Oily wastewater demulsifier and preparation process thereof

Abstract

The invention discloses an oil-containing wastewater demulsifier and a preparation process thereof.The oil-containing wastewater demulsifier comprises a component A, a component B and a component C. The component A is sodium dodecyl benzene sulfonate, the component B is ethylenediaminetetraacetic acid, the component C is sodium hydroxide, polyvinyl alcohol and a cross-linking agent, the sodium dodecyl benzene sulfonate is used for conducting reverse-phase treatment on foam of oil-containing wastewater, and the cross-linking agent is used for conducting cross-linking treatment on the foam of the oil-containing wastewater. The ethylenediamine tetraacetic acid can increase the viscosity of a solution, can promote separation between oily substances and water molecules in foams, enables the foams in the oil-containing wastewater to be broken, can promote bonding among the water molecules, and can promote foam degradation and layering of the oily substances and water, so that the blocking effect of the foams in the oil-containing wastewater on the wastewater treatment agent is solved; after the sodium hydroxide is added, charges on the surfaces of the oil drops change, and the polyvinyl alcohol interacts with the surfaces of the oil drops through hydroxyl groups on molecular chains of the polyvinyl alcohol, so that electrostatic repulsion among the oil drops can be reduced, the oil drops are gathered, and the oil-water separation efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, in particular to an oily wastewater demulsifier and a preparation process thereof. Background Art

[0002] Industrial wastewater refers to wastewater, sewage and waste liquid generated in the process of industrial production. They contain industrial production materials, intermediate products, by-products and pollutants generated in the production process that are lost with water. These wastewaters usually have the characteristics of complex composition, large discharge volume, wide pollution range and difficulty in treatment, which may cause serious harm to the environment and human health. The sources of industrial wastewater are wide, covering multiple industrial production fields, such as papermaking industry, shipbuilding, ship repair and dismantling, offshore oil and gas exploration and development industry, chemical industry, dye industry, pesticide manufacturing, mining, metallurgy, machinery manufacturing, metal products, food industry, etc. In the production process of these fields, due to the loss of raw materials, poor management and large water consumption, a large amount of wastewater may be generated.

[0003] Among industrial wastewater, the amount of oily wastewater is huge. These wastewaters usually contain natural petroleum, grease, tar and its fractions. If not properly treated, they will be directly discharged into the environment, causing serious pollution problems. The oil substances in oily wastewater will make the water turbid, affect the transparency and quality of the water, hinder the penetration of light, destroy the balance of the aquatic ecosystem, and thus affect the survival and reproduction of aquatic organisms. In addition, oil substances will penetrate into the soil, pollute the soil, destroy the structure and quality of the soil, and affect the growth and development of plants. At the same time, oil substances may also penetrate into groundwater through the soil, further polluting water resources.

[0004] There is a lot of foam in oily wastewater, which will adhere to various parts of the sewage treatment equipment. These foams will block the equipment, reduce its treatment efficiency, and even cause the equipment to fail completely. The foam contains a lot of organic matter and grease. These substances will cause corrosion and wear to the equipment after long-term accumulation, shortening the service life of the equipment. Foam will also affect the use of wastewater treatment agents, making it impossible to completely remove harmful substances in the wastewater.

[0005] Therefore, it is necessary to improve the oily wastewater in daily life to solve the above-mentioned defects. Summary of the invention

[0006] The present invention overcomes the shortcomings of the prior art, provides an oily wastewater demulsifier and a preparation process thereof, and aims to solve the problem that foam in the oily wastewater hinders the wastewater treatment agent in the prior art.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: an oily wastewater demulsifier, consisting of component A, component B and component C:

[0008] The component A is sodium dodecylbenzene sulfonate;

[0009] The B component is ethylenediaminetetraacetic acid;

[0010] The C component is sodium hydroxide, polyvinyl alcohol and a cross-linking agent, and the mass ratio of the sodium hydroxide, the polyvinyl alcohol and the cross-linking agent is 2-3:3-5:0.5-1;

[0011] The mass ratio of the A component, the B component and the C component is 45-50:30-40:20-25.

[0012] In a preferred embodiment of the present invention, the sodium dodecylbenzene sulfonate is a linear sodium dodecylbenzene sulfonate.

[0013] In a preferred embodiment of the present invention, the molecular weight of the polyvinyl alcohol is 120,000-150,000.

[0014] In a preferred embodiment of the present invention, the C component also includes triethylamine and diethylamine, the mass ratio between the triethylamine and the diethylamine is 1:0.5-1, and the ratio of the sum of the total mass of the triethylamine and the diethylamine to the total mass of the sodium hydroxide and the polyvinyl alcohol is 1:2-3.

[0015] In a preferred embodiment of the present invention, the C component also includes glycerol and sorbitol, the mass ratio between the glycerol and the sorbitol is 1:0.5-1, and the ratio of the sum of the total mass of the glycerol and the sorbitol to the total mass of the sodium hydroxide and the polyvinyl alcohol is 1:2-3.

[0016] In a preferred embodiment of the present invention, the C component further comprises zeolite, and the ratio of the total mass of the zeolite to the sodium hydroxide and the polyvinyl alcohol is 1:2-3.

