A method for treating disperse yellow 54 production wastewater

Abstract

The present application belongs to the field of wastewater treatment, and relates to a treatment method of disperse yellow 54 production wastewater, comprising the following steps: a, acid chemical separation, adding an acid chemical separation agent into the disperse yellow 54 wastewater, and then standing and separating, the upper layer is a chemical separation phase, and the lower layer is an aqueous phase; b, catalytic oxidation, adding a catalyst and an oxidant into the aqueous phase in step a to perform an oxidation reaction; c, evaporation and concentration, evaporating and crystallizing the effluent in step b to obtain a byproduct salt and evaporated water; d, acid chemical separation agent regeneration, adding an eluant into the chemical separation phase in step a to perform an acid chemical separation agent recovery reaction, and then standing and separating, and recovering the acid chemical separation agent. The treatment method can remove most of the toxic organic components in the disperse yellow 54 production wastewater, harmless the salt in the wastewater, and make the salt meet the byproduct salt or general solid waste standard, ensure the treatment effect, control the treatment cost, and improve the biodegradability of the wastewater.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and its purpose is to provide a method for treating wastewater from the production of Dispersed Yellow 54. Background Technology

[0002] Disperse Yellow 54#, also known as Disperse Yellow E3G, is mainly used for dyeing polyester fibers. It is suitable for high-temperature and high-pressure dyeing, as well as room-temperature dyeing and room-temperature carrier dyeing or printing. It has good leveling properties, high light fastness, and can be used to dye single colors or blended with blue to dye a bright fruit green.

[0003] The structure of Disperse Yellow 54 is as follows:

[0004]

[0005] Currently, the preparation of Dispersible Yellow 54 mainly involves reacting 2-methyl-3-hydroxyquinoline with phthalic anhydride in a high-boiling solvent such as trichlorobenzene at 200°C for 8 hours. After the reaction, the solvent is evaporated by steam or partially evaporated under high vacuum, followed by steam distillation to remove the remaining solvent. The mixture is then filtered, washed to obtain the product, and finally dried and pulverized to obtain the final product. The production process of Dispersible Yellow 54 generates a large amount of wastewater, which is characterized by high color, high COD, high toxicity, high salinity, carcinogenicity, mutagenicity, and poor biodegradability, making it difficult to treat.

[0006] Currently, there is no clear treatment method for the production wastewater of Disperse Yellow 54 in China. Current domestic treatment technologies for similar disperse dyes mainly focus on reducing COD, removing organic matter, removing color, neutralizing acids in the water, and removing solvents from the water. Current methods for treating acidic disperse wastewater include: 1) Lime neutralization. During precipitation, organic matter is loaded onto the surface of calcium sulfate, making it difficult to recover using conventional processes, thus generating new solid waste. This method essentially transfers pollutants from one system to another, without achieving complete elimination; 2) Chemical oxidation methods, such as reagent oxidation, O3 oxidation, and photo-oxidation. These methods exhibit significantly low degradation efficiency and are insufficient in removing color. Furthermore, severe color reversal occurs during the storage of the treated solution, greatly affecting the treatment effect.

[0007] Patent [CN113788586B] discloses a process for treating wastewater from disperse dye production and recovering salt resources. This application targets disperse dye wastewater containing sulfuric acid, employing a process of neutralizing acidic water to obtain sodium sulfate, ECO subcritical water catalytic oxidation, gas-liquid separation, freeze crystallization, nanofiltration membrane, concentration separation, and biochemical treatment to achieve water quality standards, while recovering salt from the disperse dye wastewater during the process. The ECO subcritical water catalytic oxidation process is a high-temperature, high-pressure process, which places high demands on equipment and results in high investment and operating costs. The acid and salt generated in the feed will precipitate during the reaction, and some salts have high viscosity, which may cause blockage of the reactor or pipelines, affecting normal equipment operation. Nanofiltration membranes are currently widely used, but they suffer from membrane fouling and repair issues. In wastewater treatment, membranes have high resistance, short service life, and inability to effectively control pollutants, leading to increased equipment operating and maintenance costs.

[0008] Patent [CN104692576A] discloses a method for treating wastewater from the production of indigo, an intermediate of Dispersible Yellow 54. This method involves pretreatment, ClO2 oxidation, and concentration crystallization. The pretreatment includes Fenton oxidation, adsorbent adsorption, and macroporous resin adsorption. Hazardous waste is generated during the pretreatment process, causing secondary pollution. The oxidant chlorine dioxide has poor stability and is explosive, posing certain safety risks during use and storage. The preparation of chlorine dioxide using a chlorine dioxide generator is complex and relatively costly. In water treatment and other applications, the strong corrosiveness of chlorine dioxide places high demands on the equipment used, and the operating and maintenance costs are relatively high.

[0009] Xiang Yongshui et al. (Research on Fenton Method for Treating Indigo Dye Wastewater) used Fenton reagent to carry out Fenton oxidation reaction under photocatalytic conditions. This method generates hazardous waste and causes secondary pollution during operation. The industrialization process of the scheme introduced in this article is quite difficult. Generally speaking, the production wastewater of disperse dyes is large and cannot meet the needs of large-capacity industrial-grade wastewater treatment.

[0010] The key to treating the wastewater from the production of Dispersible Yellow 54 lies in the targeted treatment of the toxic organic components in the water, so that most of the toxic organic components are removed, the salt in the wastewater reaches the general solid waste standard of harmlessness, the treatment effect is guaranteed while the treatment cost is controlled, and the biodegradability of the wastewater is improved. Summary of the Invention

[0011] The main objective of this invention is to provide a method for treating wastewater from the production of Dispersible Yellow 54, which solves the problem of the difficulty in eradicating macromolecular pollutants. It not only achieves good results in wastewater treatment, but also recovers inorganic salts from the wastewater, thereby reducing the amount of hazardous waste.

[0012] The method for treating wastewater from the production of Dispersible Yellow 54 provided by this invention includes the following steps:

[0013] Step a, acidic chemical separation reaction: Add an alkaline solution to the wastewater from the production of Dispersible Yellow 54 to neutralize it to a pH range of 6-9. Add an acidic chemical separation agent to the neutralized wastewater for chemical separation reaction treatment. After the reaction is completed, allow it to stand and separate into layers to obtain an upper chemically separated phase and a lower aqueous phase. The acidic chemical separation agent is prepared by reactant, co-solvent and diluent. The reactant is selected from one or more of naphthic acid, bis(2,4,4-trimethylpentyl)phosphonic acid or 5,8-dinonyl-2-naphthalenesulfonic acid. The co-solvent is an alcohol compound with a carbon chain of 8-20. The diluent is aviation kerosene or diesel oil.

[0014] Step b, catalytic oxidation: Add catalyst and oxidant to the aqueous phase in step a. The oxidant reacts with the organic matter in the wastewater in the catalytic environment. After the reaction is complete, add alkaline solution to separate the catalyst in solid form by filtration. The filtrate is then used for later use.

