JPH11114593A - Treatment of water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the good quality of water by reducing and removing the oxide dissolved in the water in a water tank, drinking water and washing water for the domestic animal and human being, agricultural water, water for livestock industry or industrial waste water. SOLUTION: An oxygen-poor region low in oxygen concn. is formed in the water, and an org. carbon source is supplied to the heterotropic bacteria implanted in an environment low in dissolved oxygen in the oxygen-poor region. Consequently, the activation of the heterotropic bacteria is promoted, the oxide and final oxide present in the water are converted to a harmless gas by the reduction such as denitrification, the reduction of the oxide continuously formed in the water is everlastingly promoted, and the water quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an aquarium for aquarium fish used for home and business, a large aquarium installed in an aquarium for a live fish used for business, or a garden, It is installed in golf courses, etc. and maintains the quality of water stored in ponds where fish are bred for a long period of time.It can also be used for drinking water for domestic animals and humans, general water used for washing water, etc. Final oxides such as nitrate nitrogen dissolved in well water, etc., or denitrification when oxides such as nitrite nitrogen are dissolved, or oxidation dissolved in agriculture, livestock industry, industrial wastewater, etc. The present invention relates to a water treatment method for water for reducing substances, final oxides, and the like, or seawater, fouled water, industrial water, and treated water.

[0002]

2. Description of the Related Art Small or large domestic aquariums,
Organic wastes such as food residues and excretions of aquatic organisms existing in water are oxidized and replaced by metabolic functions of aerobic microorganisms in commercial water tanks or reservoirs, and nitrite nitrogen and nitrate are removed. It accumulates in water as oxides or final oxides such as nitrogen, sulfate and phosphate. When these oxidants accumulate in water, they cause eutrophication of the water and promote the generation of algae and moss, which not only causes water pollution and deterioration of water quality, but also lowers the PH value and reduces acidity. May shift to the side. For this reason, not only does it significantly hinder the breeding of inhabitants underwater, but it also becomes a major hindrance to maintaining the water environment in the natural environment. Therefore, it is extremely important to control the water quality so that the inhabitants in the water can be stably bred for a long period of time, even if the excrement and residual food of the inhabitants exist in the water or the water quality changes. Also, general living water and well water for drinking water and washing water for livestock and humans, and oxides dissolved in agricultural, livestock or industrial wastewater,
Purification by reducing and removing the final oxide by denitrification, etc.
The treated water can be used for a variety of purposes and significantly increase its value. Conventionally, the simplest method of purifying water is to use a pump or the like to pass water through a circulation system having a filtration device, and to filter and purify the water passing through the filtration device. However, in this method, fine contaminants and oxides present in the water are only removed by a filtration device, and this is not an essential improvement in water quality. Also, a method for biologically purifying water by utilizing the action of aerobic and anaerobic microorganisms is described in JP-A-1-281198.

[0003]

In the above-mentioned conventional water purification method, a dedicated filtration space is provided inside or outside a water tank to form a space, and a wool mat or a filter sponge is provided in the filtration space. Osmotic filtration using a physical filtration material such as, or adsorption filtration using a chemical filtration material such as activated carbon, or more toxic from toxic substances by metabolic alteration of microorganisms using a biological water purification method Although it is a method to promote substance replacement to low-species chemicals,
These conventional biological water purification methods are configured to form a zone having a high oxygen content suitable for occupation by aerobic microorganisms by using a filter medium suitable for occupation only by aerobic microorganisms. However, in the physical filtration method and the chemical filtration method, it is extremely difficult to maintain the water quality for a long period of time due to a decrease in filtration ability due to clogging of the physical filtration medium and a decrease in filtration ability due to the adsorption limit of the chemical adsorption filtration medium. In addition, in a biological water purification method mainly composed of metabolic alternation of aerobic microorganisms, a solute (organic waste) generated in a metabolic system of aerobic microorganisms (autotrophic bacteria) that is implanted on a filter medium is removed. Since the substance alteration is biased only in the oxidation direction, the generated oxidant accumulates in the water,
It is not possible to maintain good water quality for a long period of time or to perform a long-term water purification action, and frequent water changes requiring great effort are required. Therefore, if oxidizing substances present in water, seawater or foul water are reduced by denitrification or the like to release harmless gas, the water for breeding aquatic inhabitants such as fish is frequently changed. This is effective in the fish farming industry because it is possible to maintain the optimum water quality for breeding fish for a very long time without requiring significant labor. In addition, oxides such as nitrate nitrogen and nitrite nitrogen in general living water or well water provided for drinking water or washing water for livestock and humans, and denitrification when final oxides are dissolved, It is also very effective for water supply and drainage treatment for reducing and removing oxides and final oxides dissolved in agricultural, livestock, and industrial wastewater.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional drawbacks, and has been proposed in order to achieve the above-mentioned object of the present invention. An oxygen-deficient region having a low oxygen concentration is formed in water. By supplying an organic carbon source to a heterotrophic bacteria group that is implanted in an environment with a low amount of dissolved oxygen in the anoxic region, the activation of the heterotrophic bacteria group is promoted to promote the presence of oxides present in water. The feature is that the final oxide is converted into harmless gas by a reducing action such as denitrification, so that the continuously generated oxides in the water are permanently promoted in the reducing action to improve the water quality. I do.

