JP2003225639A - Method for treating jellyfishes getting mixed into sea water intake line - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for treating the mixed jellyfishes entering sea water intake line with which solid waste disposal quantity is reduced, treatment is easy and cost is reduced. <P>SOLUTION: In this method for treating the mixed jellyfishes which flow and enter when sea water is taken as industrial coolant, jellyfishes and fishery product are landed and separated from the seawater intake line by using a draining net conveyor, etc., and the separated jellyfishes and fishery product are transferred to a tank and are stored for several days in a tight closure state of air interruption. Therein, after confirming that the jellyfishes are naturally dissolved and liquefied by anaerobic decomposition, the liquefied matter is separated and then is subjected to deodorization treatment by a deodorizer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for treating jellyfish mixed in a seawater intake line as industrial cooling water,
In particular, the present invention relates to a method for treating jellyfish that is mixed in a seawater intake line to liquefy and deodorize all of the jellyfish that are landed to reduce the volume as solid waste and reduce the treatment cost.

[0002]

2. Description of the Related Art Since a large amount of cooling water is required for condensers of thermal power plants near the coast and large heat exchangers in the chemical equipment industry, there is an opportunity to use seawater as industrial cooling water. There are many. However, foreign substances such as jellyfish and seafood easily flow into the seawater intake line as industrial cooling water, and block pumps, pipes, heat transfer pipes, etc., or adhere to the heat transfer pipe wall to deteriorate heat transfer efficiency. It is necessary to prevent these from being mixed in as much as possible. As for the type of jellyfish,
Water jellyfish (Umbrella diameter 1 cm to 30 cm, very rarely 1 m
And the majority of collected jellyfish), red jellyfish (umbrella diameter 9cm-12cm, large one 50cm)
The degree is collected and the tentacles are highly poisonous. ), Horseshoe jellyfish (egg-shaped, small and large, transparent and jelly-like with a size of about 10 cm. It easily passes through a jellyfish prevention net).

From the middle of June to the end of August, a large amount of such jellyfish is generated and the amount of the jellyfish flowing into the seawater intake line is also large. For example, a seawater intake line used as condenser cooling water in a thermal power plant is usually equipped with a jellyfish inflow prevention network (about 75 mm □) at its tip, and further along the inflow line to the intake pit on the way, Multiple rake bar screens, rotary screens, etc. are installed, and with this, jellyfish and seafood are sequentially scraped off from seawater as solid dust and transferred to the dust discharge line. Pour into trash pit (waste pit). The jellyfish and seafood accumulated on the trash pits are sucked up into a vacuum truck etc. as solid waste, or they are scraped out manually and carried out to be treated as industrial general waste, while the remaining washing water is seawater. Returned to the intake line.

[0004]

As a method of treating such solid waste as industrial general waste, landfilling, incineration, fermentation and the like are generally used, but the water content of the jellyfish component is about 95. %, Organic matter such as protein is about 5%, and since a large amount of seawater is mixed, it is difficult to collect and the processing cost becomes high. Therefore,
It is strongly desired to take measures to further reduce the treatment amount of jellyfish and reduce the treatment cost. In view of the present situation, an object of the present invention is to provide a treatment method for reducing the volume of solid waste such as mixed jellyfish flowing into a seawater intake line and reducing the treatment cost.

[0005]

Means for Solving the Problems As a result of various studies on the above problems, the present inventors have found that jellyfish can be easily anaerobically decomposed into a liquefied solid by simply storing it in a plastic tank or the like for several days in an airtight closed state. The present invention has been completed by focusing on the new fact that the volume of an article is reduced. That is, the present invention is a method of treating mixed jellyfish that flows in when seawater is taken in as industrial cooling water, wherein solids such as jellyfish and seafood from the seawater intake line are landed and separated by a draining net conveyor or the like, The separated jellyfish are transferred to a tank and stored for several days in an air-tight closed state, and after confirming that the jellyfish spontaneously dissolved and liquefied by anaerobic decomposition, the liquefact is separated and Is a method for treating jellyfish mixed in a seawater intake line, which is characterized in that the deodorant is treated with a deodorant agent.

