JPH04219117A - Method for sprinkling water in filter bed-type biological deodorization tower - Google Patents

Abstract

PURPOSE:To prevent the deterioration of the deodorizing performance when water is sprinkled over a biological filter bed. CONSTITUTION:Water is intermittently sprinkled over the filter bed in a filter bed-type biological deodorization tower for one part at a time. Consequently, the amt. of water staying in the filter bed is reduced, movement of the malodorous gas is not significantly disturbed by the liq. laminar film, and high deodorizing performance is maintained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water sprinkling method in a filter bed type biological deodorizing tower in which microorganisms involved in deodorization are immobilized.

0002

BACKGROUND OF THE INVENTION As one of the measures to control odors generated from sewage treatment plants, a deodorization method using a biological filter bed type deodorization tower has been adopted. This method fixes and grows microorganisms such as sulfur-oxidizing bacteria and nitrifying bacteria on the filter bed, and removes malodorous components such as reducing sulfur compounds and reducing nitrogen compounds in the malodorous gas that dissolves in the water sprinkled on the filter bed. It is decomposed by microorganisms.

The above-mentioned biological filter bed type deodorizing system has conventionally been composed of a biological deodorizing tower A', a neutralization equipment B, and an activated carbon adsorption tower C or soil deodorizing equipment, as shown in FIG. The biological deodorizing tower A', which is the main part of the biological deodorizing tower A', is provided with a filter bed 1 in which microorganisms involved in deodorization are immobilized, and a water tank 2 is formed at the bottom of the tower below the filter bed 1.
A water sprinkler 3 is provided on the top of the holder.

0004

[Problems to be Solved by the Invention] The deodorizing mechanism of the above-mentioned filter bed type biological deodorizing tower is such that the odor gas is supplied to the lower part of the filter bed 1 and rises inside the filter bed 1, and during that time, the odor components first pass through the filter bed 1. Dissolves in the water contained in the filling. Then, it is oxidized and decomposed by microorganisms immobilized on the filling to make it odorless. On the other hand, oxides (SO4, N03, etc.) produced as a result of decomposition are p
This will lower H. Therefore, this method requires water supply to dissolve odors, moisture to keep microorganisms alive, and water sprinkling to wash away oxidation products.

[0005] Water is sprayed onto the entire surface of the filter bed 1 at once using a large number of nozzles 8, 8 provided in the water sprinkler 3. In addition, there are continuous water sprinkling methods, but in that case, the amount of water sprinkled is large, so generally, for example,
Intermittent watering is performed on a cycle of watering for 5 minutes every 0 minutes.

By the way, in the above deodorizing treatment, it is known that the deodorizing performance deteriorates when water is sprinkled. This is because the gas residence time within the filter bed is reduced by the amount of water retained within the filter bed. Another reason is that odor gases that are directly taken in by microorganisms are less likely to be taken in by the liquid film of the sprinkled water. As described above, if the deodorizing performance deteriorates, the activated carbon life of the activated carbon adsorption tower C in the latter stage will be shortened. If the degree of deterioration in deodorizing performance is large, odor will remain in the exhaust gas.

The present invention was proposed in view of the problems of the prior art as described above, and aims to provide a new water sprinkling method that can effectively treat odor gas in a filter bed type biological deodorization tower. The purpose is

[0008]

[Means for Solving the Problems] In order to achieve the above object, the present invention deodorizes malodorous gas using a deodorizing tower having a filter bed in which microorganisms involved in deodorization are immobilized and a water sprinkler installed above the filter bed. In this method, water is sprinkled onto the filter bed from a water sprinkler intermittently, one part at a time.

[0009]

[Operation] Water is sprinkled partially and intermittently onto the filter bed using the method of sprinkling water in an aerated manner. Therefore, the amount of water remaining in the filter bed is kept low, and the inhibition of odor gas movement by the liquid film can be kept as low as possible. Therefore, the amount of odor gas directly taken into microorganisms increases,
Deterioration of deodorizing performance during watering can be prevented. Furthermore, since water is sprinkled locally and sequentially, the capacity of the watering pump can be reduced.

0010

[Example] In Figures 1 and 2, A is a filter bed type biological deodorizing tower, and microorganisms such as nitrifying bacteria and sulfur oxidizing bacteria that are involved in deodorization are immobilized in the upper and lower intermediate parts of the vertically formed tower body. A filter bed 1 filled with a carrier for growth is provided, and a water tank 2 to which a drain pipe 4 is connected is formed at the bottom of the deodorizing tower A, and a space between the water tank 2 and the filter bed 1 is provided. 5 is connected to a supply pipe 6 for odor gas to be treated. Further, a water sprinkler 3 is provided above the filter bed 1, and a gas exhaust pipe 7 is connected to the upper end of the deodorizing tower A.

