Method and equipment for treating hydrazine-containing wastewater.
The photocatalytic treatment of hydrazine-containing wastewater using a photocatalyst addresses the inefficiencies of existing methods by eliminating the need for metals and aeration, enabling efficient decomposition and hydrogen recovery.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MURATA MFG CO LTD
- Filing Date
- 2023-02-20
- Publication Date
- 2026-05-25
AI Technical Summary
Existing hydrazine-containing wastewater treatment methods require continuous addition of metals or metal salts, dilution to avoid adverse effects on microorganisms, and aeration for reaction rate increase, leading to economic inefficiencies and energy consumption without recovering chemical energy.
A photocatalytic treatment using a photocatalyst to oxidatively decompose hydrazine in wastewater, eliminating the need for metals, dilution, and aeration, and enabling hydrogen recovery from the reaction products.
The method achieves efficient hydrazine decomposition without dilution or aeration, allowing for energy recovery as hydrogen gas, reducing operational costs and resource consumption.
Smart Images
Figure 2026085271000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for treating hydrazine-containing wastewater and a facility for treating hydrazine-containing wastewater.
Background Art
[0002] For example, Patent Documents 1 and 2 describe a method for treating hydrazine-containing wastewater in which hydrazine in the hydrazine-containing wastewater is oxidized and decomposed in the presence of copper(II) sulfate or metallic copper as shown in the following reaction formula. Reaction formula: N2H4 + O2 → N2 + 2H2O
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, the treatment methods described in Patent Documents 1 and 2 have problems in the following aspects. · Since it is necessary to continuously add a metal or a metal salt, there are problems in terms of economy and effective utilization of tests. · In order to meet the wastewater (drainage) standards during river discharge, it is necessary to dilute the added metal or metal salt. Also, when a biological treatment process is provided after this process, dilution is necessary to avoid adverse effects on microorganisms. · Aeration is required to increase the reaction rate. · That is, the wastewater is treated by consuming energy and resources. · Furthermore, there is no process for recovering the chemical energy contained in the wastewater.
[0005] The causes of these problems are as follows: This is because, in order to keep the above chemical reaction going, it is necessary to continuously add metals or metal salts. This is because the metal ions derived from the added metals and metal salts are not consumed in the above chemical reaction but remain in the wastewater. The above chemical reaction requires aeration to supply oxygen, as oxygen is a reactant in this reaction. • The oxidative decomposition reaction of hydrazine is a standard reaction with Gibbs free energy (Δ r Although G° is negative and energy could normally be recovered, the above chemical reaction cannot recover energy because its products are nitrogen and water (nitrogen and water cannot be used as fuel and therefore cannot be used as an energy source).
[0006] The present invention has been made to solve the above problems and aims to provide a hydrazine-containing wastewater treatment method and hydrazine-containing wastewater treatment equipment that do not require dilution and aeration. [Means for solving the problem]
[0007] The present invention provides a method for treating hydrazine-containing wastewater, which includes a photocatalytic treatment step in which hydrazine in the hydrazine-containing wastewater is oxidized and decomposed by a photocatalyst.
[0008] The hydrazine-containing wastewater treatment apparatus of the present invention comprises a reaction tank for containing hydrazine-containing wastewater and a photocatalyst provided in the reaction tank. [Effects of the Invention]
[0009] According to the present invention, it is possible to provide a hydrazine-containing wastewater treatment method and hydrazine-containing wastewater treatment equipment that do not require dilution and aeration. [Brief explanation of the drawing]
[0010] [Figure 1]FIG. 1 is a flowchart showing an example of a method for treating hydrazine-containing wastewater according to an embodiment of the present invention. [Figure 2] FIG. 2 is a flowchart showing another example of a method for treating hydrazine-containing wastewater according to an embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view schematically showing an example of a hydrazine-containing wastewater treatment facility according to an embodiment of the present invention. [Figure 4] FIG. 4 is a diagram schematically showing an experimental apparatus according to Example 1. [Figure 5] FIG. 5 is a graph showing the experimental results of Example 1, indicating the concentrations of each component in the hydrazine-containing wastewater before and after the reaction. [Figure 6] FIG. 6 is a graph showing the experimental results of Example 1, indicating the change over time in the amount of hydrogen gas generated.
