Green water treatment agent with corrosion inhibition and antibacterial properties, and preparation method and application thereof

Abstract

The invention belongs to the technical field of industrial circulating water treatment, and provides a green water treatment agent with corrosion inhibition and antibacterial performance and a preparation method and application thereof.The water treatment agent has the structure as shown in # imgabs0. Piperazine groups are introduced into a polyaspartic acid peptide bond structure through a graft copolymerization method, and the novel water treatment agent is synthesized; the corrosion inhibitor can be adsorbed on the metal surface to form a protective film, and has good corrosion inhibition and antibacterial properties. The water treatment agent also has bacteriostatic specificity, and can inhibit escherichia coli and retain bacillus cereus. Therefore, the corrosion inhibition performance and the antibacterial performance of the polyaspartic acid are efficiently improved, meanwhile, the application of phosphorus-containing compounds is reduced, and the influence on the environment is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of industrial circulating water treatment, and in particular to a green water treatment agent with corrosion inhibition and antibacterial properties, a preparation method and application thereof. Background Art

[0002] Carbon steel is a low-cost, high-strength metal material that has been widely used in factory equipment such as transportation pipelines and storage tanks. At the same time, acid solutions are widely used in various industrial practices, such as acid descaling and pickling. Therefore, the corrosion of carbon steel becomes an inevitable problem in the acid treatment process. In order to inhibit corrosion, the use of organic corrosion inhibitors is an important strategy. Among organic corrosion inhibitors, compounds containing heteroatoms (oxygen, nitrogen, sulfur) and aromatic rings have been reported as effective corrosion inhibitors. However, most synthetic organic compounds can cause potential harm to human health and cause environmental pollution. Therefore, natural products that are harmless to the human body, such as kiwi leaves, marigolds, pectin, etc., are often studied as green corrosion inhibitors. However, it should be noted that the antibacterial effect of natural products is limited by their chemical structure and elemental composition.

[0003] As a representative green and biodegradable polymer, polyaspartic acid (PASP) has attracted more and more attention as a scale inhibitor and dispersant in water treatment. Although the corrosion inhibition performance of polyaspartic acid is poor, its application and modification are still worth further exploration due to its typical non-toxic and biodegradable properties. Most of the research on the modification of polyaspartic acid is to improve its scale inhibition performance. Previous studies have rarely reported modified polyaspartic acid as a corrosion inhibitor and antibacterial agent. Summary of the invention

[0004] In order to solve the technical problem that the existing polyaspartic acid has poor corrosion inhibition performance, the present invention provides a green water treatment agent with corrosion inhibition and antibacterial properties, as well as a preparation method and application. The present invention intends to graft 1,4-bis(3-aminopropyl)piperazine and carboxyl groups into the side chains of polyaspartic acid molecules through a chemical modification method, which not only improves its corrosion inhibition performance, but also achieves specific antibacterial properties, inhibits Escherichia coli, and retains Bacillus cereus.

[0005] The present invention adopts the following technical solutions:

[0006] The present invention provides a green water treatment agent with corrosion inhibition and antibacterial properties, wherein the water treatment agent has a structure as shown in the following formula I:

[0007]

[0008] Wherein, A represents an unmodified structural unit, and its degree of polymerization is n, and B represents a modified structural unit, and its degree of polymerization is m. n+m represents the total degree of polymerization. In formula I, m / (n+m)×100%=55%.

[0009] 1,4-Bis(3-aminopropyl)piperazine is an important organic intermediate widely used in organic synthesis. Its molecular designed compounds have corrosion inhibition and bactericidal effects. The carboxyl functional group has many important properties in water treatment, including scale inhibition, dispersion, high temperature resistance, non-hydrolysis, low toxicity and no pollution.

[0010] The invention uses 1,4-bis(3-aminopropyl)piperazine with amino group to open the ring of polysuccinimide, introduces functional groups into the polyaspartic acid peptide bond structure, and synthesizes a novel water treatment agent, which is recorded as PASP-BBA.

[0011] The present invention also provides a method for preparing a green water treatment agent with corrosion inhibition and antibacterial properties, comprising the following steps:

[0012] Step 1: Mix polysuccinimide and distilled water, add 1,4-bis(3-aminopropyl)piperazine, and react. After the reaction is completed, purify to obtain a PASP intermediate product;

[0013] Step 2: The PASP intermediate product is completely dissolved in distilled water, and a bromoacetic acid aqueous solution is first added, and then a sodium carbonate aqueous solution is added to react. After the reaction is completed, the target product, i.e., a water treatment agent, is obtained by separation and purification.

