KR101297816B1 - Apparatus for Reuse of Wastewater from Terephthalic Acid Manufacture Process and Method for Treating Terephthalic Acid Wastewater Using The Same - Google Patents

Abstract

The present invention relates to an apparatus for recycling wastewater of a terephthalic acid manufacturing process and a method of treating the wastewater, and more particularly, it is possible to reuse wastewater generated in a terephthalic acid manufacturing process as water for a production process stably without biological treatment, and easy to maintain, The present invention relates to a terephthalic acid production process wastewater recycling apparatus and a method for treating terephthalic acid production process wastewater using the same, which are capable of recycling terephthalic acid, catalysts, and the like contained in the wastewater, thereby improving production yield and reducing the load of the wastewater treatment.
The device for recycling terephthalic acid manufacturing process wastewater according to the present invention is capable of stably recycling wastewater generated in terephthalic acid manufacturing process without using biological treatment as water for production process, simple maintenance, and recycling terephthalic acid, catalyst, etc. contained in wastewater. It can improve the production yield and reduce the load of waste water treatment, which has economic effect on resource recovery, environmental protection and recycling.

Description

Apparatus for Reuse of Wastewater from Terephthalic Acid Manufacture Process and Method for Treating Terephthalic Acid Wastewater Using The Same}

The present invention relates to an apparatus for recycling wastewater of a terephthalic acid manufacturing process and a method of treating the wastewater, and more particularly, it is possible to reuse wastewater generated in a terephthalic acid manufacturing process as water for a production process stably without biological treatment, and easy to maintain, The present invention relates to a terephthalic acid production process wastewater recycling apparatus and a method for treating terephthalic acid production process wastewater using the same, which are capable of recycling terephthalic acid, catalysts, and the like contained in the wastewater, thereby improving production yield and reducing the load of the wastewater treatment.

As the world's population continues to grow and the standard of living improves, the demand for various polymer resins, such as PET and polyester, is rapidly increasing, and the production of terephthalic acid (PTA), which is a raw material of polymer resins, is also rapidly increasing. A large amount of wastewater is generated in a process of a factory for producing terephthalic acid and the like.

Wastewater of the terephthalic acid manufacturing process includes a small amount of benzoic acid (BA), para-toluic acid (TA), and aromatic acids (2000 to 4000 ppm) such as cobalt, manganese, and bromide oxidation catalysts (30). ~ 50ppm), most of which are water. The oxidation catalyst may be recovered and reused in the aromatic acid oxidation process, and the aromatic acid may be recovered and reused in the aromatic acid manufacturing process or used in a production process such as polyol resin. In addition, the wastewater of the terephthalic acid process is separated and purified from the aromatic acid and the catalyst, and then recycled to the aromatic acid purification process, and the environmental effect can be seen in terms of enormous economic effect and at the same time reduce the load of wastewater treatment.

The existing recycling equipment of terephthalic acid wastewater mainly consists of reverse osmosis membrane and its pretreatment process through organic treatment of organic matter. In case of biological treatment process, the treatment water quality is changed according to the surrounding environment or situation, which adversely affects the stable reverse osmosis membrane process.

Accordingly, Dickerson et al., US Pat. No. 4,540,493, passing the wash water through a sand filter to separate terephthalic acid solids, passing the filtrate through a cation exchange resin to separate a metal catalyst, and passing the cation exchange resin. Passing water through an anion exchange resin to separate dissolved organic matter and passing the anion exchange resin pass through a mixed bed containing a mixture of a cation exchange resin and an anion exchange resin for final treatment. Disclosed is a method for treating terephthalic acid wastewater comprising a.

However, this method is difficult to maintain the SDI (slit density index) of 5 or less due to the low removal effect of organic matter and turbidity by using sand filter, and dissolved organic matter on the surface of ion exchange resin by using only ion resin at the back stage Precipitates reduce resin activity, and purified water is contaminated with sodium ions (Na ⁺ ), organics, and acetic acid, and thus cannot be used for PTA purification.

In addition, Korean Patent No. 0715024 discloses a filtration step for separating solid organics, dissolving unfiltered fine organics with sodium hydroxide, separating a catalyst using a cation exchange resin, and precipitating the separated catalyst with caustic soda. A method is provided that includes recovering.