Embodiments for Carrying Out the Invention
[0011] Hereinafter, the method for treating hydrazine-containing wastewater and the hydrazine-containing wastewater treatment facility of the present invention will be described. However, the present invention is not limited to the following configurations, and can be appropriately changed and applied within the scope of not changing the gist of the present invention. In addition, combinations of two or more of the individual desirable configurations described below are also within the scope of the present invention.
[0012] <Method for Treating Hydrazine-Containing Wastewater> First, the method for treating hydrazine-containing wastewater according to an embodiment of the present invention will be described. The method for treating hydrazine-containing wastewater according to the present embodiment includes a photocatalytic treatment step of oxidatively decomposing hydrazine in the hydrazine-containing wastewater by a photocatalyst. According to this method, since there is no need to add metals or metal ions to the hydrazine-containing wastewater, there is no need for dilution. In addition, since the reactants do not contain oxygen, there is no need for aeration. Hereinafter, this treatment step will be described in detail.
[0013] When using a photocatalyst, it is possible to oxidatively decompose hydrazine, which is a reducing agent, according to the following reaction formula. Reaction formula: N2H4 → 2H2 + N2 This is a combination of the reduction reaction: 2H2O + 2e - → H2 + 2OH - and the oxidation reaction: N2H4 → N2 + 4H + + 4e - Therefore, there is no need to add metals or metal ions, and the hydrazine-containing wastewater does not contain metal ions derived from metals or metal salts, so there is no need to dilute it. Also, since oxygen is not contained in the reactants of the above chemical reaction, there is no need for aeration. Moreover, since the product of the above chemical reaction is hydrogen, energy can be recovered as hydrogen gas. Furthermore, when comparing the reaction: N2H4 + O2 → N2 + 2H2O described in Patent Documents 1 and 2 with the reaction of this embodiment: N2H4 → 2H2 + N2, it can be seen that in the former, H in hydrazine reacts with O to form water, while in the latter, H in hydrazine is taken out as hydrogen. That is, the energy equivalent to the formation of water by the oxidation of hydrogen 2H2 + O2 → 2H2O (Δ r G° = -474.28 kJ / mol) cannot be utilized in principle by the method described in Patent Documents 1 and 2, but can be utilized in this embodiment.
[0014] FIG. 1 is a flowchart showing an example of a method for treating hydrazine-containing wastewater according to an embodiment of the present invention. As shown in FIG. 1, in this embodiment, hydrazine-containing wastewater (hydrazine) discharged from various processes (S1) is oxidatively decomposed by a photocatalyst in a photocatalyst treatment step (S2). More specifically, the photocatalyst in the hydrazine-containing wastewater is irradiated with light (preferably ultraviolet light) under the condition that the photocatalyst is present, and hydrazine is oxidatively decomposed by the oxidation action of the photocatalyst. Then, the wastewater in which hydrazine has been oxidatively decomposed is treated without dilution, for example, discharged into a river (S3).
[0015] The type of photocatalyst mentioned above is not particularly limited, but it is preferable that it has alkali resistance. This is because hydrazine-containing wastewater may be alkaline due to the hydrazine content.
[0016] More specifically, the above-mentioned photocatalyst preferably contains strontium titanate. This allows the photocatalyst to stably exhibit catalytic activity in hydrazine-containing wastewater, thereby enabling the stable decomposition of hydrazine.
[0017] Other photocatalysts that can be used include, for example, titanium dioxide and tungsten oxide.
[0018] The above-mentioned photocatalyst (e.g., strontium titanate) is preferably doped with impurity elements. This makes it possible to improve the activity of the photocatalyst. Examples of impurity elements include aluminum and rhodium.
[0019] The above-mentioned photocatalyst (for example, strontium titanate doped with impurity elements) can be prepared, for example, by a solid-phase method or a flux method.
[0020] In the photocatalytic treatment process, sunlight may be irradiated onto the photocatalyst. This allows for energy-efficient oxidative decomposition of hydrazine compared to using an ultraviolet light source, as described later.
[0021] On the other hand, in the photocatalytic treatment process, the photocatalyst may be irradiated with ultraviolet light from an ultraviolet light source. As a result, the ultraviolet light is absorbed by the photocatalyst, and the catalytic activity of the photocatalyst is activated, allowing for effective oxidative decomposition of hydrazine.
[0022] The type of ultraviolet light source is not particularly limited; examples include LEDs (light-emitting diodes) and ultraviolet lamps (such as mercury lamps and metal halide lamps).
