JP2017164709A - Manufacturing method of degraded carbon improved article and application method of degraded carbon improved article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a degraded carbon improved article using degraded carbon and an application method therefor.SOLUTION: A degraded carbon 9, which is used in a water treatment of a purification plant or the like, is contacted with a storage solution 15 and stored at an impregnation or wet state at a storage temperature capable of maintaining nitrification activity. Since nitrification bacteria adhere to the degraded carbon improved article 9a after storage, a nitrification reaction is initiated in short time. Therefore the degraded carbon improved article 9 can be used widely as an agent for removing inoculum of the nitrification bacteria or ammonia nitrogen in places needs for removal of ammonia nitrogen such as the purification plant or feeding of fish and shellfish.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to the production of a deteriorated charcoal product that can be used for advanced water purification treatment at a water purification plant and seafood breeding farms, aquaculture farms, aquariums, and domestic water tanks where ammonia nitrogen removal is desired, and a method for using the same.

  In recent years, activated carbon has been widely used for water treatment in manufacturing establishments, aquariums, farms, etc., and water treatment for waterworks. In particular, activated carbon (biological activated carbon) with microorganisms attached is used to decompose ammonia and organic matter. ing.

  Water purification treatment that combines one or more of treatment with biological activated carbon, ozone treatment, etc. with normal water treatment using coagulation sedimentation or filtration is called advanced water purification treatment, and it has been used in water purification plants in urban areas in recent years. ing.

  Fig. 4 (a) is an example of advanced water purification treatment incorporating biological activated carbon. As shown in Fig. 4 (a), ozone treatment (ozone decomposition) is performed for the purpose of oxidizing and decomposing trihalomethane precursors and mold odor-causing substances. Although it may be incorporated, ozone treatment is not always necessary.

  When ozone treatment is introduced When not introduced, in any case, it is possible to intentionally attach microorganisms to activated carbon by avoiding chlorination before the activated carbon treatment, and activated carbon with microorganisms attached in this way Becomes biological activated carbon.

  FIG. 4B and FIG. 4C are flowcharts specifically showing treatment with biological activated carbon. In FIG. 4 (b), a packed bed formed of activated carbon is used for water treatment as a biofilm. In FIG. 4 (c), raw water is treated with activated carbon in a fluidized state, and raw water after water treatment (hereinafter, (Also called treated water) and activated carbon are separated by a membrane.

  The raw water contains microorganisms such as nitrifying bacteria, and the raw water is brought into contact with the activated carbon 90 to attach the microorganisms (FIG. 5 (a)). For example, activated carbon 90 is filled in a biofilm filtration tank, and raw water is passed through the packed bed to bring it into contact with activated carbon 90, thereby attaching microorganisms (FIG. 5B). Alternatively, activated carbon 90 is put into a biological treatment tank, and the activated carbon 90 is brought into contact with raw water in a fluid state to attach microorganisms. The treated water is separated from the activated carbon by a membrane module and discharged to the outside of the biological treatment tank ( FIG. 5 (c)).

  In either case, microorganisms such as nitrifying bacteria naturally adhere to the activated carbon over a period of several months to become biological activated carbon, and ammonia nitrogen in the raw water is biologically removed by the nitrifying bacteria. Moreover, biological activated carbon has other effects such as insolubilization of soluble manganese in addition to the removal of ammoniacal nitrogen.

  In the above description, the case where microorganisms are naturally attached has been described. However, with this type of conventional technology, a method of attaching an intended microorganism to activated carbon without depending on natural attachment, or a medium composition and culture suitable for culturing nitrifying bacteria. The method is also known.

  For example, Patent Document 1 discloses activated carbon in which a microorganism having an ability to generate an adhesive substance and an adhesive substance thereof, and other microorganisms as necessary are attached to the activated carbon to immobilize the cells.

  On the other hand, the ability of nitrifying bacteria to remove ammoniacal nitrogen is used for purposes other than advanced water purification treatment, and one of them is the fishery breeding field. In a closed rearing environment such as an aquarium, ammonia nitrogen derived from seafood discharges and foods is highly toxic, and thus rapid removal is desired.

  Patent Document 2 discloses a technique for removing ammonia nitrogen by a nitrifying bacteria curing device. Non-Patent Document 1 discloses an aquaculture filter material that removes ammonia nitrogen by allowing nitrifying bacteria to naturally adhere to glass waste material.

JP-A-6-239608 JP 2002-125515 A

3rd Construction Top Runner Forum Report, “Expanding Overseas with Miracle Sol”, Nippon Construction Technology Co., Ltd., p.17-20 (July 2008)

  However, the use and utilization of activated carbon in the prior art have the following problems.

I) Maintaining nitrification activity of deteriorated charcoal In the above water treatment process, activated carbon whose adsorbing performance of mold odor-causing substances, trihalomethanes and the like has been lowered after several years from the start of use is called deteriorated charcoal. Although some are used for horticultural soil, most of them are discharged as industrial waste. In particular, thousands of tons are discharged annually in advanced water purification treatment processes at water purification plants, and sufficient effective use is not achieved.

  However, although the deteriorated charcoal has a reduced adsorption performance, it is presumed that many nitrifying bacteria responsible for the decomposition of ammoniacal nitrogen are attached.

  In general, nitrifying bacteria are known to be extremely weak in resistance to environmental changes such as temperature and drying. Even if you try to use the nitrifying activity of deteriorated charcoal, nitrifying bacteria can be rapidly exposed to the atmosphere. There was a problem that the nitrification activity disappeared rapidly.

  As described above, in the prior art, there is no technology for maintaining the nitrification activity of the deteriorated coal, and in the first place there is an idea that the deteriorated coal is preserved (stored) while maintaining the nitrification activity, and an improved deteriorated coal is produced. Not done.

II) Shortening the start-up time of biological activated carbon tanks In general, raw water (river water, etc.) flowing into a water purification plant is constantly desirable for the growth of nitrifying bacteria because the concentration of nitrogen and phosphorus sources such as ammoniacal nitrogen is constantly changing. It cannot be said to be environment or pH.