[0014] The present invention uses polysuccinimide (PSI), 1,4-bis(3-aminopropyl)piperazine (BAPP), bromoacetic acid (BA), and sodium carbonate (Na2CO3) as main materials, firstly obtains a PASP intermediate product by ring-opening grafting of 1,4-bis(3-aminopropyl)piperazine to polysuccinimide, and then reacts the PASP intermediate product with bromoacetic acid under alkaline conditions to obtain the target product PASP-BBA. The specific reaction route is shown in the following formula:

[0015]

[0016] The present invention uses 1,4-bis(3-aminopropyl)piperazine with an amino group to open the ring of polysuccinimide, and modifies the polysuccinimide through a ring-opening reaction to prepare a multifunctional polyaspartic acid derivative with corrosion inhibition and antibacterial properties, which can effectively improve the corrosion inhibition and antibacterial properties of an industrial circulating water treatment agent.

[0017] Furthermore, the molar ratio of the polysuccinimide to 1,4-bis(3-aminopropyl)piperazine is (1-3):(1-3), preferably, the molar ratio is 2:2.

[0018] Furthermore, the molar ratio of the PASP intermediate, bromoacetic acid and sodium carbonate is (0.1-0.7):(1-5):(1-10), preferably, the molar ratio is 0.55:2.75:5.5.

[0019] Furthermore, the reaction temperature of step 1 is room temperature, preferably 15°C to 35°C, and the reaction time is 20h to 30h. Further preferably, the reaction temperature is 25°C, and the reaction time is 24h.

[0020] Furthermore, the reaction temperature of step 2 is 50°C to 70°C, and the reaction time is 20h to 30h. Preferably, the reaction temperature is 60°C, and the reaction time is 24h.

[0021] Furthermore, 1 mL of distilled water was added for every 1 mmol of polysuccinimide, 1.5 mL of water was added for every 1 mmol of 1,4-bis(3-aminopropyl)piperazine, 0.11 mmol of PASP intermediate was dissolved in 1 mL of water, the concentration of the bromoacetic acid aqueous solution was 0.55 mmol / mL, and the concentration of the sodium carbonate aqueous solution was 1.1 mmol / mL.

[0022] Furthermore, the pH value of the sodium carbonate aqueous solution is 9-11.

[0023] The present invention also provides a green water treatment agent with corrosion inhibition and antibacterial properties, which is used as a corrosion inhibitor or antibacterial agent in circulating cooling water. The present invention introduces a functional group into the side chain of polyaspartic acid, which not only improves the corrosion inhibition performance of polyaspartic acid, but also improves the antibacterial performance of polyaspartic acid.

[0024] Compared with the prior art, the present invention has the following technical effects:

[0025] 1. The present invention introduces carboxyl groups and 1,4-bis(3-aminopropyl)piperazine into the side chain of polyaspartic acid to synthesize a new type of water treatment agent.

[0026] 2. The degree of polymerization of the structural unit modified by the water treatment agent of the present invention accounts for 55% of the total degree of polymerization. The water treatment agent synthesized under this degree of polymerization has good corrosion inhibition performance.

[0027] 3. The structure of the water treatment agent allows it to be adsorbed on the metal surface to form a thin film, protecting carbon steel from corrosion by dissolved oxygen and microorganisms in the water, thus having a corrosion inhibition effect. In addition, the structure also has antibacterial specificity, can inhibit Escherichia coli, and retain Bacillus cereus. Escherichia coli is a source of pollution in the water environment, and the Bacillus cereus biofilm has anti-scaling and corrosion inhibition properties, achieving a high efficiency improvement in the corrosion inhibition and antibacterial properties of polyaspartic acid.

[0028] 4. The synthesis process of the present invention is simple and green, and the synthesized product is a new type of green phosphorus-free water treatment agent, which is easily degraded by microorganisms and has good biological and environmental compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The PASP-BBA prepared in Example 1 of the present invention 1 H NMR spectrum;

[0030] Figure 2 The PASP prepared in Comparative Example 1 of the present invention 1 H NMR spectrum;

[0031] Figure 3 Polarization curves of aqueous solutions of PASP-BBA at different concentrations prepared in Example 2 of the present invention;

[0032] Figure 4 Polarization curves of aqueous solutions of PASP at different concentrations prepared in Comparative Example 2 of the present invention;

[0033] Figure 5 The inhibition zone diagram of PASP and PASP-BBA prepared in Example 4 of the present invention against Escherichia coli;

[0034] Figure 6 The inhibition zone diagram of PASP and PASP-BBA prepared in Example 4 of the present invention against Bacillus cereus;

[0035] Figure 7 This is a graph showing the effect of the concentration of PASP-BBA prepared in Example 5 of the present invention on the survival rate of Escherichia coli. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0037] In the following examples and comparative examples, unless otherwise specified, the raw materials used are common commercial products that can be directly purchased or can be prepared by conventional methods in the art.

