AMPS-ethylenediaminetetraacetic acid antibacterial composite hydrogel membrane for removing heavy metal ions in industrial wastewater as well as preparation method and application of AMPS-ethylenediaminetetraacetic acid antibacterial composite hydrogel membrane

Abstract

The invention discloses an AMPS-ethylenediaminetetraacetic acid antibacterial composite hydrogel film for removing heavy metal ions in industrial wastewater as well as a preparation method and application of the AMPS-ethylenediaminetetraacetic acid antibacterial composite hydrogel film. According to the composite hydrogel film, carbon felt is used as a reinforcing carrier and a skeleton, 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and ethylenediamine tetraacetic acid are subjected to cross-linking polymerization through polyethylene glycol diacrylate to form a three-dimensional network active matrix, and methacryloyloxyethyl trimethyl ammonium chloride is introduced to provide antibacterial performance. The hydrogel membrane prepared by adopting a cross-linking polymerization-solid solution pouring method has the advantages of large heavy metal ion adsorption capacity, excellent antibacterial property, good mechanical property and the like, and can realize simultaneous and efficient removal of various heavy metal ions such as copper, lead, nickel, cadmium and the like in industrial wastewater and stable operation of the membrane process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high molecular adsorption materials, and particularly relates to an AMPS-ethylenediaminetetraacetic acid antibacterial composite hydrogel membrane for removing heavy metal ions in industrial wastewater, a preparation method and application thereof. BACKGROUND

[0002] With the continuous development of society and the accelerating process of industrialization, environmental pollution problems, especially water pollution, are becoming increasingly serious. Various pollutants exist in industrial wastewater, including metal ions, pathogenic microorganisms, organic compounds and inorganic salts, so these wastewater needs to be treated before discharge to meet regulatory requirements, ecological system requirements and sustainable development goals. Membrane treatment is a common means for removing metals from wastewater. It is a process that can achieve efficient separation, in which the membrane retains metal ions on the feed side of the membrane by virtue of its selective permeability. However, due to the limitations of hydrogels that are prone to swelling after absorbing water and have weak mechanical strength, it is difficult to fix them in filtration equipment, which limits their large-scale application.

[0003] In the prior art, hydrogels used for treating metal ions in industrial wastewater have been studied. Patent CN115282936 A discloses a preparation method of a hydrogel membrane material that can efficiently adsorb lead ions, but due to its complex preparation process, slow adsorption rate, limited acid resistance, it is difficult to be applied on a large scale. Patent CN 110885463 A discloses a preparation method of a PVA hydrogel with a three-dimensional network structure. Due to the limited mechanical strength and unsatisfactory water resistance, its application in water treatment field is affected. Patent CN 114130210 A discloses a preparation method of a layer-by-layer self-assembly antibacterial hydrogel filtration membrane. In practical application, it may not be adaptable to complex water quality environment, affecting the stability and reusability of the adsorption effect. Patent CN 114053882 A discloses a preparation method of an acid and ion co-crosslinked salt-tolerant hydrogel filtration membrane, but the filtration membrane has the risk of metal ion residue, which may affect its long-term stability and safety.

[0004] As can be seen from the above, adsorption has obvious advantages in removing metal ions in industrial wastewater, and has important research value and engineering application significance. It is of great significance to provide a hydrogel membrane with excellent effect, low cost and strong practicality for removing metal ions in industrial wastewater. SUMMARY

[0005] The purpose of the present application is to construct a new type of adsorption hydrogel membrane preparation method and application, to improve the adsorption capacity under the working condition of treating metal ions in industrial wastewater, to solve the problems of poor adsorption effect and low mechanical strength of the existing hydrogel membrane, and to endow it with new antibacterial properties.