  In addition, the biological activated carbon tank also has a seasonal temperature change, so it is not in an environment where nitrifying bacteria can stably adhere to the activated carbon. In addition, the amount of nitrifying bacteria contained in the raw water (river water) of the water purification plant is very small, and its division rate is significantly slower than other microbial species (eg, division cycle of 24 hours or more). For this reason, in water treatment plants, it usually takes several months for nitrifying bacteria to spontaneously adhere to the activated carbon adsorption pond after charging the activated carbon. As a result, it is long to obtain sufficient ammonia nitrogen removal performance in the activated carbon adsorption pond. There was a problem that required a period.

  Furthermore, due to the slow rise of ammonia nitrogen removal, there is a concern that sometimes harmful microorganisms such as coliforms and Pseudomonas may adhere in addition to nitrifying bacteria.

  In the activated carbon in which the bacterial cells of Patent Document 1 described above are immobilized, microorganisms that produce an adhesive substance are limited to some genera such as Pseudomonas, and many genera such as nitrifying bacteria do not correspond.

  Therefore, when trying to attach nitrifying bacteria using microorganisms that produce adhesive substances, the area around the activated carbon is covered with adhesive substances and adhesive substance-producing bacteria. Has the problem that bacteria adherence is inefficient.

III) Ammonia removal in fish rearing environment It is known that in an environment rearing fish and shellfish, if ammonia nitrogen derived from food and effluent accumulates in the aquarium, ammonia poisoning occurs in the seafood.

  In general, nitrate ions do not affect fish and shellfish up to about 1,000 mg / L, but ammonia and nitrite ions are said to affect fish and shellfish even at about 1 mg / L.

  In an environment where nitrifying bacteria are established in the aquarium, ammonia is sequentially oxidized by the nitrifying action of the nitrifying bacteria (ammonia-> nitrite ion-> nitrate ion), and toxicity decreases, but nitrifying bacteria naturally adhere to the aquarium. Since it takes a long period of several months to do so, early reduction of the ammoniacal nitrogen concentration is one of the problems at the initial breeding stage.

  For example, Patent Document 2 discloses nitrifying bacteria-containing water for rearing seafood, but requires a curing (culturing) step for growing nitrifying bacteria, and a culture apparatus and substrate (medium components) for curing are required. Cost increases. Furthermore, since the curing days are required, it cannot be said that the apparatus can be used quickly after introduction.

  In Non-Patent Document 1, glass waste is used as a carrier for attaching nitrifying bacteria, but since nitrifying bacteria do not adhere to the glass waste itself, nitrification rises slowly and ammonia nitrogen starts to be removed. It takes 10 days or more.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to effectively use deteriorated coal discharged in large quantities as industrial waste to produce deteriorated coal improved products. The purpose is to use deteriorated charcoal-improved products for various purposes such as seafood breeding.

  As a result of intensive studies by the present inventors to solve the above problems, the nitrification activity of the deteriorated coal is maintained and the deterioration of the deteriorated coal is improved with the idea of not existing in the prior art that the deteriorated coal is brought into contact with the preservation solution. It was found that it can be reused as a product.

The present invention based on such knowledge can be configured as follows.
(1) The deteriorated charcoal (used activated carbon) used in the water treatment is brought into contact with a storage solution containing inorganic salts, and the nitrifying bacteria adhering to the deteriorated charcoal are not killed and stored at a storage temperature at which nitrification activity can be maintained. Therefore, the deteriorated charcoal after storage shall be an improved deteriorated charcoal.
(2) As a preservation | save solution, the thing whose inorganic salt density | concentration is 0.017 mol / L-1.8 mol / L is used, and it contacts with deteriorated charcoal.
(3) Moreover, this invention is not limited to said (1), The deterioration charcoal used by water treatment is made to contact the preservation | save solution containing an inorganic salt, and the nitrification activity adhering to the deterioration charcoal is made into the nitrification activity. Includes a method of applying osmotic stress that can be maintained, and storing the deteriorated coal after storage as a deteriorated coal improvement product.
(4) In the method of applying the osmotic stress, the inorganic salt concentration of the storage solution is preferably 0.017 mol / L to 1.8 mol / L.
(5) Although the kind of inorganic salt is not specifically limited, For example, sodium chloride and any one or both of potassium chloride are used.

There are the following methods for using the improved deteriorated charcoal produced according to the present invention.
(6) The deteriorated coal improved product manufactured by any one of the above manufacturing methods can be used as a part or all of the activated carbon used in the advanced water purification treatment process.
(7) Moreover, the deteriorated charcoal improvement goods manufactured with one of the said manufacturing methods can also be used as an ammoniacal nitrogen removal agent at the time of seafood breeding.

  According to the present invention, it is possible to store deteriorated charcoal for a long time while maintaining nitrification activity. The improved degraded charcoal after storage can be used to decompose and remove ammonia. The deteriorated charcoal improved product is a reused product of deteriorated charcoal, which is one type of industrial waste, and also does not require a culturing process. Therefore, the manufacturing cost is low, and the reduction to the environmental load is greatly expected. Moreover, since the deteriorated charcoal can be stored for a long time, it is possible to distribute the deteriorated charcoal improved product as a product.

  Since the nitrification activity of the deteriorated charcoal improved product is high, if it is used as an inoculum, the start-up period of the biological activated carbon tank in the advanced water purification treatment process can be greatly shortened. In addition, the deteriorated charcoal improved product can be used as an ammonia nitrogen removing agent for domestic use, aquaculture industry, aquaculture, etc.