[0017] To achieve the above object, the third technical solution adopted by the present invention is: a preparation process of an oily wastewater demulsifier, comprising the following steps:

[0018] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively;

[0019] S2: mixing and stirring the sodium dodecylbenzene sulfonate solution, the ethylenediaminetetraacetic acid solution and the polyvinyl alcohol solution in S1 to obtain a mixed solution;

[0020] S3: adding a crosslinking agent dropwise to the mixed solution in S2, and stirring to form microcapsules;

[0021] S4: taking out the microcapsules in S3, spraying the remaining substances in the C component onto the microcapsules by a spraying method, and then drying to obtain an oily wastewater demulsifier.

[0022] In a preferred embodiment of the present invention, the concentrations of the sodium dodecylbenzene sulfonate solution, the ethylenediaminetetraacetic acid solution and the polyvinyl alcohol solution are 1-3%, 0.5-2% and 5-10% respectively, and the concentration of hydrochloric acid in the polyvinyl alcohol solution is 5-7%.

[0023] In a preferred embodiment of the present invention, the cross-linking agent in S3 is glutaraldehyde.

[0024] In order to achieve the above-mentioned purpose, the third technical solution adopted by the present invention is: application of an oily wastewater demulsifier, wherein the oily wastewater demulsifier is used for treating oily wastewater in the electroplating industry.

[0025] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0026] (1) The present invention provides an oil-containing wastewater demulsifier, comprising: component A, component B and component C, wherein component A is sodium dodecylbenzene sulfonate, component B is ethylenediaminetetraacetic acid, and component C is sodium hydroxide, polyvinyl alcohol and a cross-linking agent. Sodium dodecylbenzene sulfonate performs reverse phase treatment on the foam of the oil-containing wastewater, and ethylenediaminetetraacetic acid can increase the viscosity of the solution. Compared with the oil-containing wastewater demulsifier in the prior art, the demulsifier can promote the separation between oily substances and water molecules in the foam, so that the foam in the oil-containing wastewater breaks, and can promote the adhesion between water molecules, promote the degradation of the foam and the stratification of the oily substances and water, thereby solving the problem of the obstruction of the foam in the oil-containing wastewater to the wastewater treatment agent in the prior art.

[0027] (2) In the present invention, sodium hydroxide is one of sodium hydroxide and potassium hydroxide, and polyvinyl alcohol is polyvinyl alcohol. By adding sodium hydroxide or potassium hydroxide, the charge on the surface of the oil droplets will change. The polyvinyl alcohol interacts with the surface of the oil droplets through the hydroxyl groups on its molecular chain to reduce the oil-water interfacial tension. Compared with the prior art, the electrostatic repulsion between the oil droplets can be reduced, making it easier for the oil droplets to aggregate together, thereby improving the efficiency of oil-water separation and making it easier for the oil droplets to aggregate together. At the same time, the dispersed oil droplets can be connected into larger oil clusters through adsorption and bridging, thereby improving the efficiency of oil-water separation.

[0028] (3) In the present invention, EDTA can carry out targeted complex adsorption of chromium ions and lead ions, so that heavy metal ions are separated from foam. Compared with the prior art, the stabilizing effect of heavy metal ions on foam is eliminated, and the effect of sodium dodecylbenzene sulfonate on reducing the oil-water interfacial tension on the foam surface is promoted, so that foam can be effectively eliminated.

[0029] (4) In the present invention, component C also includes triethylamine and diethylamine. Both triethylamine and diethylamine are organic amine compounds, which can react with chromium ions and lead ions in wastewater to form insoluble precipitates. Moreover, as organic amine compounds, triethylamine and diethylamine have surface activity. Compared with the prior art, they can be adsorbed on the oil-water interface to reduce interfacial tension, and can make oil droplets gather together more easily to form larger oil clusters, thereby improving the efficiency of oil-water separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 It is a method step diagram of a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0034] like Figure 1 As shown, an oily wastewater demulsifier is composed of component A, component B and component C:

[0035] Component A is sodium dodecylbenzene sulfonate; the benzene ring and alkyl chain in the SDBS molecule make it lipophilic, while the sodium sulfonate group is hydrophilic. At high concentrations, SDBS can adsorb on the oil-water interface, changing the hydrophilic-lipophilic balance of the interface, thereby affecting the type of emulsion. The adsorption of SDBS on the oil-water interface can cause oil droplets to aggregate together to form an oil-in-water emulsion.

[0036] Component B is ethylenediaminetetraacetic acid; ethylenediaminetetraacetic acid itself has a certain surface activity and can be adsorbed on the oil-water interface to change the properties of the interface. It can reduce the interfacial tension and the interaction force between oil droplets, making the oil droplets easier to aggregate and merge, thereby promoting reverse demulsification.

[0037] Component C is sodium hydroxide, polyvinyl alcohol and a cross-linking agent, and the mass ratio of sodium hydroxide, polyvinyl alcohol and the cross-linking agent is 2-3:3-5:0.5-1; sodium hydroxide can adjust the pH value of the wastewater to a range suitable for polyvinyl alcohol to exert its best effect, and at a suitable pH value, the charge on the surface of the oil droplets will change, reducing the electrostatic repulsion between the oil droplets, making it easier for the oil droplets to gather together, thereby improving the efficiency of oil-water separation. Polyvinyl alcohol, as a high molecular weight organic polyvinyl alcohol, can interact with the surface of the oil droplets through the hydroxyl groups on its molecular chain, reduce the oil-water interfacial tension, and make the oil droplets easier to gather together. At the same time, polyvinyl alcohol can also connect the dispersed oil droplets into larger oil clusters through adsorption and bridging, thereby improving the efficiency of oil-water separation.

