KR20070088002A - Photocatalyst oxidization process and module type photocatalyst reactor for waste water - Google Patents

Abstract

A method for oxidizing waste water and a module type photocatalyst reactor are provided to treat the waste water efficiently and economically, by simultaneously performing a photocatalytic oxidation reaction and a filtering process of filtering ununiform-state photocatalysts in a hybrid type. A first module(3) performs the photocatalytic oxidation on reactant where ununiform-state photocatalysts and waste water are mixed. A second module(8) discharges the reactant processed by the first module. A membrane(M) is inserted between the first module and the second module to filter the ununiform-state photocatalysts. The first module, the second module, and the membrane are installed within the same space in a hybrid type.

Description

Photocatalyst Oxidization Process and Module Type Photocatalyst Reactor for Waste Water

1 is an external conceptual view of a photocatalytic reactor according to the present invention.

2 is an internal exploded view of the photocatalytic reactor.

3 is a cross-sectional view of a photocatalytic reactor.

4 is an overall flowchart of a process in which the photocatalytic process and the membrane filtration process are hybridized.

Figure 5 (a) is a conceptual diagram showing how the photocatalyst reactors are connected in parallel

Figure 5 (b) is a conceptual diagram showing how the photocatalytic reactor is connected in series

<Description of the symbols for the main parts of the drawings>

1: top cover 3: top module of the photocatalytic reactor

4: ultraviolet lamp 5: reflection shade

6 Membrane Support 7 Perforated Hole of Membrane Support

8: lower module of photocatalytic reactor

10: lower cover 13: wastewater storage tank

14 funnel 15 pump

16 valve 17 pressure gauge

18: photocatalytic reactor 19: permeate flow path (permeate)

20: retentate (retentate flow)

21: valve 22: pump

M: membrane

a: inlet b, c: outlet

The present invention relates to a photocatalytic oxidation process and a photocatalytic reactor for decomposing organic compounds contained in domestic wastewater and industrial wastewater, wherein a predetermined amount of a photocatalyst, such as titanium dioxide (TiO2), is mixed with wastewater containing organic compounds, followed by ultraviolet rays. The present invention relates to a photocatalytic reactor capable of a continuous process of decomposing organic compounds in wastewater by irradiation. Photocatalyst is a material that oxidatively decomposes harmful substances such as organic compounds using light (especially ultraviolet rays), and the principle of the oxidation reaction is energy such as ultraviolet rays having energy above the band gap of the photocatalyst. The separation of electrons and holes occurs on the surface of the photocatalyst by external addition, so that products such as OH radicals and superoxides are generated on the surface and give activity to produce OH radicals by itself or organic matter. Organic compounds are oxidized by indiscriminately breaking the linkages and chains. Such photocatalysts have been researched and used as the subject of energy production using solar energy, but recently, it is used to remove environmental pollution, to clean the environment such as antibacterial and deodorization, or to apply superhydrophilic function. Therefore, it has been widely applied to various products such as glass and tiles having a self-cleaning effect, cleaners, air cleaners, refrigerators, curtains, wallpaper, and artificial houseplants. In the field of water treatment, research and use cases of water purifiers and oil sterilizers are reported mainly on the decomposition of organic matter.

However, most of the water treatment and air treatment fields have only a small number of partial processes and operations, and in the field where large volume treatment is required, such as domestic or factory wastewater treatment, the structure of the reactor and the efficiency of wastewater treatment are large. The situation is emerging. Of course, the organic matter contained in the wastewater by the photo-oxidation reaction using the conventional photocatalyst for the wastewater treatment, although the CSTR continuous stirred tank reactor (Batch type reactor) and the coil type reactor were used, still the efficiency and economical efficiency of wastewater treatment There are many challenges to overcome.

In the present invention, a photocatalyst is mixed with wastewater in a heterogeneous phase to cause a photolysis reaction, and a membrane module installed in consideration of the flow direction of the mixture of wastewater and photocatalyst (hereinafter referred to as 'reactant') is used. It is a technical object of the present invention to provide a photocatalytic oxidation process and a photocatalytic reactor for efficient and economical wastewater treatment in which a filtration process occurs at the same time.

In another aspect, the present invention provides a wastewater treatment process for generating a flow of the filtrate through the membrane module using the pressure of the inflow path flowing into the membrane module and the interlayer differential pressure of the fluid flowing without passing through the membrane module. It is a task.