[0006] A preparation method of an AMPS-ethylenediaminetetraacetic acid antibacterial composite hydrogel film for removing heavy metal ions in industrial wastewater, the preparation method comprising the following steps:

[0007] (1) Pretreatment of carbon felt

[0008] The carbon felt is placed in an oven for high-temperature treatment, and is cleaned with acid;

[0009] (2) Preparation of an acid neutralization solution

[0010] Under stirring and ultrasonic conditions, a sodium hydroxide solution is added to a 2-acrylamide-2-methylpropanesulfonic acid solution for neutralization, and the neutralization degree is 40-80%;

[0011] (3) Preparation of a mixed solution

[0012] In an ice water bath, polyethylene glycol diacrylate is added to the solution obtained in step (2) as a crosslinking agent, and ethylenediaminetetraacetic acid and methacryloyloxyethyl trimethyl ammonium chloride are added while stirring, and ammonium persulfate is added as an initiator and sodium bisulfite is added as a coagulant, and ultrasonic and stirring are performed to obtain a mixed solution;

[0013] (4) Hydrogel film forming

[0014] The pretreated carbon felt is completely immersed in the mixed solution obtained in step (3), and after the mixed solution is uniformly and fully filled in the carbon felt, it is placed in an oven for free radical polymerization to obtain the target product.

[0015] In the above preparation method: the temperature of the oven in step (1) is 130-180 DEG C; the high-temperature treatment time is 0.5-1.5 h; the acid cleaning is performed using a hydrochloric acid solution with a concentration of 5-6 mol / L.

[0016] In the above preparation method: in step (2), the concentration of the sodium hydroxide solution is 3-15 mol / L, and the mass concentration of the 2-acrylamide-2-methylpropanesulfonic acid solution is 10-30 wt%.

[0017] In the above preparation method: the mass ratio of 2-acrylamide-2-methylpropanesulfonic acid, polyethylene glycol diacrylate, ethylenediaminetetraacetic acid, methacryloyloxyethyl trimethyl ammonium chloride, ammonium persulfate and sodium bisulfite is 1:0.01-0.1:0.05-0.2:0.05-0.15:0.02-0.06:0.005-0.015.

[0018] In the above preparation method: in step (4), the oven temperature is 50-70 DEG C, and the time is 1-3 h.

[0019] The application of the AMPS-EDTA antibacterial composite hydrogel film for removing heavy metal ions in industrial wastewater prepared by the preparation method.

[0020] Further, the adsorption method is as follows:

[0021] (1) fixing the hydrogel film in a filtering device;

[0022] (2) connecting the filtering device inlet with a pressure pump by using a connecting pipe;

[0023] (3) providing the working pressure required by the membrane filtration by the pressure pump, and the system pressure is controlled at 0.1-0.5 Mpa, and the membrane unit plays a filtering role;

[0024] (4) filtering the metal ions in the water body at room temperature to 35 DEG C.

[0025] In the adsorption method, the pH is controlled at 3.0-8.0 during the actual adsorption process.

[0026] In the adsorption method, the cationic heavy metal ion is one or more of copper ions, lead ions, nickel ions and cadmium ions.

[0027] Beneficial effects 1、The raw materials used in the application are mature industrial products, which are low in cost, can be applied on a large scale, and have good environmental compatibility.

[0028] 2、2-acrylamide-2-methylpropane sulfonic acid introduces a strong acidic sulfonic acid group (-SO3H). The pKa value of the sulfonic acid group is low, which means that it can always remain ionized and carry a permanent negative charge in a wide pH range, greatly expanding its application range. At the same time, the sulfonic acid group itself is also a good metal ion coordination group. In this system, it can provide more diverse and higher density adsorption sites in cooperation with the carboxylic acid group. At the same time, the sulfonic acid group hydrogel usually has better hydrophilicity, which is conducive to the faster diffusion of water molecules and metal ions in the gel network, thereby accelerating the adsorption rate.

[0029] 3、In the 2-acrylamide-2-methylpropane sulfonic acid-ethylenediaminetetraacetic acid system introduced in the application, ethylenediaminetetraacetic acid can capture NH4 + ions produced by the initiator ammonium persulfate to form ion pairs, reduce the mobility of NH4 + ions, and help maintain the charge distribution in the solution. During the adsorption process after gelation, NH4 +The metal cations are combined with the ethylenediaminetetraacetic acid, which has a positive effect on the adsorption of the metal cations. In addition, the ethylenediaminetetraacetic acid brings a large number of amino groups and carboxyl groups into the system, which can effectively attract and stabilize the metal ions. The acetic acid groups and the amino groups stably coexist in the system, which also improves the adsorption capacity and selectivity of the system.

