Technical method for decoupling treatment and ammonia recovery of cephalosporin antibiotics

Abstract

The invention discloses a technical method for decoupling treatment and ammonia recovery of cephalosporin antibiotics, which belongs to the field of wastewater treatment, is used for wastewater treatment, and comprises the following steps: storing raw water in a water inlet tank, adjusting the alkali of the raw water in the water inlet tank by using an alkali solution in an alkali tank so as to adjust the pH value of the raw water in the water inlet tank to 10-11, nitrogen of cephalosporin antibiotics contained in the raw water can be degraded under an alkaline condition, and is fed into the reaction tank through the membrane filter in a free state; a peristaltic pump in the reaction tank pumps the acid liquor in the acid tank into the gas separation membrane curtain to form an acid liquor circulation loop; nitrogen existing in the raw water in a free state can penetrate through holes of the composite polyolefin membrane to enter the gas separation membrane curtain to react with the acid liquor. According to the method, antibiotic molecules are decoupled, organic nitrogen is converted into inorganic nitrogen, meanwhile, efficient removal of ammonia nitrogen pollutants in the antibiotic wastewater is achieved, directional recovery of ammonia nitrogen resources is completed, energy consumption can be reduced, secondary pollution is avoided, and resource utilization of products is achieved.

Description

Technical Field

[0001] This application belongs to the field of wastewater treatment. Specifically, it particularly relates to a technical method for the decoupling treatment of cephalosporin antibiotics and ammonia recovery. Background Art

[0002] In the wastewater from the pharmaceutical industry during the production of antibiotics, for example, the residual cephalosporin content in cephalosporin wastewater is about 30 mg / L, the COD content is about 30000 mg / L, and the ammonia nitrogen content is about 400 mg / L - 800 mg / L. How to effectively treat the above wastewater in an environmentally friendly manner usually faces dual challenges: on the one hand, the existing treatment processes have obvious shortcomings in the removal efficiency of total nitrogen and ammonia nitrogen, and it is difficult to achieve rapid degradation of pollutants; on the other hand, the insufficiency of this treatment efficiency directly leads to an exponential increase in the treatment difficulty of subsequent COD and cephalosporin antibiotics.

[0003] Currently, the main methods for nitrogen recovery from wastewater containing antibiotics are adsorption technology, precipitation technology, traditional stripping technology, and electrochemistry. Among them, the adsorption method is an important mechanism for removing ammonia nitrogen, which can be divided into physical adsorption and chemical adsorption. Physical adsorption mainly involves electrostatic attraction and van der Waals forces, and chemical adsorption mainly involves ion exchange, the combination of specific genes, the breaking of chemical bonds, and the formation of new chemical bonds. Although the adsorption technology has the advantages of high removal efficiency and simple operation, it is generally only applicable to the treatment of sewage with low ammonia nitrogen concentration and simple water quality components.

[0004] Precipitation technology mainly involves the process of forming insoluble salts by ammonia nitrogen, phosphate, and metal ions under certain conditions. The precipitation method has the advantages of rapid reaction, high removal efficiency, and the ability to recover ammonia nitrogen simultaneously. The common precipitation technology is the struvite precipitation method, and its mechanism is to use magnesium ions, phosphate, and ammonia nitrogen to generate magnesium ammonium phosphate. The pH is generally controlled at 8.5 - 9.5, and theoretically, the ratio of ammonia nitrogen, magnesium ions, and phosphate is controlled at 1:1:1. However, in actual applications, if the above control ratio of ammonia nitrogen, magnesium ions, and phosphate is to be achieved, the technical difficulty is relatively high, and the cost also increases accordingly.

[0005] Traditional stripping technology is generally applied to high ammonia nitrogen wastewater, and its ammonia nitrogen removal efficiency is very high. By using the gas separation law, that is, there is a difference between the actual concentration and the equilibrium concentration of volatile substances such as ammonia nitrogen contained in the wastewater, the ammonia in the wastewater is continuously discharged under the action of air blowing, so as to remove ammonia nitrogen. However, the energy consumption of the process operation is relatively high, and the amount of chemical reagent added is relatively large.

[0006] The electrochemical method is a new type of ammonia recovery method that uses capacitive deionization technology to selectively separate ammonia nitrogen. The ammonia nitrogen enters the cathode chamber through a cation exchange membrane, and the alkaline condition in the cathode chamber causes the ammonia nitrogen to become free ammonia, which is then recovered in the form of ammonium sulfate through a hydrophobic membrane. The electrochemical method mostly uses simulated wastewater, and the treatment efficiency and quality of actual wastewater need to be explored.

