Multi-effect corrosion and scale inhibition water treatment agent and preparation method thereof

Abstract

The invention discloses a multi-effect corrosion and scale inhibition water treatment agent and a preparation method thereof, modified tannic acid extracted from agricultural waste camellia oleifera shells and hydroxyapatite nano powder prepared from industrial tailings are taken as cores, and camellia oleifera shell flavonoid derivatives are compounded. The three components cooperate to realize the functions of corrosion inhibition, scale inhibition, biological inhibition, biofilm resistance and silicon scale resistance, the pathogenic bacterium inhibition rate is 98-99.5%, the silicon scale inhibition rate is 90-94%, and the biodegradation rate is 95-98%. A one-step in-situ composite process is adopted, mineral powder generation and tannic acid extraction are synchronously completed, energy consumption is reduced by 35%-45%, the product storage period is 18 months, waste is treated with waste, phosphorus pollution is avoided, and the method is suitable for high-silicon complex water quality.

Description

Technical Field

[0001] This invention relates to the field of industrial water treatment agent technology, specifically to a multi-effect corrosion and scale inhibitor water treatment agent and its preparation method. Background Technology

[0002] Currently, phosphorus-free corrosion and scale inhibitors have become a research hotspot in industrial circulating water treatment due to environmental protection requirements. However, existing products mostly rely on synthetic polymers or single natural / mineral-based materials, resulting in limited functionality and weak anti-fouling capabilities. Most phosphorus-free agents can only achieve single functions of corrosion inhibition or scale inhibition, making it difficult to simultaneously address the challenges of biological pollution, biofilm adhesion, and silica scale deposition in high-silica water. Furthermore, the raw materials are mostly chemically synthesized products, lacking environmental friendliness. Meanwhile, agricultural waste such as camellia shells and industrial tailings are often left idle and discarded, causing resource waste and environmental pressure. In addition, traditional preparation processes often employ a "separate preparation and mixing" model, which suffers from high energy consumption, poor product stability, and short shelf life, failing to meet the demands of complex water treatment and green, low-carbon production. Therefore, developing a multi-functional corrosion and scale inhibitor that utilizes waste resources as raw materials, offers comprehensive functionality, and boasts efficient processing has become an urgent need in the current industrial water treatment field. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a multi-effect corrosion and scale inhibitor water treatment agent and its preparation method. This water treatment agent uses agricultural waste camellia shells and industrial tailings as raw materials to achieve "waste treatment with waste." It has multiple functions including corrosion inhibition, scale inhibition, biofilm inhibition, anti-biofilm, and anti-silica scale. At the same time, it exhibits excellent performance in terms of environmental protection, compatibility, and stability, and can meet the industrial water treatment needs under complex water quality conditions such as high silica and high pollution.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A multi-effect corrosion and scale inhibitor water treatment agent, wherein the water treatment agent is prepared from the following raw materials in parts by weight: The mixture comprises 20-35 parts modified tannic acid, 15-25 parts hydroxyapatite nanopowder, 5-10 parts camellia oleifera shell flavonoid derivatives, 2-5 parts dispersant, and 30-50 parts deionized water. The tannic acid raw powder is extracted from agricultural waste camellia oleifera shells and then chemically modified. The hydroxyapatite nanopowder is prepared from industrial tailings. The camellia oleifera shell flavonoid derivatives are extracted from the residue after tannic acid extraction from camellia oleifera shells.

[0005] Preferably, the extraction process of the tannic acid raw powder is microwave-assisted alcoholysis technology: using 80-120 mesh camellia shell powder as raw material, ethanol as solvent, microwave power of 300-500 W, extraction temperature of 60-70℃ for 1-1.5 h, the extraction rate is 65%-75%, and the catechol structure on the molecular chain is retained after extraction.

[0006] Preferably, the chemical modification process of the modified tannic acid is as follows: tannic acid raw powder is mixed with propylene oxide with a purity of 99.5%-99.9% at a mass ratio of 1:0.3-0.5, and the mixture is stirred and reacted for 1.5-2.5 h under the conditions of a water content of 2%-5% and a temperature of 70-80℃ to introduce hydrophilic hydroxyl groups. The hydroxyl value of the modified tannic acid is 300-400 mg KOH / g.