Fig. 1 (a) shows a water treatment process for discharging deteriorated coal, Fig. 1 (b) shows a storage process for producing an improved deteriorated coal from deteriorated coal, and Fig. 1 (c) uses an improved deteriorated coal. The use process is shown. 2 (a) and 2 (b) are drawings for explaining the storage process. FIG. 3A shows a first usage method, and FIG. 3B shows a second usage method. FIG. 4 (a) is a diagram showing an outline of water treatment, FIG. 4 (b) is a diagram showing an outline of a biofilm treatment having an activated carbon packed bed, and FIG. 4 (c) is a diagram of fluidized activated carbon and membrane separation. It is a figure which shows the outline of the process utilized. FIG. 5 (a) is a schematic diagram for explaining a treatment using activated carbon, FIG. 5 (b) is a schematic diagram of a biofilm filtration treatment having an activated carbon packed bed, and FIG. 5 (c) shows a fluidized activated carbon and a membrane. It is a schematic diagram of the process using separation. FIG. 6 is a graph showing the relationship between the sodium chloride concentration of the preservation solution and the nitrification activity. FIG. 7 is a graph showing the relationship between the dissolved oxygen content of the preservation solution and the nitrification activity. FIG. 8A is a graph showing the relationship between storage temperature and nitrification activity in terms of ammonia nitrogen concentration, and FIG. 8B is a graph showing the relationship between storage temperature and nitrification activity in terms of ammonia nitrogen removal rate. It is. FIG. 9 is a graph showing nitrification activity when a deteriorated charcoal improved product is used for water purification treatment. FIG. 10 is a graph showing the relationship between (a) nitrification activity, survival medaka number and breeding days in the control group, and FIG. 10 (b) shows nitrification activity, survival medaka number and It is a graph which shows the relationship with breeding days.

  Hereinafter, the present invention will be specifically described, but the present invention is not limited to a specific example.

  FIGS. 1A to 1C are flowcharts for explaining the present invention. Activated carbon is discharged as deteriorated charcoal (used activated carbon) after being used in the water treatment step (FIG. 1A), and the present invention. Stores the deteriorated charcoal in a preservation solution to obtain a deteriorated charcoal improved product (FIG. 1 (b)), and further uses the deteriorated charcoal improved product (FIG. 1 (c)).

  First, the activated carbon and the water treatment process using activated carbon will be described.

[Activated carbon]
Activated carbon not only functions as a carrier for holding nitrifying bacteria, but also uses its adsorption ability to remove mold odor-causing substances and trihalomethanes.

  The activated carbon may be granular, crushed, molded product such as honeycomb activated carbon, or powder, but granular activated carbon is most preferred. “Granular” means that the particle size is 150 μm or more (see JIS K1474), and “powder” means that the particle size is less than 150 μm.

  The particle shape of the activated carbon is not particularly limited, and may be various shapes such as a spherical shape (manufactured by Mizuing Corporation, Evadia LG-40S, etc.), a crushed piece (manufactured by Mizuing Inc., Evadia LG-20S, etc.), and a columnar shape. However, a spherical shape or a cylindrical shape is preferable from the viewpoint of low water resistance, and a spherical shape is particularly preferable from the viewpoint that uniform filling is possible. Note that the spherical shape is a concept including not only a true sphere but also an ellipsoid (oblate sphere) and a cigar shape, and includes those having irregularities formed on the surface.

  The size of the granular activated carbon is not particularly limited, but preferably the effective diameter (10% passing diameter) is 0.3 mm to 1.3 mm, and the uniformity coefficient is 1.2 to 2.0.

The raw material of activated carbon is not particularly limited,
-Plants such as coconut shell, charcoal, sawdust, pine, bamboo, hard wood chips, grass charcoal, cellulose, etc.- Coal systems such as lignite, lignite, bituminous coal, anthracite, or
-Petroleum such as oil carbon, phenol resin, rayon, coal pitch, petroleum pitch,
These various raw materials can be used alone or in combination of two or more.

  The activated carbon may be a raw material that has not been processed (raw raw material) or a crushed product of raw raw material, or may be a molded product obtained by molding the raw material. The forming method is not particularly limited. Usually, the activated carbon raw material is pulverized, and if necessary, kneaded with a binder (organic binder, inorganic binder), water, other additives, etc., after granulation or press molding Baking (carbonization, activation) and molding.

  The activated carbon may be a commercial product or an unused product (new) immediately after production, but may also be regenerated coal that has been activated and regenerated by deteriorating coal after use in the water treatment step described below. These activated carbons are used in the following water treatment process.

[Water treatment process]
The water treatment process is a process that purifies the raw water (treated water), and the raw water is not particularly limited, and treats a variety of water such as river water, lake water, ground water, rain water, drainage, aquaculture water, and aquarium water. Can be targeted.

  The use of the water treatment process is not particularly limited, and includes water purification for waterworks, water treatment for factories, aquariums, aquaculture, etc., and wastewater treatment such as domestic wastewater and factory wastewater. In the present invention, the water treatment is not limited to the above specific examples, and treatment using biological activated carbon is widely referred to as “water treatment”.

  Among these, it is preferable to use deteriorated coal from a water treatment plant in that a large amount of emission can be expected regularly.

  The specific example of a water treatment process is not specifically limited, The advanced water purification process which combined at least activated carbon treatment with the normal water treatment which has any one or more of coagulation sedimentation, sand filtration, and chlorine disinfection is preferable, activated carbon treatment In addition, other processing steps such as ozone treatment can be combined (FIG. 4A).

  The activated carbon treatment is usually a step of bringing the raw water into contact with the activated carbon 90 such as in a biological activated carbon tank (FIG. 5A), and the specific method is not particularly limited, and the raw water is passed through the packed bed of the activated carbon 90. Alternatively, the activated carbon 90 may be brought into contact with the raw water in a fluid state (FIG. 5B).

  When chlorination is combined with this activated carbon treatment, it is preferably performed after the activated carbon treatment. By avoiding chlorine disinfection before the activated carbon treatment, and preferably by aerobic treatment under aerobic conditions, the substances to be removed (odorous substances, trihalomethane and its precursors, other pollutants, etc.) in raw water are adsorbed and removed with activated carbon. In addition, microorganisms such as nitrifying bacteria in raw water can be intentionally attached to activated carbon.