[0015] Step c, Evaporation and Concentration: The filtrate from step b is sent to an evaporator for evaporation. The resulting mother liquor is then centrifuged to obtain a by-product salt. The evaporated water can be treated in a biochemical system before being discharged. The by-product salt is one of sodium chloride, potassium chloride, or ammonium chloride, and its type depends on the materials added during the production of Disperse Yellow 54 and the type of alkaline solution added during subsequent treatment. The type of by-product salt is determined based on the implementation case and market conditions.

[0016] Step d: Regeneration of acidic chemical separating agent. An eluent is added to the upper chemical separation phase in step a to carry out an acidic chemical separating agent recovery reaction. After the reaction, the phases are allowed to stand and separate. The upper layer is the recovered acidic chemical separating agent, which can be reused in the acidic chemical separation reaction in step a. The lower layer is a concentrated solution containing oximeamine, indigo, and quinalidine contaminants.

[0017] The inventors discovered that the wastewater from the production of Dispersible Yellow 54 contains oxime amines, secondary amines, indigo and quinalidine nitrogen-containing heterocyclic organic compounds, as well as trichloroacetaldehyde, trichloroacetaldehyde oxime and other organic compounds. Directly using the oxidation process would result in excessive oxidant dosage, high treatment costs, poor treatment effect, and the salt obtained from evaporation and concentration has a high organic content, making it impossible to identify as a by-product salt. This application targets nitrogen-containing heterocyclic organic compounds such as oximeamine, indigo, and quinalidine in the wastewater from the production of Dispersible Yellow 54. First, acidic chemical separation treatment is performed. Since the concentration of these pollutants is high, chemical separation allows for targeted removal, reducing the reaction load on subsequent treatment processes. The effluent from the acidic chemical separation is then subjected to catalytic oxidation to oxidize trichloroacetaldehyde, trichloroacetaldehyde oxime, some quinalidine, and indigo in the wastewater. This method can solve the toxicity problem of organic matter in the wastewater and reduce its color. The effluent from the catalytic oxidation process is then evaporated and concentrated, allowing for the resource recovery of sodium chloride, potassium chloride, or ammonium chloride byproduct salts in the wastewater, achieving wastewater harmlessness and hazardous waste reduction.

[0018] Because the pH of the wastewater from the production of Dispersible Yellow 54 is very low, generally 1-2, and under pH < 6 conditions, the binding capacity of pollutants such as oximeamine, indigo, and quinalidine in the wastewater is low with the acidic chemical separating agent; under pH > 9 conditions, the reactants, cosolvents, and diluents in the acidic chemical separating agent are miscible and unstable, leading to the failure and decomposition of the acidic chemical separating agent; therefore, the pH value of the wastewater from the production of Dispersible Yellow 54 needs to be adjusted to 6-9 before chemical separation reaction treatment.

[0019] The inventors discovered that pollutants such as oxime, indigo, and quinalidine in wastewater possess nitrogen-containing functional groups. By selecting naphthic acid, bis(2,4,4-trimethylpentyl)phosphonic acid, or 5,8-dinonyl-2-naphthalenesulfonic acid as reactants in the acidic chemical separation agent, these reactants, with their acidic anionic structure and hydrogen bonding characteristics, can combine with the nitrogen-containing functional groups in the pollutants to form stable hydrophobic groups, thereby improving the removal of pollutants such as oxime, indigo, and quinalidine from the wastewater. Using alcohols with carbon chains of 8-20 as co-solvents can alter the interaction forces between the above substances and the acidic reagents, improving their solubility and thus increasing extraction efficiency. Using aviation kerosene or diesel oil as a diluent can adjust the density of the acidic reagents, accelerating the separation rate between the acidic reagents and water during the reaction process, while simultaneously reducing the cost of the acidic reagents.

[0020] In addition, the above-mentioned method for treating the wastewater from the production of Dispersible Yellow 54 of the present invention may also have the following additional technical features.

[0021] Preferably, in step a, the alkaline solution is one of a 10-32% sodium hydroxide solution, a 10-20% potassium hydroxide solution, or a 10-20% ammonia solution.

[0022] Preferably, in step a, the acidic chemical separating agent is composed of a reactant, a cosolvent, and a diluent mixed in a volume ratio of (1-3):(1-2):(5-8). If the reactant ratio is too high, the separated phase produced in the above reaction step will have high viscosity and be difficult to separate from water; if the reactant ratio is too low, the removal efficiency of substances such as oximeamine, indigo, and quinalidine in the Dispersible Yellow 54 wastewater will decrease; if the cosolvent ratio is too low, the solubility of the stable groups generated by the reactant and the target pollutants in the Dispersible Yellow 54 wastewater will decrease, and the acidic agent will fail to separate; if the cosolvent ratio is too high, the cost of the acidic agent will be high; if the diluent ratio is too high, it will lead to a decrease in the reactant ratio in the acidic agent, indirectly leading to a decrease in the reactant ratio and a decrease in the removal efficiency of substances such as oximeamine, indigo, and quinalidine in the Dispersible Yellow 54 wastewater; if the diluent ratio is too low, the separated phase produced in the reaction step will have high viscosity and be difficult to separate from water.

[0023] Preferably, in step a, the volume ratio of the acidic agent to the Dispersible Yellow 54 wastewater is 10%-35%; the reaction temperature is generally 10-40℃, preferably 20-30℃, and the reaction time is 20-50 min, preferably 30-40 min; the volume ratio of the acidic agent to the Dispersible Yellow 54 wastewater is related to the content of the above-mentioned pollutants in the Dispersible Yellow 54 production wastewater. If the volume ratio of the acidic agent to the Dispersible Yellow 54 wastewater is <10%, the organic matter in the wastewater is not completely removed, affecting the removal of organic matter in the wastewater. If it is >35%, there is too much acidic agent, the concentration of the recovered phase is low, and the amount of the recovered phase is large. In addition, the acidic reagent reacts efficiently with substances such as oximeamine, indigo, and quinalidine in Dispersible Yellow 54 at room temperature. If the reaction temperature is <10℃, the reaction efficiency decreases and the removal rate of the above pollutants is low. If the reaction temperature is >40℃, the acidic reagent will produce side reactions, the composition of the acidic reagent will change, and the reagent will become ineffective. If the reaction time is <20min, the reaction between the acidic reagent and the above pollutants will not be sufficient, and the reaction efficiency will decrease. If the reaction time is >50min, the acidic reagent will emulsify, and the separation rate of the acidic reagent and water will be slow.