[0007] Preferably, the hydroxyapatite nanoparticles have a particle size of 50-200 nm and a specific surface area of ​​30-60 m². 2 / g, obtained in situ through acid leaching of industrial tailings.

[0008] Preferably, the camellia husk flavonoid derivatives, in synergy with modified tannic acid and hydroxyapatite nanopowder, exhibit an inhibition rate of 98%-99.5% against Escherichia coli, sulfate-reducing bacteria, and iron bacteria, and reduce biofilm adhesion by 70%-80%.

[0009] Preferably, the water treatment agent has a scale inhibition rate of 90%-94% for silica scale and 95%-98% for calcium and magnesium scale in water with a silica content of 200-300 mg / L, and a corrosion inhibition rate of 0.050-0.075 mm / a for carbon steel.

[0010] Preferably, the dispersant is polyethylene glycol or sodium dodecylbenzenesulfonate with a molecular weight of 400-1000.

[0011] Preferably, the preparation method of the multi-effect corrosion and scale inhibitor water treatment agent includes the following specific preparation steps: S1. Crush industrial tailings to 100-150 mesh, add a mixed acid leaching solution of hydrochloric acid and sulfuric acid at a volume ratio of 1:1-1:2 and a pH of 1.5-2.5, stir and react for 1-2 hours to obtain tailings acid leaching base solution. S2. Add 80-120 mesh pretreated camellia shell powder to the base liquid, and keep it warm and stir at 50-60℃ for 2-3 hours to simultaneously achieve the generation of hydroxyapatite nanopowder and the extraction of tannic acid raw powder. S3. Add 99.5%-99.9% pure propylene oxide to the system, control the water content of the reaction system to 2%-5%, heat to 70-80℃ and react for 1.5-2.5 h to complete the tannic acid modification; S4. Add camellia oleifera shell flavonoid derivatives and dispersant, and continue stirring for 0.5-1 h to form a stable core-shell structure composite system; S5. Filter to remove impurities, cool to room temperature, and obtain the multi-effect corrosion and scale inhibitor water treatment agent.

[0012] Preferably, the pretreatment process of "pre-treated camellia shell powder" in step S2 is as follows: the camellia shells are washed with clean water to remove impurities, air-dried naturally, pulverized to 80-120 mesh, and dried at 100-110℃ for 2-3 hours, controlling the moisture content of the pre-treated powder to 1%-3%.

[0013] Preferably, the energy consumption of the preparation process is reduced by 35%-45% compared with the traditional "separate preparation and mixing" process, the product has a storage period of 16-18 months, and there is no stratification or precipitation.

[0014] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: The multi-effect corrosion and scale inhibitor water treatment agent prepared by the present invention has excellent comprehensive performance, with a scale inhibition rate of 90%-94% for silica scale and 95%-98% for calcium and magnesium scale in water with a silica content of 200-300 mg / L, a corrosion inhibition rate of 0.050-0.075 mm / a for carbon steel, an inhibition rate of 98%-99.5% for pathogenic bacteria, and a reduction of biofilm adhesion by 70%-80%; the raw materials are camellia shells, industrial tailings and other wastes, with a biodegradability rate of 95%-98% and no phosphorus residue, realizing "waste treatment with waste"; the one-step in-situ process reduces energy consumption by 35%-45%, the product has a shelf life of 16-18 months without stratification, is suitable for complex water quality, and has both environmental protection and practical value. Attached Figure Description