[0030] 4、The ethylenediaminetetraacetic acid is integrated into the cross-linked hydrogel network in the present application. The negatively charged carboxyl groups form electrostatic interactions with the amide groups and sulfonic acid groups of 2-acrylamide-2-methylpropanesulfonic acid and the quaternary ammonium groups of methacryloyloxyethyl trimethyl ammonium chloride, thereby enhancing the fixation effect. This feature can limit the migration and significantly reduce the risk of environmental overflow, while maintaining mechanical strength and stability.

[0031] 5、Pure hydrogel membranes usually have low strength, poor toughness, and are easy to swell and break. Under dynamic filtration conditions, the water flow pressure can easily break and lose the hydrogel, which cannot be used stably for a long time. In the present application, the carbon felt serves as a three-dimensional, porous, and high-strength rigid skeleton to provide support for the soft hydrogel. After the mechanical strength and stability are combined, the material can withstand the operating pressure in pressure-driven filtration and is not prone to deformation, rupture, or clogging.

[0032] 6、In view of the fact that some industrial wastewater may contain a large number of bacterial colonies, the hydrogel membrane prepared in the present application has good antibacterial properties due to the introduction of the quaternary ammonium groups in the methacryloyloxyethyl trimethyl ammonium chloride, which can significantly reduce the number of bacterial colonies in the treated wastewater.

[0033] 7、The hydrogel membrane prepared by the method has the characteristics of simple process flow, high mechanical strength, strong adsorption capacity, and environmental friendliness. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The removal rate of various metal ions in the laboratory simulated industrial wastewater of Example 1.

[0035] Figure 2 The removal rate of various metal ions in the laboratory simulated industrial wastewater of Example 2.

[0036] Figure 3 The removal rate of various metal ions in the laboratory simulated industrial wastewater of Example 3.

[0037] Figure 4 The removal rate of various metal ions in the laboratory simulated industrial wastewater of Comparative Example 1.

[0038] Figure 5 The removal rate of various metal ions in the laboratory simulated industrial wastewater of Comparative Example 2. DETAILED DESCRIPTION

[0039] The application will be described in detail below with specific examples, but is not limited to the application.

[0040] Example 1

[0041] (1) Preparation of hydrogel membrane

[0042] The carbon felt was placed in a 150℃ oven for high-temperature treatment and cleaned with 6mol / L hydrochloric acid.

[0043] A 75ml 2-acrylamido-2-methylpropanesulfonic acid solution with a concentration of 20wt% was prepared at 0℃, and 2-acrylamido-2-methylpropanesulfonic acid was partially neutralized with 5mol / L sodium hydroxide solution to obtain a 2-acrylamido-2-methylpropanesulfonic acid solution with a neutralization degree of 50%, which was stirred at a speed of 800rpm; and ultrasonic treatment was performed at 100Hz and 90w power for 10min, denoted as solution A.

[0044] 0.5g of polyethylene glycol diacrylate was added to solution A as a crosslinking agent in an ice water bath, and 2.4g of ethylenediaminetetraacetic acid and 1g of methacryloyloxyethyl trimethyl ammonium chloride were added while being magnetically stirred, and 0.45g of ammonium persulfate was added as an initiator and 0.1g of sodium bisulfite was added as a coagulant, which was stirred at a speed of 800rpm; and ultrasonic treatment was performed at 100Hz and 90w power for 10min. Subsequently, the carbon felt was completely immersed in solution B, and after the mixed solution was uniformly and fully filled in the carbon felt, it was placed in a 60℃ oven for free radical polymerization for 2 hours to obtain a 2-acrylamido-2-methylpropanesulfonic acid-ethylenediaminetetraacetic acid antibacterial composite hydrogel membrane for removing heavy metals in water. The mass ratio of 2-acrylamido-2-methylpropanesulfonic acid, polyethylene glycol diacrylate, ethylenediaminetetraacetic acid, methacryloyloxyethyl trimethyl ammonium chloride, ammonium persulfate and sodium bisulfite was 1:0.03:0.16:0.07:0.03:0.006.