[0023] Alternatively, sunlight and ultraviolet light sources may be used in combination.
[0024] The pH of the hydrazine-containing wastewater is not particularly limited and may be, for example, 12 or higher.
[0025] Furthermore, the upper limit of the pH of hydrazine-containing wastewater is not particularly limited as long as it is 14 or less.
[0026] Note that "pH of hydrazine-containing wastewater" refers to the pH of hydrazine-containing wastewater before it is supplied to the photocatalytic treatment process (before oxidative decomposition of hydrazine by photocatalysis).
[0027] Hydrazine-containing wastewater is essential for hydrazine and water, and other components are not particularly limited, but hydrazine-containing wastewater may further contain at least one compound selected from the group consisting of ammonia, triethanolamine, and citric acid. This is because such components can also be decomposed by photocatalysis. That is, in the photocatalytic treatment process, ammonia, triethanolamine, and / or citric acid in the hydrazine-containing wastewater may be decomposed by photocatalysis.
[0028] As mentioned above, aeration is not essential in the photocatalytic treatment process. However, from the viewpoint of promoting the decomposition reaction of hydrazine, hydrazine-containing wastewater may be bubbling or agitated while the hydrazine is oxidized and decomposed by the photocatalyst. Alternatively, purging with an inert gas (e.g., argon gas) may be performed. This may allow for more efficient recovery of hydrogen gas, as described later.
[0029] Furthermore, as shown in Figure 1, the hydrazine-containing wastewater treatment method according to this embodiment preferably further includes a hydrogen recovery step for recovering the hydrogen generated in the photocatalytic treatment step (S4). This allows energy to be recovered as hydrogen gas. The recovered hydrogen gas may be used, for example, to supply heat or electricity (S5).
[0030] In this case, the hydrazine-containing wastewater treatment method according to this embodiment preferably further includes a gas separation step for separating the hydrogen and nitrogen generated in the photocatalytic treatment step from each other. This makes it possible to recover hydrogen gas of higher purity.
[0031] Specifically, a gas separation membrane that separates hydrogen gas and nitrogen gas from each other can be used.
[0032] In this example, hydrazine is oxidatively decomposed to produce hydrogen and nitrogen, but at least a portion of the nitrogen may be further oxidized by a photocatalyst. Specifically, it may be converted into nitric acid, nitrite, etc.
[0033] Figure 2 is a flowchart showing another example of a hydrazine-containing wastewater treatment method according to an embodiment of the present invention. As shown in Figure 2, this embodiment may further include a biological treatment step for biologically treating the wastewater treated in the photocatalytic treatment step. Since the hydrazine-containing wastewater treated with the photocatalyst does not need to be diluted, it can be supplied directly to the biological treatment step.
[0034] Furthermore, biological treatment is not particularly limited as long as it involves treating wastewater with microorganisms. Specifically, examples include treatment using the activated sludge method.
[0035] <Hydrazine-containing wastewater treatment facility> Next, a hydrazine-containing wastewater treatment facility according to an embodiment of the present invention will be described. Furthermore, since components common to the hydrazine-containing wastewater treatment method can also be applied to the hydrazine-containing wastewater treatment equipment, their explanations will be omitted as appropriate.
[0036] Figure 3 is a schematic cross-sectional view showing an example of a hydrazine-containing wastewater treatment facility according to an embodiment of the present invention. The hydrazine-containing wastewater treatment facility 1 shown in Figure 3 comprises a reaction tank 20 for containing hydrazine-containing wastewater 10 and a photocatalyst 30 installed in the reaction tank 20. According to this facility 1, the hydrazine in the hydrazine-containing wastewater 10 can be oxidized and decomposed by the photocatalyst 30 within the reaction tank 20. Therefore, as with the treatment method described above, there is no need to introduce metals or metal ions into the wastewater, and thus dilution is unnecessary. Furthermore, since the reactants do not contain oxygen, aeration is unnecessary. However, purging with an inert gas (e.g., argon gas) may be performed. This may allow for efficient recovery of hydrogen gas, as described later.
[0037] The reaction vessel 20 is a tank that contains at least hydrazine-containing wastewater 10 and a photocatalyst 30, with a supply port 21 on one side and a discharge port 22 on the other side. The hydrazine-containing wastewater 10 is supplied into the reaction vessel 20 from a supply route (not shown) via the supply port 21, and the hydrazine-containing wastewater 10, in which the hydrazine has been oxidized and decomposed by the photocatalyst 30, is discharged to the wastewater discharge route via the discharge port 22.
