KR100467442B1 - A method of treatment for dyeing wastewater by using catalyst oxidizing water - Google Patents

Abstract

The present invention relates to a method for treating dyed wastewater using catalytic oxidation water. The method provides a strong oxidation power of oxidized water by preparing catalytic oxidation water formed by the generation of oxygenated substituents by contacting a ceramic catalyst with an aqueous sodium hypochlorite solution. Purifying dyeing wastewater reduces the load of organic matter, eliminates chemical treatment process and fundamentally suppresses the generation of all chemical sludge, and effectively reduces the generation of biological sludge. The present invention relates to a method for treating dyed wastewater using catalytic oxidation that significantly increases the purification rate and at the same time significantly reduces the cost of wastewater treatment.

To this end, the treatment method of the dyeing wastewater using the catalytic oxidation water of the present invention, the first step of filling the packed column with a ceramic catalyst and an aqueous sodium hypochlorite solution of 280 ~ 320mg / L concentration; A second step of reacting the ceramic catalyst with hypochlorous acid in an aqueous sodium hypochlorite solution to generate a generator oxygen substituent; A third step of producing a hydroxyl substituent by reacting the generator oxygen substituent with water, and producing a catalytically oxidized water composed of the generator oxygen substituent, a hydroxyl substituent, and hypochlorous acid; And a fourth step of adding 7 to 15 wt% of the catalytic oxidation water to the dyeing wastewater and reacting with the organic compound in the dyeing wastewater for 10 to 15 hours to purify it.

Description

A method of treatment for dyeing wastewater by using catalyst oxidizing water}

The present invention relates to a method of treating dyeing wastewater using catalytic oxidation water, specifically, by treating the dyeing wastewater using catalytic oxidation water (Catalyst Oxidizing Water) to reduce the load of organic matter and to eliminate the chemical treatment process The present invention relates to a method for treating dyed wastewater using catalytic oxidation that can effectively reduce the generation of sludge and biosludge and increase the purification rate of the dyeing wastewater and at the same time reduce the cost of wastewater treatment.

In general, industrial wastewater discharged during the production of various industrial products and processed products by industrialization and urbanization according to population growth and industrial development, living sewage discharged from people's daily lives, and livestock wastewater discharged from farming livestock As the sewage and wastewater containing various pollutants are rapidly increasing, the environmental pollution is increasing.

Accordingly, in order to prevent environmental pollution due to sewage and wastewater, most countries have mandatory installation of wastewater treatment facilities for workplaces or facilities where wastewater is generated through various laws and systems.

On the other hand, as various organic compounds such as dyes, terephthalic acid (TPA), and preparations are used in the dyeing process, the dyeing wastewater contains a large amount of hardly decomposable organic compounds that are difficult to decompose in the natural environment. As a wastewater treatment method, chemical treatment with chemicals such as strong acids and flocculants and biological treatment with activated sludge are commonly used.

In other words, the conventional synthetic dye wastewater treatment process: raw waste water generation → screen for filtration (sieve) → collection tank → cooling tower → chemical treatment (coagulation or pressure flotation) → chemical precipitation tank → standard activated sludge treatment tank → final precipitation tank → discharge Sludge drawn out from the chemical precipitation tank and the final precipitation tank is treated after dehydration in a concentration tank.

However, in the chemical treatment method, excessive chemical purchasing costs due to the use of various chemicals such as flocculants not only have a great influence on the overall water treatment cost, but also a large amount of chemical sludge treatment and treatment facilities additionally generated during the treatment process. There are a number of disadvantages of excessive operation and maintenance costs.

In addition, it is difficult to remove chromatic components, terephthalic acid (TPA) and other hardly decomposable substances by the conventional chemical treatment method, and it is not possible to reduce the BOD load, so the residence time is increased in the post-treatment biological treatment method. There is a problem such as increase in the amount of biosludge generation.

In addition, even after a wastewater treatment facility is installed at a high cost, there are many cases in which wastewater above the statutory discharge standard is discharged as it is without using the facilities properly, or discharging the wastewater without unauthorized treatment. There is a situation.