[0024] Preferably, in step b, the oxidant used is one or more of hydrogen peroxide, ozone, and sodium persulfate solution, and the catalyst is one or more of ferrous chloride, copper chloride, zinc chloride, and activated carbon. The amount of oxidant added is related to the amount of aqueous phase, the concentration and type of oxidant in step a. The relevant process parameters are determined based on implementation case experience. Specifically, the theoretical oxygen demand required for the target removal rate of pollutants in wastewater is equal to the theoretical oxygen supply in the added oxidant. Thus, the hydroxyl radicals produced in the oxidant completely oxidize and remove the remaining pollutants. The ratio of catalyst to oxidant is related to the concentration and type of oxidant and the concentration and type of catalyst. The inventors have found that by limiting the ratio of the amount of functional group of hydroxyl radicals produced by the oxidant to the amount of effective catalyst in the catalyst to (2-6):1, where the effective catalyst in the catalyst is Fe 2+Cu 2+ Zn 2+ The surface-active carbon in the activated carbon effectively ensures that the efficiency of the oxidant in producing hydroxyl radicals matches the reaction efficiency of pollutants with aqueous pollutants, guaranteeing high catalytic oxidation efficiency. If the ratio of oxidant to catalyst is >6:1, the efficiency of the oxidant in producing hydroxyl radicals is low, the oxidation reaction rate is low, the reaction time is long, and the industrial economics are low. If the ratio of oxidant to catalyst is <2:1, the efficiency of the oxidant in producing hydroxyl radicals is high, but the reaction rate of hydroxyl radicals with aqueous pollutants in step a is limited, and hydroxyl radicals react with excess catalyst, resulting in low actual oxidant efficiency and low economics.

[0025] Preferably, in step b, the catalytic oxidation reaction temperature is 10-40℃, more preferably 20-35℃, and the reaction time is 30-120 min, more preferably 60-90 min. The reaction temperature and reaction time are related to the type of oxidant and catalyst used, as well as the content of residual pollutants in step a. The inventors have found that if the reaction temperature is >40℃, the oxidant produces hydroxyl radicals with high efficiency, but the reaction rate of hydroxyl radicals with aqueous pollutants in step a is limited. The hydroxyl radicals react with excess catalyst, resulting in low actual efficiency of the oxidant and low economic efficiency. If the reaction temperature is <10℃, the oxidant produces hydroxyl radicals with low efficiency, low oxidation reaction rate, and long reaction time, resulting in low industrial economic efficiency. If the reaction time is too long, the industrial economic efficiency is low. If the reaction time is too short, the residual pollutants in step a cannot be completely degraded, and the by-product salt produced in step c has poor quality.

[0026] In step a, the remaining aqueous phase mainly consists of water, sodium chloride, trichloroacetaldehyde, trichloroacetaldehyde oxime, a small amount of indigo, quinalidine, and by-products. Inorganic salts in the aqueous phase can be produced as by-product salts. Trichloroacetaldehyde and trichloroacetaldehyde oxime cannot be removed by reacting with acidic chemical separating agents. The efficiency and economics of further treatment of the small amount of indigo, quinalidine, and by-products using acidic agents are low. This application uses a catalytic oxidation process to deeply treat the remaining substances in the above-mentioned aqueous phase. The inventors have found that the pH range of the aqueous phase after catalytic oxidation is generally 1-6. By adding an alkaline solution to adjust the pH of the wastewater to the range of 6-9, a solid phase can be formed and filtered to separate from the aqueous phase. The solid phase consists of water-insoluble substances produced after the oxidation of the catalyst and pollutants in the aqueous phase. The filtrate after filtration can be evaporated and centrifuged to produce salts as by-products. Preferably, the alkaline solution is one of 10-32% sodium hydroxide solution, 10-20% potassium hydroxide solution, or 10-20% ammonia solution.

[0027] Preferably, in step d, the eluent is a hydrochloric acid solution with a mass fraction of 10-20%, and the volume ratio of the eluent to the chemical separation phase is 1:(6-10). The actual ratio of the chemical separation phase to the eluent is related to the concentration of the groups generated by the reaction between the reactant and the above substances in the separation phase. If the volume ratio of the eluent to the chemical separation phase is <1:10, the above substances cannot be completely eluented into the eluent, and the efficiency of the acidic chemical separation agent will be reduced when it is reused. If the volume ratio of the eluent to the chemical separation phase is >1:6, the content of the above pollutants in the acidic eluent will be low, and the excess eluent will be wasted.

[0028] Preferably, in step d, the recovery conditions for the acidic chemical separating agent are a reaction temperature of 30-50℃, preferably 40-45℃, and a reaction time of 20-40 min, preferably 25-30 min. The acidic chemical separating agent used in this application forms a chemical separation phase with oximeamine, indigo, quinalidine, and other substances in Disperse Yellow 54. This phase is very stable at temperatures <30℃ and pH = 6-9, and the content of the above-mentioned pollutants in the separation phase is relatively high. Therefore, during the desorption process, it is necessary to increase the reaction temperature and control the reaction time to ensure the complete desorption of the acidic chemical separating agent and its reuse in step a. If the reaction temperature is too low, the acidic chemical separating agent will not be completely decomposed, resulting in a decrease in the efficiency of its reuse in step a. If the reaction temperature is too high, some substances in the acidic chemical separating agent will volatilize and be lost or dissolved in the separating agent, increasing the loss of the acidic chemical separating agent. If the reaction time is too short, the acidic chemical separating agent will not be completely decomposed, resulting in a decrease in the efficiency of its reuse in step a. If the reaction time is too long, the acidic chemical separating agent will emulsify and cannot be reused in step a.

[0029] Compared with existing technologies, this formulation has the following beneficial effects:

[0030] 1. Targeted treatment of toxic organic components in the wastewater from the production of Dispersible Yellow 54 removes most of the toxic organic components, and the salt content in the wastewater meets the general solid waste harmless standards. This ensures treatment effectiveness while controlling treatment costs and improving the biodegradability of the wastewater.

[0031] 2. Naphthalic acid, bis(2,4,4-trimethylpentyl)phosphonic acid, and 5,8-dinonyl-2-naphthalenesulfonic acid are used as reactants in the acidic chemical separation agent. This method targets acidic polar organic compounds (such as oximeamine, indigo, and quinalidine) in wastewater. By combining with nitrogen-containing functional groups in the wastewater pollutants to form stable hydrophobic groups, stable, insoluble new macromolecular organic compounds are formed, thereby effectively separating the target substances from the wastewater. After this process, the COD removal rate reaches over 65%, the oximeamine removal rate over 85%, the indigo and quinalidine removal rates over 65%, and the wastewater color removal rate over 85%.

[0032] 3. Catalytic oxidation is used for further wastewater treatment. By limiting the ratio of catalyst to oxidant, the remaining toxic organic matter in the wastewater is decomposed and removed through catalytic oxidation. After this process, most of the toxic organic matter in the wastewater is removed, and the COD removal rate reaches over 90%. The main pollutants removed are trichloroacetaldehyde, trichloroacetaldehyde oxime, a small amount of indigo, quinalidine, and by-reaction products. The color removal rate is over 95%. This improves the biodegradability of the distillate and ensures stable subsequent biological treatment effects. Attached Figure Description

[0033] Figure 1 Here is a flow chart of a process for treating wastewater from the production of Dispersible Yellow 54 according to the present invention: Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0036] The wastewater used in the following examples comes from the production wastewater of Disperse Yellow 54 from a dye factory in Heilongjiang, the production wastewater of Disperse Yellow 54 from a dye factory in Qinghai, and the production wastewater of Disperse Yellow 54 from a dye factory in Shanxi.

