WO2021235056A1 - 水槽内における硫化水素発生抑制方法 - Google Patents
水槽内における硫化水素発生抑制方法 Download PDFInfo
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- WO2021235056A1 WO2021235056A1 PCT/JP2021/010020 JP2021010020W WO2021235056A1 WO 2021235056 A1 WO2021235056 A1 WO 2021235056A1 JP 2021010020 W JP2021010020 W JP 2021010020W WO 2021235056 A1 WO2021235056 A1 WO 2021235056A1
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- water
- water tank
- hydrogen sulfide
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- reducing substance
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
- D21F1/66—Pulp catching, de-watering, or recovering; Re-use of pulp-water
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/50—Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
- C02F1/74—Treatment of water, waste water, or sewage by oxidation with air
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
- C02F1/76—Treatment of water, waste water, or sewage by oxidation with halogens or compounds of halogens
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21D—TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
- D21D5/00—Purification of the pulp suspension by mechanical means; Apparatus therefor
- D21D5/28—Tanks for storing or agitating pulp
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/101—Sulfur compounds
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/26—Nature of the water, waste water, sewage or sludge to be treated from the processing of plants or parts thereof
- C02F2103/28—Nature of the water, waste water, sewage or sludge to be treated from the processing of plants or parts thereof from the paper or cellulose industry
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/04—Oxidation reduction potential [ORP]
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/10—Solids, e.g. total solids [TS], total suspended solids [TSS] or volatile solids [VS]
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/26—H2S
- C02F2209/265—H2S in the gas phase
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2303/00—Specific treatment goals
- C02F2303/02—Odour removal or prevention of malodour
Definitions
- the present invention relates to a method for suppressing hydrogen sulfide generation in a water tank arranged in the water system of a papermaking facility.
- Papermaking is performed by papermaking a raw material slurry in which pulp raw materials are dispersed in water quality.
- pulp is generally prepared and papermaking is performed.
- a wire part process of dehydrating from the paper material by filtration action using a wire (net) and a press part process of further dehydrating by pressurization to increase the density and the strength of wet paper are performed.
- Water from a water tank (water tank) is sprinkled on the wire part and the press part in order to wash the felt from the wire.
- the water dehydrated from the pulp in the wire part and the press part and the water after sprinkling are stored in a white water silo (reservoir tank) as white water.
- Part of the white water stored in the white water silo is supplied to the pump, and the rest is supplied to the seal pit. From the viewpoint of effective utilization and reuse of water resources, this white water is used as diluted water for raw materials by circulating the water system in the papermaking process again.
- the raw materials for manufactured paper are mainly recycled cardboard and magazines. Since cardboard and magazines contain a large amount of starch, which is a nutrient source for microorganisms, they are also a nutrient source for microorganisms in the paperboard manufacturing process. In addition, corrugated cardboard and magazines, which are raw materials, are prone to the growth of microorganisms when stored in an environment exposed to rain and wind.
- additives such as starch as additives in white water
- such additives serve as a nutrient source
- the environment is such that anaerobic microorganisms can easily grow.
- Microorganisms multiply on the surface of the device and secrete sticky metabolites, forming a biofilm called slime containing pulp and filler.
- Neutral papermaking has an environment in which slime is likely to be produced, especially due to the activation of microorganisms. Then, in such an environment, hydrogen sulfide is likely to be generated by the propagation of anaerobic microorganisms.
- Hydrogen sulfide is a toxic gas that has a pungent odor (rotten egg odor) and irritates the eyes, skin, and mucous membranes. Therefore, if hydrogen sulfide is generated in the factory, there is a risk of fatal accident of the worker.
- factories that manufacture paperboard often exist in urban areas in order to reduce the distribution costs of raw materials and products, so if harmful gas such as hydrogen sulfide is generated, it will cause odor problems for the residents around the factory. Therefore, it is necessary to take some measures.
- a masking agent or the like is used to deodorize as a symptomatic treatment, or the worker is from a distant place (remote place), for example, every hour at the factory. It is conceivable to go to the factory to check the effect of the treatment agent, or to introduce a detection dog and add the treatment agent as needed.
- none of these methods suppress the generation of hydrogen sulfide in the factory itself, so it is not a drastic measure, and in addition, the slime generated is added to the white water in the aquarium.
- the amount of treatment agent (slime control agent) used cannot be optimized.
- a method in which a worker confirms the situation and records it in a daily report in order to confirm the amount of the treatment agent added, the remaining amount of the treatment agent, and the presence or absence of the effect of the treatment agent addition.
- a worker for example, a worker in a three-shift system
- confirms the situation and records it in a daily report in order to confirm the amount of the treatment agent added, the remaining amount of the treatment agent, and the presence or absence of the effect of the treatment agent addition.
- a method has a problem of increasing man-hours, such as the need to correctly communicate the situation between workers.
- Patent Document 1 it is known by sterilizing or suppressing the growth of microorganisms such as sulfate-reducing bacteria that grow in the wastewater treatment tank, especially at the bottom (sediment layer) of the wastewater treatment tank where the slurry stays.
- the suppression of the generation of hydrogen sulfide produced by these microorganisms is disclosed by adding the agent (treatment agent) of the above.
- Patent Document 1 is an experiment in which a certain amount (1 kg / day) of a known drug (treatment agent) is added and the amount of hydrogen sulfide generated is suppressed after 2 days and 5 days. Only the results are disclosed, and the appropriate amount of treatment agent is not added according to the fluctuation of the concentration of hydrogen sulfide generated, but simply to prevent the amount of hydrogen sulfide generated from exceeding the standard value. It is considered that a certain amount of treatment agent is added in a certain amount more than the required amount.
- the signs of hydrogen sulfide generation can be known in advance in the water system of the papermaking facility, especially in the water tank arranged in the water system, an appropriate amount of the treatment agent can be used without adding an excessive amount of the treatment agent. Since it can be added, it is preferable in that the generation of hydrogen sulfide itself can be suppressed and the amount of the treatment agent added for treating the water (white water) in the water tank can be saved.
- the present invention can indirectly know in advance the signs of hydrogen sulfide generation in the water tank arranged in the water system of the paper making facility, and an appropriate amount of the treatment agent for treating the water (white water) in the water tank.
- a method for suppressing hydrogen sulfide generation which can effectively suppress the generation of hydrogen sulfide by adding hydrogen sulfide.
