product is calcined at a set temperature R2 for a set time T4, and the product is cooled to room temperature and discharged to obtain tin dioxide of composite zinc oxide.

[0038] Preferably, the set time T1 is 2 to 4 hours; the set time T2 is 1 to 2 hours; the set time T3 is 1 to 2 hours; and the set time T4 is 4 to 6 hours.

[0039] Preferably, the index range of the glyceraldehyde content M is 4.5-6%.

[0040] Preferably, the set temperature R1 is 100-120°C; the set temperature R2 is 500-600°C.

[0041] Preferably, the particle size of the tin dioxide is in the range of 30 to 300 nm; and the particle size of the zinc acetate dihydrate is in the range of 30 to 50 nm.

[0042] Preferably, in the method for preparing tin dioxide of the composite zinc oxide, the mass ratio of tin dioxide, zinc acetate dihydrate, ethanol and distilled water is (10-20): (10-20): (10-20): (50-60).

[0043] In the second aspect, the present application provides a production system of a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment, the production system comprising a photocatalyst production area 1, a photocatalytic reaction and product detection area 2 and a product separation and collection area 3 connected in sequence.

[0044] Preferably, the photocatalyst production area 1 is provided with a catalyst pretreatment chamber 4 and a calcination laboratory 5 ; the calcination laboratory 5 is provided with a heat dissipation port 6 .

[0045] Preferably, the photocatalytic reaction and product detection zone 2 is provided with a crude glycerol pretreatment chamber 7 and an ultraviolet spectrophotometric detection device 8 .

[0046] Preferably, a sample transfer channel 9 is provided between the photocatalyst production area 1 and the photocatalytic reaction and product detection area 2 ; and a liquid delivery pipeline 10 is provided between the photocatalytic reaction and product detection area 2 and the product separation and collection area 3 .

[0047] The sources of experimental raw materials used in the present invention are as follows:

[0048] Tin dioxide: Bohuasi Nanotechnology (Ningbo) Co., Ltd.

[0049] Zinc acetate dihydrate: Jiangsu Bosite Chemical Technology Co., Ltd.;

[0050] Ethanol: Jiangsu Bosite Chemical Technology Co., Ltd.;

[0051] Distilled water: homemade;

[0052] Organic acid: Jinan Century Tongda Chemical Co., Ltd.

[0053] Crude glycerol: Shanghai Tuyi International Trading Co., Ltd.

[0054] The following will specifically describe a method and system for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment provided by the present application in combination with different examples.

[0055] Embodiment 1:

[0056] like Figure 1 As shown, a method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment comprises the following steps:

[0057] 1. Add tin dioxide to distilled water, disperse it ultrasonically for 1 hour under stirring, then add a mixture of zinc acetate dihydrate and ethanol to the distilled water, and continue to disperse it ultrasonically for 1 hour;

[0058] 2. Then, the ultrasonic treatment is terminated, the product is collected by centrifugation, and the product is dried at 100°C; finally, the product is calcined at 500°C for 4 hours, cooled to room temperature, and discharged to obtain tin dioxide of composite zinc oxide;

[0059] In steps 1 and 2, the mass ratio of tin dioxide, zinc acetate dihydrate, ethanol and distilled water is 10:10:10:70.

[0060] 3. Dilute the crude glycerol with distilled water, add formic acid and filter to obtain a crude glycerol dilution, and adjust the pH of the crude glycerol dilution to 4;

[0061] 4. Then add tin dioxide of composite zinc oxide to the crude glycerol dilution, and irradiate under ultraviolet light for 2 hours while stirring;

[0062] 5. Then, the concentration M of glyceraldehyde in the crude glycerol dilution after photocatalysis is measured in real time by ultraviolet spectrophotometry. When the concentration M of glyceraldehyde reaches 4.5%, stirring is stopped, and the crude glycerol dilution is filtered to obtain a filtrate, i.e., a modified glycerol carbon source;

[0063] In steps 3 to 5, the mass ratio of the crude glycerol, distilled water, formic acid, and tin dioxide of the composite zinc oxide is 55:35:5:5.