The water sprinkler 3 has a large number of nozzles 8, 8 arranged at approximately equal intervals on a plane, and a plurality of these nozzles 8, 8 form sets so that each set can sprinkle water. In the embodiment shown in the figure, a plurality of water spray sets a, b, c, d, e connected to the water pipe 8 are arranged in parallel, with a plurality of nozzles 8, 8 arranged in series in one direction as a unit, The water distribution pipes 9 of each of the groups a to e are connected to a main water supply pipe 11 via on-off valves 10 that individually supply and shut off water under manual or automatic control. However, the arrangement of the nozzles 8, 8 forming the set is not limited to the above-mentioned arrangement; for example, the nozzles 8, 8 may be disposed in a discrete manner, or several of the nozzles adjacent in the vertical and horizontal directions may be used as a unit to form a spraying set.

[0012] The watering method using the water sprinkler 3 is such that each of the watering groups a to e selects a cycle every 60 minutes, such as spraying water for 5 minutes and pausing for 55 minutes. The on-off valves 10 are operated in sequence to perform intermittent watering. Therefore, when five water spraying groups a to e are provided as shown in the figure, watering is performed for 5 minutes at 5 minute intervals.

Next, an experimental example of the method of the present invention will be shown. The filter bed type biological deodorizing tower used has a diameter of 2 m and a height of 4 m, the deodorizing air volume is 50 m3/min, and the contact time is 10 seconds. Each nozzle 4 was attached as one set to form five watering groups a to e, and each watering group was subjected to intermittent watering with a cycle of 5 minutes of spraying and a 55-minute pause. In addition, in order to compare with this, in the above deodorizing flow, all nozzles 8 and 8 were
An experiment was conducted using intermittent watering, in which water was sprinkled for 5 minutes and paused for 55 minutes.

[0014] As a result of the above experiment, the conventional watering method:
As shown in FIG. 4, a remarkable decrease in deodorizing performance during water sprinkling was observed, and in particular, the higher the odor concentration and the higher the load, the worse the deodorizing performance during water sprinkling. On the other hand, in the water sprinkling method of the present invention, as shown in FIG. 5, there was no deterioration in deodorizing performance during water sprinkling as in the conventional method, indicating that the results were good.

FIG. 3 shows an example of a deodorizing system using the filter bed type biological deodorizing tower A of the present invention. In this system, watering is not done by circulating water as in conventional systems, but the water collected in the water tank 2 is discharged through the drain pipe 4. Therefore, there is no need to install neutralization equipment. Then, the deodorized exhaust gas is further deodorized in the activated carbon adsorption tower C from the gas discharge pipe 7, and the treated gas is released into the atmosphere, as in the conventional case.

[0016]

[Effects of the Invention] As described above, according to the present invention, by sequentially sprinkling water onto the filter bed in a filter bed type biological deodorizing tower, the amount of water remaining in the filter bed can be reduced. ,
The inhibition of the movement of odor gas by the liquid film can be kept low, preventing deterioration of deodorizing performance during watering, prolonging the life of the activated carbon in the subsequent stage, and maintaining high deodorizing performance.

[0017] Furthermore, by partially sprinkling water, the capacity of the watering pump can be reduced, and economical efficiency is also improved.

[Brief explanation of the drawing]

FIG. 1 is a side view showing one embodiment of the present invention.

FIG. 2 is a plan view showing the water sprinkler portion.

FIG. 3 is an overall configuration diagram of a deodorizing system to which the present invention is applied.

FIG. 4 is an explanatory diagram of a deodorizing state using a conventional water sprinkling method.

FIG. 5 is an explanatory diagram of a deodorizing state according to the present invention.

FIG. 6 is an overall diagram of a conventional deodorizing system.

[Explanation of sign]

A, A' Deodorizing tower B Neutralization equipment C Activated carbon adsorption tower 1 Filter bed 2　Aquarium 3. Water sprinkler 4 Drain pipe 6 Gas supply pipe 7 Gas exhaust pipe 8 Nozzle 9 Water pipes 10 On-off valve 11 Water mains

Claims (1)

[Claims] A method of deodorizing foul-smelling gas using a deodorizing tower that has a filter bed with immobilized microorganisms involved in deodorization and a water sprinkler installed above it, in which water is sprinkled onto the filter bed from the water sprinkler intermittently, one part at a time. A water sprinkling method in a filter bed type biological deodorization tower, characterized in that: