Slow-release treatment method for high-salinity sulfur-containing water, anti-biodegradation corrosion inhibitor and preparation method of anti-biodegradation corrosion inhibitor

Abstract

The invention belongs to the field of wastewater treatment, and provides a slow-release treatment method for high-salinity sulfur-containing water, an anti-biodegradation corrosion inhibitor and a preparation method of the anti-biodegradation corrosion inhibitor. According to the method, an anti-biodegradation corrosion inhibitor is added into oilfield injection water and produced sewage, the water treatment agent is a water-soluble oil dispersion, and a cationic antibacterial microgel dispersion liquid, a rare earth phosphonic acid hybrid microgel dispersion liquid and a synergistic inhibitor solution are compounded; the cationic antibacterial microgel is obtained by carrying out cross-linking polymerization on a hydantoin structure-containing monomer, a sulfobetaine type monomer, palmitic acid imidazoline methacrylate quaternary ammonium salt and methacryloyloxypropyl single-terminated polydimethylsiloxane in a water-alcohol system, and the cationic antibacterial microgel is prepared by carrying out cross-linking polymerization on the monomer, the sulfobetaine type monomer, the palmitic acid imidazoline methacrylate quaternary ammonium salt and the methacryloxypropyl single-terminated polydimethylsiloxane. The water treatment agent disclosed by the invention has good biological stability and system stability in high-salinity sulfur-containing sewage, and can protect pipelines and equipment while controlling sulfides and corrosive components.

Description

Technical Field

[0001] This invention belongs to the field of water treatment and relates to a slow-release treatment method for high-mineralization sulfur-containing water and an anti-biodegradation corrosion inhibitor and its preparation method. Background Technology

[0002] Oilfield injected and produced water typically exhibits high salinity and sulfur content during reinjection and distribution. The interaction of dissolved salts, suspended solids, hydrogen sulfide, carbon dioxide, and sulfate-reducing bacteria easily leads to uniform corrosion, crevice corrosion, and localized perforation on the inner walls of gathering and transmission pipelines, injection tubing, and surface equipment, accompanied by scaling, blockage, and microbial slime problems. Currently used industrial corrosion inhibitors such as fatty acid imidazoline, quaternary ammonium salt bactericides, phosphonate water treatment agents, and rare earth salt synergistic formulations are mostly added to the system through physical blending. The large amount of organic components in these formulations can themselves act as carbon and nitrogen sources for heterotrophic and sulfate-reducing bacteria. Under conditions of high salinity, sulfur content, and complex microbial communities, these components are prone to rapid biodegradation and adaptive tolerance, resulting in rapid agent failure and high dosing frequency. This necessitates the simultaneous addition of multiple agents, including corrosion inhibitors, bactericides, and scale inhibitors, making it difficult to simultaneously ensure compatibility and long-term stability between these agents.

[0003] Although there are high-salinity corrosion inhibition schemes that combine rare earth salts with organophosphonates, they generally remain at the level of simple complexation or adsorption. They lack overall design considerations regarding the molecular structure, spatial configuration, and anti-biodegradation capabilities of water treatment agents at the microscopic interface. This makes it difficult to simultaneously achieve corrosion control, microbial control, and formulation stability in highly saline sulfur-containing water bodies. Therefore, it is necessary to develop a water treatment agent system that is stable in dispersion in the aqueous phase, has structural anti-biodegradation characteristics, and is suitable for highly saline sulfur-containing water environments. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a slow-release treatment method for high-salinity sulfur-containing water and an anti-biodegradation corrosion inhibitor and its preparation method. A dispersion with water as the continuous phase is added to oilfield injection water and produced water. The water treatment agent is composed of cationic microgels containing hydantoin structures, rare earth phosphonic acid hybrid microgels, and synergistic inhibitory components such as triazine derivatives, formaldehyde condensates, and quaternary ammonium salts. This maintains good biological stability and corrosion resistance in this type of water environment, thereby meeting the needs of actual production.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing an anti-biodegradation corrosion inhibitor, the method comprising:

[0007] S1, deionized water and anhydrous isopropanol are mixed and nitrogen gas is bubbled into the solvent to remove oxygen. 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt and methacryloyloxypropyl mono-terminated polydimethylsiloxane are added in sequence. Then N,N′-methylenebisacrylamide is added and reacted with an aqueous solution of ammonium persulfate. After the reaction is completed, triethylene glycol is added to obtain a cationic antibacterial microgel dispersion.

[0008] S2, add cerium nitrate hexahydrate to deionized water to obtain cerium salt solution and add it dropwise to cationic antibacterial microgel dispersion. Then add aminotrimethylene phosphonic acid aqueous solution to cationic antibacterial microgel dispersion, adjust the pH to 5.5-6.5 with nitric acid solution and continue stirring to obtain rare earth-phosphonic acid hybrid microgel dispersion;

[0009] S3, deionized water and triethylene glycol are mixed, and hydroxyethyl hexahydrotriazine, hexamethylenetetramine, and hexadecylpyridine chloride and 5,5-dimethylhydantoin are added sequentially to obtain a synergistic inhibitor solution;

[0010] S4. Deionized water and triethylene glycol are mixed, and rare earth-phosphonic acid hybrid microgel dispersion and synergistic inhibitor solution are added sequentially. Then, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and monoethanolamine aqueous solution are added to obtain an anti-biodegradation corrosion inhibitor.

[0011] The preparation method specifically includes:

[0012] A1. 5,5-Dimethylhydantoin and sodium hydroxide were added to an aqueous ethanol solution to obtain an alkaline solution. Under a nitrogen atmosphere, 4-vinylbenzyl chloride was added dropwise to the alkaline solution. After the addition was complete, the temperature was raised to 50-60°C, and the reaction was stirred for 3-4 hours. During the reaction, the pH was adjusted to 7.0-7.5 with hydrochloric acid solution. After the reaction was completed, the solution was cooled to room temperature, the organic phase was extracted with ethyl acetate and dried with anhydrous sodium sulfate, and then distilled under reduced pressure and dried under vacuum to obtain 3-(4-vinylbenzyl)-5,5-dimethylhydantoin.

[0013] A2, palmitic acid, diethylenetriamine, and xylene are mixed and reacted at 200-230℃ for 4-6 hours under nitrogen protection. The mixture is then distilled under reduced pressure to obtain a palmitic acid imidazoline intermediate. This palmitic acid imidazoline intermediate, 2-chloroethanol, and a first volume of anhydrous ethanol are mixed and refluxed at 80-90℃ for 4-5 hours. After the reaction, the mixture is distilled under reduced pressure to obtain hydroxyethyl palmitic acid imidazoline. This hydroxyethyl palmitic acid imidazoline is dispersed in anhydrous dichloromethane, and triethylamine is added. The mixture is stirred and dripped under ice-water bath conditions. Methacrylamide chloride was added, and the reaction was continued with stirring at room temperature. The organic phase was washed with hydrochloric acid solution, then washed with saturated sodium chloride solution, dried, and distilled under reduced pressure to obtain palmitic imidazoline methacrylate intermediate. The palmitic imidazoline methacrylate intermediate, monobromohexane, and a second part of anhydrous ethanol were mixed and refluxed at 70-80°C for 6-8 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled under reduced pressure, and recrystallized with acetone. The mixture was filtered and dried to obtain palmitic imidazoline methacrylate quaternary ammonium salt.

