Antibacterial scale inhibitor as well as compounding method and application thereof

Abstract

The invention relates to the technical field of scale inhibitors, in particular to an antibacterial scale inhibitor and a compounding method and application thereof, and the compounding method comprises the following steps: weighing 30-60% by mass of gluconic acid salt, 1-10% by mass of a special surfactant, 20-40% by mass of a scale inhibition dispersant and 10-30% by mass of water; the preparation method comprises the following steps: adding gluconic acid base salt, a special surfactant and a scale inhibition dispersant into water, and uniformly mixing to obtain a first solution; dispersing and stirring the first solution to obtain the antibacterial scale inhibitor. According to the antibacterial scale inhibitor and the compounding method and application thereof, the scale inhibition effect is improved through the synergistic effect of the components by using a compounding system formed by the gluconic acid-based salt, the special surfactant and the scale inhibition dispersing agent, and the antibacterial scale inhibitor is non-toxic, non-phosphorus, environmentally friendly and free of secondary pollution; the power plant wastewater treatment system efficiency is improved and the system service life is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of scale inhibitors, and in particular to an antibacterial scale inhibitor and a compounding method and application thereof. Background Art

[0002] Thermal power plants are one of the most water-intensive industries in my country. With increasingly stringent environmental protection requirements, the treatment of power plant wastewater has become a key issue. In the circulating cooling water treatment system, it mainly includes a circulating cooling concentrated water treatment unit system and a reverse osmosis treatment unit. The heat exchange process of circulating cooling inevitably brings about scaling and microbial slime in the equipment pipelines. These inorganic or organic scales will reduce the heat exchange efficiency, thereby reducing the service life of the pipeline. Among them, the scaling problem of the pipeline network is a key factor affecting the normal operation of the equipment. In the reverse osmosis membrane system, the growth and reproduction of scaling particles and bacteria will cause blockage of the reverse osmosis membrane, especially the organic scale such as cell secretions caused by the proliferation of microorganisms, which is a key factor affecting the normal operation of the equipment. It takes a lot of manpower and material resources to frequently replace the reverse osmosis membrane elements. Although adding scale inhibitors can increase the solubility of calcium and magnesium ions in water and inhibit scaling, fewer scale inhibitors have antibacterial effects, and the scale inhibition effect on reverse osmosis concentrated water is limited, making it difficult to play an advantage for the characteristics of the two systems.

[0003] The invention patent (CN202410426822.X) discloses a compound scale inhibitor and its preparation method, wherein the compound scale inhibitor is prepared according to the following raw materials in parts by weight: 10-30 parts of hyperbranched polymer, 30-90 parts of synthetic scale inhibitor, 10-25 parts of organic phosphine scale inhibitor, 8-20 parts of modified carbon nanotubes, 80-150 parts of deionized water and 10-30 parts of organic solvent; wherein the hyperbranched polymer needs to be firstly subjected to a one-step reaction to obtain a polyhydroxylated polymer monomer, then subjected to a one-step reaction to modify it, and finally chitosan is added to a methanol solution and stirred at 20°C for 3 h, and then filtered, washed, dried and ground to obtain a hyperbranched polymer. The modified carbon nanotubes are carbon nanotubes loaded with a modifier, sulfuric acid and nitric acid are added to the carbon nanotubes for pretreatment at 50-80°C, and then ground into carbon nanopowder after treatment, and sodium gluconate is added for stirring and dissolving for 2-5 h, and the solid after centrifugation is washed and dried. The compound scale inhibitor provided by the invention has strong functionality and is suitable for long-term and stable scale inhibition in high-temperature complex water systems. However, it has the disadvantages of complex preparation process and high cost.

[0004] The invention patent (CN202410982955.5) discloses a corrosion and scale inhibitor for high-hardness and high-alkalinity circulating cooling water and its preparation method, namely, polyepoxysuccinic acid 15-25%, branched pyridine inner salt ligand 5-15%, benzotriazole 5-10%, 2-thiouracil 3-8%, molybdenum salt 3-8%, polyol 5-10%, polyoxyethylene ether 2-4%, antibacterial agent 0.5-1.5%. Among them, the branched pyridine inner salt ligand requires multi-step preparation to ensure the quality of the controlled product. The obtained corrosion and scale inhibitor has a carbon steel corrosion rate of <0.05 mm / a, a brass corrosion rate of <0.02 mm / a, and a stainless steel corrosion rate of <0.05 mm / a. It has good corrosion inhibition effect and a certain antibacterial effect, but the preparation process is complicated and does not reflect a good scale inhibition effect.

