JP4763789B2 - Treatment method of waste generated from terephthalic acid process - Google Patents

Description

The present invention relates to a method for treating waste generated from a production process of terephthalic acid. More specifically, the invention mixes waste with water and corrosion inhibitors, pressurizes and heats to maintain a liquid state, reacts with an oxidant to decompose organic matter, such as cobalt, manganese, etc. The present invention relates to a method for treating waste generated from a terephthalic acid production process, in which a catalyst can also be recovered smoothly.

  In general, terephthalic acid is produced by partial oxidation using p-xylene, for example, a transition metal such as cobalt or manganese. In addition to the desired product terephthalic acid in this process, benzoic acid, p-tolualdehyde, p-toluic acid, 4-carboxybenzaldehyde, By-products such as 4-hydroxymetnyl benzoic acid are produced. After terephthalic acid synthesis reaction, when terephthalic acid as product and acetic acid as solvent are recovered, waste containing the side reaction organic matter, cobalt, manganese as catalyst, hydrobromic acid (HBr) as cocatalyst, etc. Things are generated.

  Organic waste produced as a by-product in the production of terephthalic acid contains a large amount of aromatic compounds and is in a solid state at room temperature, so it is very important to recover expensive cobalt and manganese catalysts from waste It is difficult. The waste generated in the terephthalic acid production process is almost difficult to process because the acetic acid as a solvent is recovered and becomes a solid state that does not flow at room temperature. The incineration method is used as a technology for treating such waste. When the waste is incinerated, catalyst components such as cobalt and manganese are discharged together with the incineration residual ash, and a technique for recovering the catalytic metal component from the residual ash has been developed (US Pat. No. 4,786,621, No. 1). 4,876,386). However, it is very difficult to continuously inject solid waste into the incinerator, so organic waste generated while collecting acetic acid as solvent is mixed with flammable oil and injected. Therefore, a technique (Korean Patent No. 0371231, Japanese Patent No. 6304157) that solves the problem of clogging the incinerator injection nozzle is used. However, such incineration technology is very difficult to recover the catalyst metal from the incineration ash, and there is a problem that new waste and waste water are generated in the recovery process. Some catalyst particles are fine particles during incineration. Therefore, it is discharged together with the exhaust gas and cannot be recovered, and additional environmental pollution prevention equipment such as air pollution prevention equipment is required.

  Another technique for recovering the catalyst from waste generated in the terephthalic acid process is to first neutralize the pH of the terephthalic acid process waste to 7.5 or lower with a waste alkaline aqueous solution generated in the ethylene process, and then to an aqueous caustic soda solution. After adjusting the pH to 8.5 to 9.0 by adding polyacrylamide, it is combined with cobalt and manganese and precipitated, and then recovered (Chinese Patent No. 1117163). This technology has the advantage of collecting the catalyst while recycling the wastewater generated from the ethylene process, but chemicals such as benzoic acid, terephthalic acid, and toluic acid, which account for the majority of the waste components from the terephthalic acid process, are chemically treated. However, since it is not decomposed and discharged as waste water, a problem arises that a large amount of organic waste water with high concentration is discharged. In this way, organic wastewater with a high concentration generated during the catalyst recovery process has a high organic content so that the chemical oxygen demand reaches several hundred thousand ppm, so it is very difficult to treat wastewater biologically. It is difficult, and wastewater treatment facilities for treating this occupy a huge area.

  As a result of research to solve the problem of the incineration treatment method for treating the waste generated from the conventional terephthalic acid production process, the present inventors uniformly mixed the waste with water and a corrosion inhibitor. The present inventors have found a method capable of decomposing organic substances while maintaining the liquid state by applying pressure and heating, and increasing the recovery efficiency of the catalyst, and based on this, the present invention has been completed.

  Accordingly, an object of the present invention is to provide a method for treating waste generated from a terephthalic acid production process, which can decompose organic components from the waste of the terephthalic acid production process and increase the catalyst recovery efficiency. .

  To achieve the above object, according to the present invention, a) providing a liquid waste water in which water and a corrosion inhibitor are uniformly mixed with a catalyst-containing organic waste generated from a terephthalic acid production process; b) pressurizing and heating within a range in which the wastewater is maintained in a liquid state; c) reacting the heated wastewater with an oxidant to decompose organic matter and form a metal oxide catalyst; d) cooling the high-temperature treated water in step c), e) depressurizing the cooled treated water, separating it into a gas component and catalyst particle-containing liquid, and discharging the gas; and f) the liquid From which cobalt and manganese catalyst particles are recovered.

