JP2005238112A - Deodorization method and apparatus for odor gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deodorization method for an odor gas capable of exhibiting excellent deodorization effect even if the concentration of an odor component of the odor gas generated from a sewage treatment facility or the like is remarkably varied, reducing an operation cost and maintaining excellent treatment performance for a long period of time, and an apparatus. <P>SOLUTION: The odor gas generated from the sewage treatment facility or the like is deodorized by previously removing hydrogen sulfide or the like by organisms deodorization using a microorganism immobilization carrier and contacting the organisms treatment gas with a metal phthalocyanine catalyst-containing solution. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for deodorizing odor gas that can efficiently remove unpleasant odor components in gas generated from sewage treatment plants, human waste treatment plants, food factories, chemical factories, and the like.

Odor gas generated from treatment facilities such as sewage and human waste and various factories has been increasingly demanded to improve the living environment, and countermeasures have been demanded. Odor gas generated in sewage treatment plants in particular contains a relatively large amount of hydrogen sulfide as an odor component. In addition, sulfur-based odor components such as methyl mercaptan, methyl sulfide, and methyl disulfide, and basic substances such as ammonia. Since gas is contained, it is necessary to remove these odor components.
Various methods such as a chemical solution cleaning method, an activated carbon adsorption method, a biological deodorization method, an ozone oxidation method, and a plasma catalyst oxidation method are known as methods for deodorizing odor gas containing these odor components.

However, the chemical cleaning method has a problem that the chemical cost is high and waste liquid treatment is required. In the activated carbon adsorption method, the amount of adsorption is limited, and when the adsorption capacity is lowered, it is necessary to replace it with a new one or perform troublesome regeneration. In particular, in the activated carbon adsorption method, when a gas with a large amount of water is processed, the adsorption amount of the odor component is significantly reduced due to the adsorption of moisture.
Even in the ozone oxidation method and the plasma oxidation method, when the treatment is performed at a low temperature, there is a problem that the performance of the solid catalyst such as a metal oxide is deteriorated due to the moisture in the gas to be treated, and the ozone and plasma generator are expensive. There is a problem that power consumption is large.

Recently, a packed tower type biological deodorization method, which is one of the biological deodorization methods, has been widely used. The packed tower type biological deodorization method is a method of decomposing and removing odor components in odor gas by passing odor gas through a biological carrier packed bed (hereinafter simply referred to as packed bed) provided in the packed tower.
However, the packed tower type biological deodorization method is generally low in running cost and easy to remove easily decomposable odor components such as hydrogen sulfide, but removes hardly degradable odor components such as methyl sulfide and methyl disulfide. Hateful. Moreover, it cannot follow the fluctuation | variation of an extreme odor density | concentration. For this reason, a method of providing a catalytic reactor filled with a solid catalyst in the coexistence of ozone in the subsequent stage of a packed tower type biological deodorization apparatus has been proposed (for example, see Patent Document 1).

However, this method has a problem in that moisture is adsorbed on the solid catalyst or sulfur, sulfuric acid or the like adheres to the catalyst, resulting in deterioration of the performance.
As another deodorization method, a method using a transition metal chelate compound as an oxidation catalyst for an odor component is known. As the transition metal chelate compound, a transition metal porphyrin derivative is effective, and metal phthalocyanine is particularly suitable.

For example, a method using a deodorizing material in which metal phthalocyanine is supported on a chemical fiber or a deodorizing filter in which a nonwoven fabric in which metal phthalocyanine is supported and an activated carbon filter is used in combination has been proposed (for example, Patent Document 2 and Patent Document 3). , See Patent Document 4).

Metal phthalocyanine has a catalytic function even at a low temperature such as room temperature, but has a problem that its deodorizing rate is slow and its deodorizing effect is not sufficient because its catalytic activity is small. In addition, there is a problem that the activity decreases due to adhesion of sulfur, sulfuric acid, etc. caused by decomposition and oxidation of odor components.
Further, in these conventional methods, since the metal phthalocyanine impregnated and supported on the fiber is dried and adjusted, there is a problem that it takes time and cost to manufacture.

JP 2000-246050 A JP-A 62-6985 JP-A-62-2986 JP-A-11-9671

  The present invention has been made in view of the circumstances as described above, and its purpose is to provide an excellent deodorizing effect even when the concentration of the odor component of odor gas generated from a sewage treatment facility or the like varies significantly. It is to provide a deodorizing method of odor gas and a deodorizing apparatus having such a function, which can reduce the operating cost and can maintain excellent processing performance for a long period of time.

The present invention has been made to achieve the above-described problems, and has been solved by the following means.
A method for deodorizing odorous gas generated from a sewage treatment facility or the like, wherein the odorous gas is biologically deodorized in advance using a microorganism-immobilized carrier, and the biological deodorized gas is further added to a metal phthalocyanine catalyst-containing solution (hereinafter simply referred to as metal phthalocyanine). Deodorized by contacting with a solution).
It is also characterized in that solid substances such as sulfur accumulated in the used metal phthalocyanine solution are removed by solid-liquid separation and recycled.