[Nitrifying bacteria]
The nitrifying bacteria in the present invention are bacteria useful for decomposing and removing ammonia nitrogen, and in particular, bacteria contributing to the oxidation of ammonia nitrogen and the oxidation of nitrite, that is, nitrite (ammonia oxidation). Bacteria) and nitrate bacteria (nitrite-oxidizing bacteria), preferably both, can be used, and in the present specification, such bacteria are referred to as nitrifying bacteria. For example, nitrite bacteria that oxidize ammonia to nitrite ions include Nitrosomonas europaea, Nitrosomonas communis, Nitrosomonas nitrosa, etc., and Nitrobacter winogradskyi etc. are not limited to these. Furthermore, in addition to the above nitrifying bacteria, autotrophic bacteria such as anammox bacteria, heterotrophic bacteria such as Bacillus and Pseudomonas, yeasts such as Candida (torula yeast), archaea such as methane, and filamentous fungi Microorganisms (yeast, fungus, bacteria) such as actinomycetes may adhere to the activated carbon.

  Since the nitrifying bacteria as described above are present in the raw water, the nitrifying bacteria may be naturally attached to the activated carbon 90 during the water treatment process, or the cultured nitrifying bacteria may be intentionally attached to the raw water or activated carbon. Also good. Furthermore, commercially available natto bacteria, nitric acid bacteria and nitrite bacteria for water tank purification, NBRC (NITE Biological Resource Center, Japanese government organization) and ATCC (American Type Culture Collection, US government organization) (Biological Resource Bank) It is also possible to attach a strain distributed from a microorganism storage organization such as

  In either case, when the raw water comes into contact with the activated carbon 90 to which nitrifying bacteria adhere, ammonia in the raw water is oxidized (nitrified) and finally removed from the treated water through a denitrification step and the like.

[Degraded coal emissions]
In general, since the growth rate of nitrifying bacteria is slow, removal of ammonia nitrogen is confirmed after at least one week, usually one month or more after the start of use of activated carbon in water treatment. In general, the longer the activated carbon is used, the greater the amount of nitrifying bacteria attached. However, activated carbon that has been used for a long time (1 month to 10 years, usually several months to 5 years) has the ability to adsorb mold odor-causing substances and trihalomethanes. descend.

  The criteria for determining the decrease in adsorption performance are not particularly limited. For example, when a preset period ends, when a predetermined amount of water is processed, water quality inspection results (trihalomethane amount, absorbance, 2-methyliso- Such as when the amount of borneol reaches the set value, or when the quality inspection result (iodine adsorption amount, other physical property test) of the activated carbon reaches the set value. Judge that it has deteriorated, take out part or all of the deteriorated charcoal from the water treatment process (water purification plant, water treatment equipment, etc.) and replace it with new charcoal.

  As necessary, the deteriorated charcoal was subjected to one or more pretreatment steps such as a step of removing impurities with a screen or a sieve, a step of draining from raw water, a step of washing with a cleaning solution such as distilled water or dechlorinated water. Later, it is used in the following storage step.

[Preservation process]
2A and 2B are schematic cross-sectional views for specifically explaining the storage process.

  The deteriorated charcoal 9 is accommodated in a container 11 or the like and immersed in the storage solution 15 or sprayed with the storage solution to bring the deteriorated charcoal 9 into contact with the storage solution 15.

  The deteriorated charcoal 9 that has come into contact with the storage solution 15 is stored in the container 11 used for the contact or another storage container 21. These containers 11 and 21 are not particularly limited in material and structure as long as the deteriorated charcoal 9 can be stored in a wet state, and various kinds of tanks, bottles, containers, bags, tubes, and the like can be used. The space containing the deteriorated charcoal 9 may be sealed with a sealing member 22 such as a lid. It is preferable to use a highly light-shielding container for these containers 11 or 21 or store the containers 11 and 21 together in a dark place.

  Moreover, in the preservation | save process, the deteriorated charcoal 9 may be left still, and the deteriorated charcoal 9 may be shaken or stirred with the preservation solution 15. Preferably, it is stored under aerobic conditions.

  When a large amount of deteriorated coal 9 discharged from a water purification plant or the like is stored, the deteriorated coal 9 can be separated (drained) from the storage solution 15 and stored. Since pores are formed in the activated carbon, the preservation solution 15 enters not only the surface of the deteriorated charcoal 9 but also the inside thereof, and the wet state is maintained.

  However, in order to prevent the storage solution 15 from drying, it is preferable to store the drained deteriorated charcoal 9 in a storage container 21 such as a sealed container and cut off from the outside air. Furthermore, you may prevent the deterioration charcoal 9 from drying by spraying or spraying the preservation | save solution 15 to the deterioration charcoal 9 once or more continuously or in steps during a preservation | save process.

  When stored under any conditions, the temperature at which the nitrifying activity of the nitrifying bacteria is maintained, that is, the nitrifying bacteria attached to the deteriorated charcoal can survive, and the deteriorated charcoal after storage is capable of nitrifying (removing ammonia nitrogen) ) Is preferably kept at the storage temperature. Specifically, the preferable range of the storage temperature is less than 40 ° C, preferably 0 to 35 ° C, more preferably 0 to 30 ° C, and particularly preferably 0 to 10 ° C (refrigerated). The storage temperature means not only the temperature of the deteriorated charcoal 9 but also the temperature around it (the storage solution 15, the container 11, 21 or the atmosphere). It is presumed that the charcoal 9 was also brought to an appropriate temperature.

  The storage temperature may be changed during the storage process, and further, may be changed to a temperature outside the above preferred range, but preferably the storage solution 15 and the deterioration from the start to the end of the storage process. The temperature of the charcoal 9 is maintained within the above-described preferred range (example: 0 to 35 ° C.).