However, the method also has a disadvantage in that only catalysts are recovered to recover only a few tens of ppm contained in the wastewater, and the remaining components have to be treated using a wastewater process. , a problem that a large amount of sodium ions (Na ⁺⁾ degrade the performance of the ion exchange resin remaining by intake / remove the catalyst by an ion exchange resin without the step of removing a large amount of sodium ions (Na ⁺⁾ for the remaining

Accordingly, the present inventors have made efforts to solve the problems of the prior art, as a result of the metal micro-filter unit for removing particulate matter contained in the wastewater of the terephthalic acid manufacturing process, pH adjusting tank for adjusting the pH of the wastewater, organic materials, ionic Terephthalic acid wastewater with a high concentration of terephthalic acid wastewater when using a recycling device of terephthalic acid manufacturing process including a reverse osmosis membrane portion for removing almost all impurities dissolved in water such as substances and chromatic substances and an ion exchange portion for removing untreated sodium ions and organic substances. It can be stably reused as water in the production process without biological treatment, simple maintenance and recycling of terephthalic acid, catalyst, etc. contained in the wastewater can improve the production yield and reduce the load of the wastewater treatment. The present invention has been completed.

It is an object of the present invention that the wastewater generated in the terephthalic acid manufacturing process can be reused as the water of the production process stably without biological treatment, the maintenance is simple, and can recycle the terephthalic acid, catalyst, etc. contained in the wastewater to improve the production yield The present invention provides a device for recycling terephthalic acid manufacturing process wastewater and a method of treating terephthalic acid manufacturing process wastewater using the same.

In order to achieve the above object, the present invention is provided with a backwashable metal microfilter to separate and remove the particulate organic material and catalyst material of the terephthalic acid manufacturing process wastewater, the particulate organic material separated from the backwashable metal microfilter A metal micro filter unit transferring the material and the catalyst material to a terephthalic acid manufacturing process and producing and transporting filtered water from which particulate matter is removed; A pH adjusting tank to which basic chemicals are added to adjust the pH of the wastewater filtered by the metal microfilter unit; A reverse osmosis membrane unit provided with a reverse osmosis membrane to remove organic substances, catalyst substances, ionic substances, and chromaticity-inducing substances remaining in the wastewater treated in the pH adjustment tank; And a cation exchange resin tower to remove sodium ions remaining in the wastewater filtered in the reverse osmosis membrane unit, or an ion exchange unit equipped with an ion exchange membrane electrodesalting unit to remove sodium ions and organic matter. Provide a device for recycling wastewater.

The present invention also (a) terephthalic acid manufacturing wastewater is filtered through a backwashable metal microfilter to separate and recover the particulate organic matter and catalyst material present in the wastewater, and then the separated particulate organic matter and catalyst material Transferring to a terephthalic acid manufacturing process to produce and transport the filtered water; (b) ionizing the organic material not removed in step (a) and adding basic chemicals to the wastewater to adjust the pH of the wastewater; (c) removing the organic material, the catalytic material, the ionic material and the chromaticity-inducing material remaining in the wastewater which passed through the step (b) using a reverse osmosis membrane; And (d) removing the sodium ions remaining in the wastewater that passed through the step (c) with a cation exchange resin tower, or removing the sodium ions and organic materials with an ion exchange membrane electrodesalting device to obtain a final treated water, and finally Provided is a method for recycling terephthalic acid production wastewater, comprising the step of recycling the treated water to terephthalic acid production process water.

The device for recycling terephthalic acid manufacturing process wastewater according to the present invention is capable of stably recycling wastewater generated in terephthalic acid manufacturing process without using biological treatment as water for production process, simple maintenance, and recycling terephthalic acid, catalyst, etc. contained in wastewater. It can improve the production yield and reduce the load of waste water treatment, which has economic effect on resource recovery, environmental protection and recycling.

1 is a process diagram schematically showing an apparatus for recycling terephthalic acid production process wastewater according to the present invention.

