Safe and efficient dephenolization and deoiling extractant and application thereof

Abstract

The application provides an efficient and safe phenol and oil removal extraction agent and application thereof, the extraction agent comprises a combination of a main extraction agent and a co-extraction agent, the main extraction agent comprises a combination of an oxime compound and a ketone compound, and the co-extraction agent comprises any one or a combination of at least two of an alcohol compound, an ether compound and an aliphatic hydrocarbon. Through component design, compounding and mutual cooperation of the main extraction agent and the co-extraction agent, the application can effectively extract and remove phenolic substances and oily substances in industrial wastewater, and has excellent extraction and removal effect on heterocyclic compounds. Meanwhile, the extraction agent is a non-major hazard source, has large use and storage capacity, effectively reduces potential risks such as fire, explosion, poisoning and suffocation caused by use and storage of the extraction agent in the wastewater treatment process, is easy to be applied on a large scale, has a positive influence on the economic benefits of enterprises and organizations, provides a new idea for economic, safe and efficient treatment of coal chemical industry wastewater, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a safe and efficient extractant for removing phenols and oils and its application. Background Technology

[0002] Coal chemical wastewater is formed during the gasification and deheating of coal. It contains a wide variety of pollutants at high concentrations and with complex compositions, and is recognized as a difficult-to-degrade organic industrial wastewater. Coal chemical wastewater contains phenols, cyanides, petroleum hydrocarbons, ammonia nitrogen, and other components, and has high color and COD. Cr The dichromate index concentration is high; and the composition of the wastewater varies due to differences in the properties of the raw coal, production processes, and operating procedures. Traditional treatment processes include deacidification and deammoniation, extraction and dephenolization, AO biodegradation, deep purification, membrane desalination, and salt separation and crystallization. Among these, the phenol and ammonia recovery unit can recover crude phenol and ammonia products, making it the unit in the entire coal coking wastewater treatment process that can convert pollutants into chemical products.

[0003] For the extraction and removal of phenols from phenol and ammonia wastewater, commonly used extractants include heavy benzene solvent oil, crude benzene, N-503 kerosene, etc. These extractants are readily available and are usually recycled within enterprises, making them relatively inexpensive. However, their distribution coefficients are not high, resulting in unsatisfactory extraction effects.

[0004] In recent years, extractants such as ethyl acetate, methyl isobutyl ketone (MIBK), and diisopropyl ether (DIPE) have been applied in phenol removal extraction due to their advantages such as low price and easy recovery. For example, CN106865674A discloses a method for extracting and removing phenols from phenol-containing wastewater using a multi-stage mixed enhanced separation process, employing methyl isobutyl ketone, diisopropyl ether, butyl acetate, sec-butyl acetate, or methyl tert-amyl ether as the extractant. CN104147808A discloses a phenol removal extractant and its application, wherein the extractant contains 80-100% by volume methyl tert-butyl ketone and 0-20% by volume methyl isobutyl ketone or isoamyl alcohol. CN105712427A discloses an extractant and extraction method with a high partition coefficient for polyphenols in phenol-containing wastewater. Methyl isobutyl ketone (MOH) is used as the main extractant, and toluene as a co-extractant. The volume fraction of MOH is 90-95%, and the volume fraction of toluene is 5-10%, using multi-stage countercurrent extraction. CN103553260A discloses a co-extraction negative pressure flash evaporation method for removing phenols from high-concentration phenol-containing wastewater containing semi-coke. Diisopropyl ether (DIE) and MOH are used as extractants for co-extraction and phenol removal. The volume ratio of DIE to MOH is 1:10-1:1. CN102874968A discloses a method for treating high-concentration industrial phenol-containing wastewater. DIE is used for extraction and phenol removal. At a certain temperature, the phenol-containing wastewater and DIE are contacted counter-currently in an extraction tower at a certain ratio. The extract is then cooled again and enters a phenol recovery tower to separate the DIE and crude phenol. CN111115740A discloses a cycloalkanamide-based phenol removal extractant, with a raw material volume ratio of 5-10% cycloalkanamide, 10-20% co-solvent, and the remainder being diluent. The co-solvent is selected from one or more of C4-C10 alkanols and tributyl phosphate, and the diluent is one or more of C5-C16 alkanes, cycloalkanes, aviation kerosene, sulfonated kerosene, and xylene. This extractant is suitable for treating high-concentration phenol-containing wastewater. CN103496757A discloses an extraction method for removing phenol from high-concentration phenol-ammonia coal chemical wastewater. In an extraction tower, the high-concentration phenol-ammonia coal chemical wastewater is countercurrently contacted with butyl acetate. An extract phase is obtained at the top of the tower, and a raffinate phase is obtained at the bottom. The extract phase is then recovered by distillation to recover the extractant and crude phenol. The extractant is recycled, and the crude phenol is sold or refined.