[0064] Embodiment 2:

[0065] like Figure 1 As shown, a method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment comprises the following steps:

[0066] 1. Add tin dioxide to distilled water, disperse it ultrasonically for 2 hours under stirring, then add a mixture of zinc acetate dihydrate and ethanol to the distilled water, and continue to disperse it ultrasonically for 2 hours;

[0067] 2. Then, the ultrasonic treatment is terminated, the product is collected by centrifugation, and the product is dried at 120°C; finally, the product is calcined at 600°C for 6 hours, cooled to room temperature, and discharged to obtain tin dioxide of composite zinc oxide;

[0068] In steps 1 and 2, the mass ratio of tin dioxide, zinc acetate dihydrate, ethanol and distilled water is 20:10:10:60.

[0069] 3. Dilute the crude glycerol with distilled water, add acetic acid and filter to obtain a crude glycerol dilution, and adjust the pH of the crude glycerol dilution to 5;

[0070] 4. Then add tin dioxide compounded with zinc oxide to the crude glycerol dilution, and irradiate under ultraviolet light for 4 hours while stirring;

[0071] 5. Then, the concentration M of glyceraldehyde in the crude glycerol dilution after photocatalysis is measured in real time by ultraviolet spectrophotometry. When the concentration M of glyceraldehyde reaches 6%, stirring is stopped, and the crude glycerol dilution is filtered to obtain a filtrate, i.e., a modified glycerol carbon source;

[0072] In steps 3 to 5, the mass ratio of the crude glycerol, distilled water, acetic acid, and tin dioxide of the composite zinc oxide is 50:30:10:10.

[0073] Embodiment 3:

[0074] like Figure 1 As shown, a method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment comprises the following steps:

[0075] 1. Add tin dioxide to distilled water, disperse it ultrasonically for 1.5 hours under stirring, then add a mixture of zinc acetate dihydrate and ethanol to the distilled water, and continue to disperse it ultrasonically for 1.5 hours;

[0076] 2. Then, the ultrasonic treatment is terminated, the product is collected by centrifugation, and the product is dried at 110°C; finally, the product is calcined at 550°C for 5 hours, cooled to room temperature, and discharged to obtain tin dioxide of composite zinc oxide;

[0077] In steps 1 and 2, the mass ratio of tin dioxide, zinc acetate dihydrate, ethanol and distilled water is 15:15:10:60.

[0078] 3. Dilute the crude glycerol with distilled water, add oxalic acid and filter to obtain a crude glycerol dilution, and adjust the pH of the crude glycerol dilution to 4.5;

[0079] 4. Then add tin dioxide of composite zinc oxide to the crude glycerol dilution, and irradiate under ultraviolet light for 3 hours while stirring;

[0080] 5. Then, the concentration M of glyceraldehyde in the crude glycerol dilution after photocatalysis is measured in real time by ultraviolet spectrophotometry. When the concentration M of glyceraldehyde reaches 5%, stirring is stopped, and the crude glycerol dilution is filtered to obtain a filtrate, i.e., a modified glycerol carbon source;

[0081] In steps 3 to 5, the mass ratio of the crude glycerol, distilled water, oxalic acid, and tin dioxide of the composite zinc oxide is 50:40:5:5.

[0082] Embodiment 4:

[0083] like Figure 1 As shown, a method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment comprises the following steps:

[0084] 1. Add tin dioxide to distilled water, disperse it ultrasonically for 1 hour under stirring, then add a mixture of zinc acetate dihydrate and ethanol to the distilled water, and continue to disperse it ultrasonically for 1.5 hours;

[0085] 2. Then, the ultrasonic treatment is terminated, the product is collected by centrifugation, and the product is dried at 100°C; finally, the product is calcined at 500°C for 5 hours, cooled to room temperature, and discharged to obtain tin dioxide of composite zinc oxide;

[0086] In steps 1 and 2, the mass ratio of tin dioxide, zinc acetate dihydrate, ethanol and distilled water is 10:20:20:50.