In one aspect, the present invention is provided with a backwashable metal microfilter for separating and removing particulate organic material and catalyst material from a wastewater of terephthalic acid manufacturing process, and the particulate organic material and catalyst material separated from the backwashable metal microfilter are separated. A metal micro filter unit for transporting to a terephthalic acid manufacturing process and producing and transporting filtered water from which particulate matter is removed; A pH adjusting tank to which basic chemicals are added to adjust the pH of the wastewater filtered by the metal microfilter unit; A reverse osmosis membrane unit provided with a reverse osmosis membrane to remove organic substances, catalyst substances, ionic substances, and chromaticity-inducing substances remaining in the wastewater treated in the pH adjustment tank; And a cation exchange resin tower to remove sodium ions remaining in the wastewater filtered in the reverse osmosis membrane unit, or an ion exchange unit equipped with an ion exchange membrane electrodesalting unit to remove sodium ions and organic matter. The present invention relates to a wastewater recycling apparatus.

Specifically, the apparatus for recycling terephthalic acid manufacturing process wastewater of the present invention includes a micro filter unit 1, a pH adjusting tank 5, a reverse osmosis membrane unit 10, and an ion exchange unit 15 as shown in FIG. 1.

The micro-filter unit 1 is a particulate organic material such as terephthalic acid, benzoic acid, para toluic acid and particulates such as manganese, chromium, cobalt, etc. generated by supersaturation of materials in the process of cooling the wastewater generated in the terephthalic acid manufacturing process. The catalyst material is physically separated and removed by using a backwashable metal micro filter (1), and then the particulate organic material and the catalyst material are transferred to a terephthalic acid manufacturing process by a backwashing process in which the air and water are sprayed, and the remaining filtrate is filtered. Flows into the pH adjustment tank 5 described later. At this time, the particulate organic material and the catalyst material transferred to the terephthalic acid manufacturing process can be converted back to terephthalic acid through the oxidation process, or solidified through the dehydration process, and then recycled as fuel.

The backwashable metal microfilter 1 is made of a stainless steel material of sintered metal form or mesh form to be backwashable, having a pore diameter of 1 to 10 μm, and having a pore diameter of more than 10 μm. When used, the pore size is so large that some of the solid filtrate may not be filtered and enter the next step with the liquid filtrate. When using a metal microfilter with a pore size of less than 1 μm, the solid filtrate may Blocking the pores can easily clog the metal microfilter or lengthen the filtration time and reduce the efficiency of the process.

In addition, the backwashable metal microfilter 1 may be backwashed by spraying air and water when the pores of the metal microfilter are clogged by contaminants during operation to increase the operating differential pressure of the metal microfilter, even after the backwashing. If the differential pressure of the metal microfilter does not drop, the organic material is washed with sodium hydroxide solution. If the filter is blocked with metal ions, the metal microfilter is washed with acidic solution such as sulfuric acid and hydrochloric acid. Continuous operation of the chemical is possible and the wastewater from chemical cleaning process is separated and treated with wastewater.

The pH adjusting tank 5 according to the present invention introduces the wastewater (filtrate) from which the particulate organic material and the catalyst material are removed from the wastewater generated in the terephthalic acid manufacturing process from the microfilter unit 1, and is hydrated in the introduced wastewater. Sodium is added and stirred to decompose the remaining organic matter, and the pH (potential of hydrogen) of the wastewater is maintained at 4.5-7.

In the wastewater from which the particulate organic material and the catalyst material are removed from the micro filter unit 1, fine organic materials such as terephthalic acid, benzoic acid, paratoluic acid, and hydrogen bromide, which are not separated from the metal microfilter, are present in a large amount. When introduced into the reverse osmosis membrane portion 10 described in this state, the concentrated portion of the reverse osmosis membrane provided in the reverse osmosis membrane portion is precipitated as a particulate material by the concentration of the fine organic material, the precipitated particulate material is a passage of the flow of water of the reverse osmosis membrane It is impossible to use the reverse osmosis membrane by blocking the hydrogen, and also because hydrogen bromide (HBr) having a strong oxidizing power oxidizes the surface of the reverse osmosis membrane, the removal efficiency is rapidly lowered, and thus it is not applicable to the separation and purification process by the reverse osmosis membrane.

Therefore, in the present invention, the basic chemicals are introduced into the wastewater in the pH adjusting tank 5 before being introduced into the reverse osmosis membrane unit 10 to ionize fine organic substances such as terephthalic acid, benzoic acid, paratoluic acid, hydrogen bromide and the like remaining in the wastewater. It improves solubility, prevents precipitation into particulate matter, and converts hydrogen bromide (HBr), which has a strong oxidizing power, to bromine ions (Br ⁻ ) to remove oxidizing power. The basic medicine is selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium carbonate, and mixtures thereof, preferably sodium hydroxide can be used.