  Next, the preservation solution 15 will be specifically described.

[Preservation solution]
Although the preservation | save solution 15 used for this invention is not specifically limited, For example, water, such as dechlorination water and distilled water, is the main component, Preferably it further contains inorganic salt.

  The inorganic salt is not particularly limited, and sodium chloride, sodium sulfate, sodium nitrate, sodium nitrite, sodium acetate, sodium bicarbonate, potassium chloride, potassium sulfate, potassium nitrate, potassium nitrite, potassium acetate, dipotassium hydrogen phosphate, phosphoric acid Any one or more inorganic salts selected from the group consisting of potassium dihydrogen, ammonium sulfate, ammonium chloride, ammonium nitrate, ammonium acetate, magnesium sulfate, and calcium chloride can be used. Among these, sodium chloride, potassium chloride, calcium chloride, sodium sulfate, potassium sulfate, and magnesium sulfate are preferable, sodium chloride or potassium chloride is more preferable, and sodium chloride is particularly preferable.

  In the present invention, when the storage temperature is within or outside the above-mentioned preferred range, the above-mentioned inorganic salt is contained in the storage solution 15, and an appropriate osmotic pressure is applied to microorganisms (nitrifying bacteria) adhering to the deteriorated coal. This includes cases where stress is applied. The osmotic pressure can be adjusted by, for example, the inorganic salt concentration.

  The inorganic salt concentration of the preservation solution is not particularly limited, and is, for example, 0.017 to 3.5 mol / L (about 1 to 200 g / L in terms of sodium chloride), preferably 0.017 to 1.8 mol / L (sodium chloride). About 1 to 100 g / L in terms of conversion, and more preferably 0.085 to 1.75 mol / L (about 5 to 100 g / L in terms of sodium chloride).

When 0.085 to 1.75 mol / L ( ^{5 to} 100 g / L in terms of sodium chloride) at 27 ° C. is converted to osmotic pressure, it becomes 4.2 × 10 ^{5 to} 8.6 × 10 ⁶ Pa (pV = nRT, R = 8.31 × 10 ³ , T = 273 + 27 ° C. = 300K). This numerical range is an example of an osmotic pressure range suitable for storing deteriorated coal.

  In addition, when storing deteriorated coal by adjusting the osmotic pressure, the nitrifying bacteria attached to the deteriorated charcoal can survive, and the pressure at which the deteriorated coal after storage maintains the nitrification ability (removal of ammonia nitrogen) The osmotic stress is such that the activity is maintained. In this way, an appropriate osmotic stress is applied to the microorganisms (nitrifying bacteria) that have come into contact with the storage solution 15 to enable long-term activity maintenance.

  As long as the osmotic pressure or the inorganic salt concentration of the storage solution 15 is within the above preferred range, the storage temperature of the deteriorated charcoal 9 is not particularly limited. Since the freezing point of the storage solution 15 depends on the inorganic salt concentration, for example, the freezing point temperature of the storage solution 15 according to the inorganic salt concentration can be set as the lower limit of the storage temperature.

  In addition, since many nitrifying bacteria are aerobic bacteria, it is preferable that the preservation solution 15 contains a certain amount of oxygen in addition to the inorganic salt. When the amount of dissolved oxygen in the storage solution 15 is small, before the deteriorated charcoal 9 is brought into contact with the storage solution 15 (before the start of the storage step) and while the deteriorated charcoal 9 is in contact with the storage solution 15 (during the storage step). One or both of the above supply oxygen to the storage solution 15.

  Although supply of oxygen is not particularly limited, it is preferable to use an oxygen-containing gas including air, compressed air, oxygen gas, or a mixed gas thereof. The method for supplying the oxygen-containing gas is not particularly limited, but a method of blowing the oxygen-containing gas into the storage solution 15 (aeration), a method of circulating or stirring the storage solution 15 in an oxygen-containing gas atmosphere, or a high-pressure oxygen-containing gas Various aeration methods such as a method of exposing the storage solution 15 to gas can be widely used.

  The amount of dissolved oxygen (concentration) of the preservation solution 15 is not particularly limited, but the amount of dissolved oxygen is, for example, 1/4 of the amount of saturated dissolved oxygen at the preservation temperature, preferably 1/2, and more specifically, 2.0 mg / L or more, preferably 4.0 mg / L or more. The upper limit is not particularly limited, and is, for example, a saturated dissolved oxygen concentration. Since the saturated dissolved oxygen amount varies depending on the temperature, for example, the preferable dissolved oxygen amount at 25 ° C. is 8.1 mg / L or less (saturated value at 25 ° C.). The amount of dissolved oxygen can be measured by the diaphragm electrode method (JIS K010201).

  During the storage process, the preferable range of the dissolved oxygen amount may be maintained in the entire process of the storage process, or only a part may be set as the preferable range.

  The amount of dissolved oxygen in the preservation solution 15 may fluctuate during the preservation step, but when the actual value or the predicted value of the amount of dissolved oxygen is below the lower limit (eg, 2.0 mg / L), the preservation step The oxygen-containing gas can be additionally supplied one or more times continuously or intermittently to the storage solution 15 therein. Furthermore, it is also possible to add an oxygen generator (including calcium peroxide) that generates oxygen by reacting with water, and gradually supply additional oxygen as the reaction proceeds.

  In addition to the inorganic salt, the preservation solution 15 includes one or more additives such as a nitrogen source, a carbon source (carbonate, glucose, etc.), a trace element (Co, Cu, Zn, Ni, etc.), and a buffer. It is also possible. However, if there are too many organic carbon sources, Escherichia coli, general bacteria, etc. may grow. For example, the preservation solution 15 before contact with deteriorated coal preferably has a total organic carbon content (TOC, combustion catalytic oxidation method) of 10 mg / L or less, more preferably 3 mg / L or less. In addition, the storage solution 15 before contact with the deteriorated charcoal preferably has a biochemical oxygen demand (C-BOD) of 10 mg / L or less, more preferably 2 mg / L or less, and particularly preferably 1 mg / L or less. C-BOD is BOD (ATU-BOD) when the nitrification action is suppressed by addition of N-allylthiourea (ATU), and means oxygen consumption accompanying organic substance decomposition.