[0087] 3. Dilute the crude glycerol with distilled water, add oxalic acid and filter to obtain a crude glycerol dilution, and adjust the pH of the crude glycerol dilution to 4;

[0088] 4. Then add tin dioxide compounded with zinc oxide to the crude glycerol dilution, and irradiate under ultraviolet light for 4 hours while stirring;

[0089] 5. Then, the concentration M of glyceraldehyde in the crude glycerol dilution after photocatalysis is measured in real time by ultraviolet spectrophotometry. When the concentration M of glyceraldehyde reaches 5.5%, stirring is stopped, and the crude glycerol dilution is filtered to obtain a filtrate, i.e., a modified glycerol carbon source;

[0090] In steps 3 to 5, the mass ratio of the crude glycerol, distilled water, oxalic acid, and tin dioxide of the composite zinc oxide is 50:35:5:10.

[0091] Embodiment 5:

[0092] like Figure 1 As shown, a method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment comprises the following steps:

[0093] 1. Add tin dioxide to distilled water, disperse it ultrasonically for 2 hours under stirring, then add a mixture of zinc acetate dihydrate and ethanol to the distilled water, and continue to disperse it ultrasonically for 1 hour;

[0094] 2. Then, the ultrasonic treatment is terminated, the product is collected by centrifugation, and the product is dried at 100°C; finally, the product is calcined at 550°C for 5.5 hours, cooled to room temperature, and discharged to obtain tin dioxide of composite zinc oxide;

[0095] In steps 1 and 2, the mass ratio of tin dioxide, zinc acetate dihydrate, ethanol and distilled water is 15:10:15:60.

[0096] 3. Dilute the crude glycerol with distilled water, add formic acid and filter to obtain a crude glycerol dilution, and adjust the pH of the crude glycerol dilution to 4.5;

[0097] 4. Then add tin dioxide of composite zinc oxide to the crude glycerol dilution, and irradiate under ultraviolet light for 3 hours while stirring;

[0098] 5. Then, the concentration M of glyceraldehyde in the crude glycerol dilution after photocatalysis is measured in real time by ultraviolet spectrophotometry. When the concentration M of glyceraldehyde reaches 6%, stirring is stopped, and the crude glycerol dilution is filtered to obtain a filtrate, i.e., a modified glycerol carbon source;

[0099] In steps 3 to 5, the mass ratio of the crude glycerol, distilled water, formic acid, and tin dioxide of the composite zinc oxide is 55:30:5:10.

[0100] Embodiment 6:

[0101] like Figure 1 As shown, a method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment comprises the following steps:

[0102] 1. Add tin dioxide to distilled water, disperse it ultrasonically for 2 hours under stirring, then add a mixture of zinc acetate dihydrate and ethanol to the distilled water, and continue to disperse it ultrasonically for 2 hours;

[0103] 2. Then, the ultrasonic treatment is terminated, the product is collected by centrifugation, and the product is dried at 120°C; finally, the product is calcined at 600°C for 4 hours, cooled to room temperature, and discharged to obtain tin dioxide of composite zinc oxide;

[0104] In steps 1 and 2, the mass ratio of tin dioxide, zinc acetate dihydrate, ethanol and distilled water is 18:12:12:58.

[0105] 3. Dilute the crude glycerol with distilled water, add acetic acid and filter to obtain a crude glycerol dilution, and adjust the pH of the crude glycerol dilution to 5;

[0106] 4. Then add tin dioxide of composite zinc oxide to the crude glycerol dilution, and irradiate under ultraviolet light for 3.5 hours while stirring;

[0107] 5. Then, the concentration M of glyceraldehyde in the crude glycerol dilution after photocatalysis is measured in real time by ultraviolet spectrophotometry. When the concentration M of glyceraldehyde reaches 5.5%, stirring is stopped, and the crude glycerol dilution is filtered to obtain a filtrate, i.e., a modified glycerol carbon source;

[0108] In steps 3 to 5, the mass ratio of the crude glycerol, distilled water, acetic acid, and tin dioxide of the composite zinc oxide is 54:30:8:8.