The present invention has been invented to solve the above problems, the treatment method of the dyeing wastewater using the catalytic oxidation water of the present invention by using the catalytic oxidation water to purify the dye wastewater discharged in the whole process of dyeing to reduce the amount of pollutants To reduce the operating costs of wastewater treatment facilities.

Another object of the present invention is to replace the chemical treatment process with a catalytic oxidation process to eliminate the use of chemicals to block the chemical sludge and at the same time to remove the biodegradable substances that were impossible by chemical treatment biological treatment (standard activated sludge method) It is to reduce the load flowing into the water to facilitate the biological treatment.

Figure 1 is a schematic diagram showing the process of dyeing wastewater according to the present invention

Figure 2 is a block diagram of Figure 1

Figure 3 is a block diagram according to another embodiment of the present invention

In order to achieve the above object, a treatment method of dyeing wastewater using catalytic oxidation water according to the present invention includes a first step of filling a ceramic catalyst and an aqueous sodium hypochlorite solution in a packed column; A second step of reacting the ceramic catalyst with hypochlorous acid in an aqueous sodium hypochlorite solution to generate a generator oxygen substituent; A third step of producing a hydroxyl substituent by reacting the generator oxygen substituent with water to produce a catalytically oxidized water composed of the generator oxygen substituent, a hydroxyl substituent, and hypochlorous acid; And a fourth step of purifying the organic material by adding the catalytic oxidation water to the dye wastewater collection tank and reacting with the organic material of the dye wastewater.

Hereinafter, the purification treatment of the dyeing wastewater using the catalytic oxidation water of the present invention will be described in detail.

Step 1: Filling Step

A packed column is filled with a ceramic catalyst and an aqueous sodium hypochlorite solution.

Prior to this step, the process of making the sodium hypochlorite aqueous solution is described, when sodium hypochlorite is dissolved in water by supplying sodium hypochlorite in the process of supplying water to the packed column, sodium hypochlorite as shown in Scheme 1 below The sodium hypochlorite aqueous solution decomposed into silver sodium hydroxide (NaOH) and hypochlorous acid (HOCl) is made, and the sodium hypochlorite aqueous solution reaches a pH of about 9 to 9.5 under the influence of sodium hydroxide (NaOH).

(Scheme 1)

NaOCl + H ₂ 0 → NaOH + HOCl

Using the sodium hypochlorite aqueous solution generated as described above, after filling the ceramic catalyst inside the packed tower (packed tower) as shown in Figure 1, 1 ~ 1000ppm sodium hypochlorite (NaOCl depending on the degree of contamination of the dyeing wastewater) ) The aqueous solution is passed through a packed column.

Second step: generating oxygen radical substituent

The aqueous sodium hypochlorite solution supplied into the packed column is a step of generating a generator oxygen substituent (O *) by a ceramic catalyst.

First, the decomposition process of hypochlorous acid in the state of not using the ceramic catalyst according to the present invention, the hypochlorous acid produced in the reaction scheme 1 is a hydrogen ion (H ^{+ +)} as shown in the reaction scheme 2a by a general decomposition reaction in water ) and hypochlorite ion (OCl ^-, and in the form of a), when the more the pH is lowered, hydrogen ions are formed and the higher the pH to form the hypochlorite ion, the pH is 9, and the temperature of the aqueous solution about 20 ℃ hypochlorite (HOCl) from about 5% hypochlorite ion (OCl ^-) are are present in a ratio of about 95%.

(Scheme 2a)

^{HOCl ← --- → H + + OCl} -

In this process, hypochlorous acid (HOCl) in the aqueous sodium hypochlorite solution generates a generator-oxygen substituent as shown in Scheme 2 in the presence of a ceramic catalyst, wherein the ceramic catalyst is iron, manganese, cobalt, titanium, aluminum, A catalyst formed by mixing metals such as copper and metal oxides and sintering at a high temperature of about 1600 ° C.

(Scheme 2)

HOCl --------- → HCl + O *

Ceramic catalyst

For reference, although hypochlorous acid is an unstable substance, it is immediately decomposed to generate oxygen, but the generation rate or amount is very small compared to using the ceramic catalyst of the present invention.