  The conventional method of incinerating by-products in the production process of terephthalic acid is that when acetic acid, which is a solvent, is recovered, the by-products are in a solid state at room temperature and are difficult to incinerate. When other liquid organic solvents were mixed in order to smoothly inject into the incinerator, a problem of solvent processing occurred. In particular, in the case of incineration, for example, catalyst particles such as cobalt and manganese are fine and are scattered and discharged to the outside together with the exhaust gas, so there is a problem that the catalyst recovery rate decreases, and when recovering from incineration ash, When dissolving and neutralizing with strong acid and strong alkali in order to increase the catalyst recovery rate, there is a problem that new waste water and waste environmental pollutants are generated and the catalyst recovery is substantially difficult.

  However, the waste treatment method of the terephthalic acid production process according to the present invention can treat organic waste by decomposing organic matter without the problems of the conventional incineration treatment method, and the catalyst recovery is also efficient. The acid production process can be performed more efficiently.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the present specification and drawings, the same or similar parts are denoted by the same reference numerals.

  As mentioned above, most of the waste in the terephthalic acid production process is an organic acid substance with a high molecular weight, so its solubility in water is so low that even if it mixes with water, it does not dissolve well and maintains a slurry state. To do. Also, hydrobromic acid (HBr) used as a co-catalyst in the terephthalic acid synthesis process is very corrosive, so a corrosion inhibitor must be added to prevent corrosion of the equipment during the organic oxidation process. . Therefore, it is preferable to select and administer an appropriate alkaline component in order to increase the solubility of organic matter in order to treat the waste and to prevent corrosion by hydrobromic acid.

  According to the present invention, after mixing the waste generated from the terephthalic acid production process with water at an appropriate concentration, a corrosion inhibitor is mixed in order to increase the solubility of organic matter in water and prevent corrosion by hydrobromic acid. To do.

Thereafter, using a high-pressure pump, the pressure is adjusted to 41 so that the wastewater remains in a liquid state at the reaction temperature.
. The temperature is raised to 5 to 260 bar and continuously injected into the processing facility. After the temperature is raised to a reaction temperature of 250 to 370 ° C. through a heat exchanger and a heater, an oxidizing agent (eg, oxygen, air, etc.) is injected. The organic components are decomposed into carbon dioxide and water. According to the present invention, the content of the organic waste mixed with the water is suitably 0.1% by weight to 30% by weight.

  In such an oxidation reaction process, the organic component is decomposed into carbon dioxide and water, but catalyst components such as cobalt and manganese are converted into metal oxide particles to form a new slurry state. In the present invention, after decomposing the organic substance at a desired concentration, the catalyst particle-containing mixture is cooled, the pressure is lowered, the catalyst metal particles are separated and recovered, and then recycled as a catalyst again.

  FIG. 1 shows an embodiment for treating waste generated from the production process of terephthalic acid according to the present invention.

  Referring to FIG. 1, the waste 10 generated from the terephthalic acid production process is in a solid state at room temperature, and includes not only unrecovered terephthalic acid but also benzoic acid, p-tolualdehyde, p-toluic acid, 4-carboxybenzaldehyde. , 4-hydroxymethylbenzoic acid and other aromatic side reaction materials having a relatively large molecular weight. These exist as solids at room temperature in a state where acetic acid as a solvent is removed. Therefore, in order to effectively oxidize and decompose these organic wastes, they must be uniformly dispersed in water. However, since most organic substances exhibit very low solubility in water, it is very difficult to disperse them uniformly. Fortunately, the waste generated from the terephthalic acid production process is an organic acid substance, so it was possible to increase the solubility in water by mixing base components and converting them to organic salts.

  As shown in FIG. 1, the waste 10 generated from the terephthalic acid production process is mixed with water 11 to be slurried. Thereafter, in order to dissolve the waste in water and neutralize hydrobromic acid as a co-catalyst, the corrosion inhibitor 12 is mixed and stored in the mixing tank 14 in a uniform waste water state.

Corrosion inhibitors (or anticorrosives) for increasing the solubility of the waste of the present invention and neutralizing with hydrobromic acid to form neutral salts include sodium hydroxide (NaOH), sodium carbonate ( At least one selected from Na ₂ CO − _{3 −} ), sodium hydrogen carbonate (NaHCO ₃ ), potassium hydroxide (KOH), and potassium carbonate (K ₂ CO ₃ ) is used. If the anticorrosive agent is not administered, the corrosion is increased by hydrobromic acid, and if too much anticorrosive agent is administered, the pH of the wastewater is increased and the corrosion due to alkali increases again. So that the pH of the solution is adjusted to the range of 4-7.

