KR100271945B1 - Treating method of sewage and waste water by radiation and TiO2catalyst - Google Patents

Abstract

PURPOSE: A wastewater treatment method using ultraviolet ray and TiO2 photocatalyst is provided to effectively treat water contamination factors such as color, COD, and TOC by irradiating high energy beam to wastewater as supplying oxygen or ozone. CONSTITUTION: As irradiating γ-rays or electronic rays as high energy beam to wastewater within 0.1 to 100kgy (0.01-10Mrad) range, ozone or pure oxygen is supplied into wastewater. Further, a photocatalyst comprising TiO2, ZnO, Fe, Zr, W, Cd, SiC, manganese oxides is added to wastewater within 0.01-0.10% range, based on the wastewater.

Description

Treatment method of sewage and waste water by radiation and TiO2catalyst}

The present invention relates to a method for treating various sewage and wastewater using a high energy beam, and more particularly, by adding a catalyst for sewage / wastewater treatment when irradiating radiation to sewage and wastewater, The present invention relates to a method that can be effectively processed.

The problem of environmental destruction caused by various pollutants caused by rapid industrialization is getting worse day by day. In particular, pollution of rivers and seawater due to domestic sewage, livestock sewage, and various factory wastewaters has become a big problem in society, and as a result, regulations to prevent environmental pollution caused by various sewage and wastewater are becoming increasingly difficult. .

The direct cause of sewage and wastewater contamination of rivers and seawater is due to various organic and inorganic substances contained in large amounts in sewage and wastewater. In other words, when the concentration of organic matter in the water is increased, the biological oxygen demand of the water (abbreviated as "BOD") is excessively increased in the process of decomposing the organic material by the action of aerobic microorganisms, and accordingly The concentration of oxygen (DO) decreases, eventually destroying the aquatic ecosystem. In addition, anaerobic products CH ₄ , NH ₃ , H ₂ S, and the like are produced to cause odors. On the other hand, when the concentration of inorganic materials in the water increases, the chemical oxygen demand (hereinafter, abbreviated as "COD") increases, the concentration of oxygen in the water (DO) decreases and destroys the aquatic ecosystem.

If the conventional methods of treating sewage and wastewater are classified by their functions, there are largely physical, chemical and biological treatment methods, and suitable treatment methods are selected according to the characteristics of the sewage and wastewater, and the above methods are used in combination with each other. It is common.

Recently, the Advanced Oxidation Process has been attracting much attention for reuse of water treated in sewage and wastewater treatment or for tertiary treatment. Among them, there is a high possibility of industrialization of sewage and wastewater using electron beams or radiation emitted from radioactive isotopes such as electron beam accelerators or ⁶⁰ Co or ¹³⁷ Cs.

On the other hand, when treating sewage and wastewater by using radiation, a method of irradiating the air while supplying air or oxygen into the reactor or by supplying ozone has been studied. Significant difference is shown. In other words, the treatment of dyed waste water or dyed waste water may increase the chemical oxygen demand (hereinafter abbreviated as "COD") than before radiation treatment, and in order to completely remove chromaticity, There are many problems in the economy because they have to be increased considerably. On the other hand, when irradiated with sewage treatment water treatment, there is a problem that the removal rate of chromaticity, COD and total organic carbon (hereinafter, abbreviated as "TOC") is slow. This is known because injecting ozone while irradiating the sewage treatment water does not generate sufficient hydroxyl radicals (OH ·) necessary for oxidative decomposition of organic matter in the sewage. In addition, when the saturated hydrocarbon material is contained in the waste water, all of the hydroxyl radicals involved in the oxidation of the saturated hydrocarbon material are consumed in the reaction itself, and the superoxide radical (O ₂ ⁻ ) generated by the radiation and ozone is It is known that the chain reaction is stopped because it is not produced.

Therefore, the inventors of the present invention, while continuing to research to solve the above-mentioned problems, when treating a variety of sewage and wastewater by irradiating a high energy beam can add a catalyst for sewage / wastewater treatment can significantly improve the treatment efficiency. The present invention has been completed by finding out that the present invention exists.

It is an object of the present invention to provide a method of improving the treatment efficiency in treating various sewage and wastewater by irradiating a high energy beam.

1A is a schematic diagram showing the method of the present invention for treating sewage and wastewater by irradiating with radiation while supplying oxygen to sewage and wastewater to which a powdery TiO ₂ catalyst is added,

A schematic view to investigate the radiation diagram illustrating a method of the invention for processing sewage and waste water, while the oxygen in the sewage and waste water addition (carrier catalyst TiO _2), Figure 1b is a TiO ₂ of the types of the catalyst supported on the carrier

2 is a graph showing the chromaticity change when the sewage treatment water is treated while varying the radiation dose by the method of the present invention.