[0005] The invention patent (CN202310509146.8) discloses a phosphorus-free reverse osmosis membrane antiscalant and a preparation method thereof. The antiscalant includes a polyetheramine compound, a surfactant and a functional auxiliary agent; the mass ratio of the polyetheramine compound, the surfactant and the functional auxiliary agent is 3:1:1-10:1:1. The preparation method of the invention is simple, non-toxic, phosphorus-free, green and environmentally friendly, and has a good antiscaling effect, but it only acts on inorganic scale in the reverse osmosis membrane system, and has no obvious antiscaling effect on organic scale.

[0006] In the above-mentioned antiscalant compounding research, more attention is paid to modifying the existing green antiscalants or compounding them with other high-efficiency antiscalants, with a focus on corrosion and scale inhibition in circulating cooling water systems and inorganic scale inhibition in reverse osmosis membrane systems. Although these antiscalants play a key role in reverse osmosis membrane systems and cooling water systems, they support microbial growth, and microbial fouling poses a major threat to water treatment processes, so new antibacterial green antiscalants need to be studied. Summary of the invention

[0007] The purpose of the present invention is to provide an antibacterial scale inhibitor and a compounding method and application thereof, and the obtained compounding system has a good scale inhibition effect on hard scale and organic scale in a circulating cooling water system of a reverse osmosis membrane system.

[0008] To achieve the above object, the present invention provides a method for compounding an antibacterial and antiscaling agent, comprising the following steps: S1. Weigh by mass percentage: 3%-35% gluconic acid salt, 0.1%-15% special surfactant, 1%-30% scale inhibitor and dispersant, and 10%-93.5% water; S2, adding gluconate, special surfactant and scale inhibitor dispersant into water, and mixing them evenly to obtain a first solution; S3. Dispersing and stirring the first solution obtained in S2 to obtain an antibacterial and antiscaling agent.

[0009] Preferably, in S1, the gluconic acid salt is one or more of D-glucarate, L-glucarate, L-guluronate, L-glucuronate and D-glucuronate.

[0010] Preferably, in S1, the special surfactant includes one or more of cetyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, cyclohexanecarboxylic acid imidazoline and alkyl imidazoline.

[0011] Preferably, in S1, the scale inhibitor dispersant includes one or more of sodium lignin sulfonate, sodium carboxymethyl cellulose and hydrolyzed polymaleic anhydride.

[0012] Preferably, in S1, the mass ratio of the special surfactant, the scale inhibitor and the gluconate is 1:6:6.

[0013] Preferably, in S2, the dispersion stirring is carried out at room temperature and 200-800 r / min for 20-50 min.

[0014] The antibacterial and scale inhibitor is prepared by the compounding method of the above-mentioned antibacterial and scale inhibitor.

[0015] The above-mentioned antibacterial and antiscaling agent is used in power plant wastewater treatment systems, circulating cooling water systems and reverse osmosis membrane systems.

[0016] Mechanism of the present invention: Compounding gluconate, special surfactant and anti-scaling dispersant in a certain proportion can improve the dispersibility and solubility of the anti-scaling agent in water, thereby enhancing the anti-scaling effect. At the same time, it can improve the stability of the compound system, which helps to stabilize the performance of the anti-scaling agent during long-term storage and use.

[0017] Potassium D-glucarate and sodium L-glucuronide have carboxyl and hydroxyl groups. After deprotonation, the carboxyl group reacts with Ca in water. 2+ The ions chelate or adsorb on the surface of calcium sulfate crystals to destroy the growth structure of the crystal, thereby increasing the Ca 2+ Ion solubility, inhibiting the formation of calcium sulfate scale in water. Hydroxyl groups can be integrated into cell membranes, interact with specific proteins on bacterial cell membranes through hydrogen bonds, produce reactive oxygen species in bacterial cells, destroy cell membrane components and functions, or bind to specific enzymes in bacteria, preventing enzymes from functioning, leading to the destruction and dysfunction of bacterial metabolic pathways, and ultimately leading to cell death, inhibiting cell growth and reproduction.