[0037] Example 1

[0038] The wastewater was taken from the Disperse Yellow 54 production workshop of a dye factory in Heilongjiang Province. The water quality was as follows: pH=1-2, COD=32184mg / L, oximeamine 2423 mg / L, indigo 1210mg / L, quinalidine 1054mg / L, and the water color was brownish-red.

[0039] Preparation of acidic chemical separating agent: Take 200 ml of 5,8-dinonyl-2-naphthalenesulfonic acid, 100 ml of isomeric 14-alkyl alcohol, and 600 ml of aviation kerosene and mix them evenly to obtain the acidic chemical separating agent.

[0040] a. Acidic chemical separation: Take 600ml of the above-mentioned Disperse Yellow 54 wastewater, adjust the pH to 7 with sodium hydroxide solution, add 200ml of acidic chemical separation agent, mix and react for 40min at 25℃, and let stand to separate into layers to obtain a chemically separated phase and an aqueous phase. The chemically separated phase is subsequently recovered and regenerated by the separation agent, and the aqueous phase is sampled for analysis.

[0041] After acidic chemical separation treatment, the COD of the Dispersible Yellow 54 wastewater was 8345 mg / L, with a COD removal rate of 74.1%; the oxime amine was 256 mg / L, with an oxime amine removal rate of 89.4%; the indigo tin was 251 mg / L, with an indigo tin removal rate of 79.2%; and the quinalidine was 245 mg / L, with a quinalidine removal rate of 76.7%. The separated aqueous phase was yellow.

[0042] b. Catalytic oxidation reaction: Take 500ml of chemically separated water. The ratio of the amount of functional group of hydroxyl radical produced by the oxidant to the amount of effective catalyst in the catalyst is 4:1. Therefore, add 7.5ml of 27.5% hydrogen peroxide, 1g of activated carbon, and 0.5g of ferrous chloride. The reaction temperature is 30℃. Mix and react for 90min. After the reaction, adjust the pH of the mixed solution to 8 with sodium hydroxide solution and filter to separate the solid phase and the aqueous phase. The solid phase is a mixture of activated carbon, ferric hydroxide, and organic matter. Take a sample of the aqueous phase for analysis.

[0043] c. After acidic chemical separation and catalytic oxidation treatment, the COD of the Dispersible Yellow 54 wastewater was 2185 mg / L, with a COD removal rate of 93.2%. Oximeamine, indigo, and quinalidine were not detected, and the aqueous phase was nearly colorless. Evaporation and concentration were then carried out for desalination. The salt, which can be used as a byproduct, is sodium chloride. Testing showed that the salt weighed 130g and contained 97.8% sodium chloride, meeting the requirements of the superior grade standard for sun-dried industrial salt in GB / T 5462-2015. The COD of the distillate was 326 mg / L, with a removal rate of 98.9%.

[0044] d. Regeneration of the acidic chemical separating agent: The chemically separated phase and a 12% hydrochloric acid solution are fed into the regeneration device at a volume ratio of 8:1. The reaction is carried out at 40°C for 40 minutes, followed by settling and separation. The upper layer is the regenerated acidic chemical separating agent, which can be reused in the next wastewater acidic chemical separation reaction; the lower layer is the recovered phase, mainly composed of compounds such as oximeamine, indigo, and quinalidine.

[0045] Recycling of acidic chemical separating agent: Take 600 ml of the above Disperse Yellow 54 wastewater, adjust the pH to 8 with sodium hydroxide solution, add 200 ml of the acidic chemical separating agent in the above regeneration step, mix and react for 40 min, and let stand to separate into layers to obtain a chemically separated phase and an aqueous phase. The chemically separated phase is subsequently recycled and regenerated by the separating agent, and the aqueous phase is sampled for analysis.

[0046] After treating the Disperse Yellow 54 wastewater with the regenerated acidic chemical separation agent, the COD was 8168 mg / L, with a COD removal rate of 74.6%; the oxime removal rate was 89.3% (258 mg / L); the indigo removal rate was 79.1% (252 mg / L); and the quinalidine removal rate was 76.8% (244 mg / L). The separated aqueous phase was yellow. Under the same conditions, the treatment effect of the regenerated acidic chemical separation agent was similar to that of the original agent.

[0047] Example 2

[0048] Wastewater was taken from the Disperse Yellow 54 production workshop of a dye factory in Qinghai Province. The water quality is as follows: pH < 0.5, COD: 27465 mg / L, oxime 2548 mg / L, indigo 1240 mg / L, quinalidine 985 mg / L, brownish-yellow.

[0049] Preparation of acidic chemical separating agent: Take 200 mL of bis(2,4,4-trimethylpentyl)phosphonic acid, 200 mL of n-octanol, and 600 mL of aviation kerosene and mix them evenly to obtain the acidic chemical separating agent;

[0050] a. Acidic chemical separation: Take 500ml of wastewater, add sodium hydroxide solution to adjust the pH to 7, then add 100ml of acidic reagent to the pH-adjusted wastewater. Mix and react for 30 minutes at 30℃, let stand and separate into layers. The upper layer is the chemically separated phase, and the lower layer is the aqueous phase. The chemically separated phase is subsequently recovered and regenerated by the separating agent, and the lower aqueous phase is sampled for analysis.

[0051] After acidic chemical separation treatment, the COD of the Dispersible Yellow 54 wastewater was 8943 mg / L, with a COD removal rate of 67.4%; the oxime amine was 305 mg / L, with an oxime amine removal rate of 88.1%; the indigo was 291 mg / L, with an indigo removal rate of 76.5%; and the quinalidine was 285 mg / L, with a quinalidine removal rate of 71.0%. The separated aqueous phase was yellow.

[0052] b. Catalytic oxidation: Take 500ml of chemically separated water. The ratio of the amount of functional group of hydroxyl radical produced by the oxidant to the amount of effective catalyst in the catalyst is 3:1. Therefore, add 10ml of 27.5% hydrogen peroxide and 2g of ferrous chloride. The reaction temperature is 40℃ and the reaction time is 2h. After the reaction, add sodium hydroxide solution to adjust the pH to 9 and filter to separate the solid phase and the aqueous phase. The solid phase is a mixture of ferric hydroxide and organic matter. The aqueous phase is sampled and analyzed.

[0053] c. The COD of the effluent from catalytic oxidation was 2120 mg / L, with a COD removal rate of 92.3%. Oximeamine, indigo, and quinalidine were not detected, and the effluent was nearly colorless. After evaporation and concentration, sodium chloride was obtained as a byproduct. Testing showed that this salt weighed 110g and contained 97.1% sodium chloride, meeting the requirements of the superior grade standard for sun-dried industrial salt in GB / T 5462-2015. The COD of the evaporated effluent was 363 mg / L, with a removal rate of 98.6%.

[0054] d. Regeneration of the acidic chemical separation agent: The chemically separated phase and a 12% hydrochloric acid solution are fed into the regeneration device at a volume ratio of 6:1. The reaction temperature is 45℃, and the reaction time is 30 minutes. After standing, the phases separate. The upper layer is the regeneration agent, which can be reused in the next acidic chemical separation reaction of wastewater; the lower layer is the recovery phase, mainly composed of compounds such as oximeamine, indigo, and quinalidine.