[0014] The cationic antibacterial microgel is formed by free radical polymerization and crosslinking agent action in an aqueous alcohol system using vinyl benzyl monomers containing a hydantoin structure, methacryloyloxyethyl sulfobetaine, imidazoline methacrylate quaternary ammonium salt of palmitate, and methacryloyloxypropyl monocapped polydimethylsiloxane. The imidazoline quaternary ammonium salt fragment provides multi-site cationic centers, which bind to oxides, sulfide corrosion products, and negatively charged adsorption layers on the steel surface through electrostatic and coordination interactions. Long-chain palmitoyl groups aggregate at the interface to form an organic adsorption layer. Polydimethylsiloxane segments are enriched at the interface, forming low-polarity regions and reducing the contact area between the aqueous phase and corrosive ions and the metal surface. The hydantoin ring structure and quaternary ammonium cations are covalently fixed in the crosslinked backbone; the degradation process depends on the breakage of the main chain or branches, which is difficult for common hydrolytic enzymes to directly cleave.

[0015] Methacryloxyethyl sulfobetaine introduces zwitterionic groups. In the hydrated state, these zwitterions form a solvation layer, constructing a directional hydrogen bond network with surrounding water molecules, creating a water-rich layer near the metal and inhibiting the adhesion of extracellular polymers. When zwitterions coexist with quaternary ammonium cations, they improve the dispersion stability of the formulation in high-salt environments in the aqueous phase, forming an adsorption layer with a fixed charge distribution at the interface. This limits the competitive adsorption of chloride ions, sulfate ions, and sulfides, reducing the number of active sites involved in anodic dissolution and cathodic reduction. Cross-linked microgel particles approach the metal surface in the aqueous phase via Brownian motion and are adsorbed under the influence of the electrical double layer. The hydrophobic segments inside the particles and the hydrophilic groups on the outer layer constitute multilayer diffusion resistance, prolonging the diffusion path of water molecules and dissolved gases to the metal surface, thus reducing the rate of mass transport and charge migration related to corrosion reactions.

[0016] When cerium nitrate and aminotrimethylene phosphonic acid are added to cationic microgels, cerium ions coordinate with phosphonate groups and carboxyl, hydroxyl, and amide groups on the chain segments, forming rare earth phosphonic acid coordination structures dispersed in the organic network. Cerium is partially reduced in a sulfur-containing environment, co-forming with oxides, hydroxides, and phosphonate groups on the iron surface to form a cerium-containing phosphate or cerium-containing oxide mixed film. This film covers active sites at the anode and alters the reduction reaction interface at the cathode, reducing the electrochemical rate of iron dissolution and reduction processes. Phosphonic acid groups complex with calcium and magnesium ions, weakening the tendency for carbonate and sulfate scaling, reducing scale porosity and localized galvanic corrosion areas. When the rare earth phosphonic acid hybrid structure is located on the surface of the microgel particles, it increases the adhesion time of the particles to the metal surface through multi-point coordination and chemisorption. Simultaneously, this structure is less likely to be recognized as a usable phosphorus source by microbial phosphorus metabolism pathways, reducing the possibility of microbial proliferation dependent on this component.

[0017] Hydroxyethyl hexahydrotriazine and hexamethylenetetramine slowly decompose in highly salinized sulfur-containing water, releasing methylene fragments and small amounts of free formaldehyde. These fragments condense or add to amino and thiol groups on bacterial cell walls and membranes, altering the conformation of extracellular proteins and peptides and weakening the biofilm stability of sulfate-reducing bacteria and other anaerobic bacteria on metal surfaces. The pyridine cationic head group of hexadecylpyridine chloride binds to negatively charged phospholipids and lipopolysaccharides on the cell surface, and the long-chain alkyl group inserts into the lipid bilayer, disrupting membrane structure and interfering with electron transport and energy metabolism. Free hydantoin generates nitrogen halide derivatives in the presence of oxidizing components or free halogens. When the nitrogen halide bond breaks, the halogen is transferred to the amino or thiol groups of proteins, causing irreversible modification. These bactericidal and bacteriostatic components are distributed around the microgel and in the aqueous phase. Some bind to the outer layer of the biofilm near the metal, while others maintain an equilibrium concentration in the bulk phase, continuously exerting chemical interference on the extracellular enzyme system and reductive metabolic chain of sulfate-reducing bacteria.

[0018] The cross-linked microgel network consists of alternating hydrophilic and hydrophobic regions. Hydantoin, imidazoline, and sulfobetaine fragments constitute the hydrophilic regions, while polydimethylsiloxane and long-chain alkyl groups constitute the hydrophobic regions. Hydrolases and oxidases first contact the surface hydrophilic groups, making it difficult for the enzyme's active site to enter the internal hydrophobic backbone. Segment length and spatial configuration restrict the geometric matching between the enzyme and substrate, making it difficult for hydrolases targeting linear ester or linear amide chains to form stable enzyme-substrate complexes. Rare earth phosphonate hybrid structures and quaternary ammonium cations introduce local rigid points on the backbone, reducing the rotational degrees of freedom of the backbone and minimizing conformational rearrangements caused by microbial ectoenzymes. A complex interface composed of organic polymers, cerium-containing phosphates or oxides, and residual biofilm forms on the metal surface. The diffusion paths of hydrogen sulfide, carbon dioxide, and dissolved oxygen are increased at this interface, the exchange current density of cathodic reduction and anodic dissolution decreases, the potential difference between the local cathodic and anodic regions decreases, and the corrosion pit expansion rate is reduced.

[0019] In a preferred embodiment of the present invention, in A1, the mass ratio of 5,5-dimethylhydantoin, sodium hydroxide, aqueous ethanol solution, and 4-vinylbenzyl chloride is (10-12):(3-4):(40-50):(14-16), for example, it can be (10.0, 10.2, 10.4, 10.6, 10.8, 11.0, 11.2, 11.4, 11.6, 11.8, or 12.0):(3.0, 3.1). 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9 or 4.0: (40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50): (14, 14.2, 14.4, 14.6, 14.8, 15.0, 15.2, 15.4, 15.6, 15.8 or 16), but not limited to the listed values; other unlisted values ​​within this range also apply.

[0020] In some alternative embodiments, the concentration of the hydrochloric acid solution is 1-1.5M, for example, it can be 1.0M, 1.05M, 1.1M, 1.15M, 1.2M, 1.25M, 1.3M, 1.35M, 1.4M, 1.45M or 1.5M, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0021] In some optional embodiments, the mass ratio of anhydrous ethanol to deionized water in the aqueous ethanol solution is 1:1.

[0022] As a preferred embodiment of the present invention, in A2, the mass ratio of palmitic acid, diethylenetriamine, xylene, 2-chloroethanol, the first part of anhydrous ethanol, anhydrous dichloromethane, triethylamine, methacryloyl chloride, monobromohexane, and the second part of anhydrous ethanol is (20-25):(10-12):(20-30):(8-10):(30-40):(30-40):(3-4):(5-6):(6-8):(30-40) 0), for example, could be (20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 24, 24.5 or 25): (10.0, 10.2, 10.4, 10.6, 10.8, 11.0, 11.2, 11.4, 11.6, 11.8 or 12.0): (20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30): (8.0, 8.2, 8). 4, 8.6, 8.8, 9.0, 9.2, 9.4, 9.6, 9.8 or 10.0: (30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40): (30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40): (3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9 or 4.0): (5. 0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9 or 6.0: (6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, 7.8 or 8.0): (30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40), but not limited to the listed values; other unlisted values ​​within this range also apply.