[0018] The sulfonic acid group in sodium lignin sulfonate in the scale inhibitor dispersant is an anionic strong hydrophilic group with strong dispersing ability. The dispersibility of the sulfonic acid group mainly comes from the negative charge carried by the ionized sulfonate ion. These negative charges enable the sulfonic acid group to combine with positively charged substances or adsorb on the surface of particles at the molecular level, preventing the particles from getting too close to agglomerate, thereby achieving the effect of dispersion and stability. And because of the high Ca 2+ Under the condition of ion concentration, the dispersing effect of scale inhibitor is dominant, and gluconate has no dispersibility. Mixing the two in a certain proportion can further increase Ca 2+ Ion concentration range of use.

[0019] Special surfactants have good interfacial activity, which can make the scale inhibitor better contact with the scaling material and penetrate into it. It can also improve the wettability and dispersibility of the scale inhibitor, so that it is evenly distributed inside the pipes and equipment, improving the cleaning effect.

[0020] Therefore, the present invention adopts the above-mentioned antibacterial and scale inhibitor and its compounding method and application, and its beneficial effects are: 1. The present invention uses a composite system composed of gluconic acid salt, special surfactant and scale inhibitor dispersant. The components have a synergistic effect to improve the scale inhibition effect. It is non-toxic and phosphorus-free, environmentally friendly and will not cause secondary pollution. 2. The present invention uses gluconic acid salts to integrate a large number of hydroxyl functional groups in its structure into the cell membrane to destroy its integrity, or to generate reactive oxygen in bacterial cells to damage cell components, including lipids, proteins and DNA, and ultimately lead to cell death. Therefore, the application of gluconic acid salts in reverse osmosis membrane systems will inhibit the growth and reproduction of bacteria, thereby extending the service life of the reverse osmosis membrane and reducing the replacement frequency. 3. The scale inhibitor used in the present invention has strong dispersing ability and can adapt to high Ca 2+ In an ion concentration environment, the carboxyl group of gluconate has a higher solubility than Ca 2+ The chelation rate of ions is fast, suitable for low Ca 2+ Ion concentration environment, the two are compounded, and the compounded scale inhibitor can increase the applicable Ca 2+ Concentration range; 4. The antibacterial and antiscaling agent provided by the present invention has good antiscaling and antibacterial effects on power plant wastewater treatment systems, circulating cooling water systems and reverse osmosis membrane systems.

[0021] The technical solution of the present invention is further described in detail below through embodiments. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with embodiments. Unless otherwise defined, the technical terms or scientific terms used in the present invention should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs. The above-mentioned features or features mentioned in the specific examples mentioned in the present invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0023] Example 1 S1. Weigh by mass percentage: 30% potassium D-glucarate, 5% hexadecyltrimethylammonium bromide, 30% sodium lignin sulfonate and 35% water.

[0024] S2. Add potassium D-glucarate, hexadecyltrimethylammonium bromide and sodium lignin sulfonate into water and mix well to obtain a first solution.

[0025] S3. Disperse and stir the first solution obtained in S2, and stir at room temperature and 500 r / min for 30 min to obtain an antibacterial and antiscaling agent.

[0026] Example 2 S1. Weigh by mass percentage: 34% potassium D-glucarate, 4% hexadecyltrimethylammonium bromide, 14% scale-inhibiting sodium lignin sulfonate and 48% water.

[0027] S2. Add potassium D-glucarate, hexadecyltrimethylammonium bromide and sodium lignin sulfonate into water and mix well to obtain a first solution.

[0028] S3. Disperse and stir the first solution obtained in S2, and stir at room temperature and 500 r / min for 30 min to obtain an antibacterial and antiscaling agent.