At this time, if an excessive amount of basic chemicals is used, the catalyst ions dissolved in the wastewater may precipitate as salts, so that the basic chemicals are added to the pH adjusting tank 5 so that the pH of the wastewater does not exceed 7, and a small amount of the basic chemicals is used. In this case, the organic substance remaining in the wastewater cannot be ionized effectively, and the basic chemical is added so that the pH is not lower than 4.5.

In addition, the present invention is further installed in the pH adjustment tank 5 by installing a secondary micro filter unit 7 equipped with a cartridge micro filter (cartridge filter) having a pore diameter of 1 ~ 5㎛ at the rear end of the pH adjustment tank (5). Residual particulate matter can be removed to increase the treatment efficiency of the wastewater, and stability can be improved by protecting the reverse osmosis membrane of the rear stage when an abnormality occurs in the apparatus.

Next, the treated water passing through the pH adjusting tank 5 or the secondary microfilter unit 7 is introduced into the reverse osmosis membrane unit 10. The reverse osmosis membrane unit 10 is provided with a reverse osmosis membrane to remain in the waste water organic materials such as terephthalic acid, benzoic acid, para toluic acid, catalyst materials such as cobalt, manganese, anion materials such as bromine, chromatic substances, pH control After separating and concentrating substances such as sodium ions, the concentrated concentrated water is introduced into a wastewater treatment plant, and the treated water filtered from the reverse osmosis membrane is introduced into an ion exchange unit 15 to be described later.

The reverse osmosis membrane may be a reverse osmosis membrane such as a polyamide reverse osmosis composite membrane and cellulose acetate, but is not limited thereto. In this case, the reverse osmosis membrane of the reverse osmosis membrane portion 10 used for a long time may be selected from the group consisting of sodium hydroxide, hydrochloric acid, citric acid, and mixtures thereof for regeneration of the reverse osmosis membrane.

The reverse osmosis membrane part 10 according to the present invention may further include an apparatus capable of backwashing the membrane to prevent fouling of the membrane, an apparatus for cleaning the membrane, and an diffuser or blower to minimize the fouling effect. have.

In addition, the reverse osmosis membrane unit 10 according to the present invention may further include a secondary reverse osmosis membrane (not shown) at the rear end to increase the removal rate of the organic material, the catalytic material, the ionic material and the color causing material and increase the stability of the device. In addition, the intermediate tank 11 may be further provided to reduce variation factors during continuous operation of the ion exchange unit 15 to be described later, and to adjust the inflow amount and the like.

In the present invention, the conveying means of the wastewater is usually possible without limitation as long as it is a means capable of conveying the wastewater, and preferably, the wastewater is transferred using a pump.

As described above, the wastewater (filtrate) treated in the reverse osmosis membrane portion 10 is used to remove sodium ions, organic substances, etc. remaining in the wastewater in the ion exchange portion 15 equipped with a cation exchange resin tower or an ion exchange membrane electrodesalting device. Remove At this time, when the water quality of the wastewater (filtrate) treated in the reverse osmosis membrane part 10 satisfies all conditions except sodium ions, the sodium ions are removed by hydrogen ion exchange with hydrogen ions using only a cation exchange resin tower. do. The cation exchange resin tower has a polystyrene-based material, uses a strong acid cation exchange resin substituted with hydrogen ions, and regenerates with hydrochloric acid or sulfuric acid to maintain ion exchange performance.

On the other hand, when the water quality of the wastewater (filtrate) treated by the reverse osmosis membrane part 10 needs to remove not only sodium ions but also organic substances, an electrodeionization apparatus equipped with a cation exchange membrane, an anion exchange membrane, a mixed ion exchange resin, and the like (electro deionization) , EDI) can be used to regenerate ion exchange resins and remove ionic impurities in the water by electric force to remove not only sodium ions but also organic substances, and to produce final treated water with a pH close to neutral. have.

The final treated water is industrial water that can be used in the terephthalic acid production process with a COD of 20 ppm or less, pH of 6.5 to 7.5, TA of 10 mg / L or less, BA of 5 mg / L or less, and chromaticity of 1 or less.