[0109] Figure 2It is a schematic diagram of the composition of the production system of the modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment. The production system comprises a photocatalyst production area 1, a photocatalytic reaction and product detection area 2 and a product separation and collection area 3 which are connected in sequence; the photocatalyst production area 1 is provided with a catalyst pretreatment room 4 and a calcination laboratory 5; wherein the calcination laboratory 5 is provided with a heat dissipation port 6; the photocatalytic reaction and product detection area 2 is provided with a crude glycerol pretreatment room 7 and an ultraviolet spectrophotometric detection device 8; a sample transfer channel 9 is provided between the photocatalyst production area 1 and the photocatalytic reaction and product detection area 2; and a liquid delivery pipeline 10 is provided between the photocatalytic reaction and product detection area 2 and the product separation and collection area 3.

[0110] In the above-mentioned Examples 1 to 6, the production system of the modified glycerol carbon source is composed of Figure 2 shown.

[0111] Comparative Example 1:

[0112] A method for producing a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment comprises the following steps:

[0113] 1. Add tin dioxide to distilled water, disperse it ultrasonically for 1 hour under stirring, and then continue to disperse it ultrasonically for 1 hour;

[0114] 2. Then, the ultrasonic treatment is terminated, the product is collected by centrifugation, and the product is dried at 100° C.; finally, the product is calcined at 500° C. for 4 hours, cooled to room temperature, and discharged to obtain the first photocatalyst;

[0115] In steps 1 and 2, the mass ratio of tin dioxide to distilled water is 20:80.

[0116] 3. Dilute the crude glycerol with distilled water, add formic acid and filter to obtain a crude glycerol dilution, and adjust the pH of the crude glycerol dilution to 4;

[0117] 4. Then, add the first photocatalyst to the crude glycerol dilution and irradiate under a UV light source for 2 hours while stirring;

[0118] 5. Continue stirring for 2 hours, filter the crude glycerol dilution to obtain a filtrate, i.e., the modified glycerol carbon source;

[0119] In steps 3 to 5, the mass ratio of the crude glycerol, distilled water, formic acid, and the first photocatalyst is 55:35:5:5.

[0120] Comparative Example 2:

[0121] A method for producing a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment comprises the following steps:

[0122] 1. Add the mixture of zinc acetate dihydrate and ethanol into distilled water, disperse it by ultrasonication for 1.5 hours under stirring, and then continue to disperse it by ultrasonication for 1.5 hours;

[0123] 2. Then, the ultrasonic treatment was terminated, the product was collected by centrifugation, and the product was dried at 110°C; finally, the product was calcined at 550°C for 5 hours, cooled to room temperature, and discharged to obtain the second photocatalyst;

[0124] In steps 1 and 2, the mass ratio of zinc acetate dihydrate, ethanol and distilled water is 20:20:60.

[0125] 3. Dilute the crude glycerol with distilled water, add oxalic acid and filter to obtain a crude glycerol dilution, and adjust the pH of the crude glycerol dilution to 4.5;

[0126] 4. Then add the second photocatalyst to the crude glycerol dilution and irradiate under a UV light source for 3 hours while stirring;

[0127] 5. Continue stirring for 1 hour, filter the crude glycerol dilution to obtain a filtrate, i.e., the modified glycerol carbon source;

[0128] In steps 3 to 5, the mass ratio of the crude glycerol, distilled water, oxalic acid and the second photocatalyst is 50:40:5:5.