3 is a graph showing the change in COD when treating the sewage treatment water while varying the radiation dose by the method of the present invention,

4 is a graph showing changes in TOC when treating sewage treatment water while varying the radiation dose by the method of the present invention.

5 is a graph showing the chromaticity change when the treated wastewater treated water while changing the radiation dose by the method of the present invention,

Figure 6 is a graph showing the change in COD when the treated wastewater treatment water while varying the radiation dose by the method of the present invention,

7 is a graph showing changes in TOC when treated with dyed wastewater while varying the radiation dose by the method of the present invention.

In order to achieve the above object, the present invention provides a method for improving the treatment efficiency in treating sewage and wastewater by irradiating high energy beam to the sewage and wastewater.

Hereinafter, the present invention will be described in detail.

The present invention provides a method for treating sewage and wastewater by adding a catalyst for sewage / wastewater treatment to sewage and wastewater, and irradiating a high energy beam while supplying ozone or oxygen thereto.

The treatment efficiency can be greatly improved when treating sewage and wastewater using the method of the present invention, which can be explained by the following two facts. First, when a high energy beam such as radiation is irradiated to sewage / wastewater, water is decomposed to generate hydroxyl radicals (OH ·) and electrons (e _aq- ). The hydroxyl radical generated is a role for the oxidation of organic material and water, an electron (e _aq-) are superoxide radicals react with the dissolved oxygen (DO) in the water ^- to increase the concentration of the (O _2). Second, when metal oxide, a photocatalytic material, is added during irradiation, electrons (e _aq- ) are first generated by irradiation, and these electrons react with dissolved oxygen in water to generate superoxide radicals to produce superoxide radicals. To increase the concentration. Increased concentrations of superoxide radicals promote the production of hydroxyl radicals that oxidize and decompose organic matter. In addition, the strong oxidation / reduction power of the metal oxide, which is a photocatalytic material, reduces the organic matters that are not decomposed only by oxidation, thereby promoting decomposition of the organic matters in water, thereby improving the treatment efficiency of sewage / wastewater.

In the present invention, metal oxides such as titanium oxide (TiO ₂ ), zinc oxide (ZnO), iron (Fe), zirconium (Zr), tungsten (W) and cadmium (Cd) as photocatalysts as catalysts for sewage / wastewater treatment. And silicon carbide (SiC) may be used. Of these, titanium oxide (TiO ₂ ) is most preferably used as a photocatalytic material, and titanium oxide (TiO ₂ ) is known as the most effective photocatalytic material among metal compounds that have been widely used as a photocatalytic material. This is because the oxidation / reduction power is strong enough to release hydrogen and oxygen and generates electrons.

In addition, the catalyst for sewage / wastewater treatment may include at least one of manganese (Mn) oxide and a compound consisting of iron (Fe), titanium (Ti), zirconium (Zr), tungsten (W) and cadmium (Cd). It may contain more.

The catalyst for sewage / wastewater treatment used in the present invention is preferably in the form of a powder or supported on a carrier. At this time, the catalyst for sewage / wastewater treatment in powder form is preferably added in an amount of 0.01 to 0.10% based on the treated sewage and wastewater.

In the catalyst supported on the carrier, the carrier may be metal, glass, quartz, ceramic, or the like. Any material having similar characteristics may be used.

In the present invention, ozone or oxygen supplied to the sewage and wastewater is injected into the sewage and wastewater through ozone-containing air, simple air or oxygen, etc., through an acid pipe of the reactor through a pump, or artificially using a high energy beam irradiator. To generate ozone. At this time, the ozone or oxygen to be supplied to the sewage and waste water is preferably supplied at a flow rate of 500 ~ 1500 ml / min.

In the present invention, the high energy beam irradiated to sewage and wastewater means radiation or electron beam, and the radiation includes gamma rays (γ-ray) generated from radioisotopes such as ⁶⁰ Co and ¹³⁷ Cs. The electron beam also includes an electron beam generated by an electron beam accelerator or the like. The irradiation dose of these high energy beams is preferably 2.5 to 4.5 kPa / hour, and the irradiation dose is preferably in the range of 0.1 to 100 kPa (0.01 to 10 MPa).

In addition, the sewage and wastewater that can be treated in the present invention is the influent water flowing into the sewage terminal treatment facility, the discharged water treated and discharged from the sewage terminal treatment facilities, dyeing wastewater, dyeing wastewater treatment water, organic substances discharged from the industry And all wastewater contained therein and treated water treated for recycling.