[0055] Example 3

[0056] Wastewater was taken from the Disperse Yellow 54 production workshop of a dye factory in Shanxi Province. The water quality is as follows: pH < 0.5, COD: 18156 mg / L, oxime 1648 mg / L, indigo 985 mg / L, quinalidine 945 mg / L, brownish-yellow.

[0057] Preparation of acidic chemical separation agent: Take 200 mL of bis(2,4,4-trimethylpentyl)phosphonic acid, 100 mL of isomeric 16-alkyl alcohol, and 600 mL of aviation kerosene and mix them evenly to obtain the acidic chemical separation agent;

[0058] a. Acidic chemical separation: Take 500ml of wastewater, add sodium hydroxide solution to adjust pH=9, then add 85ml of acidic reagent to the pH-adjusted wastewater. Mix and react for 50min at 20℃, let stand and separate into layers. The upper layer is the chemically separated phase and the lower layer is the aqueous phase. The chemically separated phase is subsequently recovered and regenerated by the separating agent, and the lower aqueous phase is sampled for analysis.

[0059] After acidic chemical separation treatment, the COD of the Disperse Yellow 54 wastewater was 5524 mg / L, with a COD removal rate of 69.5%; the oxime amine was 232 mg / L, with an oxime amine removal rate of 85.9%; the indigo tin was 263 mg / L, with an indigo tin removal rate of 73.2%; and the quinalidine was 275 mg / L, with a quinalidine removal rate of 70.8%. The separated aqueous phase was yellow.

[0060] b. Catalytic oxidation: Take 500ml of chemically separated water. The ratio of the amount of functional group of hydroxyl radical produced by the oxidant to the amount of effective catalyst in the catalyst is 3.8:1. Therefore, add 5ml of 27.5% hydrogen peroxide and 1.2g of activated carbon catalyst. The reaction temperature is 40℃ and the reaction time is 1h. After the reaction, add sodium hydroxide solution to adjust the pH to 7 and filter to separate the solid phase and the aqueous phase. The solid phase is a mixture of organic matter, and the aqueous phase is sampled for analysis.

[0061] c. The COD of the catalytic oxidation effluent is 1530 mg / L, with a COD removal rate of 92.3%. Oximeamine, indigo, and quinalidine were not detected. The effluent is nearly colorless. The catalytic oxidation effluent enters an evaporation and concentration unit for evaporation and desalination. The salt can be used as a byproduct, sodium chloride. Testing showed that the salt weighed 105g and contained 97.3% sodium chloride. This meets the requirements of the superior grade standard for sun-dried industrial salt in GB / T 5462-2015. The COD of the distillate is 275 mg / L, with a removal rate of up to 98.5%.

[0062] d. Regeneration of the acidic chemical separating agent: The extract phase and a 15% hydrochloric acid solution are fed into the regeneration device at a volume ratio of 10:1. The reaction temperature is 50℃, and the reaction time is 20 minutes. After standing, the mixture separates into layers. The upper layer is the regeneration agent, which can be reused in the next acidic chemical separation reaction of wastewater. The lower layer is the recovery phase, mainly composed of compounds such as oximeamine, indigo, and quinalidine.

[0063] Example 4

[0064] The wastewater is the same as that used in Example 1.

[0065] Preparation of acidic chemical separating agent: Take 200 ml of naphthic acid, 100 ml of isomeric n-octanol, and 700 ml of diesel oil and mix them evenly to prepare acidic chemical separating agent;

[0066] a. Acidic chemical separation: Take 600 ml of the above-mentioned Disperse Yellow 54 wastewater, adjust the pH to 7 with sodium hydroxide solution, add 200 ml of acidic chemical separation agent, mix and react for 50 min at 15℃, then let stand to separate into layers to obtain a chemically separated phase and an aqueous phase. The chemically separated phase is regenerated by a subsequent separation agent, and the aqueous phase is sampled for analysis.

[0067] After acidic chemical separation treatment, the COD of the Disperse Yellow 54 wastewater was 10264 mg / L, with a COD removal rate of 68.1%; the oxime amine was 342 mg / L, with an oxime amine removal rate of 85.8%; the indigo was 410 mg / L, with an indigo amine removal rate of 66.8%; and the quinalidine was 352 mg / L, with a quinalidine removal rate of 66.6%. The separated aqueous phase was yellow.

[0068] b. Catalytic oxidation reaction: Take 500ml of chemically separated water. The ratio of the amount of functional group of hydroxyl radical produced by the oxidant to the amount of effective catalyst in the catalyst is 4:1. Therefore, add 8ml of 20% sodium persulfate solution and 1.5g of copper chloride. The reaction temperature is 30℃. Mix and react for 90min. After the reaction, use sodium hydroxide solution to adjust the pH of the mixed solution to 8 and filter to separate the solid phase and the aqueous phase. The solid phase is a mixture of copper hydroxide and organic matter. The aqueous phase is sampled and analyzed.

[0069] c. After acidic chemical separation and catalytic oxidation treatment, the COD of the Dispersible Yellow 54 wastewater was 2826 mg / L, with a COD removal rate of 91.5%. The separated aqueous phase was nearly colorless, and the contents of oximeamine, aniline, and indigoquinalidine were not detected. The catalytic oxidation effluent entered an evaporation and concentration unit for evaporation and desalination. The salt can be used as a by-product, sodium chloride. The tested salt weighed 126g and had a sodium chloride content of 96.7%, meeting the requirements of the superior grade standard for sun-dried industrial salt in GB / T 5462-2015 Industrial Salt. The COD of the distillate was 425 mg / L, with a removal rate of 98.6%.

[0070] d. Regeneration of the acidic chemical separating agent: The extracted separation phase and a 20% hydrochloric acid solution are fed into the regeneration device at a volume ratio of 10:1. The temperature is 30℃, and the reaction is carried out for 40 minutes, followed by settling. The upper layer is the regenerated acidic chemical separating agent, which can be reused in the next wastewater acidic chemical separation reaction; the lower layer is the recovered phase, mainly composed of compounds such as oximeamine, indigo, and quinalidine.

[0071] Example 5

[0072] The wastewater is the same as that used in Example 1; the difference from Example 1 is: preparation of acidic chemical separating agent: take 50 ml of 5,8-dinonyl-2-naphthalenesulfonic acid, 200 ml of isomeric 14-alkanol, and 700 ml of aviation kerosene and mix them evenly to obtain acidic chemical separating agent.

[0073] After acidic chemical separation treatment, the wastewater containing Dispersible Yellow 54 had a COD of 11908 mg / L (COD removal rate of 63%), an oxime removal rate of 71% (oxime removal rate of 703 mg / L), an indigo removal rate of 61% (indigo removal rate of 472 mg / L), and a quinacrine removal rate of 60% (quinacrine removal rate of 422 mg / L). The separated aqueous phase was brown. The reason for this was that the proportion of 5,8-dinonyl-2-naphthalenesulfonic acid in the acidic chemical separation agent was too low, resulting in a decrease in the removal rates of COD, oxime, indigo, and quinacrine in the wastewater.