- the present inventor has a reducing substance (for example, sulfite ion (SO 3)) contained in the water (white water) in the water tank, which is a source of hydrogen sulfide generation. It was found that hydrogen sulfide began to be generated as the concentration of 2-)) began to increase.
- SO 3 sulfite ion
- the present inventors is contained in the water in the water tank periodically measures the concentration of the reducing substance comprising a source of hydrogen sulfide (e.g., sulfite ion (SO 3 2-)), the reducing substance
- a predetermined treatment such that the concentration of the reducing substance in the water in the water tank becomes the standard value or less, preferably aeration with an oxygen-containing gas, and a treatment agent (slime control agent)
- a method for suppressing the generation of hydrogen sulfide in a water tank which comprises performing a predetermined treatment so that the concentration of the reducing substance in the water in the water tank becomes equal to or less than the reference value.
- the activity of the microorganism is comprehensively evaluated by the water quality analysis value when the water quality analysis of the water in the water tank is performed and the measured value of the concentration of the reducing substance, and the microorganism is evaluated.
- the concentration of hydrogen sulfide in the atmosphere when continuously measured with a hydrogen sulfide concentration meter installed in the upper part of the water tank is in the range of 3 ppm or less, whichever is one of (1) to (7) above.
- the present invention knowing the sign of the evolution of hydrogen sulfide in the water tank which is placed in an aqueous papermaking equipment, indirectly advance by the density variations of the reducing substances (e.g. sulphite ions (SO 3 2-)) As a result, the generation of hydrogen sulfide can be effectively suppressed as a result of being able to stably add an appropriate amount of treatment agent to the water in the water tank. It is possible to shorten the air replacement time that is performed before going inside and performing maintenance, and it is possible to significantly improve safety and work efficiency. In addition, since the spoilage of water (white water) in the water tank can be effectively suppressed, the number of defects in the product (paperboard) can be reduced, and the period from the start of operation to the shutdown (stop of operation) can be extended.
- the reducing substances e.g. sulphite ions (SO 3 2-)
- the concentration of the reducing substance that is the source of hydrogen sulfide is periodically measured in the water in the water tank arranged in the water system of the paper making facility, and the concentration of the reducing substance exceeds the reference value.
- it is a method for suppressing the generation of hydrogen sulfide in the water tank, which comprises performing a predetermined treatment so that the concentration of the reducing substance in the water in the water tank becomes equal to or less than the reference value.
- FIG. 1 shows one aspect of the schematic configuration of the papermaking equipment used in the method for suppressing the generation of hydrogen sulfide in the water tank according to the present invention.
- the raw material pulp slurry produced by the raw material manufacturing apparatus 1 is charged into the machine tank 2.
- the machine tank 2 is a tank for storing the raw material pulp slurry, and the raw material pulp slurry is sent to the inlet 5 via the screen 4 by the fan pump 27 and the fan pump 3.
- the raw pulp slurry sent to the inlet 5 is supplied to the wire part 6 and dehydrated.
- the dehydrated wet sheet 7 is sent from the press part 8 to the dryer part 9.
- the white water 10 separated by the wire part 6 is stored in the white water silo 11. A part of the white water stored in the white water silo 11 is sent to the inlet 5 together with the raw material, and is also sent to the surplus white water tank 13 via the fan pump 23.
- the white water sent to the surplus white water tank 13 is sent to the solid-liquid separation device 15 via the fan pump 25, and the solid content is discharged or recovered in the raw material system (16).
- the filtrate generated by the solid-liquid separation device 15 is mixed with the pulp slurry discharged from the raw material manufacturing device 1 or the machine tank 2 via the fan pump 26 and introduced into the white water circulation system.
- the water system 19 to be introduced into the white water circulation system is stored in the treated water tank 20 and then introduced into the surplus white water tank 13 via the fan pump 24.
- the "water tank” in the present invention means at least one of a plurality of water tanks arranged in the water system of the paper making equipment.
- a white water silo 11 At least one of the surplus white water tank 13, the filtrate tank 17, and the treatment water tank 20 corresponds to this.
- white water refers to an aqueous solution discharged in a large amount from a paper machine or the like in the papermaking process at the time of papermaking.
- White water contains fine fibers derived from raw material pulp normally used for papermaking, other paper-making chemicals, and the like.
- the “white water circulation system” refers to white water that is circulated and used in the papermaking process.
- the “water system to be introduced into the white water circulation system” refers to a water system used for adjusting the concentration of pulp slurry or white water in the white water circulation system.
- the water system is not particularly limited, and examples thereof include soft water and hard water for papermaking, and a small amount of a papermaking agent may be contained within a range that does not impair the effects of the present invention.
- the concentration of the reducing substance that is the source of hydrogen sulfide is periodically measured in the water in the water tank arranged in the water system of the paper making facility, and the concentration of the reducing substance exceeds the reference value.
- an appropriate amount of treatment agent for example, slime control agent
- SC agent can be stably added, and as a result, the generation of hydrogen sulfide can be effectively suppressed.
- the anaerobic microorganisms 34 is activated, as shown enlarged in FIG. 2, the anaerobic microorganisms 34 activated, in water, for example reducing substance 32 such as sulfite ion (SO 3 2-) is generated Will be done.
- the present inventors is contained in water (white water) 29 which is present in the water tank 28, focusing on the variation of the concentration of the reducing substance to be a source of hydrogen sulfide, for example, sulfite ions (SO 3 2-) , if it exceeds the reference value with the concentration of the reducing substance, hydrogen sulfide from the water tank 28 (H 2 S) was found to be prone to occur.
- water (white water) 29 which is present in the water tank 28, focusing on the variation of the concentration of the reducing substance to be a source of hydrogen sulfide, for example, sulfite ions (SO 3 2-) , if it exceeds the reference value with the concentration of the reducing substance, hydrogen sulfide from the water tank 28 (H 2 S) was found to be prone to occur.
- the present inventors have, with water (white water) in 29 present in the water tank 28, reducing substance comprising a source of hydrogen sulfide, for example, the concentration of sulfite ion (SO 3 2-) periodically measured Predetermined treatment such that when the concentration of this reducing substance exceeds the standard value, the concentration of the reducing substance in the water (white water) in the water tank 28 becomes equal to or less than the standard value, preferably oxygen-containing gas. It has been found that the generation of hydrogen sulfide in the water tank 28 can be effectively suppressed by performing the treatment of performing at least one of the aeration and the addition of the slime control agent.