[0007] At present, the treatment of high ammonia nitrogen wastewater mainly relies on biochemical methods. However, due to problems such as large sludge production, high carbon source addition, and high operation difficulty, although it can barely meet the current discharge standards, it also increases the pollution treatment cost and wastes water resources. Summary of the Invention

[0008] The purpose of this application is to provide a method for decoupling treatment of cephalosporin antibiotics and ammonia recovery technology, which not only decouples antibiotic molecules, converts organic nitrogen into inorganic nitrogen, but also realizes the efficient removal of ammonia nitrogen pollutants in antibiotic wastewater, completes the directional recovery of ammonia nitrogen resources, can reduce energy consumption, has no secondary pollution, and realizes the resource utilization of products.

[0009] To achieve the above purpose, this application is realized through the following technical solutions: The method for decoupling treatment of cephalosporin antibiotics and ammonia recovery technology described in this application includes the following steps: storing the raw water in the inlet water tank, using the alkaline solution in the alkali tank to adjust the alkalinity of the raw water in the inlet water tank to adjust the pH of the raw water in the inlet water tank to 10 - 11. The nitrogen in the cephalosporin antibiotics contained in the raw water will degrade under alkaline conditions and be sent to the reaction tank in the form of free state through a membrane filter; the peristaltic pump in the reaction tank pumps the acid solution in the acid tank into the gas separation membrane curtain and forms an acid solution circulation loop; the nitrogen in the raw water in the form of free state will pass through the pores of the composite polyolefin membrane and enter the gas separation membrane curtain to react with the acid solution. Among them, the precision of the membrane filter is 0.45μm, the membrane curtain material of the gas separation membrane curtain is a composite polyolefin membrane, the inner diameter of the membrane pores of the composite polyolefin membrane is 0.02μm to 0.2μm, and the porosity > 50%; the gas separation membrane curtain adopts a weaving process, and the woven membrane network is assembled in layers in the form of components.

[0010] As one of the preferred technical solutions, in this application, the alkaline solution in the alkali tank is potassium hydroxide, and mechanical stirring is used during the alkalinity adjustment process.

[0011] As one of the preferred technical solutions, in this application, the mass concentration of the potassium hydroxide solution is 35% - 45%.

[0012] As one of the preferred technical solutions, in this application, the ammonia nitrogen concentration of the raw water is 100mg / L - 500mg / L.

[0013] As one of the preferred technical solutions, in the present application, the ammonia nitrogen concentration of the raw water is 300 mg / L to 500 mg / L.

[0014] As one of the preferred technical solutions, in the present application, the acid solution is dilute sulfuric acid, and the pH of the dilute sulfuric acid is between 0.5 and 1.

[0015] As one of the preferred technical solutions, in the present application, the pH of the dilute sulfuric acid is 1.

[0016] As one of the preferred technical solutions, in the present application, the pH in the acid tank is monitored by a pH monitor, and the saturated acid solution in the acid tank realizes ammonium salt recovery through low-temperature evaporation.

[0017] Compared with the prior art, the beneficial effects of the present application are as follows: 1. The present application can stably maintain the ammonia nitrogen removal rate in cephalosporin antibiotic wastewater above 90% and realize the recovery of ammonia nitrogen in cephalosporin antibiotic wastewater.

[0018] 2. The present application improves the membrane contact process by changing the flat membrane curtain to a membrane curtain with woven filament arrangement. Utilizing the regular arrangement of the filaments, it is compacted layer by layer, which not only ensures sufficient contact between the water flow and the filaments but also increases the service life of the gas separation membrane curtain, enabling long-term operation, significantly improving the stability of the filaments and the contact area with cephalosporin antibiotic wastewater, and reducing production costs and investment costs.

[0019] 3. The present application has the advantages of small floor area, simple and convenient replacement of the membrane curtain, low maintenance cost, and the absorbed ammonia nitrogen can be recycled as ammonium salt. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the process flow diagram of the method for removing and recovering ammonia nitrogen in cephalosporin antibiotic wastewater in the present application.

[0021] Figure 2 is the relationship diagram between the ammonia nitrogen concentration and the removal rate during the treatment of cephalosporin antibiotic wastewater in Example 1 of the present application.

[0022] Figure 3 is the schematic diagram of the device used in the process of the present application Figure 1 .

[0023] Figure 4 is the schematic diagram of the device used in the process of the present application Figure 2 .

[0024] Figure 5 is the schematic diagram of the device used in the process of the present application Figure 3 .