[0129] Comparative Example 3:

[0130] like Figure 1 As shown, a method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment comprises the following steps:

[0131] 1. Add tin dioxide to distilled water, disperse it ultrasonically for 2 hours under stirring, then add a mixture of zinc acetate dihydrate and ethanol to the distilled water, and continue to disperse it ultrasonically for 2 hours;

[0132] 2. Then, the ultrasonic treatment is terminated, the product is collected by centrifugation, and the product is dried at 120°C; finally, the product is calcined at 600°C for 4 hours, cooled to room temperature, and discharged to obtain tin dioxide of composite zinc oxide;

[0133] In steps 1 and 2, the mass ratio of tin dioxide, zinc acetate dihydrate, ethanol and distilled water is 18:12:10:60.

[0134] 3. Dilute the crude glycerin with distilled water and then filter to obtain a crude glycerin dilution;

[0135] 4. Then add tin dioxide of composite zinc oxide to the crude glycerol dilution, and irradiate under ultraviolet light for 3.5 hours while stirring;

[0136] 5. Continue stirring for 0.5 hours, filter the crude glycerol dilution to obtain a filtrate, i.e., the modified glycerol carbon source;

[0137] In steps 3 to 5, the mass ratio of the crude glycerol, distilled water, and tin dioxide of the composite zinc oxide is 54:38:8.

[0138] In the above comparative examples 1 to 3, the production system composition of the modified glycerol carbon source is also as follows: Figure 2 shown.

[0139] Referring to HJ / T 399-2007, the rapid digestion spectrophotometry was used to test the chemical oxygen demand of urban domestic sewage before and after the addition of modified glycerol carbon source. The chemical oxygen demand after the addition of modified glycerol carbon source to urban domestic sewage was used to evaluate the sewage treatment effect of the modified glycerol carbon source.

[0140] Table 1. Chemical oxygen demand of urban domestic sewage before and after adding different modified glycerol carbon sources

[0141]

[0142]

[0143] As can be seen from Table 1, the chemical oxygen demand of urban sewage is generally 300-400 mg / L; after adding the modified glycerol carbon source of Examples 1-6, the chemical oxygen demand of urban sewage is reduced to 15-30 mg / L; and after adding the modified glycerol carbon source of Comparative Examples 1-3, the chemical oxygen demand of urban sewage is still maintained at 80-140 mg / L, which is significantly higher than the modified glycerol carbon source of Examples 1-6.

[0144] This is because the modified glycerol carbon sources of Examples 1 to 6 are prepared under a weakly acidic catalytic environment, using tin dioxide composited with zinc oxide as a photocatalyst, with a higher catalytic selectivity. Under a weakly acidic catalytic environment, when irradiated with light, the photogenerated electrons on the conduction band of tin dioxide can be transferred to the conduction band of zinc oxide, and the photogenerated holes on the valence band of zinc oxide can be transferred to the valence band of tin dioxide, which can generate a unique electron transmission path, so that the catalytic efficiency and selectivity are significantly improved, and the proportion of glyceraldehyde generated by catalytic oxidation of crude glycerol is selectively increased under mild conditions.

[0145] In the preparation process of the modified glycerol carbon source in Comparative Examples 1 to 3, either no organic acid is added to make the catalytic environment weakly acidic, or tin dioxide composite with zinc oxide is not used as a photocatalyst, so the catalytic efficiency and selectivity are low, and the sewage treatment effect is poor.

[0146] Moreover, none of the comparative examples 1 to 3 measured the concentration of glyceraldehyde in the crude glycerol dilution after photocatalysis in real time by ultraviolet spectrophotometry, and therefore could not achieve intelligent control of the photocatalytic reaction, nor could it obtain a qualified modified glycerol carbon source more intelligently and accurately, which was not conducive to the production of the modified glycerol carbon source.

[0147] The above results show and describe the basic principles and main features of the present invention as well as the advantages of the present invention.

[0148] Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, such as producing raw materials for the biochemical industry based on the present method or the improved method of the present method, etc. These changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the equivalents of the appended claims.