Waste water as a waste aqueous solution sufficiently mixed and uniformly dissolved in the mixing tank 14 is pressurized by a pump 21 and injected into a treatment process. In accordance with the present invention, the process pressure must be raised to a pressure at which no steam is generated at the process temperature, i.e. higher than the vapor pressure at the maximum reaction temperature, so that the reactants do not vaporize. When the pressure of the reactant is lower than the vapor pressure, the reaction mixture is vaporized, and when it is violent, a steam hammering phenomenon occurs, causing the operation of the process to be uneven and unstable, generating steam. Then, since the density of the fluid rapidly decreases, it is difficult to ensure a sufficient residence time necessary for the reaction, and it is difficult to appropriately decompose the organic matter. Therefore, when the oxidation reaction temperature for decomposing organic substances varies in the range of 250 to 370 ° C., waste water must be injected at an operating pressure of 41.5 to 250 bar.

Waste water pressurized by the pump 21 is injected into the heat exchanger 22. Since the heat exchanger 22 can utilize the thermal energy of the high-temperature treated water discharged after being decomposed by the oxidation reaction in the reactor 24 for heating the inflow wastewater, it is an economical process from the viewpoint of thermal energy. To be. In particular, when the concentration of organic matter is high and the degree of COD80,000mgO 2 / _L can also be sufficiently heat the flowing waste water to the reaction temperature only in the oxidation reaction heat generated with the decomposition of organic matter.

  In the present invention, the waste water that has been primarily heated while passing through the heat exchanger 22 is caused to flow into the heater 23 in order to finally heat it to the oxidation reaction temperature. The inflowing waste water is heated to the reaction temperature selected in the range of 250 to 370 ° C. by the heater 23 and then injected into the reactor 24. If the waste water that has passed through the heat exchanger 22 is equal to or higher than the desired reaction temperature, the heater immediately injects it into the reactor 24 without supplying further heat energy. The oxidant 13 is injected into the wastewater injected into the reactor 24, and the organic matter contained in the wastewater reacts with the oxidant to decompose the organic matter into carbon dioxide and water.

  According to the present invention, the oxidant is selected from at least one of oxygen, air, a gas mixture containing oxygen, ozone, a mixture of oxygen and water, and an oxygen-containing fluid such as hydrogen peroxide. An overdose is carried out in an amount exceeding 1 to 50 mol% of the theoretical injection amount required for the decomposition of. In particular, when the concentration of organic matter in the wastewater is high, the type of oxidizing agent is selected so that the temperature of the reactor is not overheated to 374 ° C., which is a supercritical water condition, and preferably a mixture of oxygen and water is used The cooling effect of the reactor can also be shown by decomposing the organic matter of the wastewater by injecting as follows. Further, the oxidant is dispensed at at least one of the inlet of the reactor and the inside of the reactor.

  The residence time of the waste water is preferably 2 to 30 minutes so that the organic substance is sufficiently oxidized and decomposed in the reactor.

  Thereafter, the treated water discharged from the reactor 24 is cooled while exchanging heat with the inflowing waste water in the heat exchanger 22, but the pressure is lowered because it is still too high to be discharged outside. It passes through the cooler 25 again before and is cooled at a temperature of 25 to 100 ° C. so as to be suitable for discharge. The cooled treated water is reduced in pressure by passing through the pressure reducing device 26 and the pressure reducing valve 27.

  In the present invention, the primary pressure reducing device 26 is a device that lowers the pressure after cooling the treated water in a high pressure state equal to or higher than the vapor pressure at the reaction temperature. When the wastewater is decomposed, not only water but also gas components such as carbon dioxide and oxygen, as well as catalyst components such as cobalt and manganese, are deposited as metal particles and discharged together. Therefore, when such a gas-liquid-solid component is mixed in the process of decreasing the pressure, the pressure reducing valve 27 is worn violently and the service life is shortened. Therefore, if a facility for reducing the primary pressure is installed before the pressure reducing valve 27, wear of the pressure reducing valve 27 can be prevented. As the pressure reducing device 26 for preventing the wear of the pressure reducing valve, for example, a capillary pressure reducing facility in which a tube having a small inner diameter is installed can be given.