[0038] The mass ratio between component A, component B and component C is 45-50:30-40:20-25.

[0039] The invention discloses an oil-containing wastewater demulsifier, comprising: component A, component B and component C, wherein the component A is sodium dodecylbenzene sulfonate, the component B is ethylenediaminetetraacetic acid, and the component C is sodium hydroxide and polyvinyl alcohol. The sodium dodecylbenzene sulfonate performs reverse phase treatment on the foam of the oil-containing wastewater, the ethylenediaminetetraacetic acid can increase the viscosity of the solution, can promote the separation between the oily substance and the water molecules in the foam, so that the foam in the oil-containing wastewater is broken, and can promote the adhesion between the water molecules, promote the degradation of the foam, and the stratification of the oily substance and the water, thereby solving the problem that the foam in the oil-containing wastewater hinders the wastewater treatment agent in the prior art.

[0040] Sodium hydroxide is a strong base that can adjust the pH value of wastewater to a higher range, so that chromium ions and lead ions form chromium hydroxide and lead hydroxide precipitates that are insoluble in water, respectively. The addition of polyvinyl alcohol can stabilize these precipitates, prevent them from re-dissolving, and improve the thoroughness and stability of heavy metal removal. The high pH environment adjusted by sodium hydroxide helps stabilize the oil-water interface and makes it easier for oil droplets to float and separate. This is because a higher pH value increases the alkalinity of water, reduces the negative charge on the surface of the oil droplets, reduces the electrostatic repulsion between the oil droplets, and promotes the aggregation and floating of the oil droplets.

[0041] Component C also includes triethylamine and diethylamine, the mass ratio between triethylamine and diethylamine is 1:0.5-1, and the ratio of the total mass of triethylamine and diethylamine to the total mass of sodium hydroxide and polyvinyl alcohol is 1:2-3. Triethylamine and diethylamine are both organic amine compounds, which can react with chromium ions and lead ions in wastewater to form insoluble precipitates. As organic amine compounds, triethylamine and diethylamine have surface activity and can be adsorbed on the oil-water interface to reduce interfacial tension, which can make oil droplets more easily aggregated to form larger oil clusters, thereby improving the efficiency of oil-water separation. Emulsified oil in electroplating wastewater usually carries a negative charge, and triethylamine and diethylamine can neutralize these charges, destroy the stable structure of the emulsified oil, and make the oil droplets more easily aggregated and float.

[0042] Component C also includes glycerol and sorbitol, the mass ratio between glycerol and sorbitol is 1:0.5-1, and the ratio of the total mass of glycerol and sorbitol to the total mass of sodium hydroxide and polyvinyl alcohol is 1:2-3. Glycerol and sorbitol are both polyols that can increase the viscosity of the wastewater treatment liquid. Higher viscosity helps to increase the sedimentation rate of particles and oil droplets in the wastewater, making them easier to separate from the wastewater, thereby improving the efficiency of wastewater treatment.

[0043] Glycerol and sorbitol can react with chromium ions and lead ions in wastewater to form insoluble precipitates. Glycerol and sorbitol have certain surface activity and can reduce the tension of the oil-water interface. This helps to destroy the emulsified structure of the emulsified oil, making it easier for the oil droplets to gather together and float up and separate, thereby improving the effect of oil-water separation. Glycerol and sorbitol can promote the removal of oil and particulate matter in wastewater, thereby reducing the concentration of organic matter in wastewater. This helps to improve the biodegradability of wastewater, create more favorable conditions for subsequent biological treatment processes, and improve the efficiency and stability of the entire wastewater treatment system.

[0044] Component C also includes zeolite, and the total mass ratio of zeolite to sodium hydroxide and polyvinyl alcohol is 1:2-3. Zeolite has a porous structure and a large specific surface area, and can adsorb chromium ions and lead ions in wastewater. Its pore structure can provide a large number of adsorption sites for heavy metal ions, so that these ions are transferred from water to the surface of zeolite, thereby reducing the concentration of heavy metals in the wastewater. The addition of zeolite can change the properties of particles in the wastewater, making it easier to settle. Zeolite particles are heavier and can combine with suspended particles and oil droplets in the wastewater to increase their weight, thereby increasing the sedimentation rate of the particles and promoting oil-water separation.

[0045] Sodium dodecylbenzene sulfonate is a linear structure sodium dodecylbenzene sulfonate. As the alkyl chain grows, the critical micelle concentration of linear SDBS tends to decrease, which means that it can form micelles at lower concentrations, enhancing its surface activity in the demulsification process.

[0046] The molecular weight of polyvinyl alcohol is 120,000-150,000. As a high molecular weight flocculant, polyvinyl alcohol can form larger flocs during demulsification, which can adsorb and bridge oil droplets and suspended solids in wastewater, including heavy metal ions, thereby promoting oil-water separation and heavy metal removal. Polyvinyl alcohol with a high molecular weight has a larger specific surface area and more active groups, which enables it to more effectively adsorb chromium and lead ions in wastewater.