[0045] (2) Adsorption effect test

[0046] 50ml of a mixed solution containing four kinds of metal cations with a concentration of 50mg / L was taken as simulated industrial wastewater, and the pH was adjusted to 5. A pressure pump with a head of 5m and a rated power of 15w was used to make the simulated industrial wastewater pass through the hydrogel membrane once under a working pressure of 0.35Mpa through a connecting pipe with an inner diameter of 6mm. The chromium ion content of the solution after passing through the membrane was determined using an inductively coupled plasma optical emission spectrometer (ICP-OES). The single-pass membrane.

[0047] The removal rate (ƞ, %) of ions is an index for evaluating the adsorption effect of the adsorption hydrogel membrane on metal ions, and the calculation method is shown in the following formula:

[0048]

[0049] In the above formula C0(mg / L) is the initial concentration of the ion; C1(mg / L) is the ion concentration after single membrane passing.

[0050] Example 2

[0051] (1) Preparation of hydrogel membrane

[0052] The carbon felt was placed in a 150°C oven for high-temperature treatment and cleaned with 6 mol / L hydrochloric acid. A 75 ml solution of 2-acrylamido-2-methylpropanesulfonic acid with a concentration of 20 wt% was prepared at 0°C, and the 2-acrylamido-2-methylpropanesulfonic acid was partially neutralized with 7.5 mol / L sodium hydroxide solution to obtain a 2-acrylamido-2-methylpropanesulfonic acid solution with a neutralization degree of 65%, which was stirred at a speed of 800 rpm; and was subjected to ultrasonic treatment at 100 Hz and 90 w power for 10 min, denoted as solution A.

[0053] In an ice water bath, 0.75 g of polyethylene glycol diacrylate was added to solution A as a crosslinking agent, 2.4 g of ethylenediaminetetraacetic acid and 1.5 g of methacryloyloxyethyl trimethyl ammonium chloride were added while being magnetically stirred, and 0.5 g of ammonium persulfate was added as an initiator and 0.15 g of sodium bisulfite was added as a coagulant, which was stirred at a speed of 800 rpm; and was subjected to ultrasonic treatment at 100 Hz and 90 w power for 10 min. Subsequently, the carbon felt was completely immersed in solution B, and after the mixed solution was uniformly and fully filled in the carbon felt, it was placed in a 60°C oven for free radical polymerization for 2 hours to obtain a 2-acrylamido-2-methylpropanesulfonic acid-ethylenediaminetetraacetic acid antibacterial composite hydrogel membrane for removing heavy metals from water bodies. The mass ratio of 2-acrylamido-2-methylpropanesulfonic acid, polyethylene glycol diacrylate, ethylenediaminetetraacetic acid, methacryloyloxyethyl trimethyl ammonium chloride, ammonium persulfate and sodium bisulfite is 1:0.05:0.16:0.1:0.03:0.01.

[0054] (2) Adsorption effect test

[0055] 50 ml of a mixed solution containing four kinds of metal cations with a concentration of 50 mg / L was taken as simulated industrial wastewater, and the pH was adjusted to 5. A pressure pump with a head of 5 m and a rated power of 15 w was used to make the simulated industrial wastewater pass through the hydrogel membrane once under a working pressure of 0.35 Mpa through a connecting pipe with an inner diameter of 6 mm. The chromium ion content of the solution after membrane passing was determined using an inductively coupled plasma optical emission spectrometer (ICP-OES). Single membrane passing.

[0056] The removal rate (ƞ, %) of ions is a calculated index for evaluating the adsorption effect of the adsorption hydrogel film on metal ions, and the calculation method is shown in the following formula:

[0057]

[0058] In the above formula, C0(mg / L) is the initial concentration of ions; Ct(mg / L) is the ion concentration after single membrane passing.

[0059] Example 3

[0060] (1) Preparation of hydrogel film

[0061] The carbon felt was placed in a 150°C oven for high-temperature treatment and cleaned with 6 mol / L hydrochloric acid. A 75 ml 2-acrylamide-2-methylpropanesulfonic acid solution with a concentration of 20 wt% was prepared at 0°C, and 2-acrylamide-2-methylpropanesulfonic acid was partially neutralized with 10 mol / L sodium hydroxide solution to obtain a 2-acrylamide-2-methylpropanesulfonic acid solution with a neutralization degree of 80%, which was stirred at a speed of 800 rpm; and ultrasonic treatment was performed at 100 Hz and 90 w power for 10 min, denoted as solution A.