[0015] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0016] Figure 1 A bar chart comparing the scale inhibition rates of silicon, calcium and magnesium scale and the Escherichia coli inhibition rates of different samples of this invention. Figure 2 This is a bar chart comparing the biodegradation rate and total phosphorus content of different samples in this invention over 28 days. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] Example 1: This embodiment 1 describes a multi-effect corrosion and scale inhibitor water treatment agent, which is prepared from the following raw materials in parts by weight: 25 parts modified tannic acid, 20 parts hydroxyapatite nanopowder, 8 parts camellia oleifera shell flavonoid derivatives, 3 parts polyethylene glycol dispersant, and 44 parts deionized water. This embodiment describes a method for preparing a multi-effect corrosion and scale inhibitor water treatment agent. The specific preparation steps are as follows: S1. Prepare a hydrochloric acid-sulfuric acid mixed leaching solution (pH=2.0) at a volume ratio of 1:1. Add the leaching solution to 100-150 mesh phosphorus-calcium type industrial tailings at a liquid-to-solid ratio of 5:1 (mL / g). Stir the reaction at 50℃ for 1.5 h. Simultaneously adjust the pH of the system to 4.5-5.0 to promote the initial polymerization of the precursor to form hydroxyapatite microcrystals, and obtain the tailings acid leaching base solution containing hydroxyapatite precursor. S2. Extraction of tannic acid raw powder: Add 80-120 mesh pretreated camellia shell powder (washed-dried-pulverized-dried at 105℃ for 2.5 h, moisture content 2%) to the above base solution, heat to 55℃ and stir for 2.5 h; during this process, the tannic acid in the camellia shell is dissolved under microwave-assisted alcoholysis (microwave power 400 W, ethanol as extraction medium, material-liquid ratio 1:15 g / mL), and the tannic acid extract (used for subsequent modification) and camellia shell residue (retained for the extraction of flavonoid derivatives) are obtained by filtration and separation. At the same time, the hydroxyapatite microcrystals in the base solution grow into nanoparticles with a particle size of 50-200 nm under the dispersion of tannic acid. S3. Take the camellia oleifera shell residue separated in step S2, add 70% ethanol solution at a material-to-liquid ratio of 1:20 g / mL, reflux extract at 60℃ for 1.5 h, filter, adjust the pH of the filtrate to 7.0 with sodium hydroxide solution, concentrate and dry to obtain camellia oleifera shell flavonoid derivatives. S4. Add the tannic acid extract from step S2 to the base solution containing hydroxyapatite nanopowder, then add propylene oxide (tannic acid powder to propylene oxide mass ratio 1:0.4). Adjust the water content of the system to 3% by vacuum distillation, heat to 75℃ and stir for 2 h. The modification is completed by introducing hydrophilic hydroxyl groups through the ring-opening reaction between propylene oxide and the hydroxyl groups of tannic acid. S5. Add the prepared camellia shell flavonoid derivatives and dispersant, stir at 700 rpm for 0.8 h to form a core-shell composite system of "modified tannic acid-hydroxyapatite nanopowder-flavonoid derivatives". Use vacuum filtration (using a 0.45μm ceramic filter membrane) to filter and remove unreacted tailings impurities and a small amount of insoluble residues from the system. Collect the filtrate and cool it to room temperature to obtain a uniform and transparent target water treatment agent.

[0019] Example 2: This embodiment 2 presents a multi-effect corrosion and scale inhibitor water treatment agent, which is prepared from the following raw materials in parts by weight: Modified tannic acid 30 parts, hydroxyapatite nanopowder 15 parts, camellia oleifera shell flavonoid derivatives 8 parts, dispersant: polyethylene glycol 3 parts, deionized water 44 parts. The preparation method of the multi-effect corrosion and scale inhibitor water treatment agent in this embodiment is the same as that in Example 1.

[0020] Example 3: This embodiment 3 describes a multi-effect corrosion and scale inhibitor water treatment agent, which is prepared from the following raw materials in parts by weight: 20 parts modified tannic acid, 25 parts hydroxyapatite nanopowder, 8 parts camellia oleifera shell flavonoid derivatives, dispersant: 3 parts polyethylene glycol, 44 parts deionized water; The preparation method of the multi-effect corrosion and scale inhibitor water treatment agent in this embodiment is the same as that in Example 1.

[0021] Comparative Example 1: This Comparative Example 1 describes a multi-effect corrosion and scale inhibitor water treatment agent, which is prepared from the following raw materials in parts by weight: Modified tannic acid 0 parts, hydroxyapatite nanopowder 35 parts, camellia oleifera shell flavonoid derivatives 8 parts, dispersant: polyethylene glycol 3 parts, deionized water 54 parts; The preparation method of the multi-effect corrosion and scale inhibitor water treatment agent in this comparative example is the same as that in Example 1, except that tannic acid is not added.

[0022] Comparative Example 2: This Comparative Example 2 describes a multi-effect corrosion and scale inhibitor water treatment agent, which is prepared from the following raw materials in parts by weight: 25 parts modified tannic acid, 20 parts hydroxyapatite nanopowder, 0 parts camellia oleifera shell flavonoid derivatives, dispersant: 3 parts polyethylene glycol, 52 parts deionized water; The preparation method of the multi-effect corrosion and scale inhibitor water treatment agent in this comparative example is the same as that in Example 1, except that the extraction and addition of flavonoid derivatives are omitted.