Further, in the present invention, the liquefied material deodorized with a deodorant agent is detoxified in an activated sludge facility or the like, and the volume-reduced residual solid matter after the liquefied material is separated from the tank is generally This is a method for treating mixed jellyfish that is treated as solid waste. Furthermore, in the above-mentioned present invention,
For deodorizing liquefaction, it is desirable in terms of equipment cost to add a deodorant agent to the liquefaction in a circulation tank and circulate with a pump. Further, in the above-mentioned present invention, it is most desirable to use sodium hypochlorite as a deodorizing agent in terms of deodorizing effect and processing cost.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic sectional view showing a seawater intake line. FIG. 2 is a schematic perspective view showing the trash pit structure. FIG. 3 is a schematic overall work flow diagram showing a jellyfish processing situation. First, in FIG. 1, a jellyfish inflow prevention network (75 mm □) 2 is installed at the extreme end of the deep seawater intake line 1, and a plurality of rake bars are provided in the middle of the inflow line 3 to the intake pit on the land. A screen 4, a rotary screen 5, etc. are installed. With these screens, solid waste such as jellyfish and seafood is scraped from seawater and transferred to a dust discharge line (not shown) for removal. The seawater from which solid dust has been removed is stored in the intake pit 6, and is circulated by the circulating water pump 7 installed therein as industrial cooling water for a condenser or the like. In addition, the screen cleaning pump 8 for the dust discharge line is also installed in the water intake pit.

The solid dust particles such as jellyfish and seafood mentioned above are rake bar screen 4 and rotary screen 5.
After being scooped up by a cleaning machine, etc., by injecting washing water from the screen washing pump 8 from the back side of the screen, the dust discharging line 9
(See Fig. 2) While falling and flowing down, the trash pit
(Waste pit) It is discharged to 10. As shown in FIG. 2, the trash pit 10 is normally divided into A, B, and C tanks by a net-made partition weir 11, and solid dust is accumulated in each tank, and the C tank is Outlet piping line 1
From 2, only the washing water from which solid dust is removed is circulated to the intake pit described above. The solid wastes accumulated in the tanks A, B and C may be separated from the respective tanks by landing with a draining net conveyor or the like, but more preferably, a draining net is provided near the inlet from the dust discharging line to the trash pit. It is preferable to install a conveyor 13 where the solid waste is continuously scraped off the surface of the washing water by driving the net conveyor to separate it while draining water.

In the present invention, the solid waste material 14 thus separated by draining is temporarily collected in a container 15 outside the trash pit and, as shown in FIG. It is filled in a closed tank 17 such as a container. The jellyfish filled in a closed tank 17 such as a plastic container has the greatest feature in storing for several days in an air-tight closed state. Here, when jellyfish are filled in a plastic container of about 2 m ³ at about 95% of the capacity and left in an anaerobic state with air blocking, anaerobic decomposition progresses and completely dissolves naturally in about 3 days. It is confirmed that it will change. Therefore, the number of days to be left in the anaerobic state depends on the capacity and filling amount of the plastic container, but it is usually 2 to 5 days, preferably about 3 days.

When the amount of jellyfish to be processed is large, the volume of the closed tank 17 may be increased or a plurality of jellyfish may be arranged so that the jellyfish can be continuously processed while changing the container to be filled according to the elapsed days. Is desirable. Next, after confirming that the jellyfish were naturally dissolved and liquefied by such anaerobic decomposition, the liquefied material 18 was sucked up into a vacuum chamber car 19 or the like and separated from the residual solid matter 20, and then transferred to a liquefied material treatment facility. At this point, the liquefied product is deodorized to render it harmless. In particular, liquefied anaerobically decomposed jellyfish mainly contains sulfur compounds such as hydrogen sulfide and methyl mercaptan as malodorous substances, which need to be deodorized with a deodorant agent.