[0005] In general, common components of phenol removal extractants include esters, ketones, ethers, and benzenes. However, according to the "Interim Provisions on the Supervision and Management of Major Hazard Sources of Hazardous Chemicals" and GB / T 18218-2018 "Identification of Major Hazard Sources of Hazardous Chemicals," kerosene, crude benzene, ethyl acetate, diisopropyl ether, and methyl isobutyl ketone are all classified as hazardous chemicals. Their use and storage thresholds are low, making them highly susceptible to becoming major hazard sources. This significantly increases the potential risks of fire, explosion, poisoning, and asphyxiation associated with the use and storage of extractants during wastewater treatment, potentially leading to hazardous chemical accidents. With increasingly stringent national and provincial safety production policies, the use of these extractants will be gradually restricted or phased out.

[0006] Furthermore, analysis of wastewater pollutants from the perspectives of oxidation capacity and microbial degradation capacity of different organic structures revealed that heterocyclic compounds in coal chemical wastewater are difficult to oxidize, have high biotoxicity, and inhibit microbial activity. Currently, there is a lack of effective methods for the extraction and removal of heterocyclic compounds.

[0007] Considering both of the above factors, there is an urgent need in this field to develop a chemical extractant that is not a major hazard source, which can remove heterocyclic compounds while removing phenols from wastewater, thereby ensuring the efficient and stable operation of subsequent stages of wastewater treatment. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a safe and efficient extractant for phenol and oil removal and its application. By employing a combination of oxime and ketone compounds as the main extractant, and compounding it with specific component co-extractants, the extractant can deeply extract and remove phenolic and oily substances from wastewater, especially effectively removing heterocyclic compounds, thus achieving excellent wastewater treatment results. Furthermore, the extractant does not constitute a major hazard source of hazardous chemicals, is easy to apply on a large scale, and has broad application prospects.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides an extractant for removing phenols and oils, the extractant comprising a combination of a primary extractant and a co-extractant, the primary extractant comprising a combination of oxime compounds and ketone compounds, and the co-extractant comprising any one or a combination of at least two of alcohol compounds, ether compounds, and aliphatic hydrocarbons.

[0011] The extractant provided by this invention comprises a main extractant consisting of a combination of oxime compounds and ketone compounds, and a co-extractant consisting of any one or at least two of alcohols, ethers, and aliphatic hydrocarbons. Through the design, compounding, and synergistic interaction of the components, the extractant can effectively extract and remove phenolic and oily substances from industrial wastewater (coal chemical wastewater), especially exhibiting excellent extraction and removal effects on heterocyclic compounds, which is of great significance for the recycling of wastewater.

[0012] Meanwhile, the extractant does not contain highly toxic chemicals, monitored chemicals, or easily explosive hazardous chemicals, and the total amount produced, stored, and used does not constitute a major hazard source of hazardous chemicals (GB / T 18218—2018 Identification of Major Hazard Sources of Hazardous Chemicals). It has low biological toxicity, high biodegradability, and large usage and storage capacity, effectively reducing the potential risks of fire, explosion, poisoning, and suffocation caused by the use and storage of extractants during wastewater treatment, and is easy to apply on a large scale.

[0013] In this invention, the terms "oil," "oil-like substances," and "oil-like substances" refer to the definition in standard HJ 637-2018 "Determination of Petroleum and Animal / Vegetable Oils in Water - Infrared Spectrophotometry," which refers to substances that can be extracted by tetrachloroethylene under conditions of pH ≤ 2, and at a wavenumber of 2930 cm⁻¹. -1 2960cm -1 3030cm -1 Substances that exhibit characteristic absorption mainly include petroleum products and animal and vegetable oils.

[0014] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0015] Preferably, the oxime compound includes any one or a combination of at least two of benzaldehyde oxime, dimethylglyoxime, 5-nonylsalicylic acid oxime, 4-methylbenzaldehyde oxime, and salicylaldehyde oxime.

[0016] Preferably, the ketone compounds include C5-C12 (e.g., C5, C6, C7, C8, C9, C10, C11, C12) saturated aliphatic ketones and / or C5-C12 (e.g., C5, C6, C7, C8, C9, C10, C11, C12) saturated alicyclic ketones.

[0017] Preferably, the ketone compound includes any one or a combination of at least two of 2-heptanone, 4-heptanone, cycloheptanone, cyclohexanone, 3-hexanone, 5-methyl-2-hexanone, 2,4-pentanedione, 2-octanone, and 4-octanone.