[0005]

Embodiments of the present invention will be described below in detail. In the water treatment method of the present invention, as a first treatment step, the contamination used for freshwater or seawater in which a living body to be treated is bred, or general living water or well water, agriculture, livestock, industrial use, or the like An oxygen-deficient region having a low oxygen concentration is formed in water such as water or stored water. Generally, since oxygen is a gas, it has a property of being hardly dissolved in water, and the amount of dissolved oxygen is limited. The maximum amount of dissolved oxygen in water is called the dissolved oxygen saturation point. This saturation point differs depending on freshwater and seawater, and also depends on factors such as the pH value, hardness, and temperature of water. For example, when the water temperature is 25 ° C., the saturation point in fresh water such as tap water is 8.1 ppm, and the saturation point in seawater is 7 ppm. In the case of fresh water, the saturation point at 5 ° C. is 12.4 p.
pm, 10.6 ppm at 10 ° C, 9.8 p at 15 ° C
pm, 8.8 ppm at 20 ° C., 7.5 pp at 30 ° C.
m, which differs to some extent depending on the water temperature as described above. The poor oxygen region in the present invention most preferably refers to a part of the water reaching 30% or less at the dissolved oxygen saturation point. For example, in 25 ° C. fresh water, the dissolved oxygen content is approximately 2.4 ppm or less. Underwater part. In general, when the amount of dissolved oxygen in water is 0, it becomes difficult to track the oxidation and reduction states of water. Therefore, the influence of oxygen in the oxygen-deficient region is reduced by the oxidation-reduction potential (OXY).
GEN REDUCTION POTENTIAL (abbreviated as ORP). Normal river,
ORP of water existing in the natural world such as ponds and the sea is 360-
At 430 mV, in the present invention, it is recognized that if the ORP is 200 mV or less, it corresponds to the anoxic region. In the present invention, the water to be treated is used for breeding underwater inhabitants such as fish, such as aquariums for ornamental fish or live fish for general household or business use, or large aquariums installed in aquariums. In the case of water stored in the water tank, as a first example of forming a hypoxic region, sand that does not change the characteristics of water is spread on the bottom of the water tank to a thickness of about 5 to 20 cm. A stagnant area of water flow is formed in the lower part of the sand layer. Since the water in the aquarium always circulates and generates a water flow, almost no water flows through the above-mentioned stagnant area, or a very small amount of water flow is generated. Be composed.

[0006] As a second example of forming an oxygen-deficient region inside the water tank, a housing is provided with a small hole at the bottom of the water tank so that a small amount of water and gas can pass therethrough. Creates an anoxic region inside.

[0007] As a third example of forming an anoxic region inside a water tank, a double characteristic filter medium capable of forming an aerobic area on the upper side and an anaerobic area on the lower side is provided at the bottom of the water tank. Since the water passing through the aerobic region is consumed by the aerobic microorganisms that are installed and land on the aerobic region on the surface of the filter medium, the lower anaerobic region constitutes the anoxic region. become.

As a fourth example of forming an oxygen-deficient region inside a water tank, a filter housing through which a very small amount of water can circulate is provided inside the water tank, and water is circulated very slowly in the filter. Thus, an oxygen-deficient region can be formed inside the housing.