Metal phthalocyanine that deodorizes odorous gas generated from sewage treatment facilities, etc., and is equipped with a biological deodorization tower filled with a microorganism-immobilized carrier for biologically treating odorous gas, and further processes the biological deodorized gas A gas-liquid contact reaction tower (hereinafter simply referred to as a reaction tower) for spraying the solution was installed in the subsequent stage.
The reaction tower is also provided with a solid-liquid separation device that removes solids from the metal phthalocyanine solution used in the reaction tower.

By using the deodorizing method and apparatus of the present invention that removes hydrogen sulfide in advance by biological deodorization and treats the undecomposed odorous component in the treated gas with a metal phthalocyanine solution, Odor components can be sufficiently removed.
Further, it is possible to perform the treatment efficiently and stably over a long period of time. In particular, stable deodorization treatment is possible even when the odor concentration is high or when the fluctuation of the odor concentration is large.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications.
FIG. 1 is a schematic view showing a configuration example of an apparatus for carrying out the odor gas deodorizing method according to the present invention. As shown in FIG. 1, the deodorization apparatus 20 deodorizes the odor gas which generate | occur | produces, for example from a sewage treatment facility, and an odor gas is an odor component, for example, hydrogen sulfide, methyl mercaptan, methyl sulfide, methyl disulfide, Including ammonia.

The deodorization apparatus 20 includes a biological deodorization tower 1 that biologically deodorizes the odor gas, and a reaction tower 2 in which a metal phthalocyanine solution is sprayed from above. A gas to be treated, which is an odor gas, is supplied from the lower part of the biological deodorization tower 1 through the pipe 100, passes through the packed bed 3 disposed inside the biological deodorization tower 1, and passes through the pipe 101 from the upper part of the biological deodorization tower 1. Is discharged through.
The packed layer 3 is filled with a carrier such as ceramic or plastic to which microorganisms adhere.

Activated sludge treated water or the like is supplied to the packed bed 3 through the water spray pipe 4 so that microorganisms that decompose the odorous component grow. Since the gas to be treated is passed through the packed bed 3, the odor components in the gas to be treated are decomposed and deodorized by microorganisms.
In this biological deodorization tower 1, about 99% of hydrogen sulfide, about 90% of methyl mercaptan, about 70 to 80% of methyl sulfide and methyl disulfide, and about 50% of ammonia are removed. Among these, hydrogen sulfide can be efficiently removed.

In addition, the activated sludge treated water sprayed to the packed bed 3 is led from the activated sludge treated water tank 5 to the sprinkling pipe 4 by the pump 6 through the sprinkling pipe L1. Further, the bottom of the biological deodorization tower 1 is a water reservoir 7 for storing water sprinkled from the packed bed 3, and the water stored in the water reservoir 7 is adjusted so as to have an optimum pH for microorganisms. The stored water is also pumped up through the sprinkling pipe L <b> 2 by the pump 8 as sprinkling of the packed bed 3, and sprinkled into the packed bed 3 through the sprinkled pipe 4. The water spray is also used for cleaning the packed bed 3.

In the biological deodorization tower 1, only one packed bed 3 is described. However, it is possible to provide two or more packed beds 3 or two or more biological deodorizing towers 1, It is also possible to provide a water spray pipe 4 above the packed bed 3.

  The processing gas from which hydrogen sulfide has been efficiently removed in the biological deodorization tower 1 is pumped with a metal phthalocyanine solution 9 by a pump 11 and is sprinkled from the top through a pipe L3 and a sprinkling pipe 10 to the lower part of the reaction tower 2 with a pipe 101. Is introduced through. A packed bed 12 is disposed inside the reaction tower 2. The filling layer 12 is filled with a filler such as ceramics or plastics for effective gas-liquid contact.

In the packed bed 12, the odor gas reacts with oxygen by contact with the metal phthalocyanine solution 9 and the odor component in the gas is catalyzed by metal phthalocyanine in the liquid, and is decomposed or oxidized.
For example, hydrogen sulfide remaining without being decomposed in the biological deodorization tower 1 is converted into sulfur or sulfuric acid and captured in the solution. Methyl mercaptan is oxidized to odorless or low-odor gas such as methyl disulfide. Similarly, other sulfides are oxidized to odorless or low odor gas by the catalytic action of metal phthalocyanine.
The processing gas that has passed through the reaction tower 2 is discharged to the atmosphere via the pipe 102. In addition, when performing a further advanced process, after processing by providing a small activated carbon adsorption tower (not shown) etc. in the back | latter stage of the reaction tower 2, it can also discharge | release to air | atmosphere.

  The treatment gas of the biological deodorization tower 1 is almost saturated with water, has a high moisture content, and the catalytic activity of a normal solid catalyst is greatly reduced due to moisture adsorption. However, metal phthalocyanine is an aqueous catalyst. Not affected by moisture. In addition, since most of the hydrogen sulfide is removed in advance in the biological deodorization tower 1 in the previous stage, the amount of sulfur generated in the reaction tower 2 is small. Therefore, since the contamination of the metal phthalocyanine solution 9 is suppressed, it is possible to maintain stable performance for a long time.