[0023] In some alternative embodiments, the concentration of the hydrochloric acid solution is 1-1.5M, for example, it can be 1.0M, 1.05M, 1.1M, 1.15M, 1.2M, 1.25M, 1.3M, 1.35M, 1.4M, 1.45M or 1.5M, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0024] As a preferred embodiment of the present invention, in S1, the mass ratio of deionized water, anhydrous isopropanol, 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt, methacryloyloxypropyl mono-terminated polydimethylsiloxane, N,N′-methylenebisacrylamide, ammonium persulfate aqueous solution, and triethylene glycol is (40-45):(15-18):(4-4.5):(8-9):(7-8): (1-1.5): (0.1-0.15): (2-3): (10-12), for example, it could be (40, 40.5, 41, 41.5, 42, 42.5, 43, 43.5, 44, 44.5 or 45): (15, 15.3, 15.6, 15.9, 16.2, 16.5, 16.8, 17.1, 17.4, 17.7 or 18): (4, 4.05, 4.1, 4.15, 4.2, 4.25, 4.3, 4.35, 4. 4, 4.45 or 4.5: (8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9 or 9.0): (7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9 or 8.0): (1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 or 1.5): (0.1, 0.105, 0.11, 0. 115, 0.12, 0.125, 0.13, 0.135, 0.14, 0.145 or 0.15: (2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0): (10, 10.2, 10.4, 10.6, 10.8, 11.0, 11.2, 11.4, 11.6, 11.8 or 12), but not limited to the listed values; other unlisted values ​​within this range also apply.

[0025] In some optional embodiments, the number average molecular weight of the methacryloxypropyl monoterminated polydimethylsiloxane is 4000-6000, for example, it can be 4000, 4200, 4400, 4600, 4800, 5000, 5200, 5400, 5600, 5800 or 6000, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0026] In some optional embodiments, the ammonium persulfate aqueous solution has a mass fraction of 10-15 wt.%.

[0027] In some optional embodiments, the solid content of the cationic antibacterial microgel dispersion is 18-25 wt.%, for example, it can be 18 wt.%, 18.7 wt.%, 19.4 wt.%, 20.1 wt.%, 20.8 wt.%, 21.5 wt.%, 22.2 wt.%, 22.9 wt.%, 23.6 wt.%, 24.3 wt.%, or 25 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0028] As a preferred embodiment of the present invention, in S2, the mass ratio of cerium nitrate hexahydrate, deionized water, cationic antibacterial microgel dispersion, and aminotrimethylenephosphonic acid aqueous solution is (0.4-0.6):(5-7):(60-70):(0.6-0.8), for example, it can be (0.4, 0.42, 0.44, 0.46, 0.48, 0.5, 0.52, 0.54, 0.56, 0.58, or 0.6):(5.0, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.4, 6.6, 6.8 or 7.0: (60, 61, 62, 63, 64, 65, 66, 67, 68, 69 or 70): (0.6, 0.62, 0.64, 0.66, 0.68, 0.7, 0.72, 0.74, 0.76, 0.78 or 0.8), but not limited to the listed values; other unlisted values ​​within this range also apply.

[0029] In some optional embodiments, the mass fraction of the aminotrimethylenephosphonic acid aqueous solution is 40-50 wt.%, for example, it can be 40 wt.%, 41 wt.%, 42 wt.%, 43 wt.%, 44 wt.%, 45 wt.%, 46 wt.%, 47 wt.%, 48 wt.%, 49 wt.%, or 50 wt.%, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0030] In some alternative embodiments, the concentration of the nitric acid solution is 1-1.5M, for example, it can be 1.0M, 1.05M, 1.1M, 1.15M, 1.2M, 1.25M, 1.3M, 1.35M, 1.4M, 1.45M or 1.5M, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0031] As a preferred embodiment of the present invention, in S3, the mass ratio of deionized water, triethylene glycol, hydroxyethyl hexahydrotriazine, hexamethylenetetramine, hexadecylpyridine chloride, and 5,5-dimethylhydantoin is (10-12):(10-12):(3-4):(1.5-2):(1-1.5):(0.5-1), for example, it can be (10.0, 10.2, 10.4, 10.6, 10.8, 11.0, 11.2, 11.4, 11.6, 11.8, or 12.0):(10.0, 10.2, 10.4, 10.6, 10.8, 11.0, 11.2, 11.4, 11.6, 11.8, or 12). 0): (3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9 or 4.0): (1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95 or 2.0): (1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 or 1.5): (0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 or 1.0), but not limited to the listed values; other unlisted values ​​within this range also apply.

[0032] As a preferred embodiment of the present invention, in S4, the mass ratio of deionized water, triethylene glycol, rare earth-phosphonic acid hybrid microgel dispersion, synergistic inhibitor solution, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine, and monoethanolamine aqueous solution is (20-24):(12-15):(20-25):(12-16):(0.8-1.2):(0.5-1):(0.3-0.6), for example, it can be (20, 20.4, 20.8, 21.2, 21.6, 22.0, 22.4, 22.8, 23.2, 23.6 or 24):(12, 12.3, 12.6, 12.9, 13.2, 13.5, 13.8, 14.1, 14.4, 14.7 or 15):(20, 20.5, 21, 21.5). 22, 22.5, 23, 23.5, 24, 24.5 or 25: (12, 12.4, 12.8, 13.2, 13.6, 14, 14.4, 14.8, 15.2, 15.6 or 16): (0.8, 0.84, 0.88, 0.92, 0.96, 1.0, 1.04, 1.08, 1.12, 1.16 or 1.2): (0 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 or 1.0: (0.3, 0.33, 0.36, 0.39, 0.42, 0.45, 0.48, 0.51, 0.54, 0.57 or 0.6), but not limited to the listed values; other unlisted values ​​within this range also apply.

[0033] In some optional embodiments, the mass fraction of the monoethanolamine aqueous solution is 50-60 wt.%, for example, it can be 50 wt.%, 51 wt.%, 52 wt.%, 53 wt.%, 54 wt.%, 55 wt.%, 56 wt.%, 57 wt.%, 58 wt.%, 59 wt.%, or 60 wt.%, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0034] Secondly, the present invention provides a biodegradable corrosion inhibitor prepared by the preparation method described in the first aspect.

[0035] Thirdly, the present invention provides a method for slow-release treatment of high-mineralization sulfur-containing water, wherein the method involves adding an anti-biodegradation corrosion inhibitor to the high-mineralization sulfur-containing water, wherein the high-mineralization sulfur-containing water is oilfield injection water and produced wastewater, and the anti-biodegradation corrosion inhibitor is an aqueous dispersion with water as the continuous phase.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention introduces a cationic microgel framework containing a hydantoin structure, and fixes palmitic acid imidazoline quaternary ammonium salt, sulfobetaine monomer and terminal siloxane segments in an aqueous dispersion in a cross-linking manner, which effectively reduces the migration and loss and biodegradation rate of small molecule corrosion inhibitors in high-mineralization sulfur-containing water environments, and prolongs the residence time of the agent at the metal interface; rare earth salts and aminophosphonic acid complex in situ in the microgel system to form a rare earth phosphonic acid hybrid film layer with multi-point coordination with the steel surface. This film layer is superimposed with the organic adsorption layer, reducing the mass transfer channels from sulfur-containing corrosive media and dissolved salts to the metal surface; hydroxyethyl hexahydrotriazine, hexamethylenetetramine and hexadecylpyridine chloride work synergistically to destroy the biofilm structure dominated by sulfate-reducing bacteria near the metal surface. At the same time, free hydantoin can form nitrogen halide fragments with sustained activity under conditions containing oxidizing components, which have an inhibitory effect on the microbial metabolic system. Attached Figure Description

[0037] Figure 1 The structural formula of 3-(4-vinylbenzyl)-5,5-dimethylhydantoin provided in Example 1 of this invention is shown.