  According to the present invention, when the cooling treated water passes through the pressure reducing device 26, the high pressure fluid of 41.5 to 250 bar is reduced to the pressure of normal pressure to 20 bar, and finally the pressure reducing valve 27 for lowering the pressure is used. The wear rate can be reduced. Finally, after passing through the pressure reducing valve 27, the gas component 25 such as carbon dioxide generated while the organic matter is decomposed by being decomposed into the gas-liquid separator 31 and excessively injected oxygen is discharged into the atmosphere, and the remaining catalyst The liquid containing the particles flows into the solid-liquid separator 32 to recover the catalyst particles 34 in the form of metal oxide particles, and the other treated water 33 is discharged.

  The solid-liquid separator 32 is an apparatus for removing catalyst particles in a state where the catalyst particles and treated water are mixed. For example, separation by precipitation, a centrifugal separator, a filter, or the like can be used. Cobalt and manganese catalyst particles produced in the process of decomposing organic matter are very fine, on the order of a few μm, and therefore a long time is required for sufficient separation only by a simple precipitation method. Therefore, it is preferable to use a separation device in which a centrifuge and a filter are combined.

  On the other hand, when decomposing wastewater with high organic matter concentration in organic waste, an excessive amount of oxidant is used to increase oxygen emissions, and when the amount of carbon dioxide production increases, the process of reducing pressure with a decompressor May cause unstable driving conditions. Therefore, in such a case, a method of lowering the pressure after removing the gas component is more preferable than removing the gas component after depressurizing the cooled treated water.

  FIG. 2 shows a method of lowering the pressure after discharging the gaseous component during wastewater treatment with a relatively high concentration of organic matter. When the organic substance is decomposed in the reactor 24, carbon dioxide is generated. Some of the generated carbon dioxide is dissolved in water, but carbon dioxide above the equilibrium concentration exists as a gas. Further, oxygen injected in an excess amount of 1 to 50 mol% from COD does not react and is discharged from the reactor 24. When a large amount of gas component is contained in this way, when treated water is directly injected into the capillary pressure reducing device 26 as shown in FIG. 1, a slag flow in a gas-slurry state is formed. In such a slag flow, the difference in the coefficient of friction between the gas and the slurry is very large, so that the pressure fluctuation becomes severe, and the pressure control valve may be worn heavily.

Therefore, when there are many gaseous components, as shown in FIG. 2, the treated water discharged | emitted from the reactor 24 is cooled with the cooler 25 after heat-exchanging with inflow waste water with the heat exchanger 22, It is injected into the liquid separator 31 and separated into gas and liquid containing catalyst particles. The pressure of the gas-liquid separator 31 is adjusted using a gas pressure reducing valve 126 at the gas outlet. By adjusting the pressure of the gas-liquid separator 31, the overall pressure of the process is adjusted. On the other hand, when the mixed slurry of treated water and catalyst particles from which the gas has been separated by the gas-liquid separator 31 reaches or exceeds an appropriate water level by a liquid level controller (LC) that adjusts the liquid level, the automatic water level control valve 127 is opened. High pressure slurry is discharged.

  At this time, in order to prevent the wear of the valve (for example, the pressure reducing valve 27), the pressure reducing device 26 was installed next to the automatic valve 127. Thereafter, as described with reference to FIG. 1, the wear rate of the pressure reducing valve 27 that causes the high pressure fluid of 41.5 to 250 bar to drop to the pressure of normal pressure to 20 bar while passing through the pressure reducing device 26, and finally reduces the pressure. Can be reduced. After passing through the pressure reducing valve 27, the treated water and the catalyst particles flow into the solid-liquid separator 32, the catalyst is recovered, and the treated water is discharged.

  As described above, the present invention is capable of oxidizing and decomposing organic substances generated during the terephthalic acid production process and efficiently recovering catalyst components contained in waste in the form of metal oxide particles. There are advantages.

[Mode of Invention]
Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

<Example 1>
Composition components of waste generated from the terephthalic acid production process After completely removing acetic acid and water as solvents from the waste generated from the terephthalic acid production process, the organic substances and catalyst components contained in the waste were analyzed. Table 1 below shows an example of the composition of the waste generated from the terephthalic acid production process.

  From Table 1 below, the terephthalic acid process waste has a high content of about 85% terephthalic acid and benzoic acid, and contains a small amount of substances such as isophthalic acid and p-toluic acid. It can be seen that impurities are contained.

<Example 2>
Decomposition of waste generated from the terephthalic acid production process As described above, the waste generated from the terephthalic acid production process is a state in which organic substances and catalyst components are mixed. Water was mixed into this waste, and NaOH was added to dissolve it. Then, the waste was put into a treatment process in a waste water state in which some solid particles existed.