[0018] Preferably, the volume ratio of the oxime compound to the ketone compound is 1:(1.5-5), for example, it can be 1:1.8, 1:2, 1:2.2, 1:2.5, 1:2.8, 1:3, 1:3.2, 1:3.5, 1:3.8, 1:4, 1:4.2, 1:4.5, 1:4.8, etc., and more preferably 1:(2-4).

[0019] As a preferred embodiment of the present invention, the volume ratio of the oxime compound to the ketone compound is 1:1.5-1:5, more preferably 1:2-1:4. The combination of the main extractant and the co-extractant of specific components can synergistically achieve efficient removal of phenolic and oily substances from wastewater, especially for the deep removal of heterocyclic compounds. If the amount of oxime compound is too low, the extraction and removal effect on oily substances and heterocyclic compounds will decrease; if the amount of oxime compound is too high, it will cause the extractant viscosity and density to be too high, which is not conducive to extraction and phase separation, causing the extractant to be entrained into the aqueous phase during the extraction process, resulting in an increase in the content of oily substances in the raffinate phase and increased extractant loss.

[0020] Preferably, the co-extractant comprises a combination of at least two of alcohols, ethers, and aliphatic hydrocarbons.

[0021] Preferably, the co-extractant includes alcohol compounds, and also includes at least one of ether compounds and aliphatic hydrocarbons.

[0022] As a preferred embodiment of the present invention, the co-extractant includes alcohol compounds, ether compounds and / or aliphatic hydrocarbons, preferably a combination of alcohol compounds and ether compounds. The co-extractant, when combined with the main extractant, helps to optimize the extraction effect, adjust the viscosity and density of the main extractant, improve phase separation, and increase the removal rate of phenolic and oily substances from wastewater by the extractant.

[0023] Preferably, the volume percentage of alcohol compounds in the co-extractant is 30-80%, for example, it can be 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, or 78%, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0024] Preferably, the volume percentage of ether compounds in the co-extractant is ≤60%, for example, it can be 0, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, or 58%, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 10-60% is further preferred.

[0025] Preferably, the volume percentage of aliphatic hydrocarbons in the co-extractant is ≤50%, for example, it can be 0, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, or 48%, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 5-50% is further preferred.

[0026] Preferably, the alcohol compounds include C5-C12 (e.g., C5, C6, C7, C8, C9, C10, C11, C12) saturated aliphatic alcohols.

[0027] Preferably, the alcohol compound includes any one or a combination of at least two of the following: 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-3-pentanol, 1-methylpentanol, 2-ethylbutanol, 1-ethylbutanol, n-hexanol, n-heptanol, n-octanol, isooctanol, and sec-octanol.

[0028] Preferably, the ether compound includes any one or a combination of at least two of anisole, benzyl methyl ether, and n-hexyl methyl ether.

[0029] Preferably, the aliphatic hydrocarbon is a C5-C16 (e.g., C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16) aliphatic hydrocarbon containing a chain and / or cyclic structure, and more preferably a C6-C12 aliphatic hydrocarbon containing a chain and / or cyclic structure.

[0030] Preferably, the aliphatic hydrocarbon includes any one or a combination of at least two of the following: 2-cyclohexylbutane, cyclohexylisobutane, 1-cyclohexyln-butane, cyclooctane, tert-butylcyclohexane, 1,2,3-trimethylcyclohexane, 4-ethylheptane, and diethylcyclopentane.

[0031] Preferably, the volume percentage of the main extractant in the extractant is 30-60%, for example, it can be 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55% or 58%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0032] Preferably, the volume percentage of the co-extractant in the extractant is 40-70%, for example, it can be 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65% or 68%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0033] Preferably, the critical amount of the extractant is >1000t, for example, it can be 2000t, 3000t, 4000t, 5000t, 6000t, 7000t, 8000t, 9000t or 10000t, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and it is further preferred to be ≥5000t.

[0034] Preferably, the solubility of the extractant in water is <2 g / L.

[0035] In this invention, the preparation method of the extractant includes: mixing the main extractant and the co-extractant evenly to obtain the extractant.

[0036] In a second aspect, the present invention provides an application of the extractant as described in the first aspect in industrial wastewater treatment.

[0037] Preferably, the industrial wastewater includes coal chemical wastewater, and more preferably any one or a combination of at least two of coal gasification wastewater, coking wastewater, and semi-coke wastewater.

[0038] Thirdly, the present invention provides a method for treating industrial wastewater, the method comprising: extracting the industrial wastewater with the extractant as described in the first aspect to obtain an extract phase and a raffinate phase.