[0029] Example 3 S1. Weigh 22% potassium D-glucarate, 14% hexadecyltrimethylammonium bromide, 14% sodium lignin sulfonate and 50% water by mass percentage.

[0030] S2. Add potassium D-glucarate, hexadecyltrimethylammonium bromide and sodium lignin sulfonate into water and mix well to obtain a first solution.

[0031] S3. Disperse and stir the first solution obtained in S2, and stir at room temperature and 500 r / min for 30 min to obtain an antibacterial and antiscaling agent.

[0032] Example 4 S1. Weigh 3% potassium D-glucarate, 0.5% hexadecyltrimethylammonium bromide, 3% sodium lignin sulfonate and 93.5% water by mass percentage.

[0033] S2. Add potassium D-glucarate, hexadecyltrimethylammonium bromide and sodium lignin sulfonate into water and mix well to obtain a first solution.

[0034] S3. Disperse and stir the first solution obtained in S2, and stir at room temperature and 500 r / min for 30 min to obtain an antibacterial and antiscaling agent.

[0035] Comparative Example 1 S1. Weigh 26% potassium D-glucarate, 2% hexadecyltrimethylammonium bromide, 22% sodium lignin sulfonate and 50% water by mass percentage.

[0036] S2. Add potassium D-glucarate, hexadecyltrimethylammonium bromide and sodium lignin sulfonate into water and mix well to obtain a first solution.

[0037] S3. Disperse and stir the first solution obtained in S2, and stir at room temperature and 500 r / min for 30 min to obtain an antibacterial and antiscaling agent.

[0038] Comparative Example 2 S1. Weigh 25% potassium D-glucarate, 5% hexadecyltrimethylammonium bromide, 20% sodium lignin sulfonate and 50% water by mass percentage.

[0039] S2. Add potassium D-glucarate, hexadecyltrimethylammonium bromide and sodium lignin sulfonate into water and mix well to obtain a first solution.

[0040] S3. Disperse and stir the first solution obtained in S2, and stir at room temperature and 500 r / min for 30 min to obtain an antibacterial and antiscaling agent.

[0041] Comparative Example 3 S1. Weigh 24% potassium D-glucarate, 12% hexadecyltrimethylammonium bromide, 15% sodium lignin sulfonate and 49% water by mass percentage.

[0042] S2. Add potassium D-glucarate, hexadecyltrimethylammonium bromide and sodium lignin sulfonate into water and mix well to obtain a first solution.

[0043] S3. Disperse and stir the first solution obtained in S2, and stir at room temperature and 500 r / min for 30 min to obtain an antibacterial and antiscaling agent.

[0044] Test Example 1 a. Scale inhibition performance test The scale inhibition test method mainly refers to Q / SY126-2014 "Technical Specifications for Corrosion and Scale Inhibitors for Oilfield Water Treatment".

[0045] The scale inhibitors of Examples 1-3, Comparative Examples 1-3 and commercially available scale inhibitors were subjected to scale inhibition tests. The experimental temperature was 80° C. and the experimental time was 1 h. Three parallel experiments were performed in each group. The average scale inhibition rate was calculated. The results are shown in Table 1.

[0046] Table 1. Scale inhibition rate of antibacterial scale inhibitors for power plant wastewater in Examples 1-3 and Comparative Examples 1-3

[0047] Potassium D-glucarate, hexadecyltrimethylammonium bromide and sodium lignin sulfonate in the scale inhibitor constitute a compound system. When Example 1 is compared with Comparative Example 1, it is found that the scale inhibition rate of Example 1 is higher, indicating that the high mass proportion of potassium D-glucarate in the compound system will inhibit the improvement of the scale inhibition effect. When Example 2 is compared with Comparative Example 2, it is found that the scale inhibition rate of Example 2 is slightly higher, indicating that the increase in the mass proportion of sodium lignin sulfonate in the compound system has little effect on the improvement of the scale inhibition effect. When Example 3 is compared with Comparative Example 3, it is found that the scale inhibition rate of Comparative Example 3 is higher, indicating that the higher the mass proportion of hexadecyltrimethylammonium bromide in the compound system, the better the improvement of the scale inhibition effect, but it cannot exceed the concentration range of the present invention. When Example 4 is compared with a commercially available scale inhibitor, it is found that Example 4 has a better scale inhibition effect, and the scale inhibition effect can reach 90.9%, indicating that the compound scale inhibitor is effective in the reverse osmosis membrane system inlet water Ca 2+ It has good scale inhibition effect within the range of ion concentration.