Hereinafter, the sewage and wastewater treatment methods of the present invention will be described in detail with reference to the following examples. However, these Examples are only for illustrating the present invention and the present invention is not limited by the Examples.

Example 1 Treatment of Sewage Treatment Water Using Radiation and TiO ₂ Powder

First, the sewage treatment water, which is the effluent from the sewage treatment plant, is added to the reactor, and TiO ₂ in powder form is added 0.04% to the sewage treatment water. Irradiation was carried out while feeding at a flow rate of ml / min. At this time, ⁶⁰ Co was used as a radiation source, and it irradiated with the irradiation dose of 3.5 kPa / hour, changing the irradiation dose to 1-15 kPa. Then, for reuse, the TiO ₂ powder was collected by filtration with filter paper having a pore size of 0.45 μm.

The chromaticity, COD and TOC of the sewage treatment water treated by the above method were measured. As a result, when the TiO ₂ catalyst (TiO ₂ -carrier catalyst) supported in powder form or in a carrier was added to the sewage treatment water containing a large amount of undecomposed organic substances because it was discharged after biological treatment, chromaticity , COD and TOC are greatly reduced. This means that the contaminant itself is broken down and removed from the sewage treatment water, rather than a broken portion of the chromatographic inducing substance. In particular, when the radiation dose was 0.5 M㎭ (5 k㏉), the COD removal efficiency of the sewage treatment water was increased to 75% compared to before the radiation was irradiated, and the TOC removal efficiency was increased to 45%. When TiO ₂ powder is added, the material that is difficult to decompose is decomposed into CO ₂ and H ₂ O by synergy of radiation and TiO ₂ , which means that COD and TOC are greatly reduced. (See FIGS. 2-4)

Example 2 Treatment of Sewage Treatment Water Using Radiation and TiO ₂ -Carrier Catalyst

Containing the sewage to be treated to the reactor, the excited TiO ₂ is supported on a metal substrate surface to TiO ₂ - the naturally ozone a small amount of generated by-containing air via the rear air pump into the carrier catalyst at a flow rate of 1000 ㎖ / min Radiation was irradiated while feeding. At this time, ⁶⁰ Co was used as a radiation source, and it irradiated with the irradiation dose of 3.5 kPa / hour, changing the irradiation dose to 1-15 kPa. Then, after removing the TiO ₂ catalyst carrier, the chromaticity, COD and TOC of the treated sewage water were measured.

As a result, the chromaticity of the TiO ₂ sewage treatment water was drastically reduced by irradiation, and the COD and TOC were also greatly reduced. In particular, when the radiation dose was 0.5 M㎭ (5 k㏉), the COD removal efficiency of the sewage treatment water was increased to 66.7% compared to before the radiation was irradiated, and the TOC removal efficiency was 33 Increased by more than%. (See FIGS. 2-4)

Example 3 Treatment of Dyeing Wastewater Treatment Using Radiation and TiO ₂ Powder

The dyeing wastewater is placed in a reactor, where 0., 04% of powdered TiO ₂ is added to the sewage, followed by 1000 ml / min of naturally occurring traces of ozone-containing air through an air pump. Irradiation was conducted while feeding at a flow rate of. At this time, ⁶⁰ Co was used as a radiation source, and it irradiated with the irradiation dose of 3.5 kPa / hour, and changing the irradiation dose into 1-15 kPa. Then, for reuse, the TiO ₂ powder was collected by filtration with filter paper having a pore size of 0.45 μm, and the chromaticity, COD, and TOC of the treated dyed wastewater were measured.

As a result, it can be seen that chromaticity and COD and TOC of the dyeing wastewater treated water were largely removed. In particular, when the radiation dose was 1.5 M㎭ (15 k㏉), the chromaticity removal rate of the sewage treatment water was 91.6%, and the COD removal efficiency was 55%. In addition, the removal efficiency of the TOC was also increased. This does not mean that the contaminants in the dyeing wastewater are converted to other substances and thus the color is not reduced, but the colorants, COD and TOC are greatly reduced as the pollutants themselves are decomposed into CO ₂ and H ₂ O and removed from the dyeing wastewater. (See FIGS. 5-7)

Example 4 Treatment of Dyeing Wastewater Treatment Using Radiation and TiO ₂ -Carrier Catalyst

The dyeing wastewater treated water was placed in a reactor, and a TiO ₂ -carrier catalyst was added thereto, followed by irradiation while supplying naturally occurring traces of ozone-containing air at a flow rate of 1000 ml / min through an air pump. At this time, ⁶⁰ Co was used as a radiation source, and it irradiated with the irradiation dose of 3.5 kPa / hour, changing the irradiation dose to 1-15 kPa. Then, the TiO ₂ catalyst carrier was removed, and the chromaticity, COD, and TOC of the treated dyed wastewater were measured.