[0039] Preferably, the industrial wastewater includes coal chemical wastewater, such as any one of coal gasification wastewater, coking wastewater, and semi-coke wastewater.

[0040] Preferably, the industrial wastewater includes phenolic compounds and oily substances.

[0041] Preferably, the industrial wastewater includes phenolic compounds and heterocyclic compounds.

[0042] Preferably, the industrial wastewater includes phenolic compounds, oily substances, and heterocyclic compounds.

[0043] Preferably, the heterocyclic compound includes any one or a combination of at least two of thiophene compounds, pyridine compounds, quinoline compounds, and isoquinoline compounds.

[0044] Preferably, the phenolic compound includes monohydric phenols and / or polyhydric phenols, and more preferably any one or a combination of at least two of phenol, catechol, resorcinol, and hydroquinone.

[0045] Preferably, the volume ratio of the extractant to the industrial wastewater is 1:(2-10), for example, it can be 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9 or 1:9.5, etc.

[0046] Preferably, the pH value of the extraction is 5-9, for example, it can be 5.2, 5.5, 5.8, 6, 6.2, 6.5, 6.8, 7, 7.2, 7.5, 7.8, 8, 8.2, 8.5 or 8.8, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0047] As a preferred technical solution of the present invention, the pH value of the industrial wastewater to be treated is adjusted to 5-9 (e.g., 5.2, 5.5, 5.8, 6, 6.2, 6.5, 6.8, 7, 7.2, 7.5, 7.8, 8, 8.2, 8.5 or 8.8, etc.), and then an extractant is used for extraction to obtain the extract phase and the raffinate phase.

[0048] Preferably, the extraction temperature is 20-70℃, for example, it can be 22℃, 25℃, 28℃, 30℃, 32℃, 35℃, 38℃, 40℃, 42℃, 45℃, 48℃, 50℃, 52℃, 55℃, 58℃, 60℃, 62℃, 65℃ or 68℃, as well as specific values ​​between the above-mentioned values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0049] Preferably, the raffinate phase enters a biochemical system, and / or the extract phase is back-extracted using a back-extraction agent.

[0050] Preferably, the back-extraction agent comprises an alkaline aqueous solution.

[0051] Preferably, the alkaline substance in the alkaline aqueous solution includes metal hydroxides, and more preferably NaOH and / or KOH.

[0052] Preferably, the mass concentration of alkaline substances in the back-extraction agent (alkaline aqueous solution) is 10-50%, for example, it can be 112%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, or 48%, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0053] Preferably, the back-extraction process yields an aqueous phase and an oil phase. The aqueous phase includes an aqueous solution of phenol salts, and the oil phase includes an extractant, as well as oily substances, heterocyclic compounds, etc., extracted and removed from industrial wastewater.

[0054] Preferably, the oil phase obtained from the back-extraction process includes an extractant, and the oil phase is optionally purified for use in the extraction of industrial wastewater.

[0055] Preferably, the purification method includes distillation to remove oily substances from the oil phase, and the resulting extractant is recycled for the extraction of industrial wastewater.

[0056] As a preferred technical solution of the present invention, the extractant of the present invention is used to treat industrial wastewater (coal chemical wastewater), and the total phenol removal rate is >95%, preferably ≥96%, reaching 96.2-99.5%; the removal rate of oily substances is >95%, preferably ≥96%, reaching 96.0-99.1%; and the removal rate of heterocyclic compounds is ≥95%, reaching 95.1-99.7%.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] (1) The extractant provided by this invention, through the component design, compounding, and synergistic interaction of the main extractant and co-extractant, can effectively extract and remove phenolic and oily substances from industrial wastewater, especially exhibiting excellent extraction and removal effects on heterocyclic compounds containing structures such as pyridine, thiophene, and quinoline. When the extractant is used to treat industrial wastewater, the total phenol removal rate and oil removal rate are both ≥96%, and the heterocyclic compound removal rate is ≥95.1%. The raffinate phase enters the biochemical system, which is beneficial for subsequent biochemical treatment and is of great significance for wastewater recycling.

[0059] (2) The extractant provided by this invention has low water solubility, minimal loss, low boiling point, is easy to recover, low biotoxicity, and high biodegradability. The extractant is not a major hazard source, and its use and storage volume are large, effectively reducing potential risks such as fire, explosion, poisoning, and suffocation arising from the use and storage of the extractant during wastewater treatment. It is safe, efficient, and easy to apply on a large scale, positively impacting the economic benefits of enterprises and organizations. It provides a new approach for the economical, safe, and efficient treatment of coal chemical wastewater and has broad application prospects. Detailed Implementation

[0060] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0061] In the following specific embodiments of the present invention, all components in the extractant are commercially available chemicals.