As a fifth example of forming an anoxic region inside a water tank, a water stagnation area is provided inside a bottom filter laid on the inner bottom surface of the water tank or outside a water passage opening, and a very small amount of water is provided in the stagnation area. By circulating the water, an oxygen-deficient region can be formed.

The above five examples show the case where the oxygen-deficient region is formed in the water of the water tank. However, it is also possible to configure a poor oxygen region outside the water tank to circulate a small amount of water in the water tank. As a first example of such a configuration, a partition is provided inside a filter housing installed outside a water tank to form a stagnant area of water through which only a very small amount of water passes, and the upper surface of the stagnant area is connected to the atmosphere. By blocking, an oxygen-deficient region can be formed.

As a second example of forming an oxygen-deficient region outside a water tank, a return pipe for returning water from a filter housing provided outside the water tank to the inside of the water tank is provided with a bypass having a filter and returning to the water tank. Only a very small amount of water passes through the bypass filter, forming an anoxic region in the bypass filter.

As a third example of forming an anoxic region outside the water tank, an aerobic area can be formed on the upper side and an anaerobic area can be formed on the lower side inside the filter housing installed outside the water tank. A filter material having dual characteristics is installed, and water passing through the aerobic region is consumed by oxygen by the aerobic microorganisms that land on the aerobic region on the surface of the filter material. It constitutes an anoxic region.

In each of the above examples, the case where the oxygen-deficient region is formed inside or outside the water tank has been described. However, if the water to be treated is water that exists in nature, such as stored water from a purification plant, rivers, ponds, or sea water, a small amount of water will pass under the soil at the bottom of the water. Anoxic regions can be set. In addition, by installing a filter housing that can circulate a fixed amount of water outside the water or in the water, and by circulating the water in the filter inside the housing very slowly, the anoxic region can be reduced. Can be configured. Further, even if the water to be treated is domestic water, domestic wastewater, wastewater from agriculture, livestock industry or industry, by installing a filter housing in the same manner as described above, the oxygen-deficient region is formed. be able to.

According to the present invention, the oxygen-deficient region in which the amount of dissolved oxygen is small is constituted even inside or outside the water tank as described above, or inside or outside water existing in nature. Can be. In the present invention, an organic carbon source is supplied to the anoxic region, and nitrate-reducing bacteria, heterotrophic bacteria such as denitrifying bacteria are grown and implanted while being implanted, and the activity of the heterotrophic bacteria is increased. It promotes the transformation.

In the present invention, two types of organic carbon sources, solid and liquid, can be proposed as examples. The first example of the organic carbon source is a solid one,
It is obtained by compression molding a copolyester composed of hydroxybutyrate and hydroxyvariate, which are high molecular biodegradable resins. When the above-mentioned organic carbon source is subjected to compression molding, it is preferable that the contact area with water be extremely wide so that the heterotrophic bacteria can be easily implanted, instead of simply forming the organic carbon source into a spherical or massive form. As a specific example, two hemispheres formed by arranging a plurality of thin plate members in parallel, a sphere formed by joining the thin plate members at a diameter portion so that the thin plate members are orthogonal to each other, or a plurality of fins are arranged in parallel. When a prismatic body or the like is buried in the anoxic region, the heterotrophic bacteria are easily implanted, and the heterotrophic bacteria are easily consumed as an energy source. The polymer biodegradable resin is not limited to those whose main components are the above-mentioned copolymerized polyesters. For example, polycaprolactone, polybutylene succinate / adipate, polyethylene succinate, polylactic acid, polylactic acid polyester, 4-hydroxybutyric acid, γ Resins containing butyrolactone, 1,4-butanediol, 1,6 hexanediol, 4-chlorobutyric acid and the like as main components can also be used.