As a result, it can be seen that chromaticity and COD and TOC of the dyeing wastewater treated water were largely removed. In particular, when the radiation dose was 1.5 M㎭ (15 k㏉), the chromaticity removal rate of the sewage treatment water was 81%, and the COD removal efficiency was 52%. In addition, the removal efficiency of the TOC was also increased. (See FIGS. 5-7)

Comparative Example 1 Treatment of Sewage Treatment Water Using Radiation

The sewage treatment water, which is the effluent from the sewage treatment plant, was placed in a reactor and irradiated with air while supplying naturally occurring traces of ozone-containing air at a flow rate of 1000 ml / min through an air pump. At this time, ⁶⁰ Co was used as a radiation source, and it irradiated with the irradiation dose of 3.5 kPa / hour, changing the irradiation dose to 1-15 kPa. Then, the chromaticity, COD and TOC of the treated sewage treatment water were measured. As a result, the chromaticity hardly decreased when the radiation dose was 0.5 MPa (5 kPa) or more. In addition, when the radiation dose was 1.5 MPa (15 kPa), the treatment efficiency of the COD of the sewage treatment water was 34.7%. In addition, as can be seen in Figure 3, the COD value increased and decreased, which seems to increase the COD is changed to a material that can be easily oxidized due to the irradiation of radiation.

On the other hand, the treatment efficiency of TOC was 12% in the said irradiation amount. In addition, as can be seen in Figures 2 and 3, when irradiated with radiation only reduced the chromaticity, it can be seen that the chromaticity is reduced simply because the bonding of the portion causing the color is broken. (See FIGS. 2-4)

Comparative Example 2 Treatment of Dyeing Wastewater Treatment Using Radiation

The dyeing wastewater treated water was placed in a reactor and irradiated with a supply of naturally occurring traces of ozone-containing air at a flow rate of 1000 ml / min through an air pump. At this time, ⁶⁰ Co was used as a radiation source, and it irradiated with the irradiation dose of 3.5 kPa / hour, changing the irradiation dose to 1-15 kPa. Then, the chromaticity, COD and TOC of the treated dyed wastewater were measured. As a result, when the radiation dose was 1.5 MPa (15 kPa) or more, the chromaticity removal efficiency was 60.4%, and the COD treatment efficiency was 41.3%. On the other hand, TOC was found that the lower the processing efficiency than in the case with the TiO ₂ catalysts supported on TiO ₂ powder or carrier. (See FIGS. 5-7)

As described above, the method of the present invention, when treating the sewage and wastewater by irradiating a high energy beam while supplying oxygen or ozone to the sewage and wastewater, by adding a catalyst for sewage / wastewater treatment, It is possible to reduce the chromaticity, COD and TOC more efficiently to improve the treatment efficiency, and also to shorten the treatment time, which can be usefully used for the treatment of various sewage and wastewater. As it can be reused as industrial water, it is a very effective way of recycling water resources.

Claims (4)

In the method of treating sewage / wastewater by irradiating a high energy beam (high energy beam), While irradiating gamma rays or electron beams with high energy beams within the range of 0.1 to 100 k㏉ Ozone naturally generated inside the high energy beam irradiation chamber or artificially generated using a high energy beam irradiation device; Or supply oxygen by using ozone-containing air, simple air, or oxygen gas naturally generated inside the high energy beam irradiation chamber, A method for treating sewage and wastewater, comprising adding a catalyst for sewage / wastewater treatment. The catalyst for sewage / wastewater treatment according to claim 1, further comprising: titanium oxide (TiO ₂ ); Zinc oxide (ZnO); Oxides of iron (Fe), zirconium (Zr), tungsten (W) and cadmium (Cd); And silicon carbide (SiC) alone or in addition to at least one of the compounds consisting of manganese oxide and iron (Fe), titanium (Ti), zirconium (Zr), tungsten (W) and cadmium (Cd). A method for treating sewage and wastewater, further comprising and using. The catalyst for sewage / wastewater treatment according to claim 1 or 2, wherein the catalyst for sewage / wastewater treatment is in powder form or supported on a carrier, and the catalyst for sewage / wastewater treatment in powder form is added at 0.01 to 0.10% of the treated sewage and wastewater. Method for treating sewage and wastewater, characterized in that. The method for treating sewage and wastewater according to claim 2, wherein the carrier of the catalyst for sewage / wastewater treatment in the form supported on the carrier is selected from metals, glass, quartz and ceramics.