[0038] The molecular weight of the polysuccinimide used in the following examples and comparative examples is 7000-8000 and is purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0039] Example 1

[0040] Synthesis of PASP-BBA

[0041] Weigh 2mmol of polysuccinimide (PSI) in a reaction vessel, add 2mL of distilled water (H2O), add a mixed solution of 2mmol 1,4-bis(3-aminopropyl)piperazine (BAPP) and 3mL of distilled water, and continue to react at room temperature for 24h. The resulting solution is placed in a dialysis bag with a molecular weight cutoff of 1000, dialyzed in distilled water for 3 days, and the retained liquid is spin-dried with a rotary evaporator to obtain a PASP intermediate product. Weigh 2.75mmol bromoacetic acid (BA), 5.5mmol sodium carbonate and 0.55mmol PASP intermediate, and add 5mL of distilled water to completely dissolve them. First add the PASP intermediate product aqueous solution and bromoacetic acid aqueous solution to the reaction vessel, and then slowly add sodium carbonate aqueous solution. The reaction vessel is placed in a 60℃ water bath and heated for 24h. The reaction time is continued. The resulting solution is placed in a dialysis bag with a molecular weight cutoff of 1000, dialyzed in distilled water for 1 day, and the retained liquid is spin-dried with a rotary evaporator to obtain the target product PASP-BBA.

[0042] Figure 1 The target product PASP-BBA 1 In the H NMR spectrum, the two broad peaks at 4.47ppm and 2.75ppm have chemical shifts similar to those of PASP. Meanwhile, the new peaks at 1.70ppm, 1.91ppm, 2.53ppm, 2.87ppm, 3.2ppm, and 3.60ppm are consistent with the peaks of -CH2- in the side chain structure of the product PASP-BBA. This proves that PASP-BBA was successfully prepared. Figure 1 Based on the peak area calculation of -CH2- on 1,4-bis(3-aminopropyl)piperazine and -CH2- in the side chain structure of PASP-BBA, the m / (n+m)×100% of the synthetic target product PASP-BBA is 55%.

[0043] Example 2

[0044] Determination of the corrosion inhibition effect of PASP-BBA by corrosion electrochemical method

[0045] The electrochemical test was carried out using a CHI660E electrochemical workstation. The reference electrode was a saturated calomel electrode, the auxiliary electrode was a platinum electrode, and the working electrode was a 20# carbon steel electrode with a working area of ​​1 cm. 2 . Before the test, the working electrode was polished with sandpaper, then cleaned with ethanol, acetone and distilled water, and dried with cold air. At 25°C, the electrode was first immersed in 500mL of the test solution for 60min to obtain a stable open circuit potential (OCP), and then the impedance (EIS) and polarization curve were measured. The polarization curve scanning interval was ±250mV (vs.OCP), and the scanning rate was 1mV / s. The corrosion inhibition efficiency (η) is obtained by formula (1):

[0046]

[0047] Where: and J corr Corrosion current density of carbon steel electrode in 3.5% NaCl solution without and with PASP-BBA, respectively.

[0048] The parameters corresponding to the polarization curves are presented in Table 1, including the corrosion potential (E corr ), corrosion current density (J corr ) and the anodic and cathodic Tafel slopes (β α ,β c ).

[0049] The PASP-BBA prepared in Example 1 was configured to different concentrations, and the polarization curve was measured by electrochemical method. The polarization curve is shown in the attached Figure 3 , the test results are shown in Table 1:

[0050] Table 1 Potentiodynamic polarization parameters of PASP-BBA aqueous solutions with different concentrations

[0051]

[0052]

[0053] Example 2 uses electrochemical methods to explore the effect of different concentrations of PASP-BBA on corrosion inhibition performance. As the concentration of PASP-BBA increases, the current density J corr The corrosion inhibition efficiency was significantly reduced and η was significantly increased. When the concentration was 70 mg / L, the maximum corrosion inhibition efficiency was 54.28%. Compared with the control example 2, its maximum corrosion inhibition efficiency was increased by 33.53%.