- reducing substance comprising a source of hydrogen sulfide, for example, the concentration of sulfite ion (SO 3 2-) periodically measured
- Predetermined treatment such that when the concentration of this reducing substance exceeds the standard value, the concentration of the reducing substance in the water (white water) in the water tank 28 becomes equal to or less than the standard value, preferably oxygen
- FIG. 3 is a diagram for explaining the state of deposits deposited in the water tank arranged in the water system of the conventional paper making equipment and the water flow F1
- FIG. 4 is a diagram of the paper making equipment used in the present embodiment. It is a figure for demonstrating each member constituting a water tank arranged in a water system, and a water flow F2.
- the broken line arrow shown in FIGS. 3 and 4 indicates the flow direction of water
- the alternate long and short dash arrow shown in FIG. 4 indicates the flow direction of the oxygen-containing gas ejected from the air diffuser.
- the solid line extending from the control device shown in FIG. 4 shows the flow of the communication system.
- water (white water) is supplied into the water tank 101 from the white water injection port 102 arranged at the upper part of the water tank 101, and the white water in the water tank 101 is supplied to the water tank 101.
- It has a so-called circulation type device configuration in which white water is discharged to another water tank or the like through a fan pump 105 arranged on the outside of the bottom side, and although a water flow F1 as shown in FIG. 3 is generated to some extent, an oxygen-containing gas. No aeration treatment is performed.
- the white water 103 existing in the water tank is often not sufficiently stirred, and therefore, as shown in FIG. 3, usually, a suspension containing a filler or the like is included. Muddy substances settle and accumulate at the bottom of the aquarium, especially if the aquarium is a large aquarium that stores a large amount of water, or if the aquarium has a corner at the bottom, the bottom of the aquarium, Sediments tend to accumulate especially in the corners of the bottom.
- a retention portion 104 When suspended solids are deposited in the tank to form a retention portion 104 in this way, the amount of sediment is gradually increased, oxygen is not supplied to the inside of the deposit, and a so-called anaerobic state is formed. Become.
- water white water
- the white water in the water tank 50 is supplied.
- It has a so-called circulation type device configuration in which white water is discharged to another water tank or the like through a fan pump 62 arranged on the outside of the bottom side of the water tank 50, and for example, an aerator (aeration pipe) 60 is provided in the water tank to provide oxygen. Since the aeration treatment with the contained gas is also performed, it becomes difficult to form the retention portion 104 as shown in FIG.
- aeration with the oxygen-containing gas by adjusting the amount of aeration so that the concentration of the reducing substance is equal to or less than the reference value.
- the redox potential can be shifted (changed) to the positive potential side, which makes it difficult to form an anaerobic state.
- the generation of hydrogen sulfide can be further suppressed.
- the "oxygen-containing gas” may be any gas containing oxygen, and is not particularly limited, and examples thereof include a single oxygen (O 2 ) gas, a mixed gas containing oxygen such as air, and the like. Among these, a mixed gas is preferable, and air is more preferable, from the viewpoint of availability.
- the mixed gas may contain nitrogen, carbon dioxide, or the like as a gas other than oxygen.
- the oxygen-containing gas one type may be used alone, or two or more types may be used in combination.
- the "a reducing substance comprising a source of hydrogen sulfide” specifically, sulfite ion (SO 3 2-), thiosulfate (S 2 O 3 2-), and the like.
- an aeration device such as an aerator (diffusing pipe) 60 is arranged at the bottom of the water tank so that bubbles 61 are generated in the water in the water tank. It is preferable to blow air into the air to aerate it.
- the aeration device it is particularly preferable to use the aerator 60 because the aeration can be performed stably and continuously, the aeration is inexpensive, and the cost burden is low.
- aeration devices when deposits due to water flow are likely to occur in the water tank, it is preferable to install aeration devices at a plurality of places in the water tank.
- the air bubble discharge port is directed upward from the bottom of the tank to discharge the bubble 61, which enhances the contact efficiency between oxygen and water (particularly the deposited suspended solids).
- the air diffuser is not particularly limited, and examples thereof include an exhaust port having a diameter of 1 mm or more and 5 mm or less. It should be noted that one or a plurality of air diffusers may be used. When a plurality of air diffusers are used, such exhaust ports are arranged at intervals of, for example, 5 cm or more and 50 cm or less.
- the position of the air diffuser is not particularly limited as long as it is a position where oxygen-containing gas is blown into the water existing in the tank, and it may be provided at at least one place inside and outside the tank.
- the position in the tank is not particularly limited, but at least one is preferably to discharge oxygen-containing gas upward from the bottom of the tank as described above.
- the horizontal air bubbles ejected from the air diffuser are blown toward the wall surface in the tank at a moving speed of about 180 cm / sec. ..
- This blown air coupled with the ascending action of the bubbles, collides with the opposite wall surface, producing a strong ascending and descending flow of about 30 cm / sec.
- This ascending flow reaches the water surface in the tank, changes from the horizontal flow, and agitates the water in the tank.
- the generated downward flow changes into a flow that strongly pushes the bottom surface of the water tank, whereby the inside of the water tank can be strongly agitated. Therefore, the water can continue to flow without deposits on the bottom of the aquarium.
- the air discharged from the aerator (air diffuser) 60 is blown upward into the water in the water tank at a moving speed of about 180 cm / sec. Is preferable.
- This blown air becomes a strong ascending current, and then changes to a strong horizontal current when it reaches the water surface.
- a strong downward flow of about 30 cm / sec is generated. This downward flow changes into a flow that strongly pushes the bottom surface of the water tank, whereby the inside of the water tank can be strongly agitated. Therefore, the water can continue to flow without deposits on the bottom of the aquarium.
- the amount of air blown by the air diffuser is not particularly limited, but for example, 0.5 m 3 / hour or more per unit bottom area (1 m 2 ) of the tank per air diffuser, 10 m or more. It is preferably 3 / hour or less.
- the oxygen-containing gas may be blown continuously or intermittently.
- the time for blowing the oxygen-containing gas at one time is not particularly limited, but is 3 minutes or more and 30 days or less, preferably 4 minutes or more and 20 days or less.
- oxygen-containing gas is blown in for 3 minutes or more, oxygen can be sufficiently supplied to water (particularly the deposited suspended solids). Even if the oxygen-containing gas is blown in for more than 30 days, oxygen can be sufficiently supplied to the water, but the effect commensurate with the supply cannot be obtained.
