JP2000343092A - Method and device for purifying water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further increase a purifying function for org. waste water by utilizing characteristics of charcoal. SOLUTION: In the device, a char tank 6 for adsorbing heavy metal, a low temp. carbonized char tank 3, a high temp. carbonized char tank 4 and a mixed char tank 5 are disposed in order from the upstream side of natural river 1 toward downstream side. Each char tank is formed by dividing both upstream and downstream sides with partitions 7 and 7 and packing the chars carbonized at a prescribed carbonizing temp. A low temp. carbonized char layer 32 is formed with the char 31 carbonized at 400-700 deg.C and having pH of 6-8, a high temp. carbonized char layer 42 is formed with the char 41 carbonized at 700-900 deg.C and having pH of >=8, a mixed char layer 52 is formed by mixing the char 31 and the char 41 and a char layer 2 for adsorbing the heavy metal is formed with the char carbonized at 900-1200 deg.C. The low temp. carbonized char layer becomes a proliferation zone of fungi and protozoans and the high temp. carbonized char layer becomes a proliferation zone of waterweed and a same phased biological purifying process as the self-purifying function inherent in a river is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water purification method and a water purification apparatus in which organic wastewater is used as water to be purified, and more particularly, to a water purification method suitably used for water purification of a river into which domestic wastewater flows. .

[0002]

2. Description of the Related Art Conventionally, a charcoal tank filled with charcoal is disposed in running water for river water into which organic wastewater such as domestic wastewater flows, and water purification is performed by the action of microorganisms that propagate on the charcoal. A water purification method and a water purification apparatus are known (for example, JP-A-7-000983,
0-231510).

[0003]

By the way, it is known that general rivers have a self-cleaning action in which organic substances in running water are purified by oxidative decomposition. That is, in a river, even if organic wastewater flows into the river, a phenomenon is known in which the water quality temporarily deteriorates, but becomes better as it goes downstream, and is purified. Such phenomena are caused by the diffusion, dilution, or sedimentation of large amounts of river water, as well as the absorption and decomposition of organic matter in the water during the growth and growth of microorganisms and organisms living in the water and river beds. It is due to the reduction.
The purification by oxidative decomposition of the organic matter is called self-cleaning action (biological self-cleaning action) inherent in rivers.
Such a self-cleaning action is caused by physicochemical changes as shown in FIG. 1 (see A and B in FIG. 1) and microbial changes (see C in FIG. 1).
(HPNHynes, The Biology of Polluted Waters, pp94,
Liverpool Univ. Press, 1978).

That is, when organic wastewater flows into a river,
First, the organic matter into which fungi (sewage fungi) and bacteria have grown and flowed is taken up by the fungi and bacteria. Next, the fungi and bacteria are ingested by the protozoa and the protozoa proliferate, while the protozoa are eaten by the microanimal and the microanimal by the large aqueous animal in order. Then, the algae will grow preferentially. During these times, water is purified by reducing BOD (biochemical oxygen demand) and salts. Further, the dissolved oxygen decreases most at the stage where heterotrophic microorganisms such as the above fungi grow most, and then gradually recovers. Although NH ₄ initially increases due to decomposition of organic nitrogen, NH ₄ increases.
Some of the after a nitrification to be oxidized NO ₃ by nitrifying bacteria and nitrate bacteria, nutrient salts, such as NH _4, NO ₃ and PO ₄ is lowered by being ingested algae.

[0005] However, although a certain amount of organic wastewater can be expected to be purified by the self-cleaning action as described above, if the inflow of organic wastewater increases, it becomes impossible to purify the organic wastewater only by the self-cleaning action.