[0038] Figure 2 The FTIR spectrum of the cationic antibacterial microgel dispersion provided in Example 1 of the present invention. Detailed Implementation

[0039] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0040] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products and have not undergone any further purification treatment.

[0041] Example 1

[0042] This embodiment provides a method for slow-release treatment of high-mineralization sulfur-containing water and an anti-biodegradation corrosion inhibitor and its preparation method, specifically including:

[0043] A method for slow-release treatment of high-salinity sulfur-containing water, the method comprising: adding an anti-biodegradation corrosion inhibitor to the high-salinity sulfur-containing water, wherein the high-salinity sulfur-containing water is oilfield injection water and produced wastewater, and the anti-biodegradation corrosion inhibitor is an aqueous dispersion with water as the continuous phase;

[0044] The preparation method of the anti-biodegradation corrosion inhibitor is as follows:

[0045] A1. 5,5-Dimethylhydantoin and sodium hydroxide were added to an aqueous ethanol solution, wherein the mass ratio of anhydrous ethanol to deionized water in the aqueous ethanol solution was 1:1, to obtain an alkaline solution. Under a nitrogen atmosphere, 4-vinylbenzyl chloride was added dropwise to the alkaline solution. After the addition was complete, the temperature was raised to 50°C, and the reaction was stirred for 4 hours. During the reaction, the pH was adjusted to 7.0 with 1M hydrochloric acid solution. After the reaction was completed, the solution was cooled to room temperature, the organic phase was extracted with ethyl acetate and dried with anhydrous sodium sulfate, and then distilled under reduced pressure and dried under vacuum to obtain 3-(4-vinylbenzyl)-5,5-dimethylhydantoin. The mass ratio of 5,5-dimethylhydantoin, sodium hydroxide, aqueous ethanol solution and 4-vinylbenzyl chloride was 12:3:50:14.

[0046] A2, palmitic acid, diethylenetriamine, and xylene were mixed and reacted at 200°C for 6 hours under nitrogen protection. The mixture was then distilled under reduced pressure to obtain a palmitic acid imidazoline intermediate. This palmitic acid imidazoline intermediate, 2-chloroethanol, and a first volume of anhydrous ethanol were mixed and refluxed at 80°C for 5 hours. After the reaction, the mixture was distilled under reduced pressure to obtain hydroxyethyl palmitic acid imidazoline. This hydroxyethyl palmitic acid imidazoline was dispersed in anhydrous dichloromethane, and triethylamine was added. The mixture was stirred and methacryloyl chloride was added dropwise under ice-water bath conditions, and the reaction was continued at room temperature for 3 hours. The mixture was washed with 1M hydrochloric acid solution, then washed with saturated sodium chloride solution, dried, and then distilled under reduced pressure. The intermediate of imidazoline palmitate methacrylate was obtained by pressure distillation. The intermediate of imidazoline palmitate methacrylate, bromohexane and the second part of anhydrous ethanol were mixed and refluxed at 70°C for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, distilled under reduced pressure, and recrystallized with acetone. The mixture was filtered and dried to obtain the quaternary ammonium salt of imidazoline palmitate methacrylate. The mass ratio of palmitic acid, diethylenetriamine, xylene, 2-chloroethanol, the first part of anhydrous ethanol, anhydrous dichloromethane, triethylamine, methacryloyl chloride, bromohexane and the second part of anhydrous ethanol was 20:12:30:8:40:30:4:5:8:30.

[0047] S1, deionized water and anhydrous isopropanol are mixed, and nitrogen gas is bubbled into the solvent to remove oxygen. Then, 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt, and methacryloyloxypropyl mono-terminated polydimethylsiloxane are added sequentially. The number average molecular weight of the methacryloyloxypropyl mono-terminated polydimethylsiloxane is 4000. Next, N,N′-methylenebisacrylamide and an aqueous solution of ammonium persulfate are added. The mass fraction of the ammonium persulfate aqueous solution is 10 wt.%. The mixture is then subjected to a nitrogen atmosphere. The reaction was carried out at 75℃ for 3 hours. After the reaction was completed, it was naturally cooled to room temperature. Triethylene glycol was added and stirred. The mixture was then filtered to obtain a cationic antibacterial microgel dispersion. The mass ratio of the deionized water, anhydrous isopropanol, 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt, methacryloyloxypropyl mono-terminated polydimethylsiloxane, N,N′-methylenebisacrylamide, ammonium persulfate aqueous solution, and triethylene glycol was 40:18:4.5:8:8:1:0.15:2:12.

[0048] S2, cerium nitrate hexahydrate is added to deionized water to obtain a cerium salt solution, which is then added dropwise to a cationic antibacterial microgel dispersion. 50 wt.% of an aminotrimethylenephosphonic acid aqueous solution is added to the cationic antibacterial microgel dispersion. The pH is adjusted to 6.5 with 1M nitric acid solution and stirring is continued to obtain a rare earth-phosphonic acid hybrid microgel dispersion. The mass ratio of cerium nitrate hexahydrate, deionized water, cationic antibacterial microgel dispersion, and aminotrimethylenephosphonic acid aqueous solution is 0.4:7:60:0.8.

[0049] S3, deionized water and triethylene glycol are mixed, and hydroxyethyl hexahydrotriazine, hexamethylenetetramine, hexadecylpyridine chloride, and 5,5-dimethylhydantoin are added sequentially to obtain a synergistic inhibitor solution. The mass ratio of deionized water, triethylene glycol, hydroxyethyl hexahydrotriazine, hexamethylenetetramine, hexadecylpyridine chloride, and 5,5-dimethylhydantoin is 10:12:4:1.5:1.5:0.5.

[0050] S4, deionized water and triethylene glycol are mixed, and rare earth-phosphonic acid hybrid microgel dispersion and synergistic inhibitor solution are added sequentially. Then, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and 60 wt.% monoethanolamine aqueous solution are added to obtain an anti-biodegradation corrosion inhibitor. The mass ratio of deionized water, triethylene glycol, rare earth-phosphonic acid hybrid microgel dispersion, synergistic inhibitor solution, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and monoethanolamine aqueous solution is 24:12:25:12:1.2:0.5:0.6.

[0051] Figure 1The structural formula of 3-(4-vinylbenzyl)-5,5-dimethylhydantoin provided in this embodiment is as follows; Figure 2 The FTIR spectrum of the cationic antibacterial microgel dispersion provided in this embodiment is shown at 3300 cm⁻¹. -1 This is an NH stretching vibration, corresponding to hydantoin and imidazoline structures; 2850 cm⁻¹ -1 For aliphatic CH stretching, corresponding to palm fiber and PDMS segments; 1730cm -1 The ester group and imide C=O stretching corresponds to the methacrylate and hydantoin skeletons; 1460cm -1 It is the vibration of NH bending and CH2 deformation.