Claims

1. A method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment, characterized in that: The production method of the modified glycerol carbon source comprises: preparing a photocatalyst, a photocatalytic reaction of a crude glycerol dilution, and detecting, separating and collecting the modified glycerol carbon source product; the photocatalyst comprises tin dioxide composited with zinc oxide; the photocatalytic reaction of the crude glycerol dilution comprises: obtaining glyceraldehyde through a catalytic oxidation process of the crude glycerol dilution; the photocatalytic reaction is carried out at room temperature under a weak acid environment with a pH of 4 to 5; the detection of the modified glycerol carbon source product comprises: using ultraviolet spectrophotometry to measure in real time the concentration of glyceraldehyde in the crude glycerol dilution after photocatalysis.

2. The method for producing a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment according to claim 1, characterized in that: The production method comprises the following steps: The crude glycerol is diluted with distilled water, and an organic acid is added to obtain a crude glycerol dilution after filtration, and the pH of the crude glycerol dilution is adjusted to 4-5; Then add tin dioxide compounded with zinc oxide to the crude glycerol dilution, and irradiate under ultraviolet light for a set time T1 at room temperature while stirring; Then, the concentration M of glyceraldehyde in the crude glycerol dilution after photocatalysis is measured in real time by ultraviolet spectrophotometry. When the concentration M of glyceraldehyde reaches the index range, stirring is stopped, and the crude glycerol dilution is filtered to obtain a filtrate, i.e., a modified glycerol carbon source.

3. The method for producing a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment according to claim 2, characterized in that: The organic acid is one or more of formic acid, acetic acid, and oxalic acid; the mass ratio of the crude glycerol, distilled water, organic acid, and tin dioxide of the composite zinc oxide is (50-60): (30-45): (5-10): (5-10).

4. The method for producing a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment according to claim 2, characterized in that: The method for producing the modified glycerol carbon source also includes preparing tin dioxide for composite zinc oxide; the method comprises the following steps: Add tin dioxide to distilled water, and perform ultrasonic dispersion under stirring for a set time T2, then add a mixture of zinc acetate dihydrate and ethanol to the distilled water, and then adjust the solution pH range to 1-3, and continue ultrasonic dispersion for a set time T3; Then the ultrasound is terminated, the product is collected by centrifugation, and the product is dried at a set temperature R1. Finally, the product is calcined at a set temperature R2 for a set time T4, and the product is cooled to room temperature and discharged to obtain tin dioxide of composite zinc oxide.

5. The method for producing a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment according to claim 2, characterized in that: The set time T1 is 2 to 4 hours; the set time T2 is 1 to 2 hours; the set time T3 is 1 to 2 hours; the set time T4 is 4 to 6 hours; the index range of the glyceraldehyde content M is 4.5 to 6%; the set temperature R1 is 100 to 120°C; the set temperature R2 is 500 to 600°C.

6. The method for producing a modified glycerol carbon source for improving biochemical efficiency and rate in sewage treatment according to claim 2, characterized in that: The particle size of the tin dioxide is in the range of 30 to 300 nm. In the preparation method of the tin dioxide of the composite zinc oxide, the mass ratio of tin dioxide, zinc acetate dihydrate, ethanol and distilled water is (10 to 20): (10 to 20): (10 to 20): (50 to 60).

7. A production system using the method for producing a modified glycerol carbon source for improving the biochemical efficiency and rate in sewage treatment according to any one of claims 1 to 6, characterized in that: The production system comprises a photocatalyst production area (1), a photocatalytic reaction and product detection area (2) and a product separation and collection area (3) which are connected in sequence.

8. The production system according to claim 7, characterized in that: The photocatalyst production area (1) is provided with a catalyst pretreatment room (4) and a calcination laboratory (5); the calcination laboratory (5) is provided with a heat dissipation port (6).

9. The production system according to claim 7, characterized in that: The photocatalytic reaction and product detection area (2) is provided with a crude glycerol pretreatment chamber (7) and an ultraviolet spectrophotometric detection device (8).

10. The production system according to claim 7, characterized in that: A sample transfer channel (9) is provided between the photocatalyst production area (1) and the photocatalytic reaction and product detection area (2); and a liquid delivery pipeline (10) is provided between the photocatalytic reaction and product detection area (2) and the product separation and collection area (3).

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