[0038] The hydrazine-containing wastewater 10 in the reaction tank 20 may be processed in batches or continuously.
[0039] As shown in Figure 3, it is preferable that the reaction vessel 20 has a photocatalyst immobilization layer 23 for fixing the photocatalyst 30. This allows the photocatalyst 30 to efficiently oxidize and decompose the hydrazine in the hydrazine-containing wastewater 10, and also allows for easy separation of the hydrazine-containing wastewater 10 and the photocatalyst 30 after the decomposition treatment.
[0040] The photocatalyst immobilization layer 23 is formed from a plate material capable of immobilizing (supporting) the photocatalyst 30, and powdered photocatalyst 30 is immobilized on its surface. The photocatalyst immobilization layer 23 is provided, for example, on the bottom surface of the reaction vessel 20 as shown in Figure 3. The material of the photocatalyst immobilization layer 23 is not particularly limited, but it is preferably capable of supporting the photocatalyst 30 and is resistant to hydrazine. Specifically, examples include plastic sheets such as polyethylene terephthalate (PET) film and polyimide sheets.
[0041] For example, the photocatalyst 30 can be fixed onto the photocatalyst fixed layer 23 by placing (spreading) powdered photocatalyst 30 on the photocatalyst fixed layer 23 and firing it under pressure.
[0042] Alternatively, instead of using the photocatalyst immobilization layer 23, the hydrazine may be oxidized and decomposed by the photocatalyst 30 while the powdered photocatalyst 30 is suspended in the hydrazine-containing wastewater 10. However, in this case, it is preferable to carry out a step to recover the photocatalyst 30 after the oxidative decomposition of the hydrazine.
[0043] As shown in Figure 3, it is preferable that the reaction vessel 20 has a light-transmitting window material 24. This allows light to be irradiated onto the photocatalyst 30 through the window material 24 while keeping the inside of the reaction vessel 20 a closed system. Therefore, hydrogen gas, which is a product of the hydrazine decomposition reaction, can be efficiently recovered.
[0044] The location of the window material 24 is not particularly limited; for example, it may be provided on the top surface of the reaction vessel 20 as shown in Figure 3, or it may be provided on the side or bottom surface of the reaction vessel 20.
[0045] The window material 24 is formed from a plate material that transmits light (preferably ultraviolet light). The material of the window material 24 is not particularly limited, but it is preferably one that transmits ultraviolet light and is resistant to hydrazine and hydrogen.
[0046] Furthermore, the material of the reaction vessel 20, excluding the window material 24, is not particularly limited, but it is preferable that it is resistant to hydrazine and hydrogen.
[0047] The window material 24 may be irradiated with sunlight, or, as shown in Figure 3, the hydrazine-containing wastewater treatment facility 1 may further include an ultraviolet light source 31 that irradiates the window material 24 with ultraviolet light. In either case, ultraviolet light can be irradiated onto the photocatalyst 30 through the window material 24.
[0048] The window material 24 may be irradiated with both sunlight and ultraviolet light from the ultraviolet light source 31.
[0049] From the viewpoint of efficiently recovering hydrogen gas, as shown in Figure 3, it is preferable that the reaction vessel 20 has a hydrogen recovery layer 25 for recovering hydrogen produced by the oxidative decomposition of hydrazine by the photocatalyst 30, and that the hydrazine-containing wastewater treatment facility 1 further includes a hydrogen storage facility 32 for storing the generated hydrogen.
[0050] The hydrogen recovery layer 25 is a layered space located above the hydrazine-containing wastewater 10 and is surrounded by the hydrazine-containing wastewater 10 and the upper part of the reaction tank 20. Furthermore, a hydrogen recovery port 26, connected to the hydrogen recovery layer 25, is provided on the upper side of the reaction tank 20.
[0051] The hydrogen storage facility 32 is equipped with cylinders and hydrogen adsorption towers, and is connected to the hydrogen recovery port 26 via a pressurizing pump 33. When the pressurizing pump 33 is operated, hydrogen gas generated from the hydrazine-containing wastewater 10 and stored in the hydrogen recovery layer 25 is discharged from the hydrogen recovery port 26 and stored in the cylinders and hydrogen adsorption towers of the hydrogen storage facility 32.