Terephthalic acid manufacturing process wastewater recycling apparatus according to the present invention is preferably connected to the physicochemical wastewater treatment technology in order to enable a stable wastewater treatment and simple maintenance, lower maintenance costs, terephthalic acid than conventional biological treatment process , Metal catalysts and water can be recycled.

According to another aspect of the present invention, (a) terephthalic acid manufacturing wastewater is filtered through a backwashable metal microfilter to separate and recover the particulate organic material and catalyst material present in the wastewater, and then the separated and recovered particulate organic material and Transferring the catalyst material to a terephthalic acid production process to produce and transport the filtered water from which particulate matter is removed; (b) ionizing the organic material not removed in step (a) and adding basic chemicals to the wastewater to adjust the pH of the wastewater; (c) removing the organic material, the catalytic material, the ionic material and the chromaticity-inducing material remaining in the wastewater which passed through the step (b) using a reverse osmosis membrane; And (d) removing the sodium ions remaining in the wastewater passed through the step (c) with a cation exchange resin tower, or removing the sodium ions and organics with an electrodesalting device to obtain a final treated water, and the final treated water. The present invention relates to a method for recycling terephthalic acid production process wastewater, comprising the step of recycling it into terephthalic acid production process water.

Terephthalic acid production process waste water recycling method of the present invention is to separate the particulate organic material and catalyst material using a backwashable metal microfilter of the filter tank, the separated organic material and catalyst material is backwashed by air and water Is recycled to the terephthalic acid manufacturing process.

As such, the filtrate from which the particulate organic material and the catalyst material are removed is added with basic chemicals to adjust the pH of the wastewater to 4.5-7, and the remaining organic material is ionized to increase the solubility, thereby increasing the solubility. prevent the precipitation phenomena of the particulate material due to the concentration, and enables the operation of the reverse osmosis membrane of the hydrogen bromide (HBr) having strong oxidizing power at the same time, bromine ion (Br ^-) and it was converted to remove the oxidizing surface of the reverse osmosis membrane, To prevent oxidation.

Organic substances such as terephthalic acid, benzoic acid and paratoluic acid remaining in the wastewater through the reverse osmosis membrane, catalyst materials such as cobalt and manganese; Anionic materials such as bromine; Chromatographic agents; Substances such as sodium ions used for pH adjustment are concentrated and separated into the wastewater treatment plant, and the treated water from which the substances are removed is introduced into the ion exchange unit 15 to be described later.

The treated water introduced into the ion exchange unit 15 provides high purity water that can be used in the terephthalic acid manufacturing process by removing residual sodium ions and / or organic matter using a cation exchange resin tower or an electrodesulfurization device. At this time, when the water quality of the wastewater (filtrate) treated by the reverse osmosis membrane satisfies all conditions except sodium ions, the sodium ion is removed using only a cation exchange resin tower, and the wastewater (filtrate) water treated by the reverse osmosis membrane is sodium When not only ions but also organic substances need to be removed, sodium ions and organic substances are removed using an electro deionization (EDI) using a cation exchange membrane, an anion exchange membrane, and a mixed ion exchange resin.

The method for recycling terephthalic acid manufacturing wastewater according to the present invention can recover the particulate matter by using a backwashable metal micro filter and a reverse osmosis membrane, and reuse it in the terephthalic acid manufacturing process to improve production yield and reduce wastewater treatment load. By adjusting the pH of the wastewater of terephthalic acid manufacturing process with oxidizing power and saturated organic acid, it improves the solubility and removes the oxidizing power. And easy to control the process, there is an advantage of easy automation and unmanned operation of the recycling process.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these examples are for illustrative purposes only and that the scope of the present invention is not construed as being limited by these examples.

Example  1: Measurement of Treatment Efficiency of Recycling Equipment for Wastewater from Terephthalic Acid Manufacturing Process

1-1: Backwash  Processing efficiency of metal micro filter

The raw water used was Yeocheon S's petrochemical terephthalic acid manufacturing process wastewater, and the backwashable micro filter was 250cm ^2. Stainless steel filter was used to measure the concentration of particulate matter in the treated water, permeate flux and solids concentration of the backwashing waste by the pore diameter of the filter. At this time, the pressure supplied to the filter was carried out in the range of 3.5kgf / cm ² , the concentration of particulate matter in the treated raw water is 80 ~ 100mg / L, the pressure difference between the inlet and outlet of the filter is filtered to 1.5kg / cm ² Was carried out. In addition, the raw water was supplied at 3000 L / hr for 8 hours, backwashing was performed by supplying at 3000 L / hr for 5 minutes using compressed air and water.