- the time for stopping the blowing of the oxygen-containing gas is not particularly limited, but is 3 minutes or more and 30 days or less, preferably 4 minutes or more and 20 days or less.
- the amount of aeration by the air diffuser is not particularly limited, and is preferably 0.5 m 3 / hour or more and 10 m 3 / hour or less, more preferably 0.5 m 3 / hour or more and 8 m 3 / per unit bottom area 1 m 2 of the aeration tank. It's less than an hour.
- oxygen tends to be sufficiently supplied to the water system. If the amount of aeration exceeds the above upper limit, larger equipment may be required. If the amount of aeration is less than the above lower limit, the aeration may be insufficient.
- the concentration of the reducing substance e.g., sulfite ion (SO 3 2-)
- a predetermined reference value e.g., 5 mg / L
- aeration amount of diffusing pipe which can be preferably 0.1 m 3 It is 10 m 3 / hour or less, more preferably 0.5 m 3 / hour or more and 10 m 3 / hour or less, and further preferably 0.5 m 3 / hour or more and 5 m 3 / hour or less.
- the aeration time of the oxygen-containing gas is also not particularly limited, and is usually 3 minutes or more and 30 days or less, preferably 4 minutes or more and 20 days or less.
- oxygen tends to be sufficiently supplied to the water system.
- the aeration time exceeds the above upper limit, the manufacturing cost may increase. If the amount of aeration is less than the above lower limit, the aeration may be insufficient. Further, the aeration may be continuous and may be divided into several times.
- an aeration tank having an aeration tube at the bottom of the aeration in the above aeration step is used, and the amount of aeration by the aeration tube is 0.5 m 3 / hour or more per 1 m 2 of the unit bottom area of the aeration tank 10 m 3 It is less than / hour.
- the predetermined treatment may be a treatment of adding a treatment agent (slime control agent), and the addition amount may be adjusted so that the concentration of the reducing substance is equal to or less than the reference value. Is more preferable.
- a slime control agent By adding a slime control agent, the number of microorganisms (bacteria) in the white water existing in the water tank can be reduced, and as a result, the production of slime can be suppressed, thereby preventing water spoilage. , The generation of hydrogen sulfide in the water tank can be effectively suppressed.
- the slime control agent can also suppress the generation of slime by suppressing the decomposition of organic substances such as starch contained in white water.
- the slime control agent is not particularly limited, and examples thereof include organic antibacterial agents and inorganic antibacterial agents.
- the organic antibacterial agent is not particularly limited, and is, for example, methylenebisthiocyanate, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 4,5-dichloro.
- 2,2-dibromo-3-nitrilopropionamide and 2,2-dibromo-2-nitroethanol which can be expected to have a higher antibacterial effect, are preferable.
- the inorganic antibacterial agent is not particularly limited, and is, for example, hypochlorous acid such as sodium hypochlorite, potassium hypochlorite, calcium hypochlorite, barium hypochlorite, chlorine dioxide, chlorinated isocyanuric acid. , Combined chlorine type compounds and the like.
- sodium hypochlorite and bound chlorine type compounds having moderate oxidizing power and low reactivity with dissolved organic substances are preferable.
- the bound chlorine type compound is obtained by reacting a chlorine donor that releases free chlorine with any one of ammonia, an ammonium salt and an organic nitrogen compound under appropriate conditions.
- the chlorine donor is not particularly limited, but sodium hypochlorite is preferable.
- the ammonium salt is not particularly limited, but ammonium halide such as ammonium chloride and ammonium bromide, ammonium sulfate, ammonium nitrate and the like are preferable, and the organic amine is preferably sulfamic acid, urea and the like.
- the bound chlorine type compound can be produced according to a known method, but it is also commercially available under the product name "Fajiside” (manufactured by Kurita Water Industries, Ltd.).
- “Faziside” is a 1: 1 reaction (molar ratio) of ammonium bromide and sodium hypochlorite.
- the slime control agent may be used alone or in combination of two or more. Further, the slime control agent may be added at one time, or may be divided into a plurality of times.
- the method of adding the slime control agent to the aqueous system is not particularly limited, and the slime control agent may be added as it is, or the slime control agent may be dissolved or dispersed in a solvent and used as a solution.
- the solvent is not particularly limited, and examples thereof include water, an organic solvent, and a mixed solvent thereof.
- the amount of the slime control agent added to the aqueous system is not particularly limited, and is usually 0.1 mg / L or more and 1000 mg / L or less, preferably 1 mg / L or more and 100 mg / L or less in terms of solid content.
- concentration is within the above range, the generation of slime tends to be sufficiently suppressed. If the concentration exceeds the above upper limit, the manufacturing cost may increase. If the concentration is less than the above lower limit, the generation of slime may not be suppressed.
- the concentration of the reducing substance e.g., sulfite ion (SO 3 2-)
- the amount of the predetermined reference value e.g., 5 mg / L
- slime control agent which may be a less preferably 0.1mg / L or more and 100 mg / L or less, more preferably 0.1 mg / L or more and 50 mg / L or less, still more preferably 1 mg / L or more and 10 mg / L or less.
- the predetermined treatment is performed in combination with aeration with an oxygen-containing gas and addition of a slime control agent (SC agent).
- SC agent slime control agent
- slime control agents are oxidizing agents, they react with sulfite ions derived from reducing substances such as hydrogen sulfide and mercaptan from microorganisms before they react with microorganisms, and have the desired antibacterial effect. Most of it will be consumed before it can be used. Then, a part of the slime control agent added for the slime treatment is consumed in the reaction with the produced reducing substance, and as a result, the amount of the slime control agent is larger than the amount required for the slime treatment. It may be necessary to add an amount.
- the sulfurous acid ion can be oxidized to the sulfate ion or the like by the oxygen in the oxygen-containing gas. Further, when a large amount of oxygen-containing gas is dissolved in the white water in the water tank, the partial pressure of the reducing substance such as hydrogen sulfide is lowered, and the solubility of the reducing substance can be lowered.
- a sulfite ion measuring device 56 for measuring the concentration of the reducing substance is a sulfite ion as a source of hydrogen sulfide (SO 3 2-) in water in the water tank, the water tank It is installed in the position of the water tank to be immersed in water (white water) the inner to measure the concentration of water (white water) solution of sulfite ions (SO 3 2-) in the water tank periodically (e.g. every hour), measured the concentration of the sulfite ion (SO 3 2-) is transmitted through the communication means, etc. to the controller 51.