[0062] In the following specific embodiments of the present invention, the coal chemical wastewater used is derived from coal gasification wastewater, with a pH value of 10.3. The composition information of the organic pollutants is shown in Table 1.

[0063] Table 1

[0064] Organic pollutants Content (mg / L) Total phenols 15669 oily substances 1850 Quinoline 487 Pyridine 369 Thiophene 172

[0065] The industrial wastewater treated in the following embodiments and comparative examples of this invention are all coal chemical wastewater with the components shown in Table 1; in specific embodiments of this invention, the detection methods for various organic pollutants (including the data shown in Table 1 and the content in the raffinate phase) are as follows:

[0066] The content of oily substances was determined using infrared spectrophotometry: the pH of the aqueous phase was adjusted to ≤2, and extraction was performed with tetrachloroethylene. After extraction, the organic phase was dehydrated with anhydrous sodium sulfate. The dehydrated tetrachloroethylene was then measured in an infrared oil analyzer with a wavenumber set to 2930 cm⁻¹. -1 2960cm -1 3030cm -1 For specific reference, see standard HJ 637-2018 "Determination of Petroleum and Animal Oils in Water by Infrared Spectrophotometry".

[0067] The total phenols were determined using the Folin-Schönlein method (FC method): water samples were diluted to a concentration of 0-50 mg / L and the dilution factor was recorded. For each 1 mL of diluted water sample, 5 mL of high-purity water, 3.5 mL of 7.5% sodium carbonate solution, and 1 mL of Folin-Schönlein phenol were added. The mixture was heated at 45°C for 90 min and then cooled to room temperature. The determination was performed at a wavelength of 765 nm using a UV-Vis spectrophotometer.

[0068] The content of thiophene, pyridine, and quinoline was determined by high performance liquid chromatography. The specific test conditions were as follows: the chromatographic column was a reversed-phase C-18 column (Agilent); the flow rate of the mobile phase was 0.250 mL / min, and it consisted of acetonitrile and pure water in a ratio of 4:6; the wavelengths of quinoline, pyridine, and thiophene were 313 nm, 254 nm, and 220 nm, respectively.

[0069] Example 1

[0070] An extractant for removing phenols and oils, comprising, by volume percentage:

[0071] 60% of the main extract

[0072] 40% co-extractant;

[0073] The main extractant consists of benzaldehyde oxime and 2-octanone, with a volume ratio of 1:3; the co-extractant consists of 2-octanol and anisole, with a volume ratio of 6:4. The preparation method of the extractant includes: mixing the components evenly according to the aforementioned volume ratio to obtain the extractant.

[0074] The extractant provided in this embodiment is used for the treatment of coal chemical wastewater. The treatment method includes: adjusting the pH value of the coal chemical wastewater to 5.0, extracting with the extractant, the volume ratio of the extractant to the coal chemical wastewater (extractant phase O / A) is 1:2, the extraction temperature is 20℃, the extraction time is 20min, and the extract phase and raffinate phase are obtained.

[0075] The content of each organic pollutant in the raffinate phase was detected according to the aforementioned method, and the removal rate was calculated: Removal rate = 100% × content of organic pollutants in the extract phase / content of organic pollutants in the coal chemical wastewater before extraction = 100% × (content of organic pollutants in the coal chemical wastewater before extraction - content of organic pollutants in the raffinate phase) / content of organic pollutants in the coal chemical wastewater before extraction; the data of the removal rate are shown in Table 2.

[0076] Example 2

[0077] An extractant for removing phenols and oils, comprising, by volume percentage:

[0078] 60% of the main extract

[0079] 40% co-extractant;

[0080] The main extractant consists of benzaldehyde oxime and 2-octanone, with a volume ratio of 1:4; the co-extractant consists of 2-octanol and anisole, with a volume ratio of 6:4. The preparation method of the extractant includes: mixing the components evenly according to the aforementioned volume ratio to obtain the extractant.

[0081] The extractant provided in this embodiment is used for the treatment of coal chemical wastewater. The treatment method includes: adjusting the pH value of the coal chemical wastewater to 5.0, extracting with the extractant, the volume ratio of the extractant to the coal chemical wastewater (extractant phase O / A) is 1:2, the extraction temperature is 20℃, the extraction time is 20min, and the extract phase and raffinate phase are obtained. The same method as in Example 1 is used for testing and calculation, and the removal rate data are shown in Table 2.