[0025] In the figure: 1. water inlet tank; 2. water inlet of water inlet tank; 3. water outlet of water inlet tank; 4. membrane filter; 5. acid inlet; 6. acid tank; 7. acid outlet; 8. liquid inlet of peristaltic pump; 9. membrane filter sealing ring. Specific implementation mode

[0026] The technical solution described in this application will be further described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0027] The device used in the process of this application includes a water inlet tank 1, a water inlet of the water inlet tank 2 is arranged on one side of the bottom of the water inlet tank 1, a water outlet of the water inlet tank 3 is arranged on one side of the top of the water inlet tank 1, a membrane filter 4 is arranged in the water inlet tank 1, an acid tank 6 is arranged on one side of the water inlet tank 1, the acid tank 6 includes an acid outlet 7, the acid outlet 7 is connected to the liquid inlet 8 of a peristaltic pump, the peristaltic pump pumps the acid liquid into the membrane filter 4, and the membrane filter 4 has an acid inlet 5 connected to the peristaltic pump. Membrane filter sealing rings 9 are arranged at the connection positions of the pipe fittings and the membrane filter 4.

[0028] Based on the principle of membrane separation technology, this application innovatively uses a gas separation membrane to construct a biphasic reaction system. During operation, cephalosporin pharmaceutical wastewater and acidic absorbent liquid are efficiently separated by the membrane curtain of the gas separation membrane. When the pH is adjusted to an alkaline environment of 10-11, it can promote the hydrolysis of the β-lactam ring of cephalosporin to generate primary amine derivatives, and at the same time, the original ammonia nitrogen (NH3-N) in the wastewater is converted into free ammonia (NH3) with high migration activity. Driven by the transmembrane concentration gradient, gaseous NH3 molecules selectively diffuse through the pores of the gas separation membrane to the acid liquid side and react with proton acids such as acid liquid to form ammonium salts. This process system not only decouples antibiotic molecules, converts organic nitrogen into inorganic nitrogen, but also realizes the efficient removal of ammonia nitrogen pollutants in antibiotic wastewater (removal rate > 95%), completes the directional recovery of nitrogen resources, and the purity of the obtained ammonium salt can reach the agricultural grade standard. Compared with the traditional stripping process, this technology has significant advantages such as no secondary pollution, 40% reduction in energy consumption, and the product can be recycled.

[0029] The flow of the membrane curtain operation in the following Example 1 is shown in Figure 1:Store the raw water in the inlet water tank 1, adjust the alkalinity using potassium hydroxide in the alkali tank to 10 - 11, then pass it through a 0.45 μm membrane filter 4. Use a peristaltic pump to pump the acid solution into the membrane filter 4 composed of a gas separation membrane curtain. The nitrogen in the cephalosporin antibiotics in the wastewater degrades under alkaline conditions, the ammonia nitrogen concentration will increase, and it will pass through the pores of the composite polyolefin membrane in the free state and enter the membrane. The absorbent liquid forms a circulation system inside the separation membrane. Adjust the HRT to 120 minutes, and the propeller in the inlet water tank 1 fully mixes the cephalosporin wastewater to make its degradation more uniform. The wastewater after deamination enters the further removal of COD and cephalosporin pollutants in the later stage. The saturated acid solution in the acid tank forms ammonium salts after low-temperature evaporation to achieve the purpose of recovery.

[0030] In Example 1 below, the gas separation membrane module was purchased from Hangzhou Henglv Membrane Technology Engineering Co., Ltd., and the model was HF4X40T / N.

[0031] In Example 1 below, the membrane in the membrane curtain is a composite polyolefin gas separation membrane, with an outer diameter of 400 μm - 450 μm, a pore diameter of 0.02 μm - 0.2 μm, and a porosity > 50%.

[0032] In Example 1, the ammonia nitrogen concentration was quantitatively analyzed by the Nessler reagent spectrophotometry (HJ 535 - 2009), and the detection instrument was a μV - 1800 type ultraviolet - visible spectrophotometer.

[0033] Example 1

[0034] In this experiment, the wastewater used was taken from an antibiotic pharmaceutical factory in Lanzhou New Area. The ammonia nitrogen concentration in this wastewater was about 500 mg / L, the cephalosporin content was 30 mg / L, the pH value was between 6 - 7, and there were also other types of antibiotics and other organic substances in the wastewater. The water quality was reddish - brown and there were no large particles. Since the ammonia nitrogen content in this wastewater was relatively high and the antibiotic components were complex, it would poison microorganisms, so it was very difficult to remove by biological methods.