Here, in the case of the above-mentioned conventional water purification apparatus, the charcoal of the charcoal tank is used only as a carrier as a breeding place of microorganisms, and the charcoal used is also particularly paying attention to its carbonization temperature. It did not precisely control the carbonization at a particular temperature. For this reason, various characteristics of charcoal cannot be fully utilized. Moreover, even if the charcoal tanks are arranged in multiple stages in the flow direction,
As a result of sludge accumulating on the charcoal layer in the charcoal tank and clogging the fine voids in the charcoal, oxygen shortage in the charcoal layer is caused and the biological purification function cannot be functioned sufficiently. . In addition, the clogging due to the above-mentioned sludge accumulation causes anaerobic fermentation, which in turn causes deterioration of water quality. In addition, if it is necessary to replace the charcoal layer once clogging occurs, a great deal of labor is required to remove the charcoal layer and newly set up the charcoal layer.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a water purification system capable of further increasing the purification function for organic wastewater by making full use of the characteristics of charcoal. It is to provide a method and a water purification device.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a process of self-cleaning of a river against inflowing organic wastewater, in which fungi, bacteria and protozoa are multiplied, and then algae are prioritized. Focusing on the point that it will be performed in stages by going through the process of multiplying, and the point that charcoal exhibits different characteristics and functions depending on the carbonization temperature,
By arranging the charcoal carbonized at a specific carbonization temperature in series in the flowing direction of the purification target water so as to have each function corresponding to the stepwise purification mechanism in the self-cleaning action, the same stage as the self-cleaning action is performed. The purpose is to enhance the objective purification.

More specifically, in the first invention according to the water purification method, the charcoal after the carbonization treatment is carbonized in a low temperature range where the charcoal after the carbonization treatment is mainly acidic within a carbonization temperature range of 300 ° C. to 1400 ° C. A first treatment in which the water to be purified is brought into contact with the low-temperature carbonized charcoal layer filled with the low-temperature carbonized charcoal; and the water to be purified having passed through the first treatment is converted into a basic charcoal within the above-described carbonization temperature range. And the second treatment of contacting a high-temperature carbonized charcoal layer filled with a high-temperature charcoal carbonized in a high-temperature region that exhibits stronger basicity than the low-temperature carbonized charcoal. is there.

In the first invention, the cycle consisting of the first process and the second process is repeated a plurality of times, that is, the first process and the second process are alternately repeated a plurality of times for the water to be purified. It may be performed. Finally, a final treatment of passing water to be purified may be added to a mixed charcoal layer in which charcoal carbonized in a low-temperature region and charcoal carbonized in a high-temperature region are mixed and filled.

Here, the respective settings of the “low temperature range”, which is the carbonization temperature range of the low-temperature carbonized char in the first process, and the “high temperature range”, which is the carbonization temperature range of the high-temperature charcoal in the second process, are as follows. What should I do? That is, when carbonizing wood material, the pH value of the charcoal after carbonization gradually increases as the carbonization temperature increases, that is, the acidity increases at a stage where the carbonization temperature is low, and the pH increases from the acidity as the carbonization temperature increases. It shifts to basic and becomes basic. As the “low temperature range”, acidic (for example, pH 5 to 7) or acidic to weakly basic (for example, pH 6 to 8) which is a main condition required for the low temperature carbonized charcoal to realize the function required in the first treatment is used. As shown in the figure, the carbonization temperature range may be set, and the “high temperature range” is basic (for example, pH 8 to 10), which is a main condition necessary for the high temperature carbonized charcoal to realize the function required in the second treatment. It is advisable to set the carbonization temperature range that will achieve 11). At this time, the correlation of the pH value with the carbonization temperature causes some differences depending on the wood species and the woody material as the carbonized material, and further causes a slight difference depending on the tree age, site, production area, and the like. For this reason, the “low temperature range” and the “high temperature range” may be set according to the above-mentioned wood and woody materials.

For example, as a general rule of thumb, if the "low temperature range" is approximately 300 ° C. to approximately 700 ° C.,
The “high temperature range” may be approximately 700 ° C. to approximately 1000 ° C. More specifically, the “low temperature range” is approximately 300 ° C. to approximately 50 ° C.
When the temperature is set to 0 ° C., the “high temperature range” is set to about 500 ° C. to about 100
0 ° C, when the “low temperature range” is approximately 300 ° C to approximately 550 ° C, when the “high temperature region” is approximately 550 ° C to 1000 ° C, and when the “low temperature region” is approximately 300 ° C to approximately 600 ° C, Is about 600 ° C to 1000 ° C for the “high temperature range” and about 30 for the “low temperature range”.
When the temperature is set to 0 ° C to approximately 650 ° C, the “high temperature range” is set to approximately 650 ° C.
What is necessary is just to make it respectively into 1000 degreeC-1000 degreeC. In each of the above carbonization temperature ranges, the lower limit temperature of each “low temperature range” is set to approximately 4
The temperature may be set to 00 ° C., or the upper limit temperature of each “high temperature range” may be set to approximately 900 ° C. When the lower limit temperature is set to approximately 400 ° C., the structure, specific surface area, pore size distribution, and other parameters are closer to the original charcoal than when the temperature is set to approximately 300 ° C., while the upper limit temperature is set to approximately 900 ° C. It is possible to simplify the equipment for carbonization and reduce the heating cost while expressing the pH value almost in the same manner as in the case of about 1000 ° C.