[0074] After the catalytic oxidation reaction, the COD was 5773 mg / L, with a removal rate of 82.1%. The salt obtained from the evaporation and concentration of the catalytic oxidation effluent was 124 g, with a sodium chloride content of 94.5%, meeting the requirements of the secondary standard for sun-dried industrial salt in GB / T 5462-2015. Compared to Example 1, the purity was lower, with the COD of the distillate water being 617 mg / L and a removal rate of 97.3%. The reduced effectiveness of the chemical separation treatment led to a decrease in the overall subsequent treatment effect, resulting in poorer quality salt from the evaporation.

[0075] Example 6

[0076] The wastewater used in Example 1 differs from that in Example 1 in that: a) the mixing reaction time in the acidic chemical separation is 10 min.

[0077] After acidic chemical separation treatment, the COD of Dispersible Yellow 54 wastewater was 10975 mg / L, with a COD removal rate of 65.9%; oxime amine was 480 mg / L, with an oxime removal rate of 80.2%; indigo was 363 mg / L, with an indigo removal rate of 70%; and quinalidine was 332 mg / L, with a quinalidine removal rate of 68.5%. The separated aqueous phase was red. The reason for this is that the chemical separation reaction time was too short, resulting in incomplete chemical separation and a decrease in the removal rates of COD, oxime amine, indigo, and quinalidine in the wastewater.

[0078] After the catalytic oxidation reaction, the COD was 4474 mg / L, with a removal rate of 86.1%. The salt obtained from the evaporation and concentration of the catalytic oxidation effluent was 127 g, with a sodium chloride content of 94.8%, meeting the requirements of the second standard for sun-dried industrial salt in GB / T 5462-2015. Compared to Example 1, the purity was slightly lower. The COD of the distillate was 517 mg / L, with a removal rate of 98.4%. The reduced effectiveness of the chemical separation treatment led to a decrease in the overall subsequent treatment effect, resulting in poorer quality salt from the evaporation.

[0079] Example 7

[0080] The wastewater is the same as that used in Example 1; the difference from Example 1 is that in step d, the acidic chemical separation agent is regenerated: the chemical separation phase and a hydrochloric acid solution with a mass fraction of 12% are fed into the regeneration device at a volume ratio of 12:1, and the upper layer is the regenerated acidic chemical separation agent.

[0081] Recycling of acidic chemical separating agent: Take 600 ml of the above Disperse Yellow 54 wastewater, adjust the pH to 8 with sodium hydroxide solution, add 200 ml of the acidic chemical separating agent in the above regeneration step, mix and react for 40 min, and let stand to separate into layers to obtain a chemically separated phase and an aqueous phase. The chemically separated phase is subsequently recycled and regenerated by the separating agent, and the aqueous phase is sampled for analysis.

[0082] After treating the Disperse Yellow 54 wastewater with the regenerated acidic chemical separation agent, the COD was 11876 mg / L, with a COD removal rate of 63.1%; the oximeamine concentration was 523 mg / L, with an oximeamine removal rate of 78.4%; the indigo concentration was 385 mg / L, with an indigo removal rate of 68.2%; and the quinalidine concentration was 362 mg / L, with a quinalidine removal rate of 65.7%. The separated aqueous phase was red. The reason for this was that the volume ratio of the eluent to the chemical separation phase was too small, resulting in incomplete eluent removal of substances such as oximeamine, indigo, and quinalidine from the separation phase into the eluent, leading to reduced efficiency when the acidic chemical separation agent was reused.

[0083] Example 8

[0084] The wastewater is the same as that used in Example 1; the difference from Example 1 is that in step d, the acidic chemical separating agent is regenerated: the reaction temperature is 25°C.

[0085] Recycling of acidic chemical separating agent: Take 600 ml of the above Disperse Yellow 54 wastewater, adjust the pH to 8 with sodium hydroxide solution, add 200 ml of the acidic chemical separating agent in the above regeneration step, mix and react for 40 min, and let stand to separate into layers to obtain a chemically separated phase and an aqueous phase. The chemically separated phase is subsequently recycled and regenerated by the separating agent, and the aqueous phase is sampled for analysis.

[0086] After treating the Disperse Yellow 54 wastewater with the regenerated acidic chemical separation agent, the COD was 11618 mg / L, with a COD removal rate of 63.9%; the oxime removal rate was 79.2% (504 mg / L); the indigo removal rate was 69% (375 mg / L); and the quinalidine removal rate was 66.5% (353 mg / L). The separated phase effluent was dark yellow. The reason for this was that the reaction temperature was too low, resulting in incomplete desorption of the acidic chemical separation agent. The incomplete desorption of the acidic chemical separation agent led to a decrease in the reaction efficiency when reused in step a.

[0087] Example 9

[0088] The wastewater is the same as that used in Example 1; the difference from Example 1 is that in step d, the acidic chemical separating agent is regenerated: the reaction temperature is 55°C.

[0089] Recycling of acidic chemical separating agent: Take 600 ml of the above Disperse Yellow 54 wastewater, adjust the pH to 8 with sodium hydroxide solution, add 200 ml of the acidic chemical separating agent in the above regeneration step, mix and react for 40 min, and let stand to separate into layers to obtain a chemically separated phase and an aqueous phase. The chemically separated phase is subsequently recycled and regenerated by the separating agent, and the aqueous phase is sampled for analysis.

[0090] After treating the Disperse Yellow 54 wastewater with the regenerated acidic chemical separation agent, the COD was 10552 mg / L, with a COD removal rate of 67.2%; the oxime removal rate was 81.4% (451 mg / L); the indigo removal rate was 71.2% (348 mg / L); and the quinalidine removal rate was 69.7% (319 mg / L). The separated phase effluent was yellow. The reason for this was that the reaction temperature was too high, causing some substances in the acidic chemical separation agent to volatilize or dissolve in the eluent, increasing the loss of the acidic chemical separation agent. When reused in step a, this would lead to a decrease in reaction efficiency.

[0091] Example 10

[0092] The wastewater is the same as that used in Example 1; the difference from Example 1 is that in step b, the oxidant used is sodium hypochlorite and the catalyst is polyferric chloride.

[0093] After acidic chemical separation and catalytic oxidation treatment, the COD of the Dispersible Yellow 54 wastewater was 4763 mg / L, with a COD removal rate of 85.2%. The oxime amine concentration was 512 mg / L, with an oxime amine removal rate of 78.8%. The indigo tincture concentration was 288 mg / L, with an indigo tincture removal rate of 76.2%. The quinalidine concentration was 269 mg / L, with a quinalidine removal rate of 74.5%. The separated phase effluent was yellow. The reason for this is that the oxidant and reducing agent could not provide a suitable reaction system, resulting in a reduced reaction efficiency with the characteristic pollutants in the wastewater, thus leading to a decrease in removal efficiency.