- SO 3 2- hydrogen sulfide
- the control device 51 the numerical value of the concentration of the transmitted sulfite ion (SO 3 2-) is, if it exceeds the predetermined reference value, the concentration of the reducing substance in the water in the water tank becomes equal to or less than the reference value
- an instruction may be given to the chemical injection pump 53 to supply an appropriate amount of the treatment agent (slime control agent) into the water tank.
- the worker can be remotely controlled at a place away from the water tank, so that the number of times the worker goes to the water tank can be reduced.
- the calibration of the method of determining the reference value of the concentration of reducing substances e.g. sulphite ions (SO 3 2-)
- a sulfite ion concentration in the water in advance in the water tank the concentration of hydrogen sulfide released from the water tank A line may be created and the reference value concentration of sulfite ion may be determined from this calibration curve. Therefore, the amount of the slime control agent added and the amount of aeration of the oxygen-containing gas can be determined based on the reference value of the concentration of the reducing substance in the water in the water tank.
- the sulfite ion concentration is preferably adjusted to 5.0 mgSO 3 2 / L or less, more preferably 2.0 mgSO 3 2 / L or less.
- the sulfite ion concentration in the white water is sufficiently reduced, so that the generation of hydrogen sulfide from the water tank can be suppressed to 3 ppm or less.
- the activity of the microorganism is comprehensively evaluated by the water quality analysis value when the water quality analysis of the water in the water tank is performed and the measured value of the concentration of the reducing substance, and the activity of the microorganism is evaluated. It is preferable that the treatment is performed based on the evaluation result of.
- the parameters related to the water quality analysis values in the white water storage tank for evaluating the activity of microorganisms are not particularly limited, and may be appropriately selected depending on the circumstances of the water system in which the method of the present invention is carried out.
- Parameters related to water quality analysis values include redox potential, glucose amount, organic acid amount, pH, calcium ion amount, electrical conductivity, turbidity, cation requirement, temperature, foaming degree, and COD (chemical oxygen demand). ), BOD (Biochemical Oxygen Demand), DO (Dissolved Oxygen Demand), Staple Amount, Residual Chlorine Amount, and Respiratory Rate.
- the parameters related to this water quality analysis value are measured by continuous measurement.
- the redox potential is a parameter that reflects the anaerobic or aerobic state in the water system, and the lower it is, the easier it is for slime to be formed.
- the lower the measured value of the redox potential the higher the treatment level for sterilization (eg, addition of an oxidative fungicide) or bacteriostatic (eg, cooling to water), and the higher the measured value, the higher the treatment level for sterilization or bacteriostatic. To reduce.
- the method for measuring the redox potential is not particularly limited, and examples thereof include a potentiometric method and a potentiometric titration method.
- At least one redox potential meter may be placed in the white water storage tank water to measure the redox potential of the water in the tank.
- the number of redox potential meters is not particularly limited, and the larger the number, the more accurate the measurement can be.
- the number of redox potential meters in the height direction of the tank may be, for example, 1000 or less, 500 or less, 100 or less, 50 or less, 20 or less, and 10 or less.
- the redox potential of the water tank 50 may be detected continuously or intermittently by the redox potential meter 58. Further, the obtained electrical signals and data may be continuously or intermittently transmitted to a control device 51, a computer, a data logger, a sequencer, or the like by wire or wirelessly to record their changes over time. ..
- the redox potential is usually adjusted to ⁇ 150 mV or higher, preferably ⁇ 100 mV or higher and 500 mV or lower.
- the activity of microorganisms in the storage tank can be predicted from the transition of the redox potential.
- the redox potential tends to decrease, but if the redox potential is within the above range, the amount of oxygen in the white water circulation system becomes sufficient and slime is generated. It tends to be effectively suppressed. If the redox potential exceeds the above upper limit, the amount of oxygen in the white water circulation system may become excessive more than necessary. If the redox potential is less than the above lower limit, the generation of slime may not be suppressed.
- An ultrasonic sensor is used to measure the amount of sediment. Ultrasonic waves are gradually attenuated in the middle of their transmission, but if there is a boundary where the physical properties (acoustic impedance) change in the middle of the propagation path, a part of the ultrasonic wave is reflected at that boundary and propagates in the opposite direction. Utilizing this phenomenon, an ultrasonic sensor is placed on or near the water surface to irradiate ultrasonic waves from the water surface toward the bottom of the tank, and the reflected wave is detected by the ultrasonic sensor.
- This detection result may be at least one-dimensionally obtained in the height direction of the tank or two-dimensionally obtained as an image analysis result.
- the results obtained by using the ultrasonic sensor in this way reflect the actual deposits in the tank with high accuracy, and the presence of suspended solids is highly accurate compared to other methods (the existence state of suspended solids ().
- the deposition state can be detected.
- the two-dimensional image analysis result can detect the presence state (particularly, the deposition state) of the suspended solid with higher accuracy.
- the number of ultrasonic sensors is not particularly limited, and any number of 1 or more may be provided, but measurement is possible if at least one is provided.
- the method for detecting the change over time in the presence of suspended solids is not particularly limited, and for example, a thermometer, a turbidity meter, an MLSS meter (Mixed Liquor Suspended Solids), an ultrasonic sensor, and a linear shape are used.
- a method using at least one of the pipes of the above can be mentioned.
- a method using at least one of a thermometer, a turbidity meter and an ultrasonic sensor is preferable, and a method using at least one turbidity meter is more preferable.
- the turbidity meter 57 when the turbidity meter 57 is used, when suspended solids are deposited on the bottom of the tank, the turbidity increases at that location and no suspended solids are deposited above that location. The turbidity is higher than the location. Therefore, the height of the tank or the height of water (liquid height) (or half the height, a fraction of the height) is divided into multiple equal parts (for example, two or more), and each part is divided into equal parts.
- the turbidity meter 57 is arranged at (height) so as to be in a straight line in the height direction.
- all of the plurality of turbidity meters arranged in the height direction are arranged so as to face the same direction in the horizontal direction (the plane direction perpendicular to the height direction of the tank). Then, all of the turbidity meters arranged in the height direction are measured at the same time. This makes it possible to detect the presence of suspended solids at least in places where the turbidity is significantly higher than above (for example, 30% higher than the value of the turbidity meter immediately above).