As a result, as shown in Table 1, the metal micro filter having a pore diameter of 1 to 10 μm showed a removal rate of about 98% of the particulate matter, and 9 to 16 wt% of the particulate matter in the backwash wastewater. As the concentration shows a high recovery of particulate matter such as terephthalic acid, it can be seen that the particulate matter can be transferred back to the terephthalic acid manufacturing process to increase the efficiency of terephthalic acid production.

Filter pore diameter (㎛) Treated Water Particle Concentration (mg / L) Permeate flux (L / m ² h) Particle concentration (wt%) of backwashing liquid One 1 or less 310 9.8 3 1 or less 380 11.5 5 1.5 480 13.4 10 2.5 600 16.2

1-2: pH With adjustment tank  Treatment efficiency of reverse osmosis membrane

The metal microfilter used in Example 1-1 to measure the water quality of the treated water and the saturation degree of the concentrated water in the reverse osmosis membrane tank of the rear stage according to the pH adjusted influent (pH: 4.5, 6.0 and 7.0) Pore diameter: 5㎛), treated water and operating conditions, reverse osmosis membrane (R / O) was used as the reverse osmosis membrane made of polyamide having a salt rejection rate of 99.5%, the inlet pressure of the reverse osmosis membrane was 3.5 kgf / cm ² Was carried out.

As a result, as shown in Table 2 to Table 4, it can be seen that the reverse osmosis membrane can be applied without the precipitation of organic acid in the case where the pH range of the waste water is 4.5-7, the water quality of the treated water except for the terephthalic acid It was found to be available to the manufacturing process.

division unit Influent Primary R / O Processed Water Secondary R / O Process Organic acid saturation of primary R / O concentrated water = 95%










pH mg / L 4.5 4.6 4.5 TA (toluic acid) mg / L 380 100 15 Benzoic acid (BA) mg / L 190 50 10 Acetic acid mg / L 580 350 220 Co mg / L 10 trace trace Br mg / L 18 trace trace Na mg / L 150 40 15 COD _cr mg / L 2800 390 230 Chromaticity Degree 10 1 or less 1 or less conductivity ㎲ / cm 670 190 110 Recovery rate % - 75 85

division unit Influent Primary R / O Processed Water Secondary R / O Process Organic acid saturation in primary R / O concentrated water = 80%










pH mg / L 6.0 6.0 6.1 TA (toluic acid) mg / L 380 90 11 Benzoic acid (BA) mg / L 190 40 8 Acetic acid mg / L 580 310 190 Co mg / L 10 trace trace Br mg / L 18 trace trace Na mg / L 220 45 18 COD _cr mg / L 2800 360 200 Chromaticity Degree 10 1 or less 1 or less conductivity ㎲ / cm 670 160 90 Recovery rate % - 70 80

division unit Influent Primary R / O Processed Water Secondary R / O Process Organic Acid Saturation in Primary R / O Concentrated Water = 70%










pH mg / L 7.0 7.0 7.0 TA (toluic acid) mg / L 380 85 10 Benzoic acid (BA) mg / L 190 30 5 Acetic acid mg / L 580 270 150 Co mg / L 10 trace trace Br mg / L 18 trace trace Na mg / L 220 45 15 COD _cr mg / L 2800 330 150 Chromaticity Degree 10 1 or less 1 or less conductivity ㎲ / cm 670 160 80 Recovery rate % - 70 80

1-3: pH With adjustment tank  Treatment efficiency of reverse osmosis membrane

Inflow water treated in Example 1-2 was measured using a cation exchange resin tower or an ion exchange membrane electrodesalination apparatus. At this time, the cation exchange resin tower used a strongly acidic ion exchange resin regenerated with hydrochloric acid, and the ion exchange membrane electrodesalting apparatus (EDI) used a product of G (US, MK-3).

As a result, as shown in Table 5, it can be seen that both the cation exchange resin tower and the ion exchange membrane electrodesalination unit can be used as the water of the terephthalic acid manufacturing process, especially in the case of using the ion exchange membrane electrodesalination unit It can be seen that the water can also be used in the process required.