[0047] To achieve the above object, the second technical solution adopted by the present invention is: a preparation process of an oily wastewater demulsifier, comprising the following steps:

[0048] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively;

[0049] S2: mixing and stirring the sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution in S1 to obtain a mixed solution;

[0050] S3: adding a crosslinking agent to the mixed solution in S2 and stirring to form microcapsules;

[0051] S4: taking out the microcapsules in S3, spraying the remaining substances in component C onto the microcapsules by a spraying method, and then drying them to obtain an oily wastewater demulsifier.

[0052] Microencapsulation technology can improve the stability and targeting of demulsifiers. Spraying the remaining substances in component C onto microcapsules by spraying can ensure the uniform distribution and slow release of the components of the demulsifier, thereby more effectively destroying the emulsified structure of the emulsified oil and promoting oil-water separation when treating oily wastewater.

[0053] The concentrations of sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution are 1-3%, 0.5-2% and 5-10% respectively, and the concentration of hydrochloric acid in the polyvinyl alcohol solution is 5-7%. Setting a reasonable concentration can make each part mix well in the process of preparing microcapsules.

[0054] The crosslinking agent in S3 is glutaraldehyde. The microcapsules crosslinked with glutaraldehyde have better adsorption and embedding capabilities, and can more effectively adsorb and fix the active ingredients in the demulsifier, thereby slowly releasing these ingredients when treating oily wastewater, improving the demulsification efficiency and heavy metal removal efficiency.

[0055] The specific process of using the spray method to spray the remaining substances in component C onto the microcapsules in S4 is as follows: sodium hydroxide is modulated into an aqueous solution with a concentration of 1-3%, and is sprayed on the microcapsules using an ultrasonic spray method. After standing for 2-3 hours, it is dried at 50-60°C for 30-45 minutes. Then, triethylamine, diethylamine, glycerol and sorbitol are placed in an ethanol solution and mixed. The mixed solution is sprayed on the microcapsules using an ultrasonic spray method. Zeolite particles with a particle diameter of 0.5-2μm are electrostatically sprayed on the microcapsules. After standing for 4-6 hours, they are dried at 80-90°C for 1-2 hours.

[0056] The principle of electrostatic spraying is to charge the microcapsules and generate an electrostatic field in the spraying equipment, so that the zeolite particles carry an electrostatic charge opposite to that of the microcapsules. The zeolite particles are then sprayed onto the microcapsules with opposite charges. Through electrostatic adsorption, the positive and negative charges attract each other, causing the zeolite particle powder to adhere to the surface of the microcapsules.

[0057] The outermost zeolite particles can adsorb the heavy metal ions on the original foam in the wastewater, destroying the stabilizing effect of the metal ions on the original foam in the wastewater. Sorbitol helps to produce smaller bubbles when forming foam, that is, to refine the foam pores. Small bubbles mean that the foam has a larger surface area, which can more effectively capture and separate oil droplets and other impurities in the wastewater. Glycerin can increase the viscosity of the newly generated foam, so that the newly generated foam has a good water-oil system, and can keep the zeolite particles adsorbed with heavy metal ions in the newly generated foam area. Triethylamine and diethylamine will quickly adsorb to the oil-water interface, and interact with oil droplets and water molecules through the hydrophilic and hydrophobic groups in their molecular structures, resulting in a significant reduction in interfacial tension, thereby reducing the stability of the newly generated foam. Polyvinyl alcohol dissolves in water, delaying the release of sodium dodecylbenzene sulfonate and ethylenediaminetetraacetic acid. Ethylenediaminetetraacetic acid complexes and precipitates with the remaining heavy metal ions in the original foam. Sodium dodecylbenzene sulfonate reverses and demulsifies the original foam and the newly generated foam. The coagulation effect of glycerol, triethylamine and diethylamine on the oil clusters causes the newly generated foam to break during the reverse demulsification process, and the original foam will also break after losing the stability of the heavy metal ions, thereby completing the demulsification process of the foam.

[0058] Through the design of the hierarchical structure and microcapsule structure of the demulsifier, various factors act on the oil-water mixture in the wastewater in sequence. Combined with the principles of electrostatic effect, destruction of the stability of the oil-water mixture and inversion system, the heavy metal ions in the original foam are reduced, and new unstable fine foam is generated. The oil group molecules are condensed after the foam bursts, so that the oil group and water are separated after demulsification, avoiding the generation of subsequent foam, and having a good demulsification effect.

[0059] An application of an oily wastewater demulsifier, the oily wastewater demulsifier is used for treating oily wastewater in the electroplating industry. Various chemical reagents and additives used in the electroplating process, such as emulsifiers, surfactants, etc., will form stable emulsified oils with the grease in the wastewater. These emulsified oils have small particles and are evenly dispersed, making them difficult to separate by traditional physical methods. Electroplating wastewater contains a variety of heavy metal ions, such as chromium, lead, nickel, copper, etc. These heavy metal ions are not only harmful to the environment and human health, but also affect the effect of oil-water separation. Heavy metal ions may react with certain components in the emulsified oil to form a more stable emulsified system, further hindering oil-water separation.