[0094] After the catalytic oxidation reaction, the COD was 4763 mg / L, with a removal rate of 85.2%. The salt obtained from the evaporation and concentration of the catalytic oxidation effluent was 126 g, with a sodium chloride content of 94.0%, meeting the requirements of the secondary standard for sun-dried industrial salt in GB / T 5462-2015. Compared to Example 1, the purity was slightly lower. The COD of the distillate was 547 mg / L, with a removal rate of 98.3%. The reduced effectiveness of the catalytic oxidation treatment led to a decrease in the overall subsequent treatment effect, resulting in poorer quality salt from the evaporated solution.

[0095] Example 11

[0096] The wastewater is the same as that used in Example 1; the difference from Example 1 is that in step b, 10 ml of 27.5% hydrogen peroxide, 0.5 g of activated carbon, and 0.3 g of ferrous chloride are added, and the ratio of the amount of functional group of hydroxyl radical produced by the oxidant to the amount of effective catalyst in the catalyst is 18.3:1.86.

[0097] After acidic chemical separation and catalytic oxidation treatment, the COD of the Dispersible Yellow 54 wastewater was 4152 mg / L, with a COD removal rate of 87.1%. The oxime amine concentration was 412 mg / L, with an oxime amine removal rate of 83.0%. The indigo tincture concentration was 278 mg / L, with an indigo tincture removal rate of 77%. The quinalidine concentration was 274 mg / L, with a quinalidine removal rate of 74%. The separated effluent was yellow. The reason for this was that the oxidant was excessive and failed to form a catalytic oxidation system with the reducing agent, resulting in a decrease in reaction efficiency and thus a decrease in the removal rate.

[0098] After the catalytic oxidation reaction, the COD was 4152 mg / L, with a removal rate of 87.1%. The salt obtained from the evaporation and concentration of the catalytic oxidation effluent was 122 g, with a sodium chloride content of 94.1%, meeting the requirements of the secondary standard for sun-dried industrial salt in GB / T 5462-2015. Compared to Example 1, the purity was slightly lower. The COD of the distillate was 547 mg / L, with a removal rate of 98.3%. The reduced effectiveness of the catalytic oxidation treatment led to a decrease in the overall subsequent treatment effect, resulting in poorer quality salt from the evaporated solution.

[0099] Example 12

[0100] The wastewater is the same as that used in Example 1; the difference from Example 1 is that in step b, 10 ml of 27.5% hydrogen peroxide, 5 g of activated carbon, and 3 g of ferrous chloride are added. The ratio of the amount of functional group of hydroxyl radical produced by the oxidant to the amount of effective catalyst in the catalyst is 18.3:18.6.

[0101] After acidic chemical separation and catalytic oxidation treatment, the COD of the Dispersible Yellow 54 wastewater was 4248 mg / L, with a COD removal rate of 86.8%. The oxime amine concentration was 439 mg / L, with an oxime amine removal rate of 81.9%. The indigo tincture concentration was 312 mg / L, with an indigo tincture removal rate of 74.2%. The quinalidine concentration was 298 mg / L, with a quinalidine removal rate of 71.7%. The separated phase effluent was yellow. The reason for this was that the reducing agent was excessive and failed to form a catalytic oxidation system with the reducing agent, resulting in a decrease in reaction efficiency and thus a decrease in the removal rate.

[0102] After the catalytic oxidation reaction, the COD was 4248 mg / L, with a removal rate of 86.8%. The salt obtained from the evaporation and concentration of the catalytic oxidation effluent was 127 g, with a sodium chloride content of 94.5%, meeting the requirements of the secondary standard for sun-dried industrial salt in GB / T 5462-2015. Compared to Example 1, the purity was slightly lower. The COD of the distillate was 534 mg / L, with a removal rate of 98.3%. The reduced effectiveness of the catalytic oxidation treatment led to a decrease in the overall subsequent treatment effect, resulting in poorer quality salt from the evaporated solution.

[0103] Comparative Example 1

[0104] The wastewater is the same as that used in Example 2.

[0105] The specific steps are as follows:

[0106] Catalytic oxidation: Since no chemical separation reaction step was performed, the amount of catalytic oxidation reagent used was increased. Take 500ml of wastewater, add 25ml of 27.5% hydrogen peroxide and 6g of ferrous chloride, react at 40℃ for 3 hours, adjust the pH to 7-9 with alkaline solution, and filter to separate the solid phase and aqueous phase. The solid phase is a mixture of ferric hydroxide and organic matter, and the aqueous phase is sampled for analysis.

[0107] Analysis of the effluent from catalytic oxidation revealed a COD of 17465 mg / L, a COD removal rate of 36.1%, and a brownish-black color. Treatment of effluent without chemical separation using only catalytic oxidation resulted in significantly poorer performance. The effluent from catalytic oxidation was then concentrated by evaporation, yielding an effluent COD of 3124 mg / L and a COD removal rate of 88.6%. Oximeamine, indigo, and quinalidine were undetectable, and the effluent was pale yellow. The evaporated salt was black, indicating a high accumulation of pollutants within it, rendering the salt unsuitable as a byproduct.

[0108] Comparative Example 2

[0109] The wastewater used in Example 2 is the same as that used in Example 2. The difference between Example 2 and Example 2 is that: a) in the acidic chemical separation step, the pH value of the wastewater was not adjusted and chemical separation was carried out directly, and the lower layer of chemically separated water was sampled and analyzed.

[0110] After acidic chemical separation treatment, the COD of the Dispersible Yellow 54 wastewater was 25846 mg / L, with a COD removal rate of 5.8%; the oxime amine concentration was 2382 mg / L, with an oxime amine removal rate of 6.5%; the indigo tincture concentration was 1186 mg / L, with an indigo tincture removal rate of 4.4%; and the quinalidine concentration was 956 mg / L, with a quinalidine removal rate of 2.5%. The separated aqueous phase was brownish-black. When acidic chemical separation was performed at pH 1-2, there was virtually no removal of COD and characteristic pollutants. The reason for this was that the wastewater pH was not adjusted, resulting in a low pH and low binding capacity of pollutants such as oxime amine, indigo tincture, and quinalidine to the acidic chemical separation agent.

[0111] Analysis of the catalytic oxidation effluent showed a COD of 20465 mg / L, a COD removal rate of 25.5%, and a brownish-black color. The wastewater pH was not adjusted during the chemical separation process, resulting in significantly reduced treatment efficiency. Evaporation and concentration of the catalytic oxidation effluent yielded an effluent COD of 3756 mg / L, with a COD removal rate of 86.3%. Oximeamine, indigo, and quinalidine were undetectable, and the effluent was pale yellow. The evaporated salt was black, indicating significant pollutant accumulation, rendering it unsuitable as a byproduct.

[0112] Comparative Example 3

[0113] The wastewater used in Example 2 is the same as that used in Example 2. The difference between Example 2 and Example 2 is that: a) in the acidic chemical separation step, the pH value of the wastewater was adjusted to 10 using sodium hydroxide solution before acidic chemical separation was performed; samples of the lower chemically separated effluent were taken for analysis.