[0062] In an ice water bath, 1 g of polyethylene glycol diacrylate was added to solution A as a crosslinking agent, and 2.4 g of ethylenediaminetetraacetic acid and 2 g of methacryloyloxyethyl trimethyl ammonium chloride were added while being magnetically stirred, and 0.75 g of ammonium persulfate was added as a starter and 0.2 g of sodium bisulfite was added as a coagulant, and the stirring speed was 800 rpm; and ultrasonic treatment was performed at 100 Hz and 90 w power for 10 min. Subsequently, the carbon felt was completely immersed in solution B, and after the mixed solution was uniformly and fully filled in the carbon felt, it was placed in a 60°C oven for free radical polymerization for 2 hours to obtain a 2-acrylamide-2-methylpropanesulfonic acid-ethylenediaminetetraacetic acid antibacterial composite hydrogel film for removing heavy metals in water. The mass ratio of 2-acrylamide-2-methylpropanesulfonic acid, polyethylene glycol diacrylate, ethylenediaminetetraacetic acid, methacryloyloxyethyl trimethyl ammonium chloride, ammonium persulfate and sodium bisulfite is 1:0.07:0.16:0.13:0.05:0.013.

[0063] (2) Adsorption effect test

[0064] ​Take 50 ml of mixed solution containing four kinds of metal cation concentration of 50 mg / L as simulated industrial wastewater, adjust pH to 5. Using the pressure pump with head 5 m, rated power 15 w, through the connecting pipe with inner diameter 6 mm, make the simulated industrial wastewater single pass through the hydrogel membrane under the working pressure of 0.35 Mpa. The chromium ion content of the solution after passing through the membrane is determined by inductively coupled plasma emission spectrometer (ICP-OES). Single pass through the membrane.

[0065] The removal rate (ƞ, %) of ions is a calculation index for evaluating the adsorption effect of the adsorption hydrogel membrane on metal ions, and the calculation method is shown in the following formula:

[0066]

[0067] In the above formula, (mg / L) is the initial concentration of ions; (mg / L) is the ion concentration after single pass through the membrane.

[0068] Comparative example 1

[0069] (1) Preparation of hydrogel

[0070] In step (1), no sodium hydroxide solution is added to neutralize 2-acrylamide-2-methylpropanesulfonic acid, and other conditions are the same as in example 1;

[0071] (2) Adsorption effect test

[0072] Take 50 ml of mixed solution containing four kinds of metal cation concentration of 50 mg / L as simulated industrial wastewater, adjust pH to 5. Using the pressure pump with head 5 m, rated power 15 w, through the connecting pipe with inner diameter 6 mm, make the simulated industrial wastewater single pass through the hydrogel membrane under the working pressure of 0.35 Mpa. The chromium ion content of the solution after passing through the membrane is determined by inductively coupled plasma emission spectrometer (ICP-OES). Single pass through the membrane.

[0073] The removal rate (ƞ, %) of ions is a calculation index for evaluating the adsorption effect of the adsorption hydrogel membrane on metal ions, and the calculation method is shown in the following formula:

[0074]

[0075] In the above formula, (mg / L) is the initial concentration of ions; (mg / L) is the ion concentration after single pass through the membrane.

[0076] (3) Comparative effect

[0077] If the pH is too low, the efficiency of the free radical polymerization reaction will be inhibited, resulting in low conversion rate and low molecular weight. Partial neutralization with sodium hydroxide can convert some of the acid to salt, adjust the pH of the system to a more suitable range for polymerization, and obtain a more complete and well-structured polymer network.

[0078] Comparative Example 2

[0079] (1) Preparation of hydrogel

[0080] No ethylenediaminetetraacetic acid was added in step (3), and the other conditions were the same as in Example 1.