- the number of the turbidity meters 57 is not particularly limited as long as two are provided in the height direction of the layer, but it is preferable to provide three or more in the height direction of the tank, for example, because the larger the number, the more accurate the measurement can be performed. It is more preferable to provide 4 or more, and it is further preferable to provide 5 or more.
- the number of turbidity meters in the height direction of the tank may be, for example, 1000 or less, 500 or less, 100 or less, 50 or less, 20 or less, and 10 or less.
- these detections may be performed continuously or intermittently. Further, the obtained electrical signals and data may be continuously or intermittently transmitted to a control device 51, a computer, a data logger, a sequencer, or the like by wire or wirelessly to record their changes over time. ..
- the hydrogen sulfide generated in the air layer measures the hydrogen sulfide concentration by the hydrogen sulfide measuring device 54.
- the location where the hydrogen sulfide measuring device 54 is installed is not particularly limited, but in order to be able to quickly respond to the generation of hydrogen sulfide due to the propagation of sulfate-reducing bacteria, the vicinity of the location where sulfate-reducing bacteria are likely to propagate. Alternatively, it is preferably installed in the upper part of the water tank where deposits are likely to occur.
- the hydrogen sulfide concentration is measured using a hydrogen sulfide measuring device.
- a hydrogen sulfide concentration meter (GHS-8AT) manufactured by Gastec Co., Ltd. is used.
- the measurement principle of this device uses a constant potential electrolysis method. This measuring instrument is installed at the top of the water tank to continuously measure the hydrogen sulfide concentration.
- the concentration at which the pungent odor of hydrogen sulfide in the atmosphere is not detected when continuously measured by the hydrogen sulfide measuring device generated in the water tank is 3 ppm or less, more preferably 1 ppm or less.
- the spoilage of water (white water) in the water tank can be effectively suppressed, the number of defects in the product (paperboard) can be reduced, and the period from the start of operation to the shutdown (stop of operation) can be extended.
- the deterioration of the water quality in the white water tank is eliminated, and as a result, the retention rate of the functional paper chemicals such as the paper strength agent and the coagulant on the pulp fiber is improved, and as a result, the COD in the waste water is discharged. It also has a secondary effect of reducing the load of wastewater treatment.
- the sulfite ion measuring device was measured using K-9602 Trimetric Slfite manufactured by Chemetics, and the redox potential meter was measured using TRX-98 manufactured by Toko Chemicals.
- the hydrogen sulfide measuring device was measured using GHS-8AT manufactured by Gastec.
- FIG. 5 is a graph comparing the change over time in the generation of sulfite ion and the change over time when the present invention is carried out by adding a certain amount of the conventional slime control agent (SC agent) without controlling the addition. .. Control of the slime control agent (SC agent) was observed after the 15th day after the restart at the time of shutdown (operation stop). Here, when a fixed amount of slime control agent (SC agent) was added on the 14th day (conventional method) from the start of operation, the increase in sulfite ion was remarkable after 9th day from the start of operation. It has been seen. From this, it is inferred that dirt and deposits are accumulated in the bottom tank in the water tank, and the microorganisms are activated to produce reducing substances.
- SC agent conventional slime control agent
- the sulfite ion concentration could be suppressed to 3 mg / L on the 30th day of the final day, and the total amount of the slime control agent added in 16 days was higher than that of the conventional method. It was 20% less.
- FIG. 6 is a graph showing the transition of the decrease in the reducing substance and the increase in the redox potential when the oxygen-containing gas is aerated by the conventional method.
- the measurement was performed while controlling the aeration amount of the slime control agent (SC agent) and the oxygen-containing gas. It was confirmed that the positive potential was 0 mv or more during most of the operation period, and the potential was shifted (changed) to the positive potential side. In addition, during this operation period, the concentration of the reducing substance (sulfite ion) was suppressed to 1 mg / L or less.
- Table 1 shows the results of measuring the concentration of hydrogen sulfide generated from the water tank when the operation is stopped after the operation for the same operation period (1 month) is performed by the conventional method and the method of the example. Shown in.
- the air exchangeable time from draining the water in the water tank to entering the water tank after the operation was stopped and the number of defects in the manufactured paper products were also evaluated by the conventional method and the method of the example. It is also shown in Table 1.
- the number of defects in the paper product is indicated by an index ratio when the number of defects in the paper product manufactured by the conventional method is 100, and the smaller the index ratio, the better the quality of the paper product.
- the hydrogen sulfide concentration generated from the water tank measured after the operation was stopped was 5 ppm, whereas in the method of the example, it was generated from the water tank measured after the operation was stopped. It can be seen that the hydrogen sulfide concentration is remarkably low at 1 ppm or less, and the generation of hydrogen sulfide is suppressed. Therefore, in the method of the embodiment, the air exchangeable time until entering the water tank at the time of maintenance is 3 hours, which is shortened to 1/2 of the air exchangeable time (6 hours) of the conventional method. Further, it can be seen that in the method of the embodiment, the number of defects in the paper product is as small as 80 as compared with 100 of the conventional method.