[0114] After acidic chemical separation treatment, the COD of the Dispersible Yellow 54 wastewater was 29248 mg / L. The increased COD was due to the water solubility of the reactant bis(2,4,4-trimethylpentyl)phosphonic acid in the acidic chemical separator under alkaline conditions, leading to the elevated COD in the aqueous phase. The concentrations of oximeamine (2532 mg / L), indigo (1226 mg / L), and quinalidine (975 mg / L) were also observed. The separated aqueous phase was brownish-black. The analysis suggests that the wastewater pH was adjusted too high, causing instability and miscibility between the reactants, co-solvents, and diluents in the acidic chemical separator, resulting in the separator's ineffectiveness and decomposition.

[0115] Analysis of the catalytic oxidation effluent showed a COD of 23512 mg / L, a COD removal rate of 14.4%, and a brownish-black color. Adjusting the wastewater pH to 10 during chemical separation significantly reduced the effectiveness of the treatment. Evaporation and concentration of the catalytic oxidation effluent resulted in a COD of 4132 mg / L, a COD removal rate of 85%. Oximeamine, indigo, and quinalidine were undetectable, and the effluent was pale yellow. The evaporated salt was black, indicating significant pollutant accumulation, rendering it unsuitable as a byproduct.

[0116] Comparative Example 4

[0117] The wastewater used in Example 2 is the same as that used in Example 2; the difference from Example 2 is that the reactant in the acidic chemical separating agent is N-lauro(trialkylmethyl)amine.

[0118] After acidic chemical separation treatment, the COD of the Dispersible Yellow 54 wastewater was 24927 mg / L, with a COD removal rate of 9.2%; the oxime amine concentration was 2432 mg / L, with an oxime removal rate of 4.5%; the indigo concentration was 1198 mg / L, with an indigo removal rate of 3.4%; and the quinalidine concentration was 942 mg / L, with a quinalidine removal rate of 1.6%. The separated aqueous phase was brownish-black. The reason for this is that N-lauro(trialkylmethyl)amine is a quaternary ammonium salt compound. Using it as a reactant in the Dispersible Yellow 54 wastewater resulted in low reaction efficiency with the characteristic pollutants in the wastewater, leading to low COD and characteristic pollutant removal rates.

[0119] Analysis of the catalytic oxidation effluent showed a COD of 19732 mg / L, a COD removal rate of 28.2%, and a brownish-black color. During the chemical separation process, the reactant in the acidic chemical separation agent was changed to N-lauro(trialkylmethyl)amine, significantly worsening the chemical separation effect. The catalytic oxidation effluent was then evaporated and concentrated, resulting in an effluent COD of 3412 mg / L and a COD removal rate of 87.6%. Oximeamine, indigo, and quinalidine were not detected, and the effluent was pale yellow. The evaporated salt was black, indicating a high accumulation of pollutants, making it unsuitable as a byproduct.

[0120] The above are merely specific embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for treating wastewater from the production of Dispersible Yellow 54, characterized in that, Includes the following steps: a. Acidic chemical separation reaction: An alkaline solution is added to the wastewater from the production of Dispersible Yellow 54 to neutralize it to a pH range of 6-9. An acidic chemical separation agent is then added to the neutralized wastewater for chemical separation reaction. After the reaction is completed, the mixture is allowed to stand and separate into layers, resulting in an upper chemically separated phase and a lower aqueous phase. The acidic chemical separation agent is prepared from a reactant, a co-solvent, and a diluent. The reactant is selected from one or more of naphthic acid, bis(2,4,4-trimethylpentyl)phosphonic acid, or 5,8-dinonyl-2-naphthalenesulfonic acid. The co-solvent is an alcohol compound with a carbon chain of 8-20, and the diluent is aviation kerosene or diesel fuel. b. Catalytic oxidation: Add catalyst and oxidant to the aqueous phase in step a. The oxidant reacts with the organic matter in the wastewater in the catalytic environment. After the reaction is completed, add alkaline solution to separate the catalyst in solid form by filtration. The filtrate is then used for later use. c. Evaporation and concentration: The filtrate from step b is sent to an evaporator for evaporation. The mother liquor obtained from evaporation is then centrifuged to obtain a by-product salt. The evaporated water can be treated in a biochemical system and then discharged. d. Regeneration of acidic chemical separating agent: Add an eluent to the upper chemical separation phase in step a to carry out the acidic chemical separating agent recovery reaction. After the reaction, allow the mixture to stand and separate into layers. The upper layer is the recovered acidic chemical separating agent, which can be reused in the acidic chemical separation reaction in step a. The lower layer is a concentrated solution containing oximeamine, indigo, and quinalidine contaminants.

2. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 1, characterized in that, In step a, the alkaline solution is one of the following: 10-32% sodium hydroxide solution, 10-20% potassium hydroxide solution, or 10-20% ammonia solution.

3. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 1, characterized in that, In step a, the acidic chemical separating agent is prepared by mixing the reactant, cosolvent and diluent in a volume ratio of (1-3):(1-2):(5-8).

4. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 1, characterized in that, In step a, the volume ratio of the acidic chemical separating agent to the wastewater from the production of Disperse Yellow 54 is 10%-35%.

5. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 1, characterized in that, In step a, the reaction temperature between the acidic chemical separating agent and the wastewater from the production of Disperse Yellow 54 is 10-40℃, and the reaction time is 20-50 min.

6. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 5, characterized in that, In step a, the reaction temperature between the acidic chemical separating agent and the wastewater from the production of Disperse Yellow 54 is 20-30℃, and the reaction time is 30-40 min.

7. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 1, characterized in that, In step b, the oxidant used is one or more of hydrogen peroxide, ozone, and sodium persulfate solution, and the catalyst is one or more of ferrous chloride, copper chloride, zinc chloride, and activated carbon.

8. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 7, characterized in that, In step b, the oxidant and catalyst are added according to a ratio (2-6):1 between the amount of functional group of the hydroxyl radical produced by the oxidant and the amount of effective catalyst in the catalyst, wherein the effective catalyst in the catalyst is Fe. 2+ Cu 2+ Zn 2+ Surface activated carbon in activated carbon.

9. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 1, characterized in that, In step b, the catalytic oxidation reaction temperature is 10-40℃ and the catalytic oxidation reaction time is 30-120 min.

10. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 1, characterized in that, In step b, the alkaline solution is one of the following: 10-32% sodium hydroxide solution, 10-20% potassium hydroxide solution, or 10-20% ammonia solution, and the pH of the wastewater is adjusted to a range of 6-9.

11. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 1, characterized in that, In step d, the eluent is a hydrochloric acid solution with a mass fraction of 10-20%.

12. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 11, characterized in that, In step d, the volume ratio of the eluent to the chemical separation phase is 1:(6-10).

13. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 12, characterized in that, In step d, the temperature of the recovery reaction is 30-50℃, and the reaction time is 20-40 min.

14. The method for treating wastewater from the production of Dispersible Yellow 54 according to claim 13, characterized in that, In step d, the temperature of the recovery reaction is 40-45°C, and the reaction time is 25-30 min.

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