When setting the carbonization temperature range between the "low temperature range" and the "high temperature range", the carbonization temperature in the "high temperature range" is at least higher than the carbonization temperature in the "low temperature range". It may be set as follows. As a result, the high-temperature carbonized charcoal exhibits more basic characteristics than the low-temperature carbonized charcoal, and the same mechanism as the “self-cleaning action” is achieved by performing the stepwise treatment in the first treatment and the second treatment. , Which can realize stepwise purification having

In order to produce charcoal carbonized at a specific carbonization temperature as described above, a carbonized material such as thinned wood or waste wood is charged into a carbonization furnace such as a rotary kiln or a batch type fixed furnace, and a combustion burner or the like is provided. The carbonization furnace is heated under oxygen limitation by introducing the combustion exhaust gas. At the beginning of heating, a part of self-combustion or the like may be included, but the temperature of the internal atmosphere is increased by heating, and first, moisture is evaporated. Thereafter, the heating control by the combustion exhaust gas or the like is performed so as to reach the target temperature based on the detected temperature from the detecting means of the ambient temperature in the carbonizing furnace using a thermocouple or a radiation thermometer, and when the target temperature is reached, What is necessary is just to carbonize for a predetermined time while performing heating control so as to maintain the temperature. Therefore,
It is difficult to specify the above carbonization temperature range in units of 1 ° C.
It is specified on the order of 0 ° C.

In the first invention, the low-temperature carbonized charcoal carbonized in the low-temperature region mainly has a pH in an acidic range.
Value, for example, charcoal carbonized in a carbonization temperature range of 400 ° C. to 600 ° C. shows approximately pH 6 to 8, and in this pH range of 6 to 8, 0.2 μm to 2.0 μm in size of sewage fungi and bacteria and size. Protozoa between 50 μm and 100 μm will grow with the highest growth rate. In addition, the low-temperature carbonized charcoal has a radius of 100 to 1 compared with the high-temperature charcoaled charcoal described below.
It has a wide pore distribution of 000 nm, of which relatively large pores make it suitable as a carrier for microorganisms and nitrites and nitrates.

Therefore, in the first treatment for bringing the water to be purified into contact with the low-temperature carbonized charcoal bed filled with such low-temperature carbonized charcoal, the following effects are obtained. That is, in the low-temperature carbonized charcoal layer, the above-mentioned sewage fungi, bacteria, protozoa and nematodes all proliferate actively, and organic matter in the organic wastewater to be purified is taken up by the fungi. At this time, it is preferable to perform additional aeration for promoting the growth of fungi. As the aeration, an aggressive means such as blowing air into the water may be employed, or an aeration based on the natural flow of the water to be purified may be employed. That is, the degree of filling of charcoal in the charcoal layer is set so that there is a slight gap between the charcoals and the charcoal can move with each other by buoyancy, and the air is entrained by the flow of the water to be purified, and the entrained air flows. Each charcoal in the charcoal layer may come into contact with the air by diffusing into the gap and entering the void or moving charcoal in the flow. On the other hand, since the proliferated fungi and bacteria are consumed by protozoa, sludge that causes clogging of charcoal is generated,
That is, the quantification is maintained without abnormal growth of fungi and bacteria. In addition, since the protozoa are also predated by earthworms and the like, they are maintained at a constant level. Further, in the low-temperature carbonized charcoal layer, since the low-temperature carbonized charcoal itself is mainly acidic, NH ₄ generated by decomposing organic nitrogen in the organic wastewater is well adsorbed, and the adsorbed NH ₄ is absorbed by the low-temperature carbonized charcoal. It will be oxidized NO ₃ by supported nitrifying bacteria and nitrate bacteria.