As the deodorizing equipment for liquefying jellyfish liquefaction of the present invention, a method in which the liquefying agent is put into a storage tank 21 of about 50 m ^{3 and} a deodorant agent 22 is added to the liquefying agent to circulate it by a pump 23 Since the effect and the COD reduction effect can be obtained, it is advantageous because it is simple and the equipment cost is low.
Further, as the deodorizing agent 22, sodium hypochlorite having an oxidizing action is most preferable in that it has an excellent deodorizing effect and is inexpensive, but as a commercially available product, for example, a deodorizing agent mainly containing nitrate is Stenchi Cut NX-500, Clearizer N-350 (made by Kurita Kogyo), and Thai slime DC (made by Taiho Kogyo) which is a deodorant mainly containing chlorine dioxide.
Etc. can be used. In addition, the deodorant having such an oxidizing action has almost no solubility of jellyfish, and in particular, when the liquefied jellyfish is re-introduced after adding the deodorant,
It is not desirable to re-introduce the jellyfish into the storage tank 22 because the jellyfish will not liquefy.

In the present invention, the storage tank 22 described above is used.
Pump 23 by adding liquefied substance 18 and deodorant agent 22
After confirming the deodorizing effect and the COD reducing effect up to a certain degree, the liquefied material that has been deodorized while being circulated by
By treating the activated sludge facility 24, which is a normal existing facility, the COD concentration can be discharged at a maximum concentration of 10 ppm and an average of 7 ppm. In this case, it is desirable that the liquefied material is continuously charged into the storage tank 22 and continuously withdrawn while monitoring deodorization and COD reduction. Reference numeral 25 is a drainage pit in the premises which is used as necessary. In the present invention, the volume-reduced residual solid matter 20 after separating the liquefied material from the closed tank 17 is landfilled and incinerated as general solid waste as in the conventional case, but the treatment amount is small. Yes Processing frequency is also significantly reduced.

[0013]

[Function] Just by transferring the jellyfish separated from the seawater intake line to a tank and storing them in an air-tight closed state, the jellyfish will spontaneously dissolve and liquefy due to anaerobic decomposition. It is possible to easily carry out the optimum waste treatment work according to each form by separating it into the solidified residual solid matter. That is, the liquefaction can be processed at a very low cost by simply circulating the liquid deodorant together with the deodorant in the storage tank with a pump through a piping line, and the COD concentration of the existing equipment such as activated sludge equipment can be kept below a specified value. It can be discharged in the state. Further, since the volume of solid waste is greatly reduced, it is possible to obtain operational effects such as a significant reduction in the treatment frequency.

[0014]

EXAMPLES Examples of the present invention will be described below. Example 1 Jellyfish that had been landed and separated from a seawater intake line on a draining net conveyor were filled in a 2 m ³ poly tank at a filling rate of about 95%, and stored for 3 days in a completely air-sealed state. It was confirmed that it was liquefied. This liquefied stock solution contains approximately 100 H ₂ S.
A bad odor was generated at 0 ppm, and the treatment was impossible even with the comprehensive wastewater dilution treatment. The liquefied product was transferred to a laboratory test tank, various deodorant chemicals were added, and the mixture was stirred. As a result, the most excellent ones to the least inferior ones are shown in Table 1 in the order of ⊚ to ×.

[0015]

[Table 1] Deodorant: Stenchicut NX-500 (nitrate-based deodorant: Kurita Kogyo) Deodorant: NX-500 + Clearase N350 (nitrate-based deodorant: Kurita Kogyo) Deodorant: Thai slime DC (dioxide) Chlorine deodorant cleaner:
Deodorant: Sodium hypochlorite treatment cost: Approximate multiple when deodorant treatment cost is 1.

From the results shown in Table 1, it was confirmed that the order of deodorant effect of the deodorant drug addition amount was 1%, and 0.2% was sufficient. The solubility of jellyfish as a deodorant drug is ≧ >>, and it does not liquefy when undissolved jellyfish is added. From the above, it is clear that sodium hypochlorite is the most excellent in terms of cost, although the deodorizing effects of all deodorizing agents are recognized.