[0048] b. Antibacterial performance test b1. Prepare nutrient broth: add 1.5 g beef extract, 5 g peptone and 2.5 g sodium chloride to 500 ml distilled water.

[0049] b2. Set up experimental groups: Set up three experimental groups. Add 18 ml of the nutrient broth prepared in b1 and 2 ml of a 10% 7 cfu / ml bacterial solution. Add 5 mg / L, 10 mg / L and 15 mg / L D-glucarate potassium to each experimental group, respectively, and keep the total volume in the conical flask at 40 ml.

[0050] b3. Set up a control group: Add 36 ml of nutrient broth and 4 ml of 10 7 cfu / ml bacterial solution.

[0051] The experimental group and the control group were placed in a constant temperature shaker at 37°C and 150 r / min for shaking culture. The bacterial concentration change was measured by UV-visible spectrophotometer to measure OD 600 , tests were carried out at regular intervals, and the bacterial growth rate results are shown in Table 2.

[0052] Table 2. Bacterial growth rate of experimental group and control group at different concentrations

[0053] It can be seen from Table 2 that potassium D-glucarate has a certain antibacterial effect, and the higher the concentration of potassium glucarate added, the better the antibacterial effect.

[0054] Therefore, the present invention adopts the above-mentioned antibacterial scale inhibitor for power plant wastewater, based on the fact that potassium D-glucarate has certain antibacterial properties and also has the green and environmentally friendly scale inhibition characteristics, and compound it with scale inhibition dispersants such as sodium lignin sulfonate, sodium carboxymethyl cellulose and hydrolyzed polymaleic anhydride and special surfactants such as hexadecyltrimethylammonium bromide, sodium dodecylbenzene sulfonate, cyclohexanecarboxylic acid imidazoline and alkyl imidazoline. The obtained compound system can have a good scale inhibition effect on calcium sulfate scale and organic scale in two water treatment systems.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A compounding method of an antibacterial scale inhibitor, characterized in that: The following steps are included: S1. Weigh by mass percentage: 3%-35% gluconic acid salt, 0.1%-15% special surfactant, 1%-30% scale inhibitor and dispersant, and 10%-93.5% water; S2, adding gluconate, special surfactant and scale inhibitor dispersant into water, and mixing them evenly to obtain a first solution; S3. Dispersing and stirring the first solution obtained in S2 to obtain an antibacterial and antiscaling agent.

2. The compounding method of an antibacterial scale inhibitor according to claim 1, characterized in that: In S1, the gluconic acid salt includes one or more of D-glucarate, L-glucarate, L-guluronate, L-glucuronate and D-glucuronate.

3. The compounding method of an antibacterial and antiscalant according to claim 1, characterized in that: In S1, the special surfactant includes one or more of cetyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, cyclohexanecarboxylic acid imidazoline and alkyl imidazoline.

4. The compounding method of an antibacterial and antiscalant according to claim 1, characterized in that: In S1, the scale inhibitor and dispersant includes one or more of sodium lignin sulfonate, sodium carboxymethyl cellulose and hydrolyzed polymaleic anhydride.

5. The compounding method of an antibacterial scale inhibitor according to claim 1, characterized in that: In S1, the mass ratio of the special surfactant, the scale inhibitor and the gluconate is 1:6:

6.

6. The compounding method of an antibacterial and antiscalant according to claim 1, characterized in that: In S2, the dispersion stirring is carried out at room temperature and 200-800 r / min for 20-50 min.

7. An antibacterial and antiscaling agent prepared by the compounding method of an antibacterial and antiscaling agent according to any one of claims 1 to 6.

8. The use of an antibacterial and antiscaling agent according to claim 7, characterized in that: Applied to power plant wastewater treatment systems, circulating cooling water systems and reverse osmosis membrane systems.

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