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Abstract
Description
すなわち、本発明の要旨構成は以下のとおりである。
酸素含有ガスによる曝気処理は、このような水槽内に存在する水に対して、酸素含有ガスを吹き込むことによって、撹拌および曝気を行う処理である。図3は、従来の抄紙設備の水系に配置される水槽内に堆積する堆積物の状態と水の流れF1とを説明するための図であり、図4は、本実施形態に用いる抄紙設備の水系に配置される水槽を構成する各部材と水の流れF2とを説明するための図である。なお、図3および図4に示されている破線矢印は、水の流れ方向を示し、また図4に示されている一点鎖線の矢印は、散気管から噴き出した酸素含有ガスの流れ方向を示し、そして、図4に示されている制御装置から延びている実線は、通信系統の流れを示している。
また、前記所定の処理は、処理剤(スライムコントロール剤)の添加を行う処理であってもよく、また、還元性物質の濃度が前記基準値以下になるように添加量を調整して行うことがより好ましい。スライムコントロール剤を添加することで、水槽内に存在する白水中の微生物(細菌)の数を低減することができ、その結果、スライムの生成を抑制でき、これによって、水の腐敗を防げることから、水槽内における硫化水素の発生を有効に抑制することができる。また、スライムコントロール剤は、白水中に含まれる澱粉等の有機物の分解を抑制することで、スライムの発生を抑制することもできる。
また、前記所定の処理は、酸素含有ガスによる曝気と、スライムコントロール剤(SC剤)の添加とを併用して行うことがより好ましい。所定の処理が、曝気を行わずにスライムコントロール剤の添加だけの処理であった場合、水槽内の底部に堆積した堆積物が嫌気性状態を形成すると、嫌気性微生物が繁殖して、水中に亜硫酸イオン(SO3 2-)のような還元性物質の生成量が多くなる。スライムコントロール剤の多くは、酸化剤であるため、これらは、微生物と反応する前に、微生物からの硫化水素、メルカプタン等の還元性物質に由来する亜硫酸イオンと反応してしまい、所望の抗菌効果を発揮する前にその多くが消費されてしまう。そして、スライム処理のために添加したスライムコントロール剤の一部が、生成した還元性物質との反応に消耗されることになる結果、スライムコントロール剤を、スライムの処理に必要な量よりも多めの量を添加する必要が生じる場合がある。
水槽内における還元性物質の濃度の測定は、水槽内の水中の硫化水素の発生源となる還元性物質である亜硫酸イオン(SO3 2-)の濃度を測定する亜硫酸イオン測定装置56を、水槽内の水(白水)に浸漬する水槽の位置に設置して、水槽内における水(白水)中の亜硫酸イオン(SO3 2-)の濃度を定期的(例えば1時間毎)に測定し、測定した亜硫酸イオン(SO3 2-)の濃度が、制御装置51に通信手段等を通じて送信される。制御装置51は、送信された亜硫酸イオン(SO3 2-)の濃度の数値が、所定の基準値を超えている場合には、水槽内の水中の還元性物質の濃度が基準値以下になるように、薬注ポンプ53に指示を出して、適正量の処理剤(スライムコントロール剤)を水槽内に供給すればよい。これによって、作業者が水槽から離れた場所での遠隔操作も可能になるので、作業者が水槽まで行く回数も低減できる。
さらに、所定の処理は、前記水槽内の水の水質分析を行ったときの水質分析値と、前記還元性物質の濃度の測定値とによって微生物の活性を総合的に評価し、前記微生物の活性の評価結果に基づいて施されることが好ましい。
微生物の活性を評価するための白水貯槽内の水質分析値に係るパラメータは、特に限定されず、本発明の方法を実施する水系の事情に応じて適宜選択されてよい。水質分析値に係るパラメータとしては、酸化還元電位、グルコース量、有機酸量、pH、カルシウムイオン量、電気伝導率、濁度、カチオン要求量、温度、発泡の程度、COD(化学的酸素要求量)、BOD(生物化学的酸素要求量)、DO(溶存酸素量)、デンプン量、残留塩素量、及び呼吸速度からなる群により選ばれることが好ましい。特に、酸化還元電位、堆積物の量及び懸濁物質の量のうち、少なくとも1つを測定値とすることがより好ましい。この水質分析値に係るパラメータを連続測定により測定する。
酸化還元電位は、水系内の嫌気性又は好気性の状態を反映するパラメータであり、低い程スライムが形成されやすい。酸化還元電位の測定値が低い程、殺菌(例えば酸化性殺菌剤の添加)又は静菌(例えば、水への冷却)の処理レベルを増やし、測定値が高い程、殺菌又は静菌の処理レベルを減らす。
堆積物の量を測定するにあたっては、超音波センサーを用いる。超音波は伝わっていく途中で徐々に減衰するが、その伝搬経路の途中に物性(音響インピーダンス)が変わる境界があると、その境界で超音波の一部が反射して逆方向に伝わる。この現象を利用し、水面またはその近傍に超音波センサーを配置して超音波を水面から槽の底部の方向に照射し、反射した波を超音波センサーで検出する。懸濁物質が堆積した箇所は、通常の水とは物性が異なるので、懸濁物質が堆積した箇所と、懸濁物質が堆積していない箇所を区別することができる。この検出結果は、少なくとも、槽の高さ方向に1次元的に得られるものであっても、2次元的に画像解析結果として得られるものであってもよい。このように超音波センサーを用いて得た結果は、槽内の実際の堆積物を高い精度で反映させたものであり、他の方法と比較しても高い精度で懸濁物質の存在状態(特に、堆積状態)を検出することができる。特に、2次元的な画像解析結果は、より高い精度で懸濁物質の存在状態(特に、堆積状態)を検出することができる。
懸濁物質の存在状態の経時的変化を検出する方法としては、特に限定されず、例えば温度計、濁度計、MLSS計(Mixed Liquor Suspended Solids、活性汚泥浮遊物質)、超音波センサー、直線状のパイプの少なくとも1つを用いた方法が挙げられる。このうち、温度計、濁度計および超音波センサーの少なくとも1つを用いた方法が好ましく、濁度計を少なくとも用いた方法がより好ましい。
硫化水素の発生は、還元性物質(例えば亜硫酸イオン(SO3 2-))と上述した水質連続測定により、硫化水素が発生する兆候を事前に知ることができるため、臭気問題が顕在化する前に対策を講ずることができる。
抄紙設備内に設けられた高さ4m、直径4mの円筒型の余剰白水槽内の白水に対し、水層底部に間隔をおいて複数設置された直径2mmの口径を有する散気管を用いて、散気管1つあたり、槽の底面積について単位面積1m2あたり2m3/時間の空気により連続的に曝気した。まず、余剰白水槽の清掃を行い、堆積物を完全に除去した状態から稼働を開始した。開始から14日経過した時点で稼働を一旦停止し、1日間槽内の清掃をして堆積物を完全に除去した状態から再稼働(15日間)し、最初の開始から30日経過後に稼動を再び停止した。
系内洗浄を行った後、再稼働開始から16日間にわたり、水質分析による亜硫酸イオン濃度が2mg/Lを超えた時点でスライムコントロール剤(SC剤)の添加の制御を行うとともに、水槽内に曝気処理を施した以外は、試験例と同様に実施した。
従来では、操業開始から14日間、亜硫酸イオンの濃度変動に伴うスライムコントロール剤(SC剤)の添加の制御を行わずに、一定量(6kg/日)添加したこと以外は、実施例と同様に実施した。
2 マシンタンク
3 ファンポンプ
4 スクリーン
5 インレット
6 ワイヤーパート
7 湿潤シート
8 プレスパート
9 ドライヤーパート
10 白水
11 白水サイロ(または水槽)
12,14,18,21 処理剤(またはスライムコントロール剤(SC剤))
13 余剰白水槽(または水槽)
15 固液分離装置
16 固形分を排出又は原料系統に回収
17 ろ液槽(または水槽)
19 白水循環系に導入する水系
20 処理水槽(または水槽)
23,24,25,26,27 ファンポンプ
28 水槽
29 白水
30 滞留部(または堆積物)
32 還元性物質(または亜硫酸イオン)
34 嫌気性微生物
50 水槽
51 制御装置
52 ブロワー
53 薬注ポンプ
54 硫化水素測定装置
55 白水注入口
56 亜硫酸イオン測定装置
57 濁度計
58 酸化還元電位計
59 温度計
60 エアレーター(または散気管)
61 気泡
62,105 ファンポンプ
100 抄紙設備