[0082] Example 3

[0083] An extractant for removing phenols and oils, comprising, by volume percentage:

[0084] 60% of the main extract

[0085] 40% co-extractant;

[0086] The main extractant consists of dimethylglyoxime and 2-octanone, with a volume ratio of 1:4; the co-extractant consists of 2-octanol and anisole, with a volume ratio of 6:4. The preparation method of the extractant includes: mixing the components evenly according to the aforementioned volume ratio to obtain the extractant.

[0087] The extractant provided in this embodiment is used for the treatment of coal chemical wastewater. The treatment method includes: adjusting the pH value of the coal chemical wastewater to 5.0, extracting with the extractant, the volume ratio of the extractant to the coal chemical wastewater (extractant phase O / A) is 1:2, the extraction temperature is 20℃, the extraction time is 20min, and the extract phase and raffinate phase are obtained. The same method as in Example 1 is used for testing and calculation, and the removal rate data are shown in Table 2.

[0088] Example 4

[0089] An extractant for removing phenols and oils, comprising, by volume percentage:

[0090] 60% of the main extract

[0091] 40% co-extractant;

[0092] The main extractant consists of 5-nonylsalicylaldehyde oxime and 2-octanone, with a volume ratio of 1:4; the co-extractant consists of 2-octanol and anisole, with a volume ratio of 6:4. The preparation method of the extractant includes: mixing the components evenly according to the aforementioned volume ratio to obtain the extractant.

[0093] The extractant provided in this embodiment is used for the treatment of coal chemical wastewater. The treatment method includes: adjusting the pH value of the coal chemical wastewater to 5.0, extracting with the extractant, the volume ratio of the extractant to the coal chemical wastewater (extractant phase O / A) is 1:2, the extraction temperature is 20℃, the extraction time is 20min, and the extract phase and raffinate phase are obtained. The same method as in Example 1 is used for testing and calculation, and the removal rate data are shown in Table 2.

[0094] Example 5

[0095] An extractant for removing phenols and oils, comprising, by volume percentage:

[0096] 60% of the main extract

[0097] 40% co-extractant;

[0098] The main extractant consists of 5-nonylsalicylaldehyde oxime and 4-octanone, with a volume ratio of 1:4; the co-extractant consists of 2-octanol and anisole, with a volume ratio of 6:4. The preparation method of the extractant includes: mixing the components evenly according to the aforementioned volume ratio to obtain the extractant.

[0099] The extractant provided in this embodiment is used for the treatment of coal chemical wastewater. The treatment method includes: adjusting the pH value of the coal chemical wastewater to 5.0, extracting with the extractant, the volume ratio of the extractant to the coal chemical wastewater (extractant phase O / A) is 1:2, the extraction temperature is 20℃, the extraction time is 20min, and the extract phase and raffinate phase are obtained. The same method as in Example 1 is used for testing and calculation, and the removal rate data are shown in Table 2.

[0100] Example 6

[0101] An extractant for removing phenols and oils, comprising, by volume percentage:

[0102] 60% of the main extract

[0103] 40% co-extractant;

[0104] The main extractant consists of 5-nonylsalicylaldehyde oxime and cycloheptanone, with a volume ratio of 1:4; the co-extractant consists of 2-octanol and anisole, with a volume ratio of 6:4. The preparation method of the extractant includes: mixing the components evenly according to the aforementioned volume ratio to obtain the extractant.

[0105] The extractant provided in this embodiment is used for the treatment of coal chemical wastewater. The treatment method includes: adjusting the pH value of the coal chemical wastewater to 5.0, extracting with the extractant, the volume ratio of the extractant to the coal chemical wastewater (extractant phase O / A) is 1:2, the extraction temperature is 20℃, the extraction time is 20min, and the extract phase and raffinate phase are obtained. The same method as in Example 1 is used for testing and calculation, and the removal rate data are shown in Table 2.

[0106] Example 7

[0107] An extractant for removing phenols and oils, comprising, by volume percentage:

[0108] 60% of the main extract

[0109] 40% co-extractant;

[0110] The main extractant consists of 5-nonylsalicylaldehyde oxime and cycloheptanone, with a volume ratio of 1:4; the co-extractant consists of 2-octanol and tert-butylcyclohexane, with a volume ratio of 6:4. The preparation method of the extractant includes: mixing the components evenly according to the aforementioned volume ratio to obtain the extractant.

[0111] The extractant provided in this embodiment is used for the treatment of coal chemical wastewater. The treatment method includes: adjusting the pH value of the coal chemical wastewater to 5.0, extracting with the extractant, the volume ratio of the extractant to the coal chemical wastewater (extractant phase O / A) is 1:2, the extraction temperature is 20℃, the extraction time is 20min, and the extract phase and raffinate phase are obtained. The same method as in Example 1 is used for testing and calculation, and the removal rate data are shown in Table 2.