[0054] Figure 3 The polarization curves of PASP-BBA aqueous solutions with different concentrations show that as the concentration of PASP-BBA increases, the slope of the cathode polarization curve β c The value of changes very little, and the polarization curves are almost parallel, while the polarization curve of the anode moves downward significantly, indicating that the addition of PASP-BBA can inhibit the metal dissolution of the anode. Therefore, PASP-BBA is a corrosion inhibitor mainly for inhibiting the anode.

[0055] Example 3

[0056] Determination of the corrosion inhibition effect of PASP-BBA by rotating coupon method

[0057] PASP-BBA prepared in Example 1 was tested for 20 # The corrosion inhibition performance of carbon steel is tested as follows:

[0058] According to GB / T1875-2014, the preparation of standard prepared water, weigh 7.35g calcium chloride dihydrate, 4.93g magnesium sulfate heptahydrate, 6.58g sodium chloride and dissolve them in about 7L water, and dissolve them completely; weigh 1.68g sodium bicarbonate and dissolve them in about 1L water, and dissolve them completely. Mix the two solutions, dilute with water to 10L, and mix them. The calcium ion concentration in the standard prepared water is 200.4mg / L, the magnesium ion concentration is 48.62mg / L, the chloride ion concentration is 399.1mg / L, and the bicarbonate ion concentration is 122.0mg / L.

[0059] Experimental steps:

[0060] 1) Pretreatment of test piece: Use filter paper to # Wipe clean the anti-rust grease of the carbon steel test piece, and then scrub it with absorbent cotton in anhydrous ethanol. Use no less than 50 mL of the above reagent for every ten test pieces. After scrubbing clean, dry it with filter paper, place it in a desiccator for more than 4 hours, weigh it (accurate to 0.2 mg), record it as m1, and store it in a desiccator for later use.

[0061] 2) Prepare 0, 10, 30, 50, 70, and 100 mg / L PASP-BBA solutions using standard prepared water in a 2000 mL test cup to prepare the test solutions.

[0062] 3) Insert the test piece and conduct the rotation test: When the test liquid reaches 45°C, insert the test piece and start the rotation system to rotate the test piece at 94r / min. The test starts timing and the duration is 72h.

[0063] 4) Replenishing test solution: According to the test situation, add test water sample in time to keep the liquid level at the scale line.

[0064] 5) Stop the rotation test: When the specified time is reached, stop the rotation test, take out the test piece and observe and record the appearance.

[0065] 6) Post-treatment of carbon steel test piece: clean the test piece with a brush, then wash it in the pickling solution for about 30 seconds, take it out, quickly rinse it with tap water, and immediately immerse it in sodium hydroxide solution for about 30 seconds, take it out, rinse it with water, wipe it with filter paper and dry it, soak it in anhydrous ethanol for about 3 minutes, place it on a clean filter paper, dry it with filter paper, place it in a desiccator for more than 4 hours, weigh it (accurate to 0.2 mg), and record it as m2. At the same time, do a pickling blank test of the test piece to calibrate the pickling.

[0066] 7) Alkaline washing solution: 60 g / L sodium hydroxide solution. Acid washing solution: Add 8 g hexamethylenetetramine to 1000 mL hydrochloric acid solution (mixed with 37% concentrated hydrochloric acid and water in a volume ratio of 1:4), dissolve and mix well.

[0067] Blank test: Perform a blank test without adding water treatment agent.

[0068] Result calculation.

[0069] In Table 2:

[0070] m1——the mass of the test piece before treatment, in grams (g);

[0071] m2——mass of the test piece after post-processing, in grams (g);

[0072] m – the value of the mass loss of the test piece, in grams (g).

[0073] The corrosion rate is expressed as v, in units of mm / a, and is calculated according to formula (2):

[0074]

[0075] Where:

[0076] m——the value of the mass loss of the test piece, in grams (g);

[0077] m0——the average value of the mass loss of the blank test of the test piece in acid washing, in grams (g);

[0078] s——The surface area of ​​the test piece in square centimeters (cm 2 );

[0079] p——density value of the test piece, in grams per cubic centimeter (g / cm 3 );

[0080] t——the value of the test time, in hours (h);

[0081] 8760 – the number of hours equivalent to a year, in hours per year (h / a);

[0082] 10 – The number of millimeters equivalent to 1 cm, the unit is millimeter per centimeter (mm / cm).