101 水槽
102 白水注入口
103 白水
104 滞留部(または堆積物)
Claims (8)
- 抄紙設備の水系に配置される水槽内の水中にて、硫化水素の発生源となる還元性物質の濃度を定期的に測定し、前記還元性物質の濃度が基準値を超えた場合に、前記水槽内の水中の前記還元性物質の濃度が前記基準値以下になるような所定の処理を施すことを特徴とする水槽内における硫化水素の発生抑制方法。
- 前記所定の処理は、酸素含有ガスによる曝気、及びスライムコントロール剤の添加のうちの少なくとも一方を行う処理である、請求項1に記載の水槽内における硫化水素の発生抑制方法。
- 前記酸素含有ガスによる曝気は、前記還元性物質の濃度が前記基準値以下になるように曝気量を調整して行う、請求項2に記載の水槽内における硫化水素の発生抑制方法。
- 前記スライムコントロール剤の添加は、前記還元性物質の濃度が前記基準値以下になるように添加量を調整して行う、請求項2または3に記載の水槽内における硫化水素の発生抑制方法。
- 前記所定の処理は、前記水槽内の水の水質分析を行ったときの水質分析値と、前記還元性物質の濃度の測定値とによって微生物の活性を総合的に評価し、前記微生物の活性の評価結果に基づいて施される、請求項1~4のいずれか1項に記載の水槽内における硫化水素の発生抑制方法。
- 前記水質分析値は、前記水槽内の水中での、酸化還元電位、堆積物の量および懸濁物質の量のうちの少なくとも1つの測定値である、請求項5に記載の水槽内における硫化水素の発生抑制方法。
- 前記還元性物質が、亜硫酸イオンである、請求項1~6のいずれか1項に記載の水槽内における硫化水素の発生抑制方法。
- 前記水槽の上部に設置した硫化水素濃度計で連続測定したときの大気中の硫化水素の濃度は、3ppm以下の範囲である、請求項1~7のいずれか1項に記載の水槽内における硫化水素の発生抑制方法。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
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EP21807989.5A EP4130378A4 (en) | 2020-05-22 | 2021-03-12 | METHOD FOR SUPPRESSING HYDROGEN SULFIDE PRODUCTION IN WATER RESERVOIRS |
BR112022023695A BR112022023695A2 (pt) | 2020-05-22 | 2021-03-12 | Método para suprimir a geração de sulfeto de hidrogênio em tanques de água |
KR1020227040997A KR20230002991A (ko) | 2020-05-22 | 2021-03-12 | 수조 내에 있어서의 황화수소 발생억제방법 |
CN202180036704.2A CN115667624A (zh) | 2020-05-22 | 2021-03-12 | 抑制在水槽内产生硫化氢的方法 |
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JP2020089436A JP6939949B1 (ja) | 2020-05-22 | 2020-05-22 | 水槽内における硫化水素発生抑制方法 |
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JP (1) | JP6939949B1 (ja) |
KR (1) | KR20230002991A (ja) |
CN (1) | CN115667624A (ja) |
BR (1) | BR112022023695A2 (ja) |
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57158278A (en) | 1981-03-25 | 1982-09-30 | Kumiai Chem Ind Co Ltd | Composition for prevention of evolution of hydrogen sulfide |
JPH06142661A (ja) * | 1992-11-06 | 1994-05-24 | Kurita Water Ind Ltd | 還元性物質を含む水系の抗菌方法 |
JP2003164882A (ja) * | 2001-11-29 | 2003-06-10 | Kurita Water Ind Ltd | 還元性物質を含有する工業用水系の抗菌方法 |
WO2006137183A1 (ja) * | 2005-06-22 | 2006-12-28 | Hsp Hanbai Kabushiki Kaisha | 製紙方法 |
WO2015005404A1 (ja) * | 2013-07-09 | 2015-01-15 | 栗田工業株式会社 | スライム抑制方法 |
-
2020
- 2020-05-22 JP JP2020089436A patent/JP6939949B1/ja active Active
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2021
- 2021-03-12 CN CN202180036704.2A patent/CN115667624A/zh active Pending
- 2021-03-12 BR BR112022023695A patent/BR112022023695A2/pt unknown
- 2021-03-12 WO PCT/JP2021/010020 patent/WO2021235056A1/ja unknown
- 2021-03-12 KR KR1020227040997A patent/KR20230002991A/ko unknown
- 2021-03-12 EP EP21807989.5A patent/EP4130378A4/en active Pending
- 2021-03-15 TW TW110109167A patent/TW202208282A/zh unknown
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57158278A (en) | 1981-03-25 | 1982-09-30 | Kumiai Chem Ind Co Ltd | Composition for prevention of evolution of hydrogen sulfide |
JPH06142661A (ja) * | 1992-11-06 | 1994-05-24 | Kurita Water Ind Ltd | 還元性物質を含む水系の抗菌方法 |
JP2003164882A (ja) * | 2001-11-29 | 2003-06-10 | Kurita Water Ind Ltd | 還元性物質を含有する工業用水系の抗菌方法 |
WO2006137183A1 (ja) * | 2005-06-22 | 2006-12-28 | Hsp Hanbai Kabushiki Kaisha | 製紙方法 |
WO2015005404A1 (ja) * | 2013-07-09 | 2015-01-15 | 栗田工業株式会社 | スライム抑制方法 |
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EP4130378A1 (en) | 2023-02-08 |
TW202208282A (zh) | 2022-03-01 |
JP2021183741A (ja) | 2021-12-02 |
KR20230002991A (ko) | 2023-01-05 |
JP6939949B1 (ja) | 2021-09-22 |
EP4130378A4 (en) | 2023-10-11 |
CN115667624A (zh) | 2023-01-31 |
BR112022023695A2 (pt) | 2022-12-20 |
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