[0060] Heavy metal ions can change the surface properties of wastewater and enhance surface activity. Lead ions have a natural affinity with chromate ions, and can interact with pollutants such as oil droplets in wastewater, reduce the oil-water interfacial tension, and make it easier for oil droplets to form a stable foam layer on the water surface. Heavy metal ions can react with other pollutants or treatment agents in wastewater to form insoluble precipitates or stable complexes. Under certain conditions, chromium ions can react with lead carbonate to form lead chromate precipitates, which can adsorb and fix oil droplets and other suspended particles in wastewater, making the foam layer more stable. In addition, heavy metal ions can also form stable complexes with organic matter, suspended particles, etc. in wastewater, increasing the stability of foam.

[0061] The addition of heavy metal ions will change the pH value and electrochemical properties of wastewater, thus affecting the stability of foam. For example, under acidic conditions, the reaction effect of lead ions and chromate ions is better, which is conducive to the formation of a stable foam layer. At the same time, heavy metal ions can change the conductivity and electrochemical properties of wastewater, making the charge distribution in the foam layer more uniform and enhancing the stability of foam.

[0062] Chromium ions and lead ions can interact with surfactants in wastewater to form a stable foam layer, improving the stability and durability of the foam. Heavy metal ions can form a stable structure with molecules or particles in the foam wall, increasing the strength and toughness of the foam wall, making the foam less likely to break when subjected to external disturbances such as mechanical vibration and pressure changes.

[0063] Ethylenediaminetetraacetic acid can carry out targeted complex adsorption of chromium ions and lead ions, so that heavy metal ions are separated from foam, eliminating the stabilizing effect of heavy metal ions on foam, promoting the effect of sodium dodecylbenzene sulfonate on reducing the oil-water interfacial tension on the foam surface, and can effectively eliminate foam.

[0064] EDTA is a hexadentate chelating agent, and each EDTA molecule can provide 4 oxygen atoms and 2 nitrogen atoms to form up to 6 coordination bonds with a metal ion. This multi-coordination site chelating ability enables EDTA to form stable chelates with chromium and lead ions, thereby effectively removing these heavy metal ions from foam.

[0065] EDTA has a certain selective adsorption capacity for heavy metal ions. Although EDTA can complex with a variety of metal ions, under certain conditions, it has a stronger adsorption capacity for certain heavy metal ions. For example, EDTA has a significantly better adsorption effect on lead ions than on some other metal ions. This selectivity makes EDTA more targeted and effective in treating wastewater containing heavy metal ions such as chromium and lead.

[0066] Embodiment 1

[0067] This embodiment provides a method for preparing an oily wastewater demulsifier, and the preparation process is as follows:

[0068] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively.

[0069] S2: The sodium dodecylbenzenesulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution in S1 are mixed and stirred to obtain a mixed solution.

[0070] S3: Add pentanediol dropwise to the mixed solution in S2 and stir to form microcapsules.

[0071] S4: Take out the microcapsules in S3, prepare sodium hydroxide into an aqueous solution with a concentration of 1-3%, spray it on the microcapsules by ultrasonic spraying, let it stand for 2-3 hours, and then dry it at 50-60°C for 30-45 minutes, then put triethylamine, diethylamine, glycerol and sorbitol into an ethanol solution and mix them, spray the mixed solution on the microcapsules by ultrasonic spraying, and electrostatically spray zeolite particles with a diameter of 0.5-2μm on the microcapsules, let it stand for 4-6 hours, and then dry it at 80-90°C for 1-2 hours to obtain an oil-containing wastewater demulsifier.

[0072] The mass ratio of sodium dodecylbenzene sulfonate, ethylenediaminetetraacetic acid, sodium hydroxide, polyvinyl alcohol, triethylamine, diethylamine, glycerol, sorbitol, zeolite and pentanediol is 50:35:5:5:5:2.5:5:2.5:5:2.5.

[0073] Embodiment 2

[0074] This embodiment provides a method for preparing an oily wastewater demulsifier, and the preparation process is as follows:

[0075] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively.

[0076] S2: The sodium dodecylbenzenesulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution in S1 are mixed and stirred to obtain a mixed solution.

[0077] S3: Add pentanediol dropwise to the mixed solution in S2 and stir to form microcapsules.

[0078] S4: Take out the microcapsules in S3, prepare sodium hydroxide into an aqueous solution with a concentration of 1-3%, spray it on the microcapsules by ultrasonic spraying, let it stand for 2-3 hours, and then dry it at 50-60°C for 30-45 minutes, then put triethylamine, diethylamine, glycerol and sorbitol into an ethanol solution and mix them, spray the mixed solution on the microcapsules by ultrasonic spraying, and electrostatically spray zeolite particles with a diameter of 0.5-2μm on the microcapsules, let it stand for 4-6 hours, and then dry it at 80-90°C for 1-2 hours to obtain an oil-containing wastewater demulsifier.

[0079] The mass ratio of sodium dodecylbenzene sulfonate, ethylenediaminetetraacetic acid, sodium hydroxide, polyvinyl alcohol, triethylamine, diethylamine, glycerol, sorbitol, zeolite and pentanediol is 50:35:5:7.5:5:2.5:5:2.5:5:2.5.