In addition, in the present invention, in order to double the number of lamps used to emit ultraviolet rays and to increase the photolysis efficiency even in the case of using a small lamp, the size of the photocatalytic reaction is limited within the membrane module to reduce the size thereof. Yet, another technical task is to propose a method of maximizing the area irradiated with ultraviolet rays.

In another aspect, the present invention further provides a step of increasing the photocatalytic efficiency of the photocatalyst by adding a certain amount of ozone and hydrogen peroxide to the reactant, and at the same time providing a separate oxidizing power by ozone and hydrogen peroxide.

In addition, the reactor according to the present invention is to solve the problem that the photolysis efficiency due to heat can be reduced by heat exchange to the reactants in the aqueous solution continuously flowing in the photocatalytic reactor by the heat generated from the lamp irradiating ultraviolet rays It is a technical problem.

In addition, the present invention has a cover made of a metal and a material having a corresponding strength on the upper and lower portions of the photocatalytic reactor to reduce the outflow of ultraviolet rays irradiated from the inside of the module to the skin of the reactor operator and operator by ultraviolet irradiation And another technical problem is to minimize the damage caused by ultraviolet irradiation to the human body, such as eye damage.

In another aspect, the present invention is to enable the expansion of the processing capacity by connecting the photocatalytic reactor in series or in parallel when processing a large amount of reactants as another technical problem.

The photocatalytic oxidation process of the present invention for achieving the above technical problem of the present invention is a photocatalytic oxidation process in a photocatalytic reactor in which a photocatalyst is used to photooxidize organic compounds contained in wastewater, wherein the heterogeneous photocatalyst and the wastewater The photocatalytic oxidation process for the mixed reactants and the process through which the oxidized reactants pass through the membrane and the heterogeneous photocatalyst are filtered are characterized in a hybrid system method which occurs sequentially or simultaneously in the same photocatalytic reactor. . In addition, the photocatalytic oxidation is caused by ultraviolet light emitted from a lamp attached to one side of the photocatalytic reactor, and the filtration process is performed through a pair of membrane supports and a membrane inserted therebetween in the middle of the photocatalytic reactor. It features. In order to increase the utilization of the ultraviolet light source, a reflection shade 5 made of a material having high reflectance, such as glossy SUS, may be installed on the upper side of the lamp.

In addition, the reactant, which is a mixture of wastewater and photocatalyst, is further mixed with ozone or hydrogen peroxide to promote photocatalytic oxidation, and the heat generated from the lamp and the reactant inside the reactor are heat exchanged.

In addition, a portion of the reactants that have undergone the photocatalytic oxidation process is recovered to a wastewater storage tank through a separate outlet to undergo a photocatalytic oxidation process, and the photocatalytic oxidation process is branched from the wastewater storage tank. Multiple photocatalytic reactors are connected in series by repeating the non-transmission flow paths from the photocatalytic reactors connected in parallel or connected to one inlet path supplied from the wastewater storage tank, respectively.

On the other hand, in a photocatalytic reactor in which photocatalytic photooxidation of organic compounds contained in wastewater using a photocatalyst, a module in which a photocatalytic oxidation process is performed on a reactant in which a heterogeneous photocatalyst and the wastewater are mixed, and the reactant which has undergone the oxidation reaction are discharged. Another module to be inserted, and the membrane is inserted between each module is characterized in that the hybrid system is installed in the same space all the membrane is filtered in the heterogeneous photocatalyst. At this time, a lamp for irradiating ultraviolet rays is attached to one side of the photocatalytic reactor, and the membrane is supported and fixed by a pair of membrane supports, and a plurality of membranes and membrane supports may be provided to form a plurality of layers. The membrane support is characterized in that the hole for passing the reactant is a module type in which the module inside the reactor is partitioned and formed by the layer by the membrane and the membrane support.

Hereinafter, with reference to the accompanying drawings will be described in detail the photocatalytic process and photocatalytic reactor of the present invention.

1 is an external conceptual view of a photocatalytic reactor according to the present invention, FIG. 2 is an internal exploded view of the photocatalytic reactor, FIG. 3 is a cross-sectional view of the photocatalytic reactor, and FIG. 4 is a process of hybridizing the photocatalytic process and the filtration process of the membrane. The entire flowchart is shown.