[0023] Performance testing 1. Scale inhibition performance test (1) Scale inhibition rate of silica This experiment evaluated the scale inhibition effect of the water treatment agent of this invention on silica scale by simulating a high-silica water sample. First, a stock solution with a silica content of 50 mg / L was prepared. 100 mL of the stock solution was added to two 100 mL stoppered colorimetric tubes. One tube contained the 50 mg / L water treatment agent (experimental group), and the other contained no agent (blank group). The pH of the solution was adjusted to 7.0-7.5, and the volume was brought up with deionized water to a silica content of 200-300 mg / L. Both solutions were allowed to stand in a 50℃ constant temperature water bath for 24 h to ensure silica scale precipitation. After the reaction, the solution was cooled to room temperature and filtered. The silica content in the filtrate was determined using ammonium molybdate spectrophotometry. By comparing the silica content of the experimental group and the blank group, the scale inhibition rate was calculated using the following formula:

[0024]

[0025] Where η1 is the scale inhibition rate, C 00To simulate the initial silicon content of the water sample, C1 and C0 represent the silicon content of the experimental group and the blank group after the reaction, respectively.

[0026] (2) Test procedure for calcium and magnesium scale inhibition rate (ethylenediaminetetraacetic acid (EDTA) titration method) To prepare simulated hard water, calcium and magnesium standard solutions were added to obtain a Ca concentration of 250 mg / L. 2+ and 100 mg / L Mg 2+ Hard water was divided into two groups: an experimental group (treated with 50 mg / L water treatment agent) and a control group (no treatment agent). The pH of the solution was adjusted to 7.0-8.0, and both solutions were placed in an 80℃ constant temperature water bath and allowed to stand for 10 h, gently stirred every 2 h to ensure uniform reaction. After the reaction, the solution was cooled to room temperature, filtered to remove the precipitated calcium and magnesium scale, and the filtrate was collected. Buffer solution and Eriochrome Black T indicator were added, and EDTA titration was performed until the solution changed from purple-red to pure blue. The volume of EDTA consumed was recorded. The scale inhibition rate of calcium and magnesium scale was calculated by calculating the total concentration of remaining calcium and magnesium. Three parallel experiments were performed for each sample, and the average value was taken as the final result. The relative standard deviation (RSD) of the experimental data must be ≤5%.

[0027] Table 1. Scale inhibition performance test data of different samples

[0028] Examples 1-3 showed scale inhibition rates of 91.0%-93.2% for silica scale and 96.0%-98.0% for calcium and magnesium scale, significantly better than the comparative examples (silica scale inhibition rate 45.0%-88.0%, calcium and magnesium scale inhibition rate 62.0%-95.0%), while the scale inhibition rate of the blank group was only 10.0%-20.0%, highlighting the product's targeted scale inhibition effect on high-silica (200-300 mg / L) and high-hardness water. This result verifies that the "modified tannic acid + hydroxyapatite" synergistic system can effectively inhibit silica scale polymerization and calcium and magnesium ion deposition, solving the problem of high-silica scaling in industrial circulating water.

[0029] 2. Corrosion Inhibition Performance Test The carbon steel immersion plates were precisely measured, cleaned with acetone and ethanol, dried at 105℃, and their initial mass was measured. Simulated water was prepared according to the composition of industrial circulating water and the pH was adjusted to 7.5-8.5. Examples 1-3, Comparative Examples 1-2, and the blank group were placed in 1000 mL corrosion test bottles. The experimental groups were treated with 50 mg / L water treatment agent, while the blank group received no agent. The immersion plates were fixed on a rotating immersion plate apparatus and continuously immersed for 72 h at 45℃ and 50 rpm. After the experiment, the immersion plates were removed, cleaned, dried, and their post-corrosion mass was measured. Three parallel experiments were set up for each group, and the corrosion inhibition rate was calculated. An RSD ≤ 5% was considered a valid result. Simultaneously, the corrosion inhibition rate was calculated based on the corrosion inhibition rates of the blank group and the sample group for a visual evaluation of the corrosion inhibition effect.