[0112] Example 8

[0113] A phenol-removing and oil-removing extractant differs from Example 1 only in that the volume ratio of benzaldehyde oxime and octanone in the main extractant is 1:6, while the types and amounts of other components are the same as in Example 1.

[0114] The extractant provided in this embodiment is used for the treatment of coal chemical wastewater. The pH value, extraction ratio O / A, extraction temperature and time are the same as in Example 1. The extract phase and raffinate phase are obtained. The same method as in Example 1 is used for testing and calculation. The removal rate data are shown in Table 2.

[0115] Example 9

[0116] A phenol-removing and oil-removing extractant differs from Example 1 only in that the volume ratio of benzaldehyde oxime and octanone in the main extractant is 1:1, while the types and amounts of other components are the same as in Example 1.

[0117] The extractant provided in this embodiment is used for the treatment of coal chemical wastewater. The pH value, extraction ratio O / A, extraction temperature and time are the same as in Example 1. The extract phase and raffinate phase are obtained. The same method as in Example 1 is used for testing and calculation. The removal rate data are shown in Table 2.

[0118] Comparative Example 1

[0119] A phenol-removing and oil-removing extractant differs from Example 1 only in that the main extractant is 2-octanone (without benzaldehyde oxime), while the types and amounts of other components are the same as in Example 1.

[0120] The extractant provided in this comparative example was used for the treatment of coal chemical wastewater. The pH value, extraction ratio O / A, extraction temperature and time were the same as in Example 1. The extract phase and raffinate phase were obtained, and the same method as in Example 1 was used for testing and calculation. The removal rate data are shown in Table 2.

[0121] Comparative Example 2

[0122] A phenol-removing and oil-removing extractant, which differs from Example 1 only in that the main extractant is methyl isobutyl ketone, while the types and amounts of other components are the same as in Example 1.

[0123] The extractant provided in this comparative example was used for the treatment of coal chemical wastewater. The pH value, extraction ratio O / A, extraction temperature and time were the same as in Example 1. The extract phase and raffinate phase were obtained, and the same method as in Example 1 was used for testing and calculation. The removal rate data are shown in Table 2.

[0124] Table 2

[0125]

[0126] According to the test data in Table 2, this invention uses a combination of oxime and ketone compounds as the main extractant, and combines them with a co-extractant to enable the extractant to deeply extract and remove phenolic and oily substances from wastewater. Through optimization of the ratio of oxime and ketone compounds in the main extractant, the total phenol removal rate in Examples 1-7 is 96.2-99.5%, and the oil removal rate is 96.0-99.1%. It is particularly effective in removing heterocyclic compounds, achieving a quinoline removal rate of 96.7-99.7%, a pyridine removal rate of 95.4-98.3%, and a thiophene removal rate of 95.1-99.2%. The raffinate phase enters the biochemical system, which is beneficial for subsequent biochemical treatment. Simultaneously, the extractant is not a major hazard source, and its use and storage volume are large, effectively reducing the potential risks of fire, explosion, poisoning, and asphyxiation during wastewater treatment, making it easy to apply on a large scale. In Example 8, the amount of oxime compounds in the main extractant was low, which led to a decrease in the extraction efficiency of the extractant for oily substances and heterocyclic compounds. In Example 9, the amount of oxime compounds in the main extractant was high. Although the removal rate of phenols and heterocyclic compounds such as pyridine, quinoline, and thiophene was good, the amount of oily substances in the raffinate phase was significantly increased.

[0127] In Comparative Example 1, the use of octanone as the main extractant resulted in a decrease in the extractant's removal capacity, with significant deficiencies in the removal rates of phenolic substances, oils, and heterocyclic compounds. In Comparative Example 2, conventional methyl isobutyl ketone (MIBK) was used as the main extractant. While its removal effect on total phenols was acceptable, its extraction capacity for oils and heterocyclic compounds was insufficient. Furthermore, the low critical levels for the use and storage of MIBK pose a significant hazard, increasing the potential risks associated with the use and storage of extractants during wastewater treatment.

[0128] The applicant declares that the present invention illustrates the phenol-removing and oil-removing extractant and its application through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An extractant for removing phenols and oils, characterized in that, The extractant comprises a combination of a primary extractant and a co-extractant, wherein the primary extractant comprises a combination of oxime compounds and ketone compounds, and the co-extractant comprises any one or a combination of at least two of alcohol compounds, ether compounds, and aliphatic hydrocarbons; The volume ratio of the oxime compound to the ketone compound is 1:(1.5-5); The oxime compounds include any one or a combination of at least two of benzaldehyde oxime, dimethylglyoxime, 5-nonylsalicylic acid oxime, 4-methylbenzaldehyde oxime, and salicylaldehyde oxime; The ketone compounds include C5-C12 saturated aliphatic ketones and / or C5-C12 saturated alicyclic ketones.