[0083] The corrosion inhibition rate η is calculated according to formula (3):

[0084]

[0085] Where:

[0086] V0——The value of the corrosion rate of the blank test of the specimen, in millimeters per year (mm / a);

[0087] V1——The corrosion rate of the test piece, in millimeters per year (mm / a).

[0088] The corrosion inhibition efficiency of PASP-BBA prepared in Example 1 was measured under different concentrations. The test results are shown in Table 2:

[0089] Table 2 Weight loss parameters of PASP-BBA at different concentrations

[0090]

[0091] Example 3 uses the weight loss method to explore the effect of different concentrations of PASP-BBA on corrosion inhibition performance. The test results are consistent with the trend of the corrosion inhibition effect of PASP-BBA measured by the electrochemical method. Under the optimal conditions, a PASP-BBA agent with a concentration of 70 mg / L can achieve a corrosion inhibition efficiency of 43.92%, which is 23.88% higher than the maximum corrosion inhibition efficiency of the control example 3.

[0092] Example 4

[0093] Determination of inhibition zone diameter

[0094] The PASP prepared in Control Example 1 and the PASP-BBA prepared in Example 1 were prepared into solutions with mass concentrations of 50 mg / mL and 100 mg / mL, respectively. 200 μL of the solution was taken, and Escherichia coli and Bacillus cereus were used as indicator bacteria. The diameter of the inhibition zone was measured after 24 hours, and the antibacterial effect of PASP was used as the control group.

[0095] Figure 5 is the inhibition zone of PASP and PASP-BBA against Escherichia coli, Figure 6 The inhibition zones of PASP and PASP-BBA against Bacillus cereus. The inhibition diameter of PASP against Escherichia coli and Bacillus cereus is 8.1 mm. The diameter of the inhibition zone of PASP-BBA against Escherichia coli is 18.9 mm at a concentration of 100 mg / mL and 17.0 mm at 50 mg / mL. Compared with PASP, it has excellent inhibitory effect on Escherichia coli. The diameter of the inhibition zone of PASP-BBA against Bacillus cereus is 8.1 mm at concentrations of 100 mg / mL and 50 mg / mL, which is equal to the antibacterial effect of PASP. Since PASP-BBA can inhibit Escherichia coli and retain Bacillus cereus, PASP-BBA has antibacterial specificity, can inhibit polluting bacteria in the water environment, and retain Bacillus cereus biofilm with scale and corrosion inhibition properties.

[0096] Example 5

[0097] Effect of PASP-BBA concentration on inhibition of Escherichia coli

[0098] The PASP-BBA prepared in Example 1 was configured into solutions with mass concentrations of 20, 40, 60, 80, and 100 mg / mL, respectively, to further explore the effect of PASP-BBA concentration on the inhibition of Escherichia coli.

[0099] Figure 7 The figure shows the effect of PASP-BBA concentration on the survival rate of E. coli. As the concentration of PASP-BBA increases, the survival rate of E. coli shows a clear downward trend. In contrast, the survival rate of E. coli slowly decreases with the increase of PASP concentration. Overall, the survival rate of E. coli under the action of PASP is higher than that of PASP-BBA, indicating that PASP-BBA has a good inhibitory effect on E. coli, and the higher the concentration, the better the antibacterial effect. At 100 mg / mL, the survival rate of E. coli is only 21%.

[0100] The above-mentioned embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0101] Comparative Example 1

[0102] Synthesis of PASP

[0103] Weigh 10 mmol of polysuccinimide (PSI) in a reaction container, add 10 mL of distilled water (H2O), add 10 mmol of sodium hydroxide (NaOH) and 10 mL of H2O, and continue the reaction at 40°C for 24 hours. The resulting solution is placed in a dialysis bag with a molecular weight cutoff of 1000, dialyzed in distilled water for 3 days, and the retentate is dried using a rotary evaporator to obtain the target product PASP.

[0104] Figure 2 For PASP 1 The H NMR spectrum shows two broad peaks at 4.46 ppm and 2.74 ppm, which correspond to the hydrogen of -CH- and -CH2- in the PASP structure, respectively.