Third Step: Oxidation Water Generation Step

The aqueous sodium hypochlorite solution in the packed column reacts with the generator oxygen substituent to change the catalytic oxygen-rich catalyst into the catalytic oxidation water.

In the presence of a ceramic catalyst, the water molecules in the aqueous sodium hypochlorite solution and the oxygen-oxygen substituent obtained in the above Reaction Scheme 2 react to form a hydroxyl substituent (H ₃ O ₂ *) as shown in Reaction Scheme 3 below, wherein the hydroxyl substituent is It has a strong oxidizing effect and functions as oxidation, bleaching, decomposition, antibacterial, deodorization and water purification.

H ₂ O + O * --- → H ₂ O ₂ * --- → 2 * 0H

H ₂ O + * OH --- → H ₃ O ₂ *

As such, the generator oxygen substituents (O *) and hydroxyl substituents (H) produced by the reaction schemes 2 to 3 above.₃O₂*), Hypochlorous acid (HOCl) Catalytic oxidation water containing light is produced, and such catalytic oxidation water exhibits up to 80 times more powerful oxidation than the general chlorine system to perform functions such as oxidation, bleaching, decomposition, antibacterial, deodorization, and water purification.

4th process: dyeing wastewater purification

Purifying dyeing wastewater using catalytic oxidation water.

When the catalytic oxidation water is introduced into a wastewater tank (tank) into which wastewater from a dye wastewater treatment plant is introduced, an organic compound in which the oxygen radicals in the oxidized water are composed of C, H, O, and N in the dye wastewater, for example, ethanol of Scheme 4 below. Like this, the waste water is purified through oxidation.

(Scheme 4)

O * O * O *

C ₂ H ₅ OH → CH ₃ CHO → CH ₃ COOH → CO ₂ + H ₂ O

There is dissolved organic matter contained in the wastewater by the purging operation, such as is in the oxidation state or CO ₂ emitted into the air or CO ₃ ^2- in the form to be treated, whereby the pH of the wastewater influence of the dissolved CO ₃ ^2- By about 8 ~ 8.5 will be maintained.

In addition, as the wastewater is purified by the treatment method, chemical oxygen demand, biological oxygen demand, suspended solids, total nitrogen, total phosphorus, surfactants, etc. are simultaneously reduced, and chemical costs and sludges are replaced by replacing conventional chemical treatment processes. At the same time, it reduces the microbial load and increases the microbial activity of the standard activated sludge treatment tank, which is a post-process, by reducing the amount of hardly decomposable COD components and BOD in the collection tank which cannot be removed by chemical treatment. Can improve operation and reduce operating costs.

In addition, the dyeing wastewater subjected to the wastewater treatment process using the oxidized water according to the present invention is transferred to a biological treatment process step, which is then treated.

Hereinafter, an example of purifying and treating various dyeing wastewaters of various types of dyeing wastewater through the method of treating dyeing wastewater using the oxidized water of the present invention will be described in more detail. However, the following examples are only examples to help understanding of the present invention, and the present invention is not limited thereto.

Example 1

The oxidized water produced in accordance with the present invention was put into a comprehensive dyeing wastewater collected by the wastewater discharged from the individual dyeing process in the dyeing complex, and the dyeing wastewater was purified. The reaction time was 10-15 hours, preferably 12 hours, and the amount of catalytic oxidation water was 7-15 wt%, preferably 10 wt%, and the concentration of NAOCl was 280-320 mg / L, preferably 300 mg / L, compared to the dye wastewater.

Compared with the conventional chemical treatment, the result of the treatment of the dye wastewater by the oxidized water of the present invention was compared to the chemical oxygen demand (COD), biological oxygen demand (BOD), suspended solids (SS), n-hexane (n-Hexane) and color ( Color) Total Nitrogen (TN), Total Phosphorus (TP). The results are shown in Table 1 below.

From the results in Table 1, it can be seen that the biological oxygen demand, which is the most important factor in the treatment of wastewater, can be reduced by 1/2 compared to chemical treatment, and the levels of suspended solids and total nitrogen can be greatly reduced.