[0080] Embodiment 3

[0081] This embodiment provides a method for preparing an oily wastewater demulsifier, and the preparation process is as follows:

[0082] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively.

[0083] S2: The sodium dodecylbenzenesulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution in S1 are mixed and stirred to obtain a mixed solution.

[0084] S3: Add pentanediol dropwise to the mixed solution in S2 and stir to form microcapsules.

[0085] S4: Take out the microcapsules in S3, prepare sodium hydroxide into an aqueous solution with a concentration of 1-3%, spray it on the microcapsules by ultrasonic spraying, let it stand for 2-3 hours, and then dry it at 50-60°C for 30-45 minutes, then put triethylamine, diethylamine, glycerol and sorbitol into an ethanol solution and mix them, spray the mixed solution on the microcapsules by ultrasonic spraying, and electrostatically spray zeolite particles with a diameter of 0.5-2μm on the microcapsules, let it stand for 4-6 hours, and then dry it at 80-90°C for 1-2 hours to obtain an oil-containing wastewater demulsifier.

[0086] The mass ratio of sodium dodecylbenzene sulfonate, ethylenediaminetetraacetic acid, sodium hydroxide, polyvinyl alcohol, triethylamine, diethylamine, glycerol, sorbitol, zeolite and pentanediol is 50:35:5:10:5:2.5:5:2.5:5:2.5.

[0087] Embodiment 4

[0088] This embodiment provides a method for preparing an oily wastewater demulsifier, and the preparation process is as follows:

[0089] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively.

[0090] S2: The sodium dodecylbenzenesulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution in S1 are mixed and stirred to obtain a mixed solution.

[0091] S3: Add pentanediol dropwise to the mixed solution in S2 and stir to form microcapsules.

[0092] S4: Take out the microcapsules in S3, prepare sodium hydroxide into an aqueous solution with a concentration of 1-3%, spray it on the microcapsules by ultrasonic spraying, let it stand for 2-3 hours, and then dry it at 50-60°C for 30-45 minutes, then put triethylamine, diethylamine, glycerol and sorbitol into an ethanol solution and mix them, spray the mixed solution on the microcapsules by ultrasonic spraying, and electrostatically spray zeolite particles with a diameter of 0.5-2μm on the microcapsules, let it stand for 4-6 hours, and then dry it at 80-90°C for 1-2 hours to obtain an oil-containing wastewater demulsifier.

[0093] The mass ratio of sodium dodecylbenzene sulfonate, ethylenediaminetetraacetic acid, sodium hydroxide, polyvinyl alcohol, triethylamine, diethylamine, glycerol, sorbitol, zeolite and pentanediol is 50:35:5:12.5:5:2.5:5:2.5:5:2.5.

[0094] Embodiment 5

[0095] This embodiment provides a method for preparing an oily wastewater demulsifier, and the preparation process is as follows:

[0096] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively.

[0097] S2: The sodium dodecylbenzenesulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution in S1 are mixed and stirred to obtain a mixed solution.

[0098] S3: Add pentanediol dropwise to the mixed solution in S2 and stir to form microcapsules.

[0099] S4: Take out the microcapsules in S3, prepare sodium hydroxide into an aqueous solution with a concentration of 1-3%, spray it on the microcapsules by ultrasonic spraying, let it stand for 2-3 hours, and then dry it at 50-60°C for 30-45 minutes, then put triethylamine, diethylamine, glycerol and sorbitol into an ethanol solution and mix them, spray the mixed solution on the microcapsules by ultrasonic spraying, and electrostatically spray zeolite particles with a diameter of 0.5-2μm on the microcapsules, let it stand for 4-6 hours, and then dry it at 80-90°C for 1-2 hours to obtain an oil-containing wastewater demulsifier.

[0100] The mass ratio of sodium dodecylbenzene sulfonate, ethylenediaminetetraacetic acid, sodium hydroxide, polyvinyl alcohol, triethylamine, diethylamine, glycerol, sorbitol and zeolite is 50:35:5:15:5:2.5:5:2.5:5:2.5.

[0101] Embodiment 6

[0102] This embodiment provides a method for preparing an oily wastewater demulsifier, and the preparation process is as follows:

[0103] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively.

[0104] S2: The sodium dodecylbenzenesulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution in S1 are mixed and stirred to obtain a mixed solution.

[0105] S3: Add pentanediol dropwise to the mixed solution in S2 and stir to form microcapsules.

[0106] S4: Take out the microcapsules in S3, prepare sodium hydroxide into an aqueous solution with a concentration of 1-3%, spray it on the microcapsules by ultrasonic spraying, let it stand for 2-3 hours, and then dry it at 50-60°C for 30-45 minutes, then put triethylamine, diethylamine, glycerol and sorbitol into an ethanol solution and mix them, spray the mixed solution on the microcapsules by ultrasonic spraying, and electrostatically spray zeolite particles with a diameter of 0.5-2μm on the microcapsules, let it stand for 4-6 hours, and then dry it at 80-90°C for 1-2 hours to obtain an oil-containing wastewater demulsifier.