  When sulfur has been generated or accumulated due to long-term operation of the apparatus, metal phthalocyanine is used to prevent performance degradation due to contamination of the metal phthalocyanine solution and clogging problems such as the sprinkling pipe 10 in the reaction tower 2. The solution 9 is supplied to a solid-liquid separation device 14 such as precipitation separation, filtration separation or membrane separation via a pump 13 and a pipe L4, sulfur is removed, and the solution 9 is returned to the reaction tower 2 via a pipe L5.

In the solid-liquid separator 14, dust and the like are removed from the gas to be treated by being trapped in the absorbing liquid.
Further, when the absorbing solution is remarkably acidified due to the generation and absorption of sulfuric acid or the like, an alkaline agent such as a sodium hydroxide solution is added to the metal phthalocyanine solution 9 to adjust to an appropriate pH. A suitable pH varies depending on the type of metal phthalocyanine used, but is usually about pH 4-10.

As described above, in the present invention, in the biological deodorization tower 1, hydrogen sulfide that adversely affects the subsequent reaction tower 2 is removed in advance, and even if the biological deodorization treatment gas has a high water content, it is stable in an aqueous solution. Since a simple catalyst is used, there is little influence of moisture, sulfuric acid, etc., and solid sulfur and the like that can be generated can be easily removed, so that stable and high performance can be maintained for a long period of time.

Further, by installing the reaction tower 2 at the rear stage, not only the odorous components can be efficiently removed, but also the biological deodorization tower 1 at the front stage can be downsized. Conversely, by installing the biological deodorization tower 1 in the former stage, it is possible to reduce the amount of expensive phthalocyanine catalyst used in the latter reaction tower 2.
Here, as the form of the reaction tower 2, there are various kinds such as a form in which a liquid is sprayed from the upper watering pipe 10 with a spray nozzle or the like without providing the packed bed 12 filled with ceramics or plastic in the reaction tower 2. Can be used.

  Further, the metal phthalocyanine catalyst used in the reaction tower 2 has a structural formula as shown in FIG. 2, wherein X in the structural formula represents hydrogen or a substituent, and M represents a coordination metal. Examples of the substituent X include various groups such as a carboxyl group, a sulfonic acid group, an amine salt, and a quaternary ammonium group. The substituent X is not limited to one type, and may be a group in which different groups are substituted. . Especially, what substituted about 2-8 about anionic groups or cationic groups, such as a carboxyl group, an amino group, and a quaternary ammonium group, is preferable.

Further, the coordination metal M may be Fe, Co, Mn, V, Cu or the like. These metal phthalocyanines are used dissolved or suspended in neutral, acid or alkaline water. The concentration is usually adjusted to be about 0.1 to 10%. For example, when octacarboxyphthalocyanine iron is used as the metal phthalocyanine, it is dissolved in a dilute alkaline solution of sodium hydroxide so as to be about 0.5 to 5%, and then adjusted to pH 8 to 10 with an acid such as sulfuric acid. Can be used with adjustment.
Since metal phthalocyanine is stable, an oxidizing agent such as sodium hypochlorite can be added and used in order to further enhance the oxidizing power of the metal phthalocyanine solution.

  Further, in the present invention, only when the odor concentration is low, only the biological deodorization tower 1 is operated, and the treatment gas is released into the atmosphere, and only when the odor becomes high, such as during sludge inflow, sludge transport, and stirring. The processing gas in the biological deodorization tower 1 may be further processed in the reaction tower 2.

It is the schematic which shows the structural example of the deodorizing apparatus concerning this invention. It is a figure which shows the structural formula of metal phthalocyanine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Biological deodorizing tower 2 Reaction tower 3 Packing bed 4 Sprinkling pipe 5 Activated sludge treatment water tank 6, 8, 11, 13 Pump 7 Water reservoir
9 Metal phthalocyanine solution
10 watering pipe 12 packed bed 14 solid-liquid separator

Claims (4)

  A method for deodorizing odor gas, characterized in that odor gas is biodeodorized in advance using a microorganism-immobilized carrier, and the biodeodorization treatment gas is further contacted with a metal phthalocyanine catalyst-containing solution for treatment.   2. The odor gas deodorizing method according to claim 1, wherein solid substances such as sulfur accumulated in the used metal phthalocyanine catalyst-containing solution are removed by solid-liquid separation and recycled.   A biological deodorization tower filled with a microorganism-immobilized carrier that biologically treats odorous gas is installed in the front stage, and a gas-liquid contact reaction tower that sprays a solution containing a metal phthalocyanine catalyst is installed in the rear stage, and the processing gas from the biological deodorization tower is metalized. An odor gas deodorizing apparatus comprising a pipe for introducing a phthalocyanine catalyst solution into a gas-liquid contact reaction tower. The odor gas deodorization apparatus according to claim 3, wherein the gas-liquid contact reaction tower is provided with a solid-liquid separation device for removing solids from the metal phthalocyanine catalyst-containing solution used in the gas-liquid contact reaction tower.

Images