As shown, Figure 1 is an external conceptual view of the photocatalytic reactor of the present invention, the upper cover 1 is preferably a metal material of a suitable thickness and serves to firmly support the reactor. Reference numerals 3 and 8 denote upper and lower modules of the photocatalytic reactor, respectively.

2 is a detailed exploded view for showing the internal structure of the photocatalytic reactor of FIG.

3 is a cross-sectional view of the photocatalytic reactor of FIG. 2. In the upper module 3, wastewater containing heterogeneous photocatalytic materials is introduced through an inlet a installed at one side, and organic compounds in the wastewater are decomposed by ultraviolet rays irradiated from the lamp 4 installed at the upper side. This is done. Here, the lamp 4 installed above the reactor may be configured in various embodiments in consideration of the intensity of ultraviolet rays required for the photocatalytic reaction. On the other hand, 100% photooxidation may not be completed even if the reactants undergo a photocatalytic oxidation in the upper module 3, so that the reactants are communicated with one side of the upper module 3 in order to undergo the photocatalytic oxidation and filtration again. Outflow through the outlet b is installed and bypassed to the waste water storage tank 13 via the non-transmission path 20, the remaining reactants are perforated holes (7) of the membrane support (6) installed in the lower portion of the upper module (3) It is transferred to the lower module (8) through. The membrane support 6 is manufactured in the form of a pair of sheets of elastic material, and the membrane M for photocatalytic filtration is inserted and fixed between the pair of membrane supports 6. . On one side of the lower module 8, the reaction product of which photoacidification is completed or not completed is discharged through the outlet c and the permeate flow path 19 after the heterogeneous photocatalyst is filtered through the membrane M. The photocatalytic reactor is assembled to maintain airtightness by a screw or screw penetrating through an assembly hole formed at the corner portion of the upper cover 1, and the assembling method is carried out differently under the condition that the reaction process and airtightness of the photocatalytic reactor are maintained. Yes, of course.

On the other hand, Figure 4 shows a flow chart of the hybrid (hybrid) of the overall process configured to simultaneously perform the photocatalytic oxidation process and the photocatalytic filtration process through the membrane according to the present invention. The wastewater storage tank 13 is a storage tank of various wastewater containing organic compounds for utilizing the photocatalytic oxidation process according to the present invention, where it is mixed with a heterogeneous photocatalyst and prepared as a reactant. The wastewater inlet 14 is a path for providing the reactants to the photocatalytic reactor, which is in communication with the inlet a, and the intermediate pump 15 is for introducing the reactants into the photocatalytic reactor 18, the valve 16 Is a means for controlling the flow of the reactant flowing into the photocatalytic reactor 18 with reference to the hydraulic pressure of the reactant measured by the pressure gauge 17 at the rear. The permeate flow path 19 communicates with the outlet c, and the reactant flowing out through the outlet b is recovered to the waste water storage tank 13 through the non-permeable flow path 20 to undergo the photocatalytic oxidation and filtration again. Reference numerals 21 and 22 are respectively a valve for adjusting the pressure of the reactants passed through the photocatalytic reactor and a pressure gauge for measuring the pressure.

On the other hand, in addition to the process consisting of only the ultraviolet light that causes the photocatalytic activity of the photocatalyst, by installing a separate inlet line to add a certain amount of ozone and hydrogen peroxide to increase the photocatalytic efficiency of the photocatalyst and at the same time can be given a separate oxidation power by ozone and hydrogen peroxide. . In addition, the photocatalytic reactor according to the present invention takes a heat exchange method with the reactants of the upper module 3 of the reactor heat generated from the lamp irradiating ultraviolet rays, and by fixing both upper and lower modules of the reactor with a metal cover It has a function to secure work stability by preventing skin or eye damage to process operators and managers due to UV exposure.

Figure 5 (a) shows how the photocatalytic reactor is connected in parallel to a plurality of inlet paths branched from the waste water storage tank, Figure 5 (b) is one inlet path supplied from the waste water storage tank It is shown that a plurality of photocatalytic reactors are connected in series so that the reactants that do not pass through the membrane are connected to the next photocatalytic reactor again in a path of non-transmissive flow from the photocatalytic reactor connected to.