[0052] The hydrazine-containing wastewater treatment facility 1 may be equipped with a gas separation membrane (not shown) between the hydrogen recovery port 26 and the hydrogen storage facility 32 to separate hydrogen and nitrogen from each other. This allows for the recovery of higher-purity hydrogen gas.
[0053] This specification discloses the following:
[0054] <1> A method for treating hydrazine-containing wastewater, comprising a photocatalytic treatment step of oxidatively decomposing hydrazine in hydrazine-containing wastewater using a photocatalyst.
[0055] <2> The process further includes a hydrogen recovery step for recovering the hydrogen generated in the photocatalytic treatment step. <1> The hydrazine-containing wastewater treatment method described below.
[0056] <3> The process further includes a gas separation step for separating the hydrogen and nitrogen generated in the photocatalytic treatment step from each other. <2> The hydrazine-containing wastewater treatment method described below.
[0057] <4> The aforementioned photocatalyst contains strontium titanate, <1> from <3> A method for treating hydrazine-containing wastewater as described in any one of the following.
[0058] <5> The hydrazine-containing wastewater further contains at least one compound selected from the group consisting of ammonia, triethanolamine, and citric acid. <1> from <4> A method for treating hydrazine-containing wastewater as described in any one of the following.
[0059] <6> The pH of the hydrazine-containing wastewater is 12 or higher. <1> from <5> A method for treating hydrazine-containing wastewater as described in any one of the following.
[0060] <7> In the photocatalytic treatment step, sunlight is irradiated onto the photocatalyst. <1> from <6> A method for treating hydrazine-containing wastewater as described in any one of the following.
[0061] <8> In the photocatalytic treatment step, ultraviolet light is irradiated onto the photocatalyst from an ultraviolet light source. <1> from <7> A method for treating hydrazine-containing wastewater as described in any one of the following.
[0062] <9> The process further includes a biological treatment step for biologically treating the wastewater treated in the photocatalytic treatment step, <1> from <8> A method for treating hydrazine-containing wastewater as described in any one of the following.
[0063] <10> A reaction tank for containing hydrazine-containing wastewater, A hydrazine-containing wastewater treatment facility comprising a photocatalyst provided in the reaction vessel.
[0064] <11> The reaction vessel has a photocatalyst immobilization layer for fixing the photocatalyst, <10> The hydrazine-containing wastewater treatment facility described above.
[0065] <12> The reaction vessel has a light-transmitting window material, <10> or <11> The hydrazine-containing wastewater treatment facility described above.
[0066] <13> The reaction vessel has a hydrogen recovery layer for recovering hydrogen produced by the oxidative decomposition of hydrazine by the photocatalyst, The system further includes a hydrogen storage facility for storing the generated hydrogen. <12> The hydrazine-containing wastewater treatment facility described above.
[0067] <14> When sunlight is shone on the aforementioned window material, <12> or <13> The hydrazine-containing wastewater treatment facility described above.
[0068] <15> The window material is further provided with an ultraviolet light source that irradiates ultraviolet light onto it. <12> from <14> A hydrazine-containing wastewater treatment facility as described in any one of the following. [Examples]
[0069] The following are examples that more specifically disclose the hydrazine-containing wastewater treatment method and hydrazine-containing wastewater treatment equipment of the present invention. However, the present invention is not limited to these examples.
[0070] (Example 1) Figure 4 is a schematic diagram showing the experimental apparatus according to Example 1. As shown in Figure 4, hydrazine-containing wastewater 110, in which a powdered photocatalyst (not shown) was suspended, was placed in a transparent reaction vessel 120. While stirring the hydrazine-containing wastewater 110 with a magnetic stirrer 141, ultraviolet light was irradiated onto the hydrazine-containing wastewater 110 for 8 hours from a mercury xenon lamp 131 placed to the side of the reaction vessel 120. Here, aluminum-doped strontium titanate was used as the photocatalyst.
[0071] Furthermore, during light irradiation, argon gas was introduced into the upper space of the reaction vessel 120 as a carrier gas for collecting the generated gas, and the generated gas was collected using an aluminum gas collection bag 143 connected to the upper side of the reaction vessel 120 via a silicone tube 142. The experimental apparatus was configured to prevent mixing of gases other than the carrier gas and the generated gas.