[0052] Example 2

[0053] This embodiment provides a method for slow-release treatment of high-mineralization sulfur-containing water and an anti-biodegradation corrosion inhibitor and its preparation method, specifically including:

[0054] A method for slow-release treatment of high-salinity sulfur-containing water, the method comprising: adding an anti-biodegradation corrosion inhibitor to the high-salinity sulfur-containing water, wherein the high-salinity sulfur-containing water is oilfield injection water and produced wastewater, and the anti-biodegradation corrosion inhibitor is an aqueous dispersion with water as the continuous phase;

[0055] The preparation method of the anti-biodegradation corrosion inhibitor is as follows:

[0056] A1. 5,5-Dimethylhydantoin and sodium hydroxide were added to an aqueous ethanol solution, wherein the mass ratio of anhydrous ethanol to deionized water in the aqueous ethanol solution was 1:1, to obtain an alkaline solution. Under a nitrogen atmosphere, 4-vinylbenzyl chloride was added dropwise to the alkaline solution. After the addition was complete, the temperature was raised to 60°C, and the reaction was stirred for 3 hours. During the reaction, the pH was adjusted to 7.5 with 1.5M hydrochloric acid solution. After the reaction was completed, the solution was cooled to room temperature, the organic phase was extracted with ethyl acetate and dried with anhydrous sodium sulfate, and then distilled under reduced pressure and dried under vacuum to obtain 3-(4-vinylbenzyl)-5,5-dimethylhydantoin. The mass ratio of 5,5-dimethylhydantoin, sodium hydroxide, aqueous ethanol solution and 4-vinylbenzyl chloride was 10:4:40:16.

[0057] A2, palmitic acid, diethylenetriamine, and xylene were mixed and reacted at 230°C for 4 hours under nitrogen protection. The mixture was then distilled under reduced pressure to obtain a palmitic acid imidazoline intermediate. This palmitic acid imidazoline intermediate, 2-chloroethanol, and a first volume of anhydrous ethanol were mixed and refluxed at 90°C for 4 hours. After the reaction, the mixture was distilled under reduced pressure to obtain hydroxyethyl palmitic acid imidazoline. This hydroxyethyl palmitic acid imidazoline was dispersed in anhydrous dichloromethane, and triethylamine was added. The mixture was stirred and methacryloyl chloride was added dropwise under ice-water bath conditions, and the reaction was continued at room temperature for 4 hours. The mixture was washed with 1.5M hydrochloric acid solution, then washed with saturated sodium chloride solution, and dried. Reduced pressure distillation yielded an imidazoline palmitate methacrylate intermediate. The imidazoline palmitate methacrylate intermediate, bromohexane, and a second portion of anhydrous ethanol were mixed and refluxed at 80°C for 6 hours. After the reaction was complete, the mixture was cooled to room temperature, distilled under reduced pressure, and recrystallized with acetone. The mixture was then filtered and dried to obtain the imidazoline palmitate methacrylate quaternary ammonium salt. The mass ratio of palmitic acid, diethylenetriamine, xylene, 2-chloroethanol, the first portion of anhydrous ethanol, anhydrous dichloromethane, triethylamine, methacryloyl chloride, bromohexane, and the second portion of anhydrous ethanol was 25:10:20:10:30:40:3:6:6:40.

[0058] S1, deionized water and anhydrous isopropanol are mixed, and nitrogen gas is bubbled into the solvent to remove oxygen. Then, 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt, and methacryloyloxypropyl mono-terminated polydimethylsiloxane are added sequentially. The number average molecular weight of the methacryloyloxypropyl mono-terminated polydimethylsiloxane is 6000. Next, N,N′-methylenebisacrylamide and an aqueous solution of ammonium persulfate are added. The mass fraction of the ammonium persulfate aqueous solution is 15 wt.%. The mixture is then subjected to a nitrogen atmosphere. The reaction was carried out at 65℃ for 4 hours. After the reaction was completed, it was naturally cooled to room temperature. Triethylene glycol was added and stirred. The mixture was then filtered to obtain a cationic antibacterial microgel dispersion. The mass ratio of the deionized water, anhydrous isopropanol, 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt, methacryloyloxypropyl mono-terminated polydimethylsiloxane, N,N′-methylenebisacrylamide, ammonium persulfate aqueous solution, and triethylene glycol was 45:15:4:9:7:1.5:0.1:3:10.

[0059] S2, cerium nitrate hexahydrate is added to deionized water to obtain a cerium salt solution, which is then added dropwise to a cationic antibacterial microgel dispersion. 40 wt.% of an aminotrimethylenephosphonic acid aqueous solution is added to the cationic antibacterial microgel dispersion. The pH is adjusted to 5.5 with 1.5M nitric acid solution and stirring is continued to obtain a rare earth-phosphonic acid hybrid microgel dispersion. The mass ratio of cerium nitrate hexahydrate, deionized water, cationic antibacterial microgel dispersion, and aminotrimethylenephosphonic acid aqueous solution is 0.6:5:70:0.6.

[0060] S3, deionized water and triethylene glycol are mixed, and hydroxyethyl hexahydrotriazine, hexamethylenetetramine, hexadecylpyridine chloride and 5,5-dimethylhydantoin are added sequentially to obtain a synergistic inhibitor solution. The mass ratio of deionized water, triethylene glycol, hydroxyethyl hexahydrotriazine, hexamethylenetetramine, hexadecylpyridine chloride and 5,5-dimethylhydantoin is 12:10:3:2:1:1.

[0061] S4, deionized water and triethylene glycol are mixed, and rare earth-phosphonic acid hybrid microgel dispersion and synergistic inhibitor solution are added sequentially. Then, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and 50 wt.% monoethanolamine aqueous solution are added to obtain an anti-biodegradation corrosion inhibitor. The mass ratio of deionized water, triethylene glycol, rare earth-phosphonic acid hybrid microgel dispersion, synergistic inhibitor solution, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and monoethanolamine aqueous solution is 20:15:20:16:0.8:1:0.3.

[0062] Example 3

[0063] This embodiment provides a method for slow-release treatment of high-mineralization sulfur-containing water and an anti-biodegradation corrosion inhibitor and its preparation method, specifically including:

[0064] A method for slow-release treatment of high-salinity sulfur-containing water, the method comprising: adding an anti-biodegradation corrosion inhibitor to the high-salinity sulfur-containing water, wherein the high-salinity sulfur-containing water is oilfield injection water and produced wastewater, and the anti-biodegradation corrosion inhibitor is an aqueous dispersion with water as the continuous phase;

[0065] The preparation method of the anti-biodegradation corrosion inhibitor is as follows:

[0066] A1. 5,5-Dimethylhydantoin and sodium hydroxide were added to an aqueous ethanol solution, wherein the mass ratio of anhydrous ethanol to deionized water in the aqueous ethanol solution was 1:1, to obtain an alkaline solution. Under a nitrogen atmosphere, 4-vinylbenzyl chloride was added dropwise to the alkaline solution. After the addition was complete, the temperature was raised to 55°C, and the reaction was stirred for 3.5 h. During the reaction, the pH was adjusted to 7.2 with 1.2 M hydrochloric acid solution. After the reaction was completed, the solution was cooled to room temperature, the organic phase was extracted with ethyl acetate and dried with anhydrous sodium sulfate, and then distilled under reduced pressure and dried under vacuum to obtain 3-(4-vinylbenzyl)-5,5-dimethylhydantoin. The mass ratio of 5,5-dimethylhydantoin, sodium hydroxide, aqueous ethanol solution and 4-vinylbenzyl chloride was 11:3.5:45:15.