2. The extractant according to claim 1, characterized in that, The ketone compounds include any one or a combination of at least two of the following: 2-heptanone, 4-heptanone, cycloheptanone, cyclohexanone, 3-hexanone, 5-methyl-2-hexanone, 2,4-pentanedione, 2-octanone, and 4-octanone.

3. The extractant according to claim 1, characterized in that, The volume ratio of the oxime compound to the ketone compound is 1:(2-4).

4. The extractant according to claim 1, characterized in that, The co-extractant comprises a combination of at least two of the following: alcohols, ethers, and aliphatic hydrocarbons.

5. The extractant according to claim 4, characterized in that, The co-extractant includes alcohols, and also includes at least one of ethers and aliphatic hydrocarbons.

6. The extractant according to claim 5, characterized in that, The volume percentage of alcohol compounds in the co-extractant is 30-80%.

7. The extractant according to claim 5, characterized in that, The volume percentage of ether compounds in the co-extractant is 10-60%.

8. The extractant according to claim 5, characterized in that, The volume percentage of aliphatic hydrocarbons in the co-extractant is 5-50%.

9. The extractant according to claim 1, characterized in that, The alcohols include C5-C12 saturated aliphatic alcohols.

10. The extractant according to claim 9, characterized in that, The alcohol compounds include any one or a combination of at least two of the following: 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-3-pentanol, 1-methylpentanol, 2-ethylbutanol, 1-ethylbutanol, n-hexanol, n-heptanol, n-octanol, isooctanol, and sec-octanol.

11. The extractant according to claim 1, characterized in that, The ether compounds include any one or a combination of at least two of anisole, benzyl methyl ether, and n-hexyl methyl ether.

12. The extractant according to claim 1, characterized in that, The aliphatic hydrocarbon is a C5-C16 aliphatic hydrocarbon containing chain and / or cyclic structures.

13. The extractant according to claim 12, characterized in that, The aliphatic hydrocarbons include any one or a combination of at least two of the following: 2-cyclohexylbutane, cyclohexylisobutane, 1-cyclohexyln-butane, cyclooctane, tert-butylcyclohexane, 1,2,3-trimethylcyclohexane, 4-ethylheptane, and diethylcyclopentane.

14. The extractant according to claim 1, characterized in that, The volume percentage of the main extractant in the extractant is 30-60%.

15. The extractant according to claim 1, characterized in that, The volume percentage of the co-extractant in the extractant is 40-70%.

16. The extractant according to claim 1, characterized in that, The critical amount of the extractant is >1000 t.

17. The extractant according to claim 16, characterized in that, The critical amount of the extractant is ≥5000 t.

18. The extractant according to claim 1, characterized in that, The extractant has a solubility of <2 g / L in water.

19. The application of an extractant as described in any one of claims 1-18 in industrial wastewater treatment.

20. The application according to claim 19, characterized in that, The industrial wastewater includes coal chemical wastewater.

21. The application according to claim 20, characterized in that, The industrial wastewater can be any one of coal gasification wastewater, coking wastewater, or semi-coke wastewater.

22. A method for treating industrial wastewater, characterized in that, The treatment method includes: extracting industrial wastewater with the extractant as described in any one of claims 1-18 to obtain an extract phase and a raffinate phase.

23. The processing method according to claim 22, characterized in that, The industrial wastewater includes phenolic compounds, oils, and heterocyclic compounds.

24. The processing method according to claim 23, characterized in that, The heterocyclic compounds include any one or a combination of at least two of the following: thiophene compounds, pyridine compounds, quinoline compounds, and isoquinoline compounds.

25. The processing method according to claim 22, characterized in that, The volume ratio of the extractant to the industrial wastewater is 1:(2-10).

26. The processing method according to claim 22, characterized in that, The pH value of the extraction is 5-9.

27. The processing method according to claim 22, characterized in that, The extraction temperature is 20-70℃.

28. The processing method according to claim 22, characterized in that, The raffinate phase enters the biochemical system, and / or the extract phase is back-extracted using a back-extraction agent.

29. The processing method according to claim 28, characterized in that, The stripping agent comprises an alkaline aqueous solution.

30. The processing method according to claim 29, characterized in that, The mass concentration of alkaline substances in the stripping agent is 10-50%.

31. The processing method according to claim 28, characterized in that, The oil phase obtained from the back-extraction process includes an extractant, and the purified oil phase is used for the extraction of industrial wastewater.

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