Subsequently, the cost of the treatment of the dye wastewater using the oxidized water of the present invention is shown in Table 2 below in comparison with the cost of the conventional chemical treatment.

According to the results of Table 2, when the dyeing wastewater was treated using the oxidized water of the present invention, compared to the conventional chemical treatment, it was possible to reduce the chemical treatment cost by 1/3 or more, and comprehensive treatment such as treatment of sludge or solid materials. Looking at the cost of processing, we could save about 1/5.

to the next. Chemical oxygen demand (COD), biological oxygen demand (BOD), suspended solids (SS) by comparing wastewater treatment with oxidized water and biological treatment by activated sludge method according to the present invention and conventional chemical treatment and biological treatment ), n-hexane (n-Hexane), color total nitrogen (TN), total phosphorus (TP) values. this

The results are shown in Table 3 below.

According to the results of Table 3, the results of the catalytic oxidation and biological treatment of the dyeing wastewater according to the present invention not only satisfies the effluent water quality standards as in the conventional chemical treatment and biological treatment, but also compared with the conventional method. It was possible to purify the dyeing wastewater at a fraction of the cost.

Example 2

Using the oxidation water according to the present invention was treated terephthalic acid discharged during the dyeing process.

The terephthalic acid (TPA: Terephthalic acid) is one of the hardly decomposable substances discharged from the polyester weight loss process, and is not removed by conventional chemical treatment, that is, coagulation sedimentation, and is a unit of dye wastewater due to the large amount of such hardly decomposable substances. As the pollutant load per material increases, it acts as a significant factor in the water quality and load fluctuations of the dyeing wastewater.

As a result of adding the catalytic oxidation water of the present invention to the wastewater containing terephthalic acid and reacting for 12 to 24 hours, the terephthalic acid was decomposed to reduce the load on the microbial treatment, which is a post-process, thereby increasing the efficiency of biological treatment.

In the following reference figure, the terephthalic acid was purified using catalytic oxidation water according to the present invention, and the state thereof was measured by an ultraviolet spectrophotometer, and this was compared with that of terephthalic acid by conventional chemical treatment.

As described above, the method of treating dyeing wastewater using the catalytic oxidation water of the present invention, the catalytic oxidation water formed by the generation of oxygen-containing substituents by the contact of the ceramic catalyst and the sodium hypochlorite aqueous solution so that the biological treatment process can be performed immediately without chemical treatment process. By purifying the water quality by preparing it in a comprehensive wastewater collection tank, it does not use any chemicals such as iron salt, slaked lime, and polymer required for the coagulation process in the conventional chemical treatment method except sulfuric acid which is required for pH control. By reducing the generation of sludge, the treatment cost of sludge can be greatly reduced, and biodegradation is facilitated by reducing the load in biological treatment process by removing hardly decomposable substances such as TPA that cannot be removed by chemicals. Chemical oxygen demand (COD), biological oxygen Guryang (BOD), it is possible to reduce the total nitrogen (T-N), phosphorus (T-P), suspended solids (SS), a surfactant (ABS), such as n- hexane.

Accordingly, by maximizing the treatment efficiency of the total dyeing wastewater, it is possible to treat the dyeing wastewater at a low cost, and it is economical, and the configuration of the wastewater treatment facility can be simplified, so that the burden of the initial facility cost is small, and the existing wastewater treatment facility is easy. They can be very efficient and greatly reduce the operating costs of the entire wastewater treatment plant.

Claims (1)

A first step of filling a packed column with a ceramic catalyst and an aqueous sodium hypochlorite solution at a concentration of 280 to 320 mg / L; A second step of reacting the ceramic catalyst with hypochlorous acid in an aqueous sodium hypochlorite solution to generate a generator oxygen substituent; A third step of producing a hydroxyl substituent by reacting the generator oxygen substituent with water, and producing a catalytically oxidized water composed of the generator oxygen substituent, a hydroxyl substituent, and hypochlorous acid; And 7 to 15 wt% of the catalytic oxidation water compared to the dyeing waste water treatment method of the dyeing waste water using the catalytic oxidation water, characterized in that the fourth step of reacting and purifying the organic compound in the dyeing waste water for 10 to 15 hours.