[0081] (2) Adsorption effect test

[0082] Take 50 ml of mixed solution containing four kinds of metal cations with a concentration of 50 mg / L as the simulated industrial wastewater, and adjust the pH to 5. Use a pressure pump with a head of 5 m and a rated power of 15 w, and pass the simulated industrial wastewater through the hydrogel membrane through a connecting pipe with an inner diameter of 6 mm. Use an inductively coupled plasma optical emission spectrometer (ICP-OES) to measure the chromium ion content in the solution after passing through the membrane. Single-pass through the membrane.

[0083] The removal rate of ions (ƞ, %) is an index for evaluating the adsorption effect of the adsorption hydrogel membrane on metal ions, and the calculation method is shown in the following formula:

[0084]

[0085] In the above formula, (mg / L) is the initial concentration of the ion; (mg / L) is the ion concentration after single-pass through the membrane.

[0086] (3) Comparative effect

[0087] The addition of EDTA can significantly improve the adsorption performance of the hydrogel. The introduction of EDTA is a key design to improve the adsorption performance, which greatly enhances the selectivity and adsorption capacity of the material for heavy metals through the dual mechanisms of chemical chelation and structural optimization.

Claims

1. A method for preparing an AMPS-ethylenediaminetetraacetic acid antibacterial composite hydrogel membrane for removing heavy metal ions from industrial wastewater, characterized in that: The preparation method includes the following steps: (1) Pretreatment of carbon felt The carbon felt is placed in an oven for high-temperature treatment and then cleaned with acid. (2) Prepare an acid neutralization solution Under stirring and ultrasonic conditions, sodium hydroxide solution was added to 2-acrylamide-2-methylpropanesulfonic acid solution for neutralization, with a neutralization degree of 40-80%. (3) Preparation of mixed solutions In an ice-water bath, polyethylene glycol diacrylate was added as a crosslinking agent to the solution obtained in step (2). While stirring, ethylenediaminetetraacetic acid and methacryloyloxyethyltrimethylammonium chloride were added, along with ammonium persulfate as a starter and sodium bisulfite as a coagulant aid. The mixture was ultrasonicated and stirred to obtain a mixed solution. (4) Hydrogel film forming The pretreated carbon felt is completely immersed in the mixed solution obtained in step (3). After the mixed solution is evenly and fully absorbed in the carbon felt, it is placed in an oven for free radical polymerization to obtain the target product.

2. The preparation method according to claim 1, characterized in that: The temperature of the oven in step (1) is 130℃-180℃; the high temperature treatment time is 0.5-1.5h; the acid cleaning is carried out using a hydrochloric acid solution with a concentration of 5-6mol / L.

3. The preparation method according to claim 1, characterized in that: In step (2), the concentration of sodium hydroxide solution is 3~15 mol / L, and the mass concentration of 2-acrylamide-2-methylpropanesulfonic acid solution is 10~30 wt%.

4. The preparation method according to claim 1, characterized in that: The mass ratio of 2-acrylamide-2-methylpropanesulfonic acid, polyethylene glycol diacrylate, ethylenediaminetetraacetic acid, methacryloyloxyethyltrimethylammonium chloride, ammonium persulfate, and sodium bisulfite is 1:0.01~0.1:0.05~0.2:0.05~0.15:0.02~0.06:0.005~0.

015.

5. The preparation method according to claim 1, characterized in that: The oven temperature in step (4) is 50℃-70℃, and the time is 1~3h.

6. The application of the AMPS-ethylenediaminetetraacetic acid antibacterial composite hydrogel membrane prepared by the method of claim 1 for removing heavy metal ions from industrial wastewater in the adsorption of metal cations in industrial wastewater.

7. The application according to claim 6, characterized in that, The adsorption method is as follows: (1) Fix the hydrogel membrane in the filtration device; (2) Connect the inlet of the filter device to the pressure pump using a connecting pipe; (3) The pressure pump provides the working pressure required for membrane filtration. The system pressure is controlled at 0.1-0.5 MPa, and the membrane unit performs the filtration function. (4) Filter metal ions in water at room temperature to 35°C.

8. The application according to claim 7, characterized in that, The pH was controlled between 3.0 and 8.0 during the actual adsorption process.

9. The application according to claim 6, characterized in that, The cationic heavy metal ions are one or more of copper ions, lead ions, nickel ions, and cadmium ions.

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