[0030] Table 2. Test data on corrosion inhibition performance of different samples

[0031] The corrosion inhibition rates of carbon steel in Examples 1-3 were only 0.055-0.065 mm / a, far below the industrial acceptable threshold (≤0.1 mm / a), and the corrosion inhibition effect was significantly better than that of Comparative Example 1 (0.185 mm / a, lacking modified tannic acid) and the blank group (0.600 mm / a). The data demonstrate that the adsorption film-forming effect of modified tannic acid synergistically combines with the defect-filling function of hydroxyapatite to construct a dense protective film on the carbon steel surface, effectively reducing the risk of corrosion.

[0032] 3. Antibacterial performance test Nutrient broth media for Escherichia coli, sulfate-reducing bacteria, and iron bacteria were prepared separately. The target bacterial strains were inoculated into each medium, and the bacterial concentration was adjusted to 10. 6 The water treatment agent sample of this invention was added at CFU / mL according to the actual industrial dosage. A blank control group without water treatment agent was set up. All samples were placed in a constant temperature incubator at 37℃ and continuously cultured for 24 h. After the culture, the colony count of the experimental group and the blank control group was determined by plate counting method. The 24 h inhibition rate of the three bacterial species was calculated. Three parallel experiments were set up for each sample. RSD≤5% was considered a valid result, thereby verifying the broad-spectrum antibacterial effect of the product.

[0033] Table 3. Test data on antibacterial properties of different samples

[0034] 4. Anti-biofilm performance test After being pretreated by grinding, degreasing, and sterilization, stainless steel test pieces were placed separately into a circulating water system containing a mixed bacterial solution of Escherichia coli and sulfate-reducing bacteria (the concentration of the mixed bacterial solution was 10). 6The water treatment agent of this invention was added to the experimental group (CFU / mL), and a blank control group without water treatment agent was set up. All systems were continuously soaked in a constant temperature environment of 25℃ for 7 days (during which the circulating water flow rate was kept stable). After soaking, the test pieces were taken out and gently rinsed with sterile physiological saline to remove free bacteria. The biofilm on the surface of the test pieces was stained with crystal violet. After decolorization, the absorbance of the decolorized solution was measured at a wavelength of 590 nm using a UV-Vis spectrophotometer (the absorbance value is positively correlated with the amount of biofilm attached). The reduction rate of biofilm attachment was calculated. Three parallel experiments were set up for each sample. RSD ≤ 5% was considered a valid result. The effect of the product in inhibiting biofilm attachment was evaluated.

[0035] Table 4. Test data on the anti-biofilm performance of different samples

[0036] As can be seen from Tables 3 and 4: Examples 1-3 showed a 24-hour inhibition rate of 98.3%-99.4% against Escherichia coli, sulfate-reducing bacteria, and iron bacteria, with a biofilm reduction rate of 74.0%-78.0%. In contrast, Comparative Example 2, which lacked flavonoid derivatives, showed a sharp drop in inhibition rate to 65.2%-72.3%, with a biofilm reduction rate of only 25.0%. This demonstrates that flavonoid derivatives are the core of the antibacterial effect and work synergistically with modified tannic acid to achieve the dual effect of "inhibiting microbial growth and preventing biofilm adhesion," thus avoiding equipment blockage and corrosion caused by biological slime.

[0037] 5. Environmental performance test (1) Biodegradation rate test According to the evaluation method of GB / T 20778-2006, an appropriate amount of inoculum (taken from activated sludge from an urban wastewater treatment plant and acclimated), the water treatment agent sample of this invention (as the sole carbon source), and basal culture medium were added to the reaction flask of the biochemical respiration apparatus. A blank control group (containing only inoculum and culture medium without sample) and a positive control group (using glucose as the carbon source) were also set up. The reaction flasks were placed in a constant temperature environment of 30℃±1℃ for continuous incubation for 28 days. During this period, the cumulative amount of carbon dioxide produced in each reaction flask was monitored and recorded in real time using the respiration apparatus. After the incubation period, the 28-day biodegradation rate was calculated according to the formula "Biodegradation rate = (Cumulative carbon dioxide production of the sample group - Cumulative carbon dioxide production of the blank control group) / (Theoretical carbon dioxide production) × 100%". Three parallel experiments were set up for each sample, and RSD ≤ 5% was considered a valid result, thereby verifying the biodegradability and environmental safety of the product.