Example 2 From a plurality of 2 m ³ plastic tanks used in Example 1,
20 m ^{3 of} each liquefied product was taken out, put into a circulation tank of 50 m ³ , and added with 1% of sodium hypochlorite as a deodorant, and circulated by a pump. It was confirmed that the initial COD concentration of the liquefied product was lowered from 270 ppm to 147 ppm by the circulation treatment for 15 minutes after the addition of sodium hypochlorite. In addition, the odor is reduced by the oxidation effect of gas-liquid contact due to the circulation treatment,
It was confirmed that there was no odor after about 48 hours. Also C
The OD concentration also decreased gradually, but C depending on the elapsed time
The change in OD concentration is shown in FIG. From the COD reduction situation and the odor confirmation result in Fig. 4, the tank circulation process took about 40 hours in about 72 hours.
It was found to be in equilibrium at ppm. Then COD
The liquefied substance with a concentration of 40 ppm is treated with activated sludge equipment, which is an existing integrated wastewater treatment device, and CO
The D concentration could be discharged within the range of MAX 10 ppm and average 7 ppm.

[0018]

As is clear from the above results, according to the present invention, the jellyfish separated from the seawater intake line are transferred to a tank and stored in an air-tight closed state, and the jellyfish are naturally dissolved by anaerobic decomposition to form a liquid. The volume of residual solid waste is greatly reduced because it is made into a waste. In addition, liquefaction can be processed at a very low cost by simply circulating the liquefied chemicals together with the deodorant in the storage tank with a pump through a pipe, and the COD concentration can be kept below the specified value by processing with activated sludge equipment which is an existing equipment. It exhibits excellent effects such as being able to be discharged by the treatment.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a seawater intake line.

FIG. 2 is a schematic perspective view showing a trash pit structure.

FIG. 3 is a schematic overall flow chart showing a jellyfish processing situation.

FIG. 4 shows a change in COD concentration according to a circulation treatment time in Example 2.

[Explanation of symbols]

1 Seawater intake line 3 Inflow line to the intake pit 4 rake bar screen 5 Rotary screen 7 circulating water pump 8 Screen cleaning pump 13 Draining net conveyor 14 Solid waste 17 closed tank 18 Liquid 20 Residual solid 21 Storage tank 22 Deodorant drug 23 Circulation pump 24 Activated sludge equipment 25 on-site drainage pit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshikatsu Kijima             6-4-1 Umei, Takasago, Hyogo Electric Power Development Co., Ltd.             Ceremony company Takasago Thermal Power Station (72) Inventor Tadakazu Hashikawa             6-4-1 Umei, Takasago, Hyogo Electric Power Development Co., Ltd.             Ceremony company Takasago Thermal Power Station (72) Inventor Takashi Sakamoto             3-4 Akasaki, Ishikawa-shi, Okinawa power supply opening             From Ishikawa Thermal Power Station Co., Ltd. F-term (reference) 4D004 AA02 CA17 CA48 CB04 CC11

Claims (4)

[Claims] 1. A method for treating mixed jellyfish that flows in when seawater is taken as industrial cooling water, wherein solids such as jellyfish and seafood are landed and separated from a seawater intake line using a draining net conveyor or the like. The separated jellyfish are transferred to a tank and stored for several days in an air-tight sealed state, and after confirming that the jellyfish spontaneously dissolved and liquefied by anaerobic decomposition, the liquefaction is separated and the liquefaction is removed. A method for treating jellyfish mixed in a seawater intake line, characterized by deodorizing with an odor chemical. 2. The liquefied product deodorized with a deodorant chemical is subjected to a detoxifying process for reducing COD in an activated sludge facility or the like, and
The method for treating jellyfish mixed in a seawater intake line according to claim 1, wherein the volume-reduced residual solid matter after separating the liquefied material from the tank is treated as general solid waste. 3. The treatment of jellyfish mixed in the seawater intake line according to claim 1 or 2, wherein the deodorizing treatment of the liquefied material is to add a deodorant agent to the liquefied material in a tank and circulate the liquefied material with a pump. Method. 4. The method for treating jellyfish mixed in a seawater intake line according to claim 1, wherein sodium hypochlorite is used as a deodorant.