The influent wastewater had a COD (chemical oxygen demand) of 82,300 mg O ₂ / L and was adjusted to pH 6.0 by mixing NaOH at a concentration of 1.786 wt%. The reactor uses a tubular reactor, and the reaction proceeds more and more as the reaction proceeds at an inlet temperature of 298 ° C., the reactor outlet temperature is maintained at 361 ° C., the pressure is 250 bar, and the reactor residence time is 4.3 minutes. Oxygen was injected in excess of 20% from the chemical oxygen demand, the pH of the treated water after decomposition was 7.2 and increased from the raw wastewater, and the COD was measured to be 3,570 mgO ₂ / L, thereby the decomposition rate Was found to reach 95.7%.

<Example 3>
Decomposition of organic matter by reaction time in the reactor Waste water generated from the terephthalic acid production process was mixed with water and sodium hydroxide to produce raw waste water. The COD of the raw waste water was 84,000 mg O ₂ / L, and the pH was 5.5. The process pressure was 250 bar and oxygen was injected 20% above the chemical oxygen demand. Table 2 below shows the COD and organic matter decomposition rate of the treated water under each reaction condition.

  As shown in Table 2, the reactor inflow temperature of waste water is preferably higher than 250 ° C., and it can be confirmed that the decomposition efficiency of organic matter increases as the reaction temperature and residence time increase. When the temperature is lower than 250 ° C., the initial reaction rate is so low that it is difficult to increase to 250 ° C. where the reaction starts in earnest even if the residence time is long, and it is difficult to obtain a sufficient organic matter decomposition rate. I was able to confirm.

<Example 4>
Changes in metal content of treated water due to administration of anticorrosives Waste generated from the terephthalic acid production process is composed of hydrobromic acid (HBr) and organic acids such as terephthalic acid, benzoic acid, and p-toluic acid. Therefore, when the waste is mixed with water, it becomes acidic. In addition, these organic acids are not well dissolved because the degree of dissociation with respect to water is not large. In order to prevent corrosion due to hydrobromic acid and to solve the problem of being in a slurry state due to its acidity and low dissociation degree, in the present invention, sodium hydroxide (NaOH), sodium carbonate (Na ₂ CO ₃ ) , Sodium bicarbonate (NaHCO ₃ ), potassium hydroxide (KOH), potassium carbonate (K ₂ CO ₃ ) and other alkalis are administered to dissolve the waste and produce waste water containing some solid particles By disassembling, it was possible to smoothly put into the process, and an anti-corrosion effect was obtained.

The corrosion prevention effect by administration of the anticorrosive agent according to the present invention was confirmed. The experiment was performed using a tubular reactor. The reactor outlet temperature is 360 ° C., the residence time is adjusted to 4.5-5 minutes, the pressure is maintained at 250 bar, and the oxygen exceeds 20% over the required amount of COD 84,000 mg O ₂ / L of wastewater. Injected.

Table 3 shows that after mixing the waste with water, sodium hydroxide (NaOH), sodium carbonate (Na ₂ CO ₃ ), sodium bicarbonate (NaHCO ₃ ), potassium hydroxide (KOH), potassium carbonate (K ₂ CO ₃₎ The results of analyzing the contents of the four metal components mixed in the treated water after mixing and decomposing the aqueous alkali solution or alkaline carbonate solution such as The four metal components are iron (Fe), nickel (Ni), chromium (Cr), and molybdenum (Mo), which are the main alloy materials of the nickel alloy I-625 used for the production of the reactor and the experimental apparatus. When these components are contained in a large amount in the treated water, it indicates that the corrosion of, for example, the reactor and the heat exchanger has progressed a lot.

  As shown in Table 3, it is confirmed that the corrosion progresses very severely when the anticorrosive agent is not used, but the corrosion is remarkably reduced when the anticorrosive agent is mixed so that the pH of the wastewater is maintained at 4-7. can do.

<Example 5>
Size distribution of recovered catalyst particles Waste generated from terephthalic acid production process was mixed with water, sodium hydroxide as an anticorrosive, and sodium bicarbonate at 360 ° C, and then contained in treated water The size distribution of the catalyst particles was measured. FIG. 3 shows the size distribution of the particles. Based on volume, the particles were measured to have a size of d (0.1) = 1.175 μm, d (0.5) = 3.005 μm, d (0.9) = 18.324 μm.