A second example of the organic carbon source is a liquid one, in which a high molecular carbon source of a natural polysaccharide is dissolved in deoxygenated pure water, and cellulose and the like are coagulated and removed. Liquid. Here, the reason for dissolving the high molecular carbon source of the natural polysaccharide in pure water subjected to deoxygenation is mainly to prevent pure chemical reaction between oxygen and each of the carbon source and other chemical species, The reason why cellulose and the like are coagulated and removed is that cellulose and the like may inhibit the activity of a reducing action such as denitrification, which is a metabolic function of heterotrophic bacteria. In the present invention, as the natural polysaccharide, starch-based high molecular carbon sources such as sucrose, fructose, glucose, and mannan, and any other types of natural polysaccharides can be used. Then, the above-mentioned liquid organic carbon source is quantitatively supplied to the anoxic region.To supply the liquid organic carbon source to the anoxic region, the organic carbon source is dropped into water. It can be sedimented to the hypoxic region or injected directly into the hypoxic region. Further, the liquid organic carbon source is stored in an ampoule-shaped bottle, and this bottle is set at a position close to the anoxic region in the water, and quantitatively determined through a fine hole (for example, having a diameter of 1 mm or less) formed in the bottle. In the present invention, a method of supplying a solution to an oxygen-deficient region (for example, 1 ml or less per day) and permeating it is very effective.

According to the present invention, a heterotrophic bacterium group which is implanted in the anoxic region by supplying the solid or liquid organic carbon source by constituting the anoxic region in water as described above. Grow by consuming the organic carbon source as an energy source. Furthermore, although heterotrophic bacteria require oxygen to survive, they inhabit oxygen-deficient oxygen-deficient regions, and therefore need oxygen for respiration in oxygen-deficient oxygen-deficient regions, such as nitrate or nitrite. Or the like, or from the final oxide to activate a reducing action such as denitrification. Therefore, in the case of an aquarium, excreta and residual food of living organisms and other organic wastes existing in the water, and in the case of natural ponds, treated water, industrial water, etc., countless kinds of organic substances existing in the water. Waste is oxidized and replaced by the metabolic function of aerobic microorganisms, and nitrite nitrogen, nitrate nitrogen or oxides such as sulfates and phosphates,
Alternatively, it dissolves as a final oxide and causes water quality deterioration, but in the present invention, by supplying an organic carbon source to the anoxic region in water, the heterotrophic bacteria group to be implanted is activated and decarbonized. , Etc., to significantly improve the water quality over the long term by permanently converting the oxides and final oxides into harmless gases. The water in the water tank and the water in the natural world are flowing, so only a small amount flows or circulates in the oxygen-deficient region, but even if a little water passes or circulates, it is included in the water. Oxide or final oxide is converted into harmless gas by the reducing function of the heterotrophic bacteria, so that the water quality of the water tank or the storage water can be surely improved after a certain period of time.

It is recognized that the basic process by the reducing action of heterotrophic bacteria based on the improvement of water quality is as follows. Nitrate dissolved in water (2NO3)-(heterotrophic bacteria) → nitrogen gas (N2) + oxygen (3O2)

Although the above-mentioned reducing action has various backgrounds, in many cases, a catabolic reducing action is actually performed. The following two types of typical processes of this catabolic reduction are recognized. 1) Nitrate (NO3) → nitrite (NO2) → nitric oxide (NO) → nitrous oxide (N2 O) → nitrogen gas (N2)

Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the following embodiments, and can be implemented in any manner as long as the configuration described in the claims is not changed.

Example 1 An artificial seawater having a specific gravity of 1.020 was supplied into a water tank at a rate of 50 liters, and an aerobic and anaerobic environment could be created inside a filter housing installed above the water tank. A filter medium having characteristics was stored, and water in which oxygen was consumed by the aerobic microorganisms that had settled on the surface of the filter medium was permeated into the filter medium to form a hypoxic region. 10 crabs (length 4)
Table 1 below shows the state of migration of nitrogenous chemical species in water measured with no organic carbon source supplied to the anoxic region in a state where 磯 5 cm of rocky crab) had been inhabited.

[0022]

[Table 1]

As is clear from Table 1 above, nitrate nitrogen, which is an oxide in water, is reduced by the heterotrophic bacteria that have settled in the anoxic region, and the heterotrophic bacteria grow over time. It has become clear that it will decline.