Item unit Influent Cationic resin tower treated water EDI Processed Water pH mg / L 6.0 4.5 7.0 TA (toluic acid) mg / L 11 11 5 or less Benzoic acid (BA) mg / L 8 8 3 or less Acetic acid mg / L 190 190 10 Co mg / L trace trace trace Br mg / L trace trace trace Na mg / L 18 trace trace COD _cr mg / L 200 200 15 Chromaticity Degree 1 or less 1 or less 1 or less conductivity ㎲ / cm 90 210 15 Recovery rate % 80 90 85

As described above in detail specific parts of the present invention, it will be apparent to those skilled in the art that these specific descriptions are merely preferred embodiments, and thus the scope of the present invention is not limited thereto. will be.

1: Micro filter part 5: pH adjustment tank
7: secondary microfilter unit 10: reverse osmosis membrane unit
11: intermediate bath 15: ion exchange unit

Claims (13)

Apparatus for recycling terephthalic acid production wastewater, including:
Terephthalic acid manufacturing process A metal microfilter having a backwashable pore diameter of 1 to 10 μm is provided for separating and removing particulate organic material and catalyst material from wastewater, and the particulate organic material and catalyst material separated from the backwashable metal microfilter. A micro-filter unit for transporting to a terephthalic acid manufacturing process by a back washing process injecting air and water to produce and transport filtered water from which particulate matter is removed;
A pH adjusting tank to which basic chemicals are added to ionize fine organic materials by adjusting the pH of the wastewater filtered by the microfilter unit to 4.5 to 7;
A reverse osmosis membrane unit provided with a reverse osmosis membrane to remove organic substances, catalyst substances, ionic substances, and chromaticity-inducing substances remaining in the wastewater treated in the pH adjustment tank; And
An ion exchange unit is provided with a cation exchange resin tower to remove the sodium ions remaining in the wastewater filtered in the reverse osmosis membrane unit, or an ion exchange membrane electrodesalting apparatus to remove sodium ions and organic matter.
delete 2. The apparatus of claim 1, wherein the basic drug is selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium carbonate, and mixtures thereof.
delete The apparatus of claim 1, wherein the reverse osmosis membrane unit further includes a secondary reverse osmosis membrane unit at a rear end thereof.
The method of claim 1, wherein the metal microfilter is backwashed using compressed air and backwash water, terephthalic acid production, characterized in that the drug cleaning using a material selected from the group consisting of sodium hydroxide solution, sulfuric acid solution and hydrochloric acid solution. Apparatus for recycling process wastewater.
The apparatus of claim 1, wherein the reverse osmosis membrane is cleaned using a material selected from the group consisting of sodium hydroxide, hydrochloric acid, citric acid, and mixtures thereof.
Re-use of terephthalic acid manufacturing process wastewater, comprising the following steps:
(a) terephthalic acid manufacturing wastewater is filtered through a backwashable metal microfilter having a pore diameter of 1 to 10 μm to separate and recover the particulate organic material and catalyst material present in the wastewater, and then the separated and recovered particulate organic material. And transferring the catalyst material to the terephthalic acid manufacturing process by a backwashing process injecting air and water, and producing and transporting filtered water from which particulate matter is removed.
(b) adding basic chemicals to the wastewater to ionize the organic material not removed in step (a) and to ionize the fine organic material by adjusting the pH of the wastewater to pH 4.5-7;
(c) removing the organic material, the catalytic material, the ionic material and the chromaticity-inducing material remaining in the wastewater which passed through the step (b) using a reverse osmosis membrane; And
(d) removing the sodium ions remaining in the wastewater passed through step (c) with a cation exchange resin tower, or removing the sodium ions and organic materials with an ion exchange membrane electrodesalting device to obtain a final treated water, and the final treatment Re-use of water into terephthalic acid manufacturing process water.
delete delete The method of claim 8, wherein the reverse osmosis membrane is further provided with a secondary reverse osmosis membrane at a rear end of the reverse osmosis membrane.
The method of claim 8, wherein the basic drug is selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium carbonate, and mixtures thereof.
The method of claim 8, wherein the final treated water of step (d) has a COD of 20 ppm or less, a pH of 6.5-7.5, a TA of 10 mg / L or less, a BA of 5 mg / L or less, and a chromaticity of 1 or less. A method for recycling terephthalic acid production process wastewater, characterized in that.

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