[0107] The mass ratio of sodium dodecylbenzene sulfonate, ethylenediaminetetraacetic acid, sodium hydroxide, polyvinyl alcohol, triethylamine, diethylamine, glycerol, sorbitol, zeolite and pentanediol is 50:35:5:10:5:2.5:5:2.5:3.75:2.5.

[0108] Embodiment 7

[0109] This embodiment provides a method for preparing an oily wastewater demulsifier, and the preparation process is as follows:

[0110] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively.

[0111] S2: The sodium dodecylbenzenesulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution in S1 are mixed and stirred to obtain a mixed solution.

[0112] S3: Add pentanediol dropwise to the mixed solution in S2 and stir to form microcapsules.

[0113] S4: Take out the microcapsules in S3, prepare sodium hydroxide into an aqueous solution with a concentration of 1-3%, spray it on the microcapsules by ultrasonic spraying, let it stand for 2-3 hours, and then dry it at 50-60°C for 30-45 minutes, then put triethylamine, diethylamine, glycerol and sorbitol into an ethanol solution and mix them, spray the mixed solution on the microcapsules by ultrasonic spraying, and electrostatically spray zeolite particles with a diameter of 0.5-2μm on the microcapsules, let it stand for 4-6 hours, and then dry it at 80-90°C for 1-2 hours to obtain an oil-containing wastewater demulsifier.

[0114] The mass ratio of sodium dodecylbenzene sulfonate, ethylenediaminetetraacetic acid, sodium hydroxide, polyvinyl alcohol, triethylamine, diethylamine, glycerol, sorbitol, zeolite and pentanediol is 50:35:5:10:5:2.5:5:2.5:6.25:2.5.

[0115] Embodiment 8

[0116] This embodiment provides a method for preparing an oily wastewater demulsifier, and the preparation process is as follows:

[0117] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively.

[0118] S2: The sodium dodecylbenzenesulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution in S1 are mixed and stirred to obtain a mixed solution.

[0119] S3: Add pentanediol dropwise to the mixed solution in S2 and stir to form microcapsules.

[0120] S4: Take out the microcapsules in S3, prepare sodium hydroxide into an aqueous solution with a concentration of 1-3%, spray it on the microcapsules by ultrasonic spraying, let it stand for 2-3 hours, and then dry it at 50-60°C for 30-45 minutes, then put triethylamine, diethylamine, glycerol and sorbitol into an ethanol solution and mix them, spray the mixed solution on the microcapsules by ultrasonic spraying, and electrostatically spray zeolite particles with a diameter of 0.5-2μm on the microcapsules, let it stand for 4-6 hours, and then dry it at 80-90°C for 1-2 hours to obtain an oil-containing wastewater demulsifier.

[0121] The mass ratio of sodium dodecylbenzene sulfonate, ethylenediaminetetraacetic acid, sodium hydroxide, polyvinyl alcohol, triethylamine, diethylamine, glycerol, sorbitol, zeolite and pentanediol is 50:35:5:10:5:2.5:5:2.5:7.5:2.5.

[0122] Embodiment 9

[0123] This embodiment provides a method for preparing an oily wastewater demulsifier, and the preparation process is as follows:

[0124] S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively.

[0125] S2: The sodium dodecylbenzenesulfonate solution, ethylenediaminetetraacetic acid solution and polyvinyl alcohol solution in S1 are mixed and stirred to obtain a mixed solution.

[0126] S3: Add pentanediol dropwise to the mixed solution in S2 and stir to form microcapsules.

[0127] S4: Take out the microcapsules in S3, prepare sodium hydroxide into an aqueous solution with a concentration of 1-3%, spray it on the microcapsules by ultrasonic spraying, let it stand for 2-3 hours, and then dry it at 50-60°C for 30-45 minutes, then put triethylamine, diethylamine, glycerol and sorbitol into an ethanol solution and mix them, spray the mixed solution on the microcapsules by ultrasonic spraying, and electrostatically spray zeolite particles with a diameter of 0.5-2μm on the microcapsules, let it stand for 4-6 hours, and then dry it at 80-90°C for 1-2 hours to obtain an oil-containing wastewater demulsifier.

[0128] The mass ratio of sodium dodecylbenzene sulfonate, ethylenediaminetetraacetic acid, sodium hydroxide, polyvinyl alcohol, triethylamine, diethylamine, glycerol, sorbitol, zeolite and pentanediol is 50:35:5:10:5:2.5:5:2.5:8.75:2.5.

[0129] Comparative Example 1

[0130] This comparative example uses a polyacrylate reverse demulsifier, the specific model is BH-532.

[0131] Samples of equal mass from Examples 1 to 9 and Comparative Example 1 were added to oily wastewater of equal concentration in the electroplating industry, and the demulsification data from Examples 1 to 9 and Comparative Example 1 were measured according to the standard SY / T5797-93 "Method for evaluating the performance of demulsifiers for oil-in-water emulsions", as shown in Table 1.