[0035] In this example, first adjust the pH value of the wastewater to 11. Then, use a filter membrane with a pore diameter of 0.45 microns to finely filter the cephalosporin wastewater to reduce the turbidity of the wastewater and improve the water quality. Use a composite polyolefin gas separation membrane with a pore diameter of 0.02 microns and 10M dilute sulfuric acid as the adsorbent. Through the action of the gas separation membrane, the ammonia nitrogen degraded from the cephalosporin in the wastewater and the ammonia nitrogen originally present can be effectively removed.

[0036] This example adopts a continuous - flow treatment method. The circulation flow rate of the peristaltic pump (model BT100 - 2J, brand Longer, made in China) is 132 mL / min, and the acid solution is continuously circulated. When it is detected that the pH value of the liquid rises above 3, sulfuric acid is added to the acid tank to maintain the removal efficiency of the system, and the removal rate is calculated according to the added amount.

[0037] As Figure 2 shown: After passing through the membrane module, samples were taken from the water outlet every half hour. At 0 min, the ammonia nitrogen in the wastewater was 550.81 mg / L. At 60 min, the ammonia nitrogen in the wastewater decreased to 259.09 mg / L, and the ammonia nitrogen in the acid solution increased to 340.63 mg / L. At 120 min, the ammonia nitrogen in the wastewater was 150.38 mg / L, and the ammonia nitrogen in the acid solution increased to 450.13 mg / L. The pH of the acid solution was still less than 3, and the pH of the wastewater decreased to 10.18. The treatment results are as Figure 2 .

[0038] The technical solution of the membrane curtain formed by layer-by-layer stacking after the membrane of the present invention greatly improves the service life and stability of the membrane.

[0039] Although the specific embodiments of the present invention have been described in detail above, those skilled in the art should understand that these are only for illustrative purposes. The protection scope of the present invention is actually defined by the appended claims. Without departing from the core principles and essential characteristics of the present invention, those skilled in the art can make various changes and modifications to the embodiments, and such changes and modifications are all within the protection scope of the present invention.

Claims

1. A cephalosporin antibiotic decoupling treatment and ammonia recovery technology method, characterized in that: The following steps are involved: The raw water is stored in the water inlet pool, and the alkaline solution in the alkali tank is used to adjust the raw water in the water inlet pool to adjust the pH of the raw water in the water inlet pool to 10-11. The nitrogen of the cephalosporin antibiotic contained in the raw water will be degraded under alkaline conditions and sent to the reaction pool through the membrane filter in a free state; the peristaltic pump in the reaction pool pumps the acid in the acid pool into the gas separation membrane curtain to form an acid circulation loop; the nitrogen in the raw water in a free state will pass through the composite polyolefin membrane pores into the gas separation membrane curtain to react with the acid; The membrane filter has an accuracy of 0.45 μm, and the gas separation membrane curtain is made of a composite polyolefin membrane. The inner diameter of the membrane pores of the composite polyolefin membrane is 0.02 μm to 0.2 μm, and the porosity is greater than 50%. The gas separation membrane curtain adopts a weaving process, and the woven membrane net is stacked and assembled in the form of components.

2. The cephalosporin antibiotic decoupling treatment and ammonia recovery technical method according to claim 1, characterized in that: The alkaline solution in the alkali tank is potassium hydroxide, and mechanical stirring is used in the alkali adjustment process.

3. The cephalosporin antibiotic decoupling treatment and ammonia recovery technical method according to claim 2, characterized in that: The mass concentration of the potassium hydroxide solution is 35% to 45%.

4. The cephalosporin antibiotic decoupling treatment and ammonia recovery technical method according to claim 1, characterized in that: The ammonia nitrogen concentration of the raw water is 100 mg / L~500 mg / L.

5. The cephalosporin antibiotic decoupling treatment and ammonia recovery technical method according to claim 4, characterized in that: The ammonia nitrogen concentration of the raw water is 300 mg / L~500 mg / L.

6. The cephalosporin antibiotic decoupling treatment and ammonia recovery technical method according to claim 1, characterized in that: The acid solution is dilute sulfuric acid, and the pH of the dilute sulfuric acid is between 0.5 and 1.

7. The cephalosporin antibiotic decoupling treatment and ammonia recovery technical method according to claim 6, characterized in that: The pH of the dilute sulfuric acid is 1.

8. The cephalosporin antibiotic decoupling treatment and ammonia recovery technical method according to claim 1, characterized in that: The pH in the acid pool is monitored by a pH monitor, and the saturated acid solution in the acid pool is recovered by low-temperature evaporation to realize ammonium salt recovery.

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