[0038] Table 5. Test data on biodegradation rate of different samples

[0039] The 28-day biodegradation rates of Examples 1-3 reached 96.0%-97.5%, far exceeding the environmental compliance requirement of "≥90%" and close to the positive control group (glucose, 99.0%). Although the control ratio was slightly lower (93.5%-94.3%), it still met the standard. The data verified that the natural biomass raw material system of "camellia oleifera shell flavonoid derivatives + modified tannic acid" is easily metabolized by microorganisms and has no secondary pollution after use, which is in line with the "green and environmentally friendly" development concept.

[0040] (2) Phosphorus-free verification test Accurately weigh an appropriate amount of the water treatment agent sample of this invention, dissolve it in deionized water, and dilute it to a designated volumetric flask to prepare the test solution. Simultaneously, set up a blank control group (deionized water only) and a phosphorus standard curve group (preparing a series of phosphorus standard solutions of different concentrations). Add sulfuric acid solution, ammonium molybdate solution, and ascorbic acid solution to the test solution, blank control group, and standard curve group, respectively. Heat in a boiling water bath for 15 min to develop color. After cooling to room temperature, use the blank control group as a reference to measure the absorbance of each solution at a wavelength of 700 nm using a UV-Vis spectrophotometer. Calculate the total phosphorus concentration in the test solution according to the phosphorus standard curve. Set up three parallel experiments for each sample. RSD ≤ 5% is considered a valid result. This verifies whether the total phosphorus content of the product meets the phosphorus-free environmental protection requirement of "≤ 0.5 mg / L".

[0041] Table 6. Phosphorus-free verification test data for different samples

[0042] The total phosphorus content of Examples 1-3 and the comparative examples was only 0.10-0.14 mg / L, far below the phosphorus-free standard of "≤0.5 mg / L". The blank group and the experimental water had no phosphorus residue, proving that the product formulation and production process do not introduce phosphorus, thus avoiding the problem of eutrophication of water bodies caused by phosphorus pollution from the source. This meets the current environmental protection policy requirements for the development of "phosphorus-free" water treatment agents.

[0043] 6. Product storage stability test The water treatment agent samples of this invention (Examples 1-3) were sealed in transparent sealed containers and divided into three parallel groups. They were placed in constant temperature environments of room temperature (25℃), high temperature (50℃), and low temperature (-5℃) for 1, 3, 6, 12, and 18 months respectively. After each storage cycle, the samples were taken out, and their appearance was observed and recorded (whether there were any abnormalities such as layering, precipitation, discoloration, or odor). Then, the scale inhibition rate of calcium and magnesium scale, the corrosion inhibition rate of carbon steel, and the antibacterial rate of Escherichia coli were measured according to the aforementioned standard test methods (scale inhibition performance, corrosion inhibition performance, and antibacterial performance). The performance degradation rate was analyzed by comparing the initial performance data (before storage). Three parallel experiments were set up for each storage cycle. RSD ≤ 5% was considered a valid result. This was to verify the appearance stability and core performance retention of the product within 18 months of storage under different environments and to confirm whether the target storage period requirement of 16-18 months was met.

[0044] Table 7. Data on the 18-month storage stability of different samples.

[0045] Table 7. Data on the 18-month storage stability test of different samples (continued)

[0046] Examples 1-3, after being stored for 18 months at room temperature (25℃), high temperature (50℃), and low temperature (-5℃), still maintained a uniform and transparent appearance (no layering or sedimentation), with minimal degradation in core performance: the scale inhibition rate of calcium and magnesium scale decreased by only 1.5%-2.3%, the corrosion inhibition rate increased by ≤10.9%, and the antibacterial rate decreased by only 1.0%-1.7%, with all tests showing an RSD of ≤2.5% (meeting the effective requirement of ≤5%). This indicates that the product's composite system has strong stability, is adaptable to different storage and transportation environments, and its 18-month shelf life fully meets the commercialization target (16-18 months), demonstrating long-term usability.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-effect corrosion and scale inhibition water treatment agent, characterized in that, The water treatment agent is prepared from the following raw materials by weight: The modified tannic acid is 20-35 parts, the hydroxyapatite nano powder is 15-25 parts, the oil tea shell flavonoid derivative is 5-10 parts, the dispersing agent is 2-5 parts, and the deionized water is 30-50 parts; the tannic acid raw powder is extracted from agricultural waste oil tea shell and then modified by chemistry; the hydroxyapatite nano powder is prepared from industrial tailings; the oil tea shell flavonoid derivative is extracted from the residue after extracting tannic acid from the oil tea shell.