[0132] Table 1 Demulsification data in Examples 1 to 9 and Comparative Example 1

[0133] Sample source Oil content in water phase (mg / L) Oil removal rate (%) Embodiment 1 447 81.6 Embodiment 2 386 82.8 Embodiment 3 348 84.3 Embodiment 4 367 82.9 Embodiment 5 394 81.0 Embodiment 6 371 82.5 Embodiment 7 313 86.1 Embodiment 8 331 84.9 Embodiment 9 361 83.4 Comparative Example 1 482 70.5

[0134] As can be seen from Table 1, the oil content of the water phase in Examples 1 to 9 is higher than that in Comparative Example 1, and the oil removal rate is higher than that in Comparative Example 1, and the present application has superiority.

[0135] In Examples 1 to 5, as the mass proportion of polyvinyl alcohol in the demulsifier gradually increases, the oil content of the water phase first decreases and then increases, and the oil removal first increases and then decreases. This is because increasing the mass proportion of polyvinyl alcohol can improve the adsorption capacity and bridging effect of the demulsifier, thereby more effectively capturing and aggregating oil droplets, resulting in a decrease in the oil content of the water phase and an increase in the oil removal rate. However, when the polyvinyl alcohol content is too high, polyvinyl alcohol may cause the viscosity of the demulsifier to increase, affecting its dispersibility and fluidity in the oil-water mixture, and may affect the adsorption of zeolite on heavy metal ions, thereby reducing the demulsification efficiency, resulting in an increase in the oil content of the water phase and a decrease in the oil removal rate. The preferred embodiment is Example 3.

[0136] In Example 3 and Examples 6 to 9, as the mass proportion of zeolite particles in the demulsifier gradually increases, the oil content of the water phase first decreases and then increases, and the oil removal first increases and then decreases. This is because the increase in zeolite particles provides more adsorption sites, which enhances the adsorption capacity for oil droplets and heavy metal ions, thereby reducing the oil content of the water phase and increasing the oil removal rate. However, when the zeolite content is too high, the adsorption and arrangement structure at the oil-water interface will change, which will affect the fluidity and adsorption capacity of the demulsifier, resulting in an increase in the oil content of the water phase and a decrease in the oil removal rate. The preferred embodiment is Example 7.

[0137] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A demulsifier for oily wastewater, characterized in that: It is composed of component A, component B and component C: The component A is sodium dodecylbenzene sulfonate; The B component is ethylenediaminetetraacetic acid; The C component is sodium hydroxide, polyvinyl alcohol and a cross-linking agent, and the mass ratio of the sodium hydroxide, the polyvinyl alcohol and the cross-linking agent is 2-3:3-5:0.5-1; The mass ratio of the A component, the B component and the C component is 45-50:30-40:20-25.

2. The oily wastewater demulsifier according to claim 1, characterized in that: The sodium dodecylbenzene sulfonate is a linear structure sodium dodecylbenzene sulfonate.

3. The oily wastewater demulsifier according to claim 1, characterized in that: The molecular weight of the polyvinyl alcohol is 120,000-150,000.

4. The oily wastewater demulsifier according to claim 1, characterized in that: The C component also includes triethylamine and diethylamine, the mass ratio of the triethylamine to the diethylamine is 1:0.5-1, and the ratio of the total mass of the triethylamine and the diethylamine to the total mass of the sodium hydroxide and the polyvinyl alcohol is 1:2-3.

5. The oily wastewater demulsifier according to claim 1, characterized in that: The C component also includes glycerol and sorbitol, the mass ratio between the glycerol and the sorbitol is 1:0.5-1, and the ratio of the total mass sum of the glycerol and the sorbitol to the total mass sum of the sodium hydroxide and the polyvinyl alcohol is 1:2-3.

6. The oily wastewater demulsifier according to claim 1, characterized in that: The C component further comprises zeolite, and the ratio of the total mass of the zeolite to the sodium hydroxide and the polyvinyl alcohol is 1:2-3.

7. A preparation process of an oily wastewater demulsifier, based on the oily wastewater demulsifier according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: dissolving sodium dodecylbenzene sulfonate in water, dissolving ethylenediaminetetraacetic acid in hydrochloric acid, and dissolving polyvinyl alcohol in water to obtain sodium dodecylbenzene sulfonate solution, ethylenediaminetetraacetic acid solution, and polyvinyl alcohol solution, respectively; S2: mixing and stirring the sodium dodecylbenzene sulfonate solution, the ethylenediaminetetraacetic acid solution and the polyvinyl alcohol solution in S1 to obtain a mixed solution; S3: adding a crosslinking agent dropwise to the mixed solution in S2, and stirring to form microcapsules; S4: taking out the microcapsules in S3, spraying the remaining substances in the C component onto the microcapsules by a spraying method, and then drying to obtain an oily wastewater demulsifier.

8. The preparation process of an oily wastewater demulsifier according to claim 7, characterized in that: The concentrations of the sodium dodecylbenzene sulfonate solution, the ethylenediaminetetraacetic acid solution and the polyvinyl alcohol solution are 1-3%, 0.5-2% and 5-10% respectively, and the concentration of hydrochloric acid in the polyvinyl alcohol solution is 5-7%.

9. The preparation process of an oily wastewater demulsifier according to claim 7, characterized in that: The cross-linking agent in S3 is glutaraldehyde.

10. An application of an oily wastewater demulsifier, based on the oily wastewater demulsifier according to any one of claims 1 to 6, characterized in that: The oily wastewater demulsifier is used for treating oily wastewater in the electroplating industry.

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