[0105] Comparative Example 2

[0106] Determination of the corrosion inhibition effect of PASP by corrosion electrochemical method

[0107] The experimental process is the same as that of control example 1. The prepared polyaspartic acid is configured under different concentrations and the polarization curve is measured by electrochemical method. The polarization curve is shown in the attached figure. Figure 4 , the test results are shown in Table 3:

[0108] Table 3 Potentiodynamic polarization parameters of PASP aqueous solutions with different concentrations

[0109]

[0110] Comparative Example 2 uses electrochemical methods to explore the effect of different concentrations of PASP on corrosion inhibition performance. corr The corrosion inhibition efficiency reached 20.75% at a concentration of 70 mg / L.

[0111] Comparative Example 3

[0112] Determination of the corrosion inhibition effect of PASP using the rotating coupon method

[0113] The experimental process is the same as that of control example 1, and the corrosion inhibition efficiency of the prepared PASP is measured under different concentration conditions. The test results are shown in Table 4:

[0114] Table 4 Weight loss parameters of PASP at different concentrations

[0115]

[0116] Comparative Example 3 uses the weight loss method to explore the effect of different concentrations of PASP on corrosion inhibition performance. Under the optimal conditions, a concentration of 70 mg / L of PASP-BBA can achieve a corrosion inhibition efficiency of 20.04%.

[0117] The embodiments described above are only preferred embodiments of the present invention and are only used to explain the present invention, not to limit the scope of implementation of the present invention. For those skilled in the art, other implementation methods can certainly be easily made by replacement or modification based on the technical contents disclosed in this specification. Therefore, all changes and improvements made to the principles and process conditions of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A green water treatment agent with corrosion inhibition and antibacterial properties, characterized in that: The water treatment agent has a structure as shown in the following formula I: Wherein, m and n both represent the degree of polymerization, and n+m represents the total degree of polymerization.

2. A green water treatment agent with corrosion inhibition and antibacterial properties according to claim 1, characterized in that: In formula I, m / (n+m)×100%=55%.

3. The method for preparing a green water treatment agent with corrosion inhibition and antibacterial properties according to claim 1 or 2, characterized in that: The following steps are involved: Step 1: Mix polysuccinimide with water, then add a mixed solution of 1,4-bis(3-aminopropyl)piperazine and water to react, and after the reaction is completed, obtain a PASP intermediate product; Step 2: The PASP intermediate product is completely dissolved in water, and a bromoacetic acid aqueous solution is first added, and then a sodium carbonate aqueous solution is added to react. After the reaction is completed, the target product, i.e., a water treatment agent, is obtained.

4. The method for preparing a green water treatment agent with corrosion inhibition and antibacterial properties according to claim 3, characterized in that: The molar ratio of the polysuccinimide to 1,4-bis(3-aminopropyl)piperazine is (1-3):(1-3).

5. The method for preparing a green water treatment agent with corrosion inhibition and antibacterial properties according to claim 3, characterized in that: The molar ratio of the PASP intermediate product, bromoacetic acid and sodium carbonate is (0.1-0.7): (1-5): (1-10).

6. The method for preparing a green water treatment agent with corrosion inhibition and antibacterial properties according to claim 3, characterized in that: The reaction temperature of step 1 is 15°C to 35°C, and the reaction time is 20h to 30h; the reaction temperature of step 2 is 50°C to 70°C, and the reaction time is 20h to 30h.

7. The method for preparing a green water treatment agent with corrosion inhibition and antibacterial properties according to claim 3, characterized in that: 1 mL of water was added for every 1 mmol of polysuccinimide, 1.5 mL of water was added for every 1 mmol of 1,4-bis(3-aminopropyl)piperazine, 0.11 mmol of PASP intermediate was dissolved in 1 mL of water, the concentration of bromoacetic acid aqueous solution was 0.55 mmol / mL, and the concentration of sodium carbonate aqueous solution was 1.1 mmol / mL.

8. The method for preparing a green water treatment agent with corrosion inhibition and antibacterial properties according to claim 3, characterized in that: The pH of the sodium carbonate aqueous solution is 9-11.

9. The method for preparing a green water treatment agent with corrosion inhibition and antibacterial properties according to claim 3, characterized in that: The molar ratio of the polysuccinimide to 1,4-bis(3-aminopropyl)piperazine is 2:2, the molar ratio of the PASP intermediate, bromoacetic acid and sodium carbonate is 0.55:2.75:5.5, the reaction temperature of step 1 is 25°C, the reaction time is 24h, and the reaction temperature of step 2 is 60°C, and the reaction time is 24h.

10. Use of the green water treatment agent with corrosion inhibition and antibacterial properties according to claim 1 as a corrosion inhibitor or antibacterial agent in circulating cooling water.

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