As described above, the present invention is efficient and economical because it is a hybrid system method in which a photocatalytic oxidation reaction for a reactant mixed with wastewater and a photocatalyst and a membrane filtration process for filtering heterogeneous photocatalysts are simultaneously performed in the photocatalyst reactor. It has the effect of being able to treat wastewater. In the present invention, by adding a certain amount of ozone and hydrogen peroxide to the reactant to increase the photocatalytic efficiency of the photocatalyst and at the same time give a separate oxidizing power by ozone and hydrogen peroxide, and through the reprocessing process through the recovery process of some reactants This has the effect of additionally increasing the efficiency of the photocatalytic oxidation reaction. In addition, in the present invention, when treating a large amount of reactants, the membrane-inserted photocatalytic reactor is connected in series (connecting a fluid flowing through the membrane to another photocatalytic reactor) or in parallel (inlet line of each photocatalytic reactor is a separate wastewater storage tank). By connecting to, it is possible to expand the processing capacity.

Claims (15)

In the photocatalytic oxidation step of photooxidizing the organic compound contained in the waste water in the photocatalytic reactor using a photocatalyst, Photocatalytic oxidation of a reactant formed by mixing a heterogeneous photocatalyst and the wastewater, The reaction of the oxidized reaction passes through the membrane and the heterogeneous photocatalyst is filtered, Photocatalytic oxidation process of wastewater using a photocatalyst, characterized in that the hybrid system sequentially occurring in the same photocatalyst reactor. The method of claim 1, The photocatalytic oxidation reaction is a photocatalytic oxidation process of wastewater using a photocatalyst, characterized in that is caused by the ultraviolet rays irradiated from a lamp attached to one side of the photocatalytic reactor. The method of claim 1, The filtration process is a photocatalytic oxidation process of wastewater using a photocatalyst, characterized in that it is made through a pair of membrane supports and a membrane inserted therebetween in the middle of the photocatalytic reactor. The method according to any one of claims 1 to 3, The photocatalytic oxidation process of wastewater using a photocatalyst, characterized in that the reactant is further mixed with ozone or hydrogen peroxide. The method of claim 2 or 3, Photocatalytic oxidation process of wastewater using a photocatalyst, characterized in that the heat generated from the lamp and the reactant inside the reactor are provided to exchange heat. The method according to any one of claims 1 to 3, The photocatalytic oxidation process of the wastewater using the photocatalyst, wherein a part of the reactants that have undergone the photocatalytic oxidation process is recovered to the wastewater storage tank through a separate outlet in order to undergo the photocatalytic oxidation process. The method according to any one of claims 1 to 3, The photocatalytic oxidation process is a photocatalytic oxidation process of wastewater using a photocatalyst, characterized in that the photocatalyst reactors are connected in parallel to a plurality of inflow paths branched from the wastewater storage tank. The method according to any one of claims 1 to 3, In the photocatalytic oxidation process, photocatalytic oxidation of wastewater using photocatalysts is characterized in that a plurality of photocatalytic reactors are connected in series by repeating a non-transmissive flow path from a photocatalytic reactor connected to one inflow path supplied from a wastewater storage tank. fair. In the photocatalytic reactor for photo-oxidation of the organic compound contained in the waste water by using a photocatalyst, A module in which a photocatalytic oxidation process is performed on a reactant in which a heterogeneous photocatalyst and the wastewater are mixed; Another module to discharge the reactant after the oxidation reaction, A membrane inserted between each module to filter the heterogeneous photocatalyst, Modular photocatalyst reactors, characterized in that all are installed in the same space hybrid. The method of claim 9, One side of the photocatalytic reactor is a modular photocatalytic reactor, characterized in that a lamp for ultraviolet irradiation is attached. The method of claim 10, Modular photocatalyst reactor, characterized in that the reflection shade is provided on the upper side of the lamp. The method of claim 9, And the membrane is supported and fixed by a pair of membrane supports. The method of claim 12, The membrane and the membrane support is provided with a plurality of modular photocatalytic reactor, characterized in that to form a plurality of layers. The method according to claim 12 or 13, The membrane support is a modular photocatalytic reactor, characterized in that a plurality of holes for passing through the reactants. The method according to claim 12 or 13, Module type photocatalytic reactor, characterized in that the module in the reactor is partitioned and formed by the layer by the membrane and the membrane support.

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