That is, the low-temperature charcoal charcoal layer subjected to the first treatment functions as a growth zone for the above-mentioned sewage fungi, bacteria and protozoa. Conversely, the low-temperature carbonized charcoal is specified and selected in order to fulfill the function as the above-mentioned breeding zone in the “river self-cleaning action”. Therefore, the carbonization temperature for obtaining low-temperature carbonized charcoal in the present invention may be determined so as to exhibit the function as the breeding zone as described above. One of the indicators is a pH range at which the growth rate is maximized, that is, an acidic range or a weakly acidic range (for example, acidic pH 5 to 7), or a range from acidic to weakly basic or a range from weakly acidic to weakly basic. (For example, in the range of pH 6 to 8), and the carbonization temperature range that provides such a pH range may be determined by testing in advance for each carbonized material.

On the other hand, the high-temperature charcoal carbonized in the high-temperature region has a pH value in a basic range at least stronger than that of the low-temperature charcoal, for example, charcoal carbonized in a carbonization temperature range of 600 ° C. to 1000 ° C. has a pH value of approximately 8 to 10. Will be shown.
The high-temperature carbonized charcoal layer contains NO ₃ and N ₃ generated by nitrification as described above through the first treatment in the low-temperature carbonized charcoal layer.
The water to be purified, which is rich in nutrients such as H ₄ and PO _4, comes into contact.

Therefore, in the second treatment in which the water to be purified after the first treatment is brought into contact with the high-temperature charcoal charcoal layer, the following effects are obtained. That is, in the high-temperature carbonized charcoal layer, algae grow preferentially in the presence of the above-mentioned nutrients, and the dissolved oxygen amount gradually increases and recovers due to the carbon assimilation effect accompanying the growth of the algae. Therefore,
Even when the water to be purified after the second treatment is brought into contact with the same new low-temperature carbonized charcoal layer again, new aerobic bacteria grow in the presence of the organic matter, and the first treatment and the second treatment The same cycle processing is performed again on the purification target water that has passed through the cycle. In the recovery of the dissolved oxygen amount, sunlight or artificial light (infrared rays to visible rays to ultraviolet rays) should be actively irradiated to promote the carbonic acid assimilation of the algae and the like. Therefore, it is preferable to dispose the high-temperature carbonized charcoal layer in a state where it is exposed to the sunlight or artificial light. By receiving such light irradiation, in addition to the above-described carbonic acid assimilation action, energy for growing algae and the like and for maintaining life activity is provided, and particularly, it is called a growing light beam (growing electromagnetic wave). Light rays (electromagnetic waves) in a low-frequency range (for example, a frequency range of 789 tera Hz or less, a wavelength of 0.38 μm or more) close to ultraviolet light can achieve growth, maintenance of life, and recovery from damage of certain microorganisms. From such a viewpoint, it is preferable that the above-mentioned irradiation of sunlight or the like is similarly performed not only on the high-temperature charcoal charcoal layer but also on the low-temperature charcoal charcoal layer. On the other hand, if the nutrients are present in an excessively large amount, abnormal growth of algae occurs and water pollution is caused. On the other hand, in the high-temperature carbonized charcoal layer, the water pollution is prevented by the following actions. That is, since the high-temperature carbonized charcoal exhibits relatively strong basicity, it appropriately adsorbs acidic nutrients, and a part of the adsorbed salts is decomposed by reducing bacteria carried on the high-temperature charcoal. become. As a result, the charcoal is always in a regenerated state and maintains the ability to adsorb salts, and as a result, the amount of salts is appropriately maintained so that abnormal growth of algae does not occur.

In short, the high-temperature carbonized charcoal subjected to the second treatment functions as a growth zone for algae as described above. Conversely, the low-temperature carbonized charcoal is specified and selected in order to function as an algal growth zone in "river self-cleaning action". Therefore, the high-temperature carbonized charcoal in the present invention employs the order of contacting with the water to be purified after being brought into contact with the low-temperature carbonized charcoal layer, while the carbonization temperature for obtaining the high-temperature carbonized charcoal is the degree of algal growth as described above. May be determined so as to exhibit an adsorption function for maintaining the pressure appropriately. One of the indices is a carbonization temperature that indicates a basic range on the more basic side than low-temperature carbonized charcoal.If such a carbonization temperature range is determined in advance by testing each carbonized material, Good.