Example 2 50 liters of artificial seawater having a specific gravity of 1.020 was supplied into a water tank, and a partition was provided inside a filter housing installed above the water tank to form a stagnant area of water. Then, eight solid organic carbon sources were placed, and the upper portion of the stagnant area was covered with artificial sand of 5 to 8 mesh to shut off the air, thereby forming an anoxic region.
This hypoxic region has a volume of 0.8 liters. In a state where 10 crabs (4 to 5 cm long shore crabs) inhabited in the water of the aquarium, the state of migration of nitrogenous chemical species in the water was measured, and the results are as shown in Table 2 below. The solid organic carbon source is a sphere obtained by compression-molding a copolyester composed of hydroxybutyrate and hydroxyvariate such that a plurality of thin plates are vertically arranged in parallel, and has a diameter of 30 mm. is there.

[0025]

[Table 2]

As is apparent from Table 2 above, when a sphere obtained by compression-forming a copolyester composed of hydroxybutyrate and hydroxyvariate into a thin plate and arranging them in parallel is supplied in a state of being buried in an oxygen-deficient region. The metabolic function of the heterotrophic bacteria is enhanced, the reducing action is activated, the value of oxides in water changes at a significantly lower value compared to Example 1, and the value of total nitrogen dissolved in water is zero. In Example 1, it took 35 days or more, but in Example 2, it took 35 days or less.
In this case, the reducing action of oxides and final oxides in water is significantly activated.

[Example 3] An artificial seawater having a specific gravity of 1.020 was supplied by 50 liters to a water tank in which sand having a thickness of 10 cm was spread on the bottom, and a stagnant area where only a small amount of water flowed was formed below the sand. To form a hypoxic region. With 10 crabs (4 to 5 cm long crabs) inhabiting the water in the aquarium,
A liquid organic carbon source was supplied from the surface of water to settle in an oxygen-deficient region, and the state of migration of nitrogen-based chemical species in the water was measured. The liquid organic carbon source is a high molecular carbon source of a natural polysaccharide (a concentrated solution of sap of a coconut tree, which is rich in sucrose, fructose, etc.),
A liquid that is dissolved in pure water that has been deoxygenated and that has undergone coagulation and removal of cellulose, etc., once a week.
Milliliter volumes were fed into water.

[0028]

[Table 3]

When a liquid organic carbon source is supplied to the oxygen-deficient region, the reduction of oxides and final oxides in water is remarkably activated, as in the second embodiment.

[0030]

As is apparent from the above, according to the present invention, a heterotrophic substance which forms an oxygen-deficient region with low oxygen concentration in water and implants in an environment with a low dissolved oxygen content in the oxygen-deficient region. By supplying the organic carbon source to the bacterial group, the activation of the heterotrophic bacterial group is promoted, and the oxides and final oxides present in the water are converted into harmless gases by a reducing action such as denitrification. The present invention is characterized in that it continuously promotes a reducing action of continuously generated oxides in water to improve water quality.

Therefore, merely supplying a solid or liquid organic carbon source to the anoxic region causes the heterotrophic bacteria that are implanted in the anoxic region not only to grow by consuming as an energy source, but also to grow. By performing denitrification or the like, the reducing action can be activated. Therefore, excretions and residual foods of inhabitants existing in water, and other organic wastes, and all kinds of organic wastes in nature such as ponds, treated water and industrial water, are caused by heterotrophic bacteria. Since the activation is activated by significantly increasing the reducing action, the oxides and final oxides are permanently converted to harmless nitrogen gas, so that the water quality is improved in the long term,
Not only prevents the growth of algae and moss, but also does not deteriorate the water quality, can significantly contribute to water quality management,
It significantly enhances practical value not only for water for fish farming but also for purification of agricultural, livestock or industrial wastewater.

Claims (2)

[Claims] 1. The method according to claim 1, wherein an oxygen-deficient region having a low oxygen concentration is formed in water, and an organic carbon source is supplied to a heterotrophic bacteria group that is implanted in an environment with a low amount of dissolved oxygen in the oxygen-deficient region. Promotes the activation of heterotrophic bacteria and converts oxides and final oxides present in water into harmless gases by reduction such as denitrification. A water treatment method characterized by promoting a reducing action to improve water quality. 2. The organic carbon source to be supplied to the heterotrophic bacteria group is a solid polymer biodegradable resin which has been processed, and a liquid high molecular carbon source generated from the high molecular carbon of a natural polysaccharide. The water treatment method according to 1.