  Further, an inorganic nutrient source (P, S, K, Ca, Mg, Fe, Na, etc.) can be added to the preservation solution 15. As an inorganic nutrient source, phosphorus is preferable, and more preferably, phosphoric acid is added so that the concentration as phosphorus is 1-10 mg / L.

  It is also possible to adjust the pH by adding at least one buffer or pH adjuster (acid, alkali) or the like to the preservation solution. For example, the buffer is used to prevent the stock solution pH from fluctuating by nitrifying bacteria metabolites, and is HEPES (2- [4- (2-hydroxyethyl) -1-piperazinyl] ethanesulfonic acid), Tris (Tris). Hydroxymethylaminomethane) and the like can be used. Although the pH of a preservation | save solution is not specifically limited, For example, it adjusts and uses pH 4-10, Preferably it is about 4-9.

  Moreover, when it is estimated that the nitrification activity of degraded charcoal is low and the concentration of nitrifying bacteria is low, commercially available nitrifying bacteria can be added to the preservation solution.

  Additives to be added to the preservation solution 15 are not limited to the above, but abnormal growth of organisms other than nitrifying bacteria (fry, shellfish, protists, algae, yeast, fungi, actinomycetes, archaea, bacteria, etc.) In order to prevent this, an antifungal agent or an antibacterial agent can be added.

  The use of the storage solution 15 as described above enables storage for a long period of time, for example, 1 to 720 days, preferably 1 to 360 days. In the present invention, the period from the start of contact (mixing) of the deteriorated charcoal 9 and the storage solution 15 to the start of use in the method of use described later is defined as the storage period, 60 days or longer is defined as a long period, and 60 days or longer. Storage is long-term storage.

  Since the deteriorated charcoal 9 stored in the storage solution 15 maintains the activity of nitrifying bacteria, it can be used as a deteriorated charcoal improved product by the methods shown in FIGS. 3 (a) and 3 (b).

[First usage]
FIG. 3A is a schematic view showing an example of the method of use, and shows a method of using the deteriorated charcoal improved product 9a for water treatment. This water treatment process is not particularly limited, and may be, for example, any of the water treatment processes described above for discharging the deteriorated charcoal 9, preferably the same water treatment process as the water treatment process discharging the deteriorated charcoal 9 Used for.

  If an example of the use in a water treatment process is demonstrated, the deterioration charcoal improvement goods 9a will be accommodated in a biological activated carbon tank as a part or all of activated carbon. If the components (inorganic salts, etc.) of the preservation solution 15 are not a problem, the deteriorated charcoal improvement product 9a may be accommodated together with the preservation solution 15, but preferably the deterioration charcoal improvement product 9a is separated from the preservation solution 15 (drained). ) And wash before use.

  The raw water is passed through a packed bed of activated carbon containing the deteriorated charcoal improved product 9a (FIG. 5 (b)), or the activated carbon containing the deteriorated charcoal improved product 9a is brought into contact with the raw water in a fluid state (FIG. 5 (c)). The raw water is brought into contact with the deteriorated charcoal improved product 9a and the activated carbon 90 by various methods.

  Since the nitrifying bacteria have already adhered to the deteriorated charcoal improved product 9a and the nitrifying activity is high, the removal of ammonia from the raw water is started in a very short time compared to when the activated carbon treatment is performed with only the new charcoal. . Moreover, since the deteriorated charcoal improved product 9a is used in the same water treatment process as the process of discharging the deteriorated charcoal 9, the growth conditions of the nitrifying bacteria are approximate, and the environmental adaptation of the nitrifying bacteria is high.

  When the deteriorated charcoal improved product 9a is used in the water treatment process, all of the activated carbon can be changed to the deteriorated charcoal improved product 9a. However, the deteriorated charcoal improved product 9a may be inferior in its original adsorption ability depending on the storage state. Therefore, the activated carbon 90 (new coal) and the deteriorated coal improved product 9a are preferably mixed and used. The use ratio of the deteriorated charcoal improved product 9a is not particularly limited, but when the total of the deteriorated charcoal improved product 9a and the activated carbon 90 is 100% by volume, the amount of the deteriorated charcoal improved product 9a is preferably less than 20% by volume, preferably 1 volume% or more and less than 20 volume%, More preferably, it is 1 volume% or more and less than 10 volume%.

[Second usage]
FIG. 3B is a schematic view showing another example of the method of use, and shows a method of using deteriorated charcoal improved product 9a as an ammoniacal nitrogen removing agent for raising seafood.

  The seafood is not particularly limited to freshwater fish, saltwater fish, shellfish, arthropods (crustaceans), cnidarians (jellyfish), etc., but in any case, deteriorated charcoal-improved products for seafood breeding grounds (water tanks, etc.) Add 9a.

  The deteriorated charcoal improved product 9a may be added after being separated (drained and washed) from the preservation solution 15, but when used for breeding salt-tolerant organisms such as seawater organisms, the preservation charcoal improved product 9a (without draining) is used. ) Deteriorated charcoal improved product 9a may be added.

  The addition amount is not particularly limited, but 0.01 to 10% (weight / volume) of the deteriorated charcoal improvement product 9a is added to the capacity of the aquarium or the volume of breeding water (fresh water, seawater) accommodated in the aquarium. . The addition method is not particularly limited, and the addition method may be directly added (sprayed) to the breeding water, or may be hung in the breeding water after being housed in a water-permeable bag such as a net. Further, the deteriorated charcoal improved product 9a may be filled in the column, the breeding water may be passed through the column using a pump or the like, and the breeding water may be circulated between the column and the water tank.