By the first and second treatments described above, the organic wastewater as the water to be purified is purified by microorganisms in the low-temperature carbonized charcoal layer, which is a growth zone for fungi and protozoa, and the high-temperature carbonization, which is a growth zone for algae. Purification is performed by a stepwise purification action consisting of an increase in dissolved oxygen in the charcoal layer and adsorption and decomposition of salts.

Further, by repeating one cycle consisting of the first process and the second process over a plurality of stages,
The degree of purification can be further improved, and the purification target water including the organic wastewater can be more reliably purified. In this case, as a final stage, the water to be purified is further brought into contact with a mixed charcoal layer obtained by mixing the low-temperature charcoal and the high-temperature charcoal in an arbitrary mixing ratio,
It is possible to adsorb soluble organic substances, which have not been removed by the first or second treatment, and acidic salts and basic salts, thereby further improving the degree of purification. become.

Further, when the water to be purified contains a heavy metal element or a heavy metal compound thereof (hereinafter, also referred to as "heavy metal or the like") such as factory wastewater in addition to organic wastewater such as household wastewater, the above-mentioned low-temperature carbonization is carried out. In order to prevent biological purification steps in the first treatment with the charcoal layer and the second treatment with the high-temperature charcoal charcoal layer from being hindered by the presence of the heavy metal or the like, the first step before the first treatment is performed. It is necessary to remove the heavy metals. In order to remove this heavy metal, a pretreatment of first contacting the water to be purified with a charcoal layer for adsorbing heavy metals to adsorb heavy metals in the water to be purified to the charcoal layer and removing the heavy metal in advance should be performed. Good. The charcoal layer for heavy metal adsorption may be formed by filling charcoal charcoalized in a temperature range in which the adsorption efficiency for the heavy metal to be adsorbed is high, although the preferable carbonization temperature range varies depending on the type of heavy metal to be adsorbed. In order to obtain such charcoal for heavy metal adsorption, the carbonized material may be carbonized by a production method similar to the aforementioned method for producing low-temperature or high-temperature charcoal charcoal. However, the carbonization temperature is considerably high (for example, 140
If the temperature exceeds 0 ° C.), firing may be performed in combination with an electric resistance furnace. In addition, as said heavy metal,
Examples include Zn, Cd, Hg, Sn, and Pb.

The carbonization temperature of the charcoal for heavy metal adsorption is charcoal.
For heavy metals in the range of 400 ° C to 1400 ° C
Demonstrates excellent adsorption performance, especially HgCl₂, HgBr
₂, HgI₂Carbonization temperature 4 for mercury halides such as
Charcoal carbonized at 00 ° C to 1400 ° C is Hg (C₂H₃
O₂) (Mercury acetate) and other organic mercury compounds
Each charcoal carbonized at a temperature of 800 ° C to 1400 ° C
Exhibits almost 100% adsorption performance and is comparable to that of commercial activated carbon
Demonstrates significantly higher adsorption performance. Also, Zn
(NO₃)₂For 600 ° C to 1400 ° C
Charcoal carbonized in the above range has the same or higher adsorbability than the above activated carbon
Shows CdCl₂, Pb (NO₃) ₂Against charcoal
Of charcoal carbonized at 1000 ℃ is almost 100%
Show performance.

Therefore, the carbonization temperature is 400 ° C. to 1400 ° C.,
500 ° C to 1400 ° C, 600 ° C to 1400 ° C, 700
℃ ~ 1400 ℃, 800 ℃ ~ 1400 ℃, 900 ℃ ~ 1
The charcoal for heavy metal adsorption carbonized in the temperature range of 400 ° C. or 1000 ° C. to 1400 ° C. exhibits almost 100% adsorptivity to mercury and a high selection for zinc, lead, cadmium, arsenic, etc. It becomes to show the target adsorptivity. In addition,
In these temperature ranges, the upper limit temperature is 1200
℃, 1100 ℃ or 1000 ℃,
A charcoal exhibiting high heavy metal adsorption performance while ensuring the ease and economy