[0067] A2, palmitic acid, diethylenetriamine, and xylene were mixed and reacted at 215°C for 5 h under nitrogen protection. The mixture was then distilled under reduced pressure to obtain a palmitic acid imidazoline intermediate. This palmitic acid imidazoline intermediate, 2-chloroethanol, and a first volume of anhydrous ethanol were mixed and refluxed at 85°C for 4.5 h. After the reaction, the mixture was distilled under reduced pressure to obtain hydroxyethyl palmitic acid imidazoline. This hydroxyethyl palmitic acid imidazoline was dispersed in anhydrous dichloromethane, and triethylamine was added. The mixture was stirred and methacryloyl chloride was added dropwise under ice-water bath conditions, and the reaction was continued at room temperature with stirring for 3.5 h. The mixture was washed with 1.2 M hydrochloric acid solution, then washed with saturated sodium chloride solution, and dried. Reduced pressure distillation yielded an imidazoline palmitate methacrylate intermediate. This intermediate, along with monobromohexane and a second portion of anhydrous ethanol, were mixed and refluxed at 75°C for 7 hours. After the reaction, the mixture was cooled to room temperature, distilled under reduced pressure, and recrystallized with acetone. The mixture was then filtered and dried to obtain the quaternary ammonium salt of imidazoline palmitate methacrylate. The mass ratio of palmitic acid, diethylenetriamine, xylene, 2-chloroethanol, the first portion of anhydrous ethanol, anhydrous dichloromethane, triethylamine, methacryloyl chloride, monobromohexane, and the second portion of anhydrous ethanol was 22:11:25:9:35:35:3.5:5.5:7:35.

[0068] S1, deionized water and anhydrous isopropanol are mixed, and nitrogen gas is bubbled into the solvent to remove oxygen. Then, 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt, and methacryloyloxypropyl mono-terminated polydimethylsiloxane are added sequentially. The number average molecular weight of the methacryloyloxypropyl mono-terminated polydimethylsiloxane is 5000. Next, N,N′-methylenebisacrylamide and an aqueous solution of ammonium persulfate are added. The mass fraction of the ammonium persulfate aqueous solution is 12 wt.%. Under a nitrogen atmosphere, the temperature is raised to 70°C. The reaction was allowed to proceed for 3.5 hours. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. Triethylene glycol was then added and stirred. The mixture was filtered to obtain a cationic antibacterial microgel dispersion. The mass ratio of the deionized water, anhydrous isopropanol, 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt, methacryloyloxypropyl mono-terminated polydimethylsiloxane, N,N′-methylenebisacrylamide, ammonium persulfate aqueous solution, and triethylene glycol was 42:16:4.2:8.5:7.5:1.2:0.12:2.5:11.

[0069] S2, cerium nitrate hexahydrate is added to deionized water to obtain a cerium salt solution, which is then added dropwise to a cationic antibacterial microgel dispersion. 45 wt.% of an aminotrimethylenephosphonic acid aqueous solution is added to the cationic antibacterial microgel dispersion. The pH is adjusted to 6.0 with 1.2 M nitric acid solution, and stirring continues to produce a rare earth-phosphonic acid hybrid microgel dispersion. The mass ratio of cerium nitrate hexahydrate, deionized water, cationic antibacterial microgel dispersion, and aminotrimethylenephosphonic acid aqueous solution is 0.5:6:65:0.7.

[0070] S3, deionized water and triethylene glycol are mixed, and hydroxyethyl hexahydrotriazine, hexamethylenetetramine, hexadecylpyridine chloride, and 5,5-dimethylhydantoin are added sequentially to obtain a synergistic inhibitor solution. The mass ratio of deionized water, triethylene glycol, hydroxyethyl hexahydrotriazine, hexamethylenetetramine, hexadecylpyridine chloride, and 5,5-dimethylhydantoin is 11:11:3.5:1.8:1.2:0.8.

[0071] S4, deionized water and triethylene glycol are mixed, and rare earth-phosphonic acid hybrid microgel dispersion and synergistic inhibitor solution are added sequentially. Then, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and 55 wt.% monoethanolamine aqueous solution are added to obtain an anti-biodegradation corrosion inhibitor. The mass ratio of deionized water, triethylene glycol, rare earth-phosphonic acid hybrid microgel dispersion, synergistic inhibitor solution, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and monoethanolamine aqueous solution is 22:14:22:14:1.0:0.8:0.5.

[0072] Example 4

[0073] This embodiment provides a method for slow-release treatment of high-mineralization sulfur-containing water and an anti-biodegradation corrosion inhibitor and its preparation method, specifically including:

[0074] A method for slow-release treatment of high-salinity sulfur-containing water, the method comprising: adding an anti-biodegradation corrosion inhibitor to the high-salinity sulfur-containing water, wherein the high-salinity sulfur-containing water is oilfield injection water and produced wastewater, and the anti-biodegradation corrosion inhibitor is an aqueous dispersion with water as the continuous phase;

[0075] The preparation method of the anti-biodegradation corrosion inhibitor is as follows:

[0076] A1. 5,5-Dimethylhydantoin and sodium hydroxide were added to an aqueous ethanol solution, wherein the mass ratio of anhydrous ethanol to deionized water in the aqueous ethanol solution was 1:1, to obtain an alkaline solution. Under a nitrogen atmosphere, 4-vinylbenzyl chloride was added dropwise to the alkaline solution. After the addition was complete, the temperature was raised to 58°C, and the reaction was stirred for 3.2 h. During the reaction, the pH was adjusted to 7.4 with 1.4 M hydrochloric acid solution. After the reaction was completed, the solution was cooled to room temperature, the organic phase was extracted with ethyl acetate and dried with anhydrous sodium sulfate, and then distilled under reduced pressure and dried under vacuum to obtain 3-(4-vinylbenzyl)-5,5-dimethylhydantoin. The mass ratio of 5,5-dimethylhydantoin, sodium hydroxide, aqueous ethanol solution and 4-vinylbenzyl chloride was 11.5:3.8:48:15.5.

[0077] A2, palmitic acid, diethylenetriamine, and xylene were mixed and reacted at 225°C for 4.5 h under nitrogen protection. The mixture was then distilled under reduced pressure to obtain a palmitic acid imidazoline intermediate. This palmitic acid imidazoline intermediate, 2-chloroethanol, and a first volume of anhydrous ethanol were mixed and refluxed at 88°C for 4.2 h. After the reaction, the mixture was distilled under reduced pressure to obtain hydroxyethyl palmitic acid imidazoline. This hydroxyethyl palmitic acid imidazoline was dispersed in anhydrous dichloromethane, and triethylamine was added. The mixture was stirred and methacryloyl chloride was added dropwise under ice-water bath conditions, and the reaction was continued at room temperature with stirring for 3.8 h. The mixture was washed with 1.4 M hydrochloric acid solution, then washed with saturated sodium chloride solution, dried, and then distilled under reduced pressure. Distillation yielded an imidazoline palmitate methacrylate intermediate. The imidazoline palmitate methacrylate intermediate, bromohexane, and a second portion of anhydrous ethanol were mixed and refluxed at 78°C for 6.5 h. After the reaction was complete, the mixture was cooled to room temperature, distilled under reduced pressure, and recrystallized with acetone. The mixture was then filtered and dried to obtain the quaternary ammonium salt of imidazoline palmitate methacrylate. The mass ratio of palmitic acid, diethylenetriamine, xylene, 2-chloroethanol, the first portion of anhydrous ethanol, anhydrous dichloromethane, triethylamine, methacryloyl chloride, bromohexane, and the second portion of anhydrous ethanol was 24:11.5:28:9.5:38:38:3.8:5.8:7.5:38.

[0078] S1, deionized water and anhydrous isopropanol are mixed, and nitrogen gas is bubbled into the solvent to remove oxygen. Then, 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt, and methacryloyloxypropyl mono-terminated polydimethylsiloxane are added sequentially. The number average molecular weight of the methacryloyloxypropyl mono-terminated polydimethylsiloxane is 5500. Next, N,N′-methylenebisacrylamide and an aqueous solution of ammonium persulfate are added. The mass fraction of the ammonium persulfate aqueous solution is 14 wt.%. The mixture is heated to 72°C under a nitrogen atmosphere. After 3.2 hours of reaction, the mixture was allowed to cool naturally to room temperature. Triethylene glycol was then added and stirred. The mixture was filtered to obtain a cationic antibacterial microgel dispersion. The mass ratio of the deionized water, anhydrous isopropanol, 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt, methacryloyloxypropyl mono-terminated polydimethylsiloxane, N,N′-methylenebisacrylamide, ammonium persulfate aqueous solution, and triethylene glycol was 43:17:4.3:8.8:7.8:1.3:0.14:2.8:11.5.