  In any case, it is preferable to add the deteriorated charcoal improved product 9a from the initial stage of seafood breeding. The food, carcasses, and discharges of seafood are decomposed and become a source of ammonia. However, since nitrifying bacteria adhere to the deteriorated charcoal improved product 9a, it is possible to decompose and remove ammonia from the initial breeding stage. Prevents poisoning of ammonia and enables stable breeding.

  Moreover, even after the initial stage of breeding has passed, the deteriorated charcoal improved product 9a can be added, and the deteriorated charcoal improved product 9a may be added not only once but intermittently a plurality of times. The continuous use of the deteriorated charcoal improved product 9a makes it possible to prevent a temporary increase in concentration of ammonia nitrogen due to excessive input of feed or increase in emissions, and to prevent ammonia poisoning for a long time.

  The deteriorated charcoal-improved product 9a as an ammoniacal nitrogen removing agent can be used under various conditions from household use to industrial use (culture farm). Moreover, it can be used not only in a closed space such as an aquarium but also in an open space such as aquaculture.

  In addition, the usage method of the deteriorated charcoal improved product 9a is not limited to the above, and if it is necessary to decompose or remove ammoniacal nitrogen, for example, a nitrification tank such as a human waste treatment plant, gardening, soil improvement, hydroponics It can also be used for cultivation. Furthermore, nitrifying bacteria are peeled from the deteriorated charcoal-improved product by ultrasonic treatment or the like, and a cell suspension or cell powder product can be used for decomposition or removal of ammonia nitrogen.

  Hereinafter, the present invention will be described more specifically with reference to examples.

  Sodium chloride was added to distilled water, and 7 types of stock solutions with sodium chloride concentrations of 0, 1, 5, 10, 50, 100, and 200 g / L were prepared in 100 ml each in separate medium bottles. The amount of dissolved oxygen in the storage solution of each medium bottle is 6.0 mg / L, and then 10 g (wet weight) of deteriorated charcoal collected from the water purification plant is immersed in each storage solution and stored refrigerated at 4 ° C. for 30 days. A deteriorated charcoal improved product was produced.

  Add 1.95 mg / L ammonium chloride (equivalent to 0.5 mg / L ammonia nitrogen), 5.86 mg / L sodium hydrogen carbonate, 0.58 mg / L disodium hydrogen phosphate dodecahydrate to distilled water. Simulated raw water (pH unadjusted) was prepared.

  Each of the above-mentioned deteriorated charcoal improved products and the deteriorated charcoal for comparison experiments (without soaking of the preservation solution) were added to 50 ml of simulated raw water, respectively, and shaken at 120 rpm, 30 ° C. for 1 hour, A degradation test was performed.

  25 ml of the supernatant of the simulated raw water after shaking was collected, and the ammoniacal nitrogen concentration was measured by an absorptiometric method using 1-naphthol. The measurement results are shown in FIG.

  As shown in FIG. 6, in the test section that was not immersed in a storage solution containing an inorganic salt, the resolution (nitrification activity) of ammoniacal nitrogen was not confirmed, whereas the test immersed in a storage solution containing an inorganic salt In the ward, nitrification activity was confirmed.

  As for the inorganic salt concentration, high nitrification activity was confirmed in the range of sodium chloride salt concentration of 1 to 100 g / L (inorganic salt concentration of 0.017 mol / L to 1.712 mol / L). On the other hand, when sodium chloride was added excessively and the concentration exceeded 200 g / L (3.423 mol / L), the nitrification activity decreased.

  From the above results, it was confirmed that the inorganic salt concentration of the preservation solution is preferably 3.5 mol / L or less, more preferably 0.017 mol / L to 1.8 mol / L.

  A stock solution having a sodium chloride concentration of 10 g / L was prepared under the same conditions as in Example 1. 100 ml of this stock solution was placed in each of five medium bottles. These stock solutions were degassed and aerated, and the amount of dissolved oxygen was adjusted to 0, 2.0, 4.0, 6.0, and 8.1 mg / L, respectively. Aeration is performed at a room temperature of 21 ° C., and 8.1 mg / L is a saturated dissolved oxygen amount at 21 ° C. and a sodium chloride concentration of 10 g / L. Therefore, the storage solution of 8.1 mg / L is aerated until it is saturated. That's right.

  10 g (wet weight) of the same deteriorated charcoal as in Example 1 was immersed in each storage solution in which the amount of dissolved oxygen was adjusted, covered, and stored in a refrigerator (4 ° C.) for 30 days. Thereafter, ammonia nitrogen decomposing ability was investigated by the same method as in Example 1. The result is shown in FIG.

  As shown in FIG. 7, high nitrification activity was confirmed at a dissolved oxygen content of 4.0 mg / L or more. From this, it is considered that the amount of dissolved oxygen in the preservation solution is preferably 4.0 mg / L or more.

  Under the same conditions as in Example 2 above, 100 ml of a stock solution having a sodium chloride concentration of 10 g / L and a dissolved oxygen content of 6.0 mg / L was prepared in each of a plurality of medium bottles. For the deteriorated charcoal (degraded charcoal improved product) stored at different temperatures and stored at zero temperature, 180 days, 360 days, 540 days, and 720 days respectively, the resolution of ammoniacal nitrogen was reduced in the same manner as in Example 1. investigated. FIG. 8A shows the concentration of decomposed ammonia nitrogen as the concentration, and FIG. 8B shows the ammonia nitrogen removal rate calculated as the concentration.

  As shown in FIG. 8, the nitrification activity was maintained for a long time (1 to 360 days) at a storage temperature of 0 to 30 ° C., but the disappearance of the nitrification activity was extremely fast and stored at a storage temperature of 40 ° C. to 50 ° C. On the 180th day, the removal rate decreased to 40% or less.

  From the above, it has been confirmed that if the storage temperature is less than 40 ° C, preferably 0 ° C to 35 ° C, more preferably 0 to 30 ° C, nitrification activity is maintained even after long-term storage for about 1 year. .