2. The multi-effect corrosion and scale inhibitor water treatment agent according to claim 1, characterized in that, The extraction process of the tannic acid raw powder is microwave-assisted alcoholysis technology: using 80-120 mesh oil tea shell powder as raw material and ethanol as solvent, the extraction is carried out at a microwave power of 300-500 W and an extraction temperature of 60-70 DEG C for 1-1.5 h, the extraction rate is 65%-75%, and the o-diphenol structure on the molecular chain after extraction is reserved.

3. The multi-effect corrosion and scale inhibitor water treatment agent according to claim 1, characterized in that, The chemical modification process of the modified tannic acid is: the tannic acid raw powder is mixed with propylene oxide with a purity of 99.5%-99.9% at a mass ratio of 1:0.3-0.5, the reaction system has a water content of 2%-5%, the temperature is 70-80 DEG C, and the stirring reaction is carried out for 1.5-2.5 h, the hydrophilic hydroxyl group is introduced, and the hydroxyl value of the modified tannic acid is 300-400 mg KOH / g.

4. The multi-effect corrosion and scale inhibitor water treatment agent according to claim 1, characterized in that, The particle size of the hydroxyapatite nanopowder is 50-200 nm, and the specific surface area is 30-60 m 2 / g, obtained in situ after acid leaching of industrial tailings.

5. The multi-effect corrosion and scale inhibitor water treatment agent according to claim 1, characterized in that, The oil tea shell flavonoid derivative, the modified tannic acid and the hydroxyapatite nano powder have a synergistic effect, and the inhibition rate of the three on escherichia coli, sulfate-reducing bacteria and iron bacteria is 98%-99.5%, and the biofilm adhesion amount is reduced by 70%-80%.

6. The multi-effect corrosion and scale inhibitor water treatment agent according to claim 1, characterized in that, The water treatment agent has a silica scale inhibition rate of 90%-94% for water with a silicon content of 200-300 mg / L, a calcium and magnesium scale inhibition rate of 95%-98%, and a corrosion inhibition rate of 0.050-0.075 mm / a for carbon steel.

7. The multi-effect corrosion and scale inhibitor of claim 1, wherein the multi-effect corrosion and scale inhibitor is characterized by, The dispersing agent is polyethylene glycol or sodium dodecylbenzenesulfonate with a molecular weight of 400-1000.

8. The method for preparing a multi-effect corrosion and scale inhibitor for water treatment according to any one of claims 1-7, characterized in that, The specific preparation steps are as follows: S1, the industrial tailings are crushed to 100-150 mesh, a mixed acid of hydrochloric acid and sulfuric acid is added, the volume ratio is 1:1-1:2, the pH is 1.5-2.5, and the stirring reaction is carried out for 1-2 h to obtain a tailings acid leaching base solution; S2, 80-120 mesh pretreated oil tea shell powder is added to the base solution, and the system is stirred and heated at 50-60 DEG C for 2-3 h to realize the generation of hydroxyapatite nano powder and the extraction of tannic acid raw powder at the same time; S3, the purity of propylene oxide is 99.5%-99.9%, the water content of the reaction system is controlled to be 2%-5%, the temperature is raised to 70-80 DEG C, and the reaction is carried out for 1.5-2.5 h to complete the modification of tannic acid; S4, the oil tea shell flavonoid derivative and the dispersing agent are added, and the stirring is continued for 0.5-1 h to form a stable core-shell structure composite system; S5, impurities are removed by filtration, and the system is cooled to room temperature to obtain the multi-effect corrosion and scale inhibition water treatment agent.

9. The method according to claim 8, wherein the method is characterized by, The pretreatment process of the "pretreated oil tea shell powder" in step S2 is as follows: the oil tea shell is washed with clean water to remove impurities, naturally dried, crushed to 80-120 mesh, and dried at 100-110 DEG C for 2-3 h, and the water content of the pretreated powder is controlled to be 1%-3%.

10. The method according to claim 8, wherein the method is characterized by, The preparation process can reduce energy consumption by 35%-45% compared with the traditional "separate preparation and mixing" process, and the product storage period is 16-18 months without stratification and precipitation.

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