[0079] S2, cerium nitrate hexahydrate is added to deionized water to obtain a cerium salt solution, which is then added dropwise to a cationic antibacterial microgel dispersion. 48 wt.% of an aminotrimethylenephosphonic acid aqueous solution is added to the cationic antibacterial microgel dispersion. The pH is adjusted to 6.2 with 1.3M nitric acid solution, and stirring continues to produce a rare earth-phosphonic acid hybrid microgel dispersion. The mass ratio of cerium nitrate hexahydrate, deionized water, cationic antibacterial microgel dispersion, and aminotrimethylenephosphonic acid aqueous solution is 0.55:6.5:68:0.75.

[0080] S3, deionized water and triethylene glycol are mixed, and hydroxyethyl hexahydrotriazine, hexamethylenetetramine, hexadecylpyridine chloride, and 5,5-dimethylhydantoin are added sequentially to obtain a synergistic inhibitor solution. The mass ratio of deionized water, triethylene glycol, hydroxyethyl hexahydrotriazine, hexamethylenetetramine, hexadecylpyridine chloride, and 5,5-dimethylhydantoin is 11.5:11.5:3.8:1.9:1.3:0.9.

[0081] S4, deionized water and triethylene glycol are mixed, and rare earth-phosphonic acid hybrid microgel dispersion and synergistic inhibitor solution are added sequentially. Then, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and 58 wt.% monoethanolamine aqueous solution are added to obtain an anti-biodegradation corrosion inhibitor. The mass ratio of deionized water, triethylene glycol, rare earth-phosphonic acid hybrid microgel dispersion, synergistic inhibitor solution, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and monoethanolamine aqueous solution is 23:13.5:23.5:15:0.9:0.6:0.4.

[0082] Comparative Example 1

[0083] This embodiment provides a method for slow-release treatment of high-mineralization sulfur-containing water and an anti-biodegradation corrosion inhibitor and its preparation method. The difference between this embodiment and Example 1 is that 3-(4-vinylbenzyl)-5,5-dimethylhydantoin is not added in S1, and 5,5-dimethylhydantoin is not added in S3. Other process parameters and operating conditions are exactly the same as in Example 1.

[0084] Comparative Example 2

[0085] This embodiment provides a method for slow-release treatment of high-mineralization sulfur-containing water and an anti-biodegradation corrosion inhibitor and its preparation method. The difference between this embodiment and Example 1 is that N,N′-methylenebisacrylamide is not added in S1, while other process parameters and operating conditions are exactly the same as in Example 1.

[0086] Comparative Example 3

[0087] This embodiment provides a method for slow-release treatment of high-mineralization sulfur-containing water and an anti-biodegradation corrosion inhibitor and its preparation method. The difference between this embodiment and Example 1 is that step S3 is not performed. In step S4, only the rare earth-phosphonic acid hybrid microgel dispersion is mixed with deionized water, triethylene glycol, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and monoethanolamine aqueous solution. Other process parameters and operating conditions are exactly the same as in Example 1.

[0088] Performance testing:

[0089] The corrosion rate and corrosion inhibition rate testing method is as follows: N80 steel specimens with dimensions of 50mm × 25mm × 2mm are selected. Both sides and edges of the specimen are subjected to corrosion, and the geometric surface area is approximately 28cm³. 2After being sanded in sequence with 240#, 400#, and 600# sandpaper, degreased with acetone, rinsed with deionized water, and dried at 50℃ for 1 hour, the material was placed in a desiccator to cool to room temperature and then accurately weighed, and the initial mass m0 was recorded. A simulated high-mineralization sulfur-containing corrosive medium was prepared: 80.0 g of sodium chloride, 5.0 g of calcium chloride dihydrate, 3.0 g of magnesium chloride hexahydrate, 1.0 g of sodium bicarbonate, and 2.0 g of sodium sulfate were weighed and dissolved in deionized water, and the volume was adjusted to 1.00 L. The total sulfide concentration was adjusted to 200 mg / L using sodium hydrosulfide solution, the pH was adjusted to 4.5 ± 0.1, and nitrogen gas was purged for 0.5 h to remove dissolved oxygen. Then, a mixed gas (5% hydrogen sulfide, 20% carbon dioxide, and the remainder nitrogen) was purged at a flow rate of 50 mL / min for 30 min to establish a sulfuric acid atmosphere. The pretreated carbon steel test piece was vertically suspended in the solution, ensuring complete immersion. The reaction vessel was closed and the sample was left to soak in an 80°C constant temperature water bath for 72 hours. After the test, the test piece was removed and immediately rinsed with deionized water to remove surface corrosion products. It was then soaked in a pre-selected chemical rust remover (10 wt.% ferric chloride solution) at room temperature for 3–5 minutes to remove rust. After rust removal, it was rinsed thoroughly with plenty of deionized water, dehydrated with acetone, dried at 50°C for 1 hour, and then placed in a desiccator to cool to room temperature before weighing. The mass m1 after the test was recorded. The mass loss was calculated using Δm = m0 – m1. The corrosion rate can be calculated using the formula v = 8.76 × 10⁻¹⁰. 4 The calculation is based on ×Δm / (ρ·S·t), with units of mm / a, where ρ is the density of the sample material, taken as 7.85 g / cm³. 3 S represents the eroded area of ​​the sample, in cm². 2 t represents the immersion time in hours. Parallel experiments were conducted under the same conditions in a blank corrosive medium without added water treatment agent to obtain the blank corrosion rate v0. The corrosion inhibition rate η was calculated as (v0 - v) / v0 × 100%.

[0090] Anti-biodegradation aging conditions: The aging medium for the anti-biodegradation aging test was simulated high-mineralization sulfur-containing water, prepared using the same method as the aforementioned corrosive medium, but with an initial pH adjustment of 7.0±0.1. Two 1L glass bottles were used, each containing 800mL of simulated high-mineralization sulfur-containing water, to form a sterile aging system and a bacterial aging system, respectively. The sterile aging system was autoclaved at 121℃ for 30min, purged with nitrogen for 15min to remove dissolved oxygen, sealed, and placed in a 37℃ constant temperature incubator for 14d of static aging. The bacterial aging system was inoculated with mixed sludge from oilfield injection water and produced water at room temperature, with an inoculation amount of 5% (v / v) of the system volume. Sodium lactate and yeast extract were added as carbon and nitrogen sources, respectively, with a sodium lactate concentration of 1.0g / L and a yeast extract concentration of 0.5g / L. After purging with nitrogen for 15min to remove dissolved oxygen, the system was sealed and placed in a 37℃ constant temperature anaerobic environment for 14d of static aging. No water treatment agent is added during the aging process. The water is gently shaken periodically to ensure that the agent comes into full contact with the water and bacteria. At the end of the aging process, a water treatment agent system aged under sterile conditions and a water treatment agent system aged under bacterial conditions are obtained respectively.

[0091] The corrosion inhibition performance test after aging was conducted as follows: aging solutions that had undergone sterile aging and bacterial aging were used to prepare simulated corrosion media with the same initial conditions, and the corrosion rate and corrosion inhibition rate of carbon steel were determined using the same static weight loss method.