  In addition, in the case of storing deteriorated charcoal without using a storage solution (sodium chloride aqueous solution) containing an inorganic salt, the nitrification activity completely disappears within 10 days at any temperature range of 0 to 50 ° C. I found that I could only save it.

-First method of use A test was conducted assuming that the deteriorated charcoal improved product was introduced into the biological activated carbon tank of the water treatment plant as an inoculum of nitrifying bacteria.

  As the deteriorated charcoal improved product to be used for the test, a deteriorated charcoal stored at 4 ° C. for a long period (180 days) in the same storage solution as in Example 3 was used. After storage, the deteriorated charcoal improved product is washed lightly with pure water to remove sodium chloride, and then 63 ml of new charcoal (dried granular activated carbon with no nitrifying bacteria attached) and 7 ml of deteriorated charcoal improved product on the column (diameter 20 mm). (Equivalent to 10%) was filled.

Simulated raw water (pH unadjusted) was prepared under the same conditions as in Example 1, and this simulated raw water was added to the above-mentioned column to which a deteriorated charcoal improved product was added at a room temperature and a space flow rate of SV = 5 h ^−1. A water flow test was conducted by passing water through a column (100% fresh coal, control group) packed only with water.

  Ammonia nitrogen was measured by a 1-naphthol method for simulated raw water and treated water in each test section. The result is shown in FIG.

  In the test plot with deteriorated charcoal improved products after long-term storage, it was confirmed that ammonia nitrogen equivalent to 0.5 mg / L decreased to about 0.1 mg / L on the 15th day of water flow, and thereafter 0 .1 mg / L was not exceeded.

  On the other hand, in the control group, it finally fell below 0.2 mg / L on the 120th day of water flow due to spontaneous attachment of nitrifying bacteria. From this, it was demonstrated that by using the deteriorated charcoal preserved according to the present invention, it is possible to shorten the trial operation period required in the control zone (equivalent to a conventional water purification plant) by 100 days or more.

-Second method of use A test was conducted in which the deteriorated charcoal after long-term storage was used for fish breeding as ammonia nitrogen removal.

  Ammonia chloride was added to a fish tank (water volume: 12 L) to intentionally make the concentration of ammoniacal nitrogen in the water for breeding (water tank water) 100 mg / L.

  A deteriorated charcoal improved product was produced under the same conditions as in Example 4, and 200 g (wet weight) of the deteriorated charcoal improved product was added to the water tank and deposited on the bottom of the water tank. After ten medaka (Oryzias latipes) were introduced into this aquarium as a model organism, they were reared at room temperature for 5 days while aerated. During breeding, the medaka was fed twice a day (every 12 hours) by an auto feeder.

  In addition, instead of the deteriorated charcoal improved product, a test group using activated carbon to which nitrifying bacteria did not adhere (new coal of dry granular activated carbon) was provided as a control group, and the same breeding test was conducted.

  Ammonia nitrogen concentration (1-naphthol method) and nitric acid concentration (ion chromatography method) in the aquarium water were measured over time, and the number of surviving medaka fish was counted. FIG. 10 (a) shows the test results of the control group, and FIG. 10 (b) shows the test results using the deteriorated coal improved product.

  As shown in FIG. 10 (a), in the control group, the ammoniacal nitrogen increased with the passage of the breeding days, and accordingly, the number of living medaka decreased. On the other hand, as shown in FIG. 10 (b), in the test plot using the deteriorated charcoal improved product, the amount of nitric acid increased at the same time as the decrease of ammoniacal nitrogen started from the second day of breeding, and There was no decrease. From this, it was confirmed that due to the nitrifying action of nitrifying bacteria, ammonia nitrogen was converted to nitric acid with low toxicity through nitrous acid, and an environment suitable for the growth of Japanese medaka could be maintained.

  From the above results, it became possible to prevent the death of fish and shellfish by effectively using the deteriorated charcoal at the initial breeding stage where ammonia nitrogen is likely to accumulate in the tank. Moreover, since the preferable sodium chloride density | concentration of the preservation | save solution in Example 1 was 1-100 g / L, and the salt concentration of seawater is about 35 g / L, marine organisms, such as not only freshwater fish but marine fish, are also raised. It was confirmed that it could be a target.

9 Deteriorated Charcoal 9a Improved Degraded Charcoal 11, 21 Container (storage container)
15 Storage solution 22 Sealing member (lid)
90 Activated carbon (new charcoal)

Claims (7)

  Deterioration characterized by contacting deteriorated charcoal after use in water treatment with a storage solution containing an inorganic salt and storing it at a storage temperature at which the nitrifying activity of nitrifying bacteria attached to the deteriorated charcoal is maintained. A method for producing charcoal improvements.   The method for producing an improved deteriorated coal according to claim 1, wherein the preservation solution has an inorganic salt concentration of 0.017 mol / L to 1.8 mol / L.   Degraded charcoal after use in water treatment is brought into contact with a preservation solution containing an inorganic salt, and osmotic stress is applied to the nitrifying bacterium so that the nitrifying activity of the nitrifying bacterium adhering to the degraded charcoal is maintained. The manufacturing method of the deteriorated charcoal improvement goods characterized by giving.   The method for producing a deteriorated coal improved product according to claim 3, wherein the preservation solution has an inorganic salt concentration of 0.017 mol / L to 1.8 mol / L.   The said preservation | save solution is a manufacturing method of the deteriorated charcoal improvement goods of any one of Claims 1-4 which contain sodium chloride, and any one or both of potassium chloride as inorganic salt.   A method for using a deteriorated charcoal improvement product, wherein the deteriorated charcoal improvement product produced by the production method according to any one of claims 1 to 5 is used as at least a part of activated carbon used in an advanced water purification treatment process.   A method for using a deteriorated charcoal improved product, wherein the deteriorated charcoal improved product produced by the production method according to any one of claims 1 to 5 is used as an ammoniacal nitrogen removing agent for rearing fish and shellfish.

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