[0072] For the analysis of the generated gas collected in the aluminum gas collection bag 143, a gas chromatograph (Agilent 7890A, manufactured by Agilent Technologies) was used. The individual components of the hydrazine-containing wastewater 110 were analyzed using the following equipment. Hydrazine: UV-Vis spectrophotometer (U-4100, manufactured by Hitachi High-Tech Science Corporation) Citric acid: Capillary electrophoresis system (Agilent 7100, manufactured by Agilent Technologies) Other equipment: Ion chromatograph (Dionex ICS-5000, manufactured by Thermo Fisher Scientific) The analysis results are shown in Figures 5 and 6 and Table 1 below.
[0073] Figure 5 is a graph showing the experimental results of Example 1, illustrating the concentrations of each component in the hydrazine-containing wastewater before and after the reaction. Figure 6 is a graph showing the experimental results of Example 1, illustrating the change in the amount of hydrogen gas generated over time.
[0074] [Table 1]
[0075] As shown in Figure 5 and Table 1, when a photocatalyst is present in hydrazine-containing wastewater, irradiating the photocatalyst with ultraviolet light removes hydrazine and ammonia (NH4) from the hydrazine-containing wastewater. + ), it was able to decompose citric acid and triethanolamine (TEA). Furthermore, as shown in Figure 6, we were able to recover the hydrogen gas generated by the decomposition of the above components. [Explanation of Symbols]
[0076] 1. Wastewater treatment facility containing hydrazine 10, 110 Hydrazine-containing wastewater 20 reaction vessels 21 Supply port 22 Outlet 23 Photocatalyst fixed layer 24 Window materials 25 Hydrogen recovery layer 26 Hydrogen recovery port 30 Photocatalyst 31 Ultraviolet light source 32 Hydrogen storage facilities 33. Pressurizing pump 120 reaction vessels 131 Mercury xenon lamp 141 Magnetic Stirrer 142 Silicone Tube 143 Aluminum gas collection bag
Claims
1. A method for treating hydrazine-containing wastewater, comprising a photocatalytic treatment step of oxidatively decomposing hydrazine in hydrazine-containing wastewater using a photocatalyst.
2. The hydrazine-containing wastewater treatment method according to claim 1, further comprising a hydrogen recovery step for recovering hydrogen generated in the photocatalytic treatment step.
3. The hydrazine-containing wastewater treatment method according to claim 2, further comprising a gas separation step for separating the hydrogen and nitrogen generated in the photocatalytic treatment step from each other.
4. The hydrazine-containing wastewater treatment method according to claim 1 or 2, wherein the photocatalyst contains strontium titanate.
5. The hydrazine-containing wastewater treatment method according to claim 1 or 2, wherein the hydrazine-containing wastewater further contains at least one compound selected from the group consisting of ammonia, triethanolamine, and citric acid.
6. The hydrazine-containing wastewater treatment method according to claim 1 or 2, wherein the pH of the hydrazine-containing wastewater is 12 or higher.
7. The hydrazine-containing wastewater treatment method according to claim 1 or 2, wherein in the photocatalytic treatment step, sunlight is irradiated onto the photocatalyst.
8. The hydrazine-containing wastewater treatment method according to claim 1 or 2, wherein in the photocatalytic treatment step, ultraviolet light is irradiated onto the photocatalyst from an ultraviolet light source.
9. The hydrazine-containing wastewater treatment method according to claim 1 or 2, further comprising a biological treatment step of biologically treating the wastewater treated in the photocatalytic treatment step.
10. A reaction tank for containing hydrazine-containing wastewater, A hydrazine-containing wastewater treatment facility comprising a photocatalyst provided in the reaction vessel.
11. The hydrazine-containing wastewater treatment apparatus according to claim 10, wherein the reaction tank has a photocatalyst immobilization layer for fixing the photocatalyst.
12. The hydrazine-containing wastewater treatment apparatus according to claim 10 or 11, wherein the reaction tank has a light-transmitting window material.
13. The reaction vessel has a hydrogen recovery layer for recovering hydrogen produced by the oxidative decomposition of hydrazine by the photocatalyst, The hydrazine-containing wastewater treatment apparatus according to claim 12, further comprising a hydrogen storage facility for storing the generated hydrogen.
14. The hydrazine-containing wastewater treatment apparatus according to claim 12, wherein sunlight is irradiated onto the window material.
15. The hydrazine-containing wastewater treatment apparatus according to claim 12, further comprising an ultraviolet light source for irradiating the window material with ultraviolet light.