[0092] The test results are shown in Table 1.

[0093] Table 1. Test results of anti-biodegradation corrosion inhibitors in Examples 1-4 and Comparative Examples 1-3

[0094]

[0095] As shown in Table 1, compared to Example 1, the corrosion rate of Comparative Example 1 increased and the corrosion inhibition rate decreased; the corrosion rate of Comparative Example 2 increased and the corrosion inhibition rate decreased; and the corrosion rate of Comparative Example 3 increased and the corrosion inhibition rate decreased. This is because Comparative Example 1 did not contain hydantoin monomer or free hydantoin, and the polymer skeleton lacked a restricted imide structure. Microorganisms were more likely to attack the quaternary ammonium salt and sulfobetaine side chains. After bacterial aging, the microgel network underwent chain breakage and ring opening, and the integrity of the cation adsorption membrane decreased, resulting in a decrease in the corrosion inhibition rate. Comparative Example 2 did not contain N,N′-methylenebisacrylamide and only formed a linear cation copolymer. The film layer adsorbed on the metal surface by electrostatics was loose. During the aging process, the chain segments were easily desorbed, swollen, and hydrolyzed under high salt and sulfide conditions, resulting in a decrease in the interfacial polymer packing density. During bacterial aging, biological metabolism further damaged the adsorption layer, resulting in a decrease in the corrosion inhibition rate. Comparative Example 3 did not include hydroxyethyl hexahydrotriazine, hexamethylenetetramine, and hexadecylpyridine chloride. The system lacked components that synergistically inhibit bacteria and biofilm. After bacterial aging, sulfate-reducing bacteria and other bacteria rapidly multiplied on the metal surface, leading to increased corrosion and reduced corrosion inhibition rate.

[0096] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing an anti-biodegradation corrosion inhibitor, characterized in that, The preparation method includes: S1, deionized water and anhydrous isopropanol are mixed, and 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt and methacryloyloxypropyl mono-terminated polydimethylsiloxane are added in sequence. Then N,N′-methylenebisacrylamide is added and reacted with ammonium persulfate aqueous solution. After the reaction is completed, triethylene glycol is added to obtain cationic antibacterial microgel dispersion. S2, add cerium nitrate hexahydrate to deionized water to obtain cerium salt solution and add it dropwise to cationic antibacterial microgel dispersion. Then add aminotrimethylene phosphonic acid aqueous solution to cationic antibacterial microgel dispersion, adjust the pH with nitric acid solution and continue stirring to obtain rare earth-phosphonic acid hybrid microgel dispersion. S3, deionized water and triethylene glycol are mixed, and hydroxyethyl hexahydrotriazine, hexamethylenetetramine, and hexadecylpyridine chloride and 5,5-dimethylhydantoin are added sequentially to obtain a synergistic inhibitor solution; S4. Deionized water and triethylene glycol are mixed, and rare earth-phosphonic acid hybrid microgel dispersion and synergistic inhibitor solution are added sequentially. Then, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and monoethanolamine aqueous solution are added to obtain an anti-biodegradation corrosion inhibitor.

2. The method for preparing an anti-biodegradation corrosion inhibitor according to claim 1, characterized in that, The preparation method of the 3-(4-vinylbenzyl)-5,5-dimethylhydantoin is as follows: A1. 5,5-Dimethylhydantoin and sodium hydroxide were added to an aqueous ethanol solution to obtain an alkaline solution. 4-Vinylbenzyl chloride was then added dropwise to the alkaline solution to react and obtain 3-(4-vinylbenzyl)-5,5-dimethylhydantoin.

3. The method for preparing an anti-biodegradation corrosion inhibitor according to claim 1, characterized in that, The preparation method of the palmitic acid imidazoline methacrylate quaternary ammonium salt is as follows: A2, palmitic acid, diethylenetriamine and xylene are mixed and reacted to obtain palmitic acid imidazoline intermediate. The palmitic acid imidazoline intermediate, 2-chloroethanol and a first part of anhydrous ethanol are mixed and reacted to obtain hydroxyethyl palmitic acid imidazoline. The hydroxyethyl palmitic acid imidazoline is dispersed in anhydrous dichloromethane, triethylamine is added and methacryloyl chloride is added dropwise to obtain palmitic acid imidazoline methacrylate intermediate. The palmitic acid imidazoline methacrylate intermediate, monobromohexane and a second part of anhydrous ethanol are mixed and reacted to obtain palmitic acid imidazoline methacrylate quaternary ammonium salt.

4. The method for preparing an anti-biodegradation corrosion inhibitor according to claim 1, characterized in that, In S1: The mass ratio of the deionized water, anhydrous isopropanol, 3-(4-vinylbenzyl)-5,5-dimethylhydantoin, methacryloyloxyethyl sulfobetaine, imidazoline palmitate methacrylate quaternary ammonium salt, methacryloyloxypropyl mono-terminated polydimethylsiloxane, N,N′-methylenebisacrylamide, ammonium persulfate aqueous solution, and triethylene glycol is (40-45):(15-18):(4-4.5):(8-9):(7-8):(1-1.5):(0.1-0.15):(2-3):(10-12).

5. The method for preparing an anti-biodegradation corrosion inhibitor according to claim 1, characterized in that, In S2: The mass ratio of cerium nitrate hexahydrate, deionized water, cationic antibacterial microgel dispersion to aminotrimethylenephosphonic acid aqueous solution is (0.4-0.6):(5-7):(60-70):(0.6-0.8).

6. The method for preparing an anti-biodegradation corrosion inhibitor according to claim 1, characterized in that, In S3, the mass ratio of deionized water, triethylene glycol, hydroxyethyl hexahydrotriazine, hexamethylenetetramine, hexadecylpyridine chloride, and 5,5-dimethylhydantoin is (10-12):(10-12):(3-4):(1.5-2):(1-1.5):(0.5-1). The mass ratio of deionized water, triethylene glycol, rare earth-phosphonic acid hybrid microgel dispersion, synergistic inhibitor solution, fatty alcohol polyoxyethylene ether, cocamidopropyl betaine and monoethanolamine aqueous solution in S4 is (20-24):(12-15):(20-25):(12-16):(0.8-1.2):(0.5-1):(0.3-0.6).

7. The method for preparing an anti-biodegradation corrosion inhibitor according to claim 2, characterized in that, In A1: The mass ratio of the 5,5-dimethylhydantoin, sodium hydroxide, aqueous ethanol solution and 4-vinylbenzyl chloride is (10-12):(3-4):(40-50):(14-16).

8. The method for preparing an anti-biodegradation corrosion inhibitor according to claim 3, characterized in that, In A2: The mass ratio of palmitic acid, diethylenetriamine, xylene, 2-chloroethanol, the first part of anhydrous ethanol, anhydrous dichloromethane, triethylamine, methacryloyl chloride, monobromohexane and the second part of anhydrous ethanol is (20-25): (10-12): (20-30): (8-10): (30-40): (30-40): (3-4): (5-6): (6-8): (30-40).

9. A biodegradable corrosion inhibitor, characterized in that, Prepared by the preparation method according to any one of claims 1-8.

10. A method for slow-release treatment of highly mineralized sulfur-containing water, characterized in that, The slow-release treatment method includes: adding the anti-biodegradation corrosion inhibitor of claim 9 to high-salinity sulfur-containing water, wherein the high-salinity sulfur-containing water is oilfield injection water and produced wastewater, and the anti-biodegradation corrosion inhibitor is an aqueous dispersion with water as the continuous phase.

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