<Example 6>
Catalyst recovery Oxidative decomposition of wastewater was carried out at 360 ° C. and 250 bar. The pH of the wastewater was adjusted using a combination of sodium hydroxide and sodium bicarbonate as a corrosion inhibitor. The contents of cobalt and manganese catalysts contained in the wastewater were analyzed by ICP-MS, and the amount of catalyst injected was calculated. The catalyst was recovered using a filter after stagnation of the treated water. Table 4 below summarizes the amount of catalyst injected and the amount of recovered catalyst analyzed for each component. Table 4 shows that according to the present invention, the catalyst recovery efficiency is excellent.

It is the schematic of the process of processing the waste generated from a terephthalic-acid manufacturing process by this invention. It is the schematic of a suitable process in case the density | concentration of the organic substance in the waste generated from a terephthalic-acid manufacturing process by this invention is high, and there are many exhaust gas. 4 is a graph illustrating a size distribution of catalyst particles recovered by treating waste generated during a terephthalic acid manufacturing process according to an embodiment of the present invention.

Explanation of symbols

10: Terephthalic acid process waste 11: Water 12: Corrosion inhibitor 13: Oxidizing agent 14: Mixing tank 21: Waste water pump 22: Heat exchanger 23: Heater 24: Reactor 25: Cooler 26: Depressurizer 27: Pressure reducing valve 31: Gas-liquid separator 32: Solid-liquid separator 33: Discharged treated water 34: Recovered catalyst 35: Exhaust gas 126: Gas exhauster 127: Water level control valve

Claims (11)

a) Water and sodium hydroxide are added to the catalyst-containing organic waste generated from the terephthalic acid production process in which cobalt and manganese catalyst particles are used and hydrobromic acid is used as a co-catalyst to partially oxidize p-xylene . Providing liquid waste water in which a corrosion inhibitor selected from the group consisting of sodium bicarbonate, sodium carbonate, potassium hydroxide, potassium carbonate, and combinations thereof is uniformly mixed;
b) pressurizing and heating at a temperature of 250 to 370 ° C. within a range where the wastewater is maintained in a liquid state;
c) reacting the heated wastewater with an oxidant to decompose organic matter to form a metal oxide catalyst;
d) cooling the high temperature treated water of step (c),
e) depressurizing the cooled treated water, separating it into a gas component and catalyst particle-containing liquid, and discharging the gas;
and f) recovering cobalt and manganese catalyst particles from the liquid. A method for treating waste generated from a terephthalic acid production process.   The treatment of waste generated from the terephthalic acid production process according to claim 1, wherein the organic waste content of the liquid waste water in the step (a) is 0.1 wt% to 30 wt%. Method.   The step (e) is generated from the terephthalic acid production process according to claim 1, wherein the cooling treatment water is replaced with a step of depressurizing after separating the cooling water into a gas component and a catalyst particle-containing liquid. Waste disposal method.   The method for treating waste generated from a terephthalic acid production process according to claim 1, wherein the corrosion inhibitor is added so that the pH of the wastewater is maintained at 4-7. The step (b) is performed under a pressure of 41.5 to 250 bar, and the step (c) is performed at a pressure of 41.5 to 250 bar and a temperature of 250 to 370 ° C. A method for treating waste generated from the terephthalic acid production process according to Item 1.   2. The terephthalate according to claim 1, wherein the oxidant is selected from the group consisting of oxygen, air, a gas mixture containing oxygen, ozone, an aqueous hydrogen peroxide solution, oxygen-containing water, and combinations thereof. A method for treating waste generated from the acid production process.   [2] The terephthalic acid production according to claim 1, wherein the oxidizing agent is used in an amount exceeding 1 mol% to 50 mol% than an amount necessary for complete oxidative decomposition of the organic matter in the wastewater. A method for treating waste generated from processes.   The method for treating waste generated from a terephthalic acid production process according to claim 1, wherein the cooling is performed at 25 to 100 ° C. in the step (d).   The method for treating waste generated from a terephthalic acid production process according to claim 1 or 3, wherein in step (e), the pressure is reduced to a range of normal pressure to 20 bar.   The method for treating waste generated from a terephthalic acid production process according to claim 1 or 3, wherein the step (e) is performed by a capillary pressure reducer.   The terephthalic acid according to claim 1, wherein the step (f) is performed in a solid-liquid separator in which at least one selected from the group consisting of a precipitator, a centrifuge, and a filter is installed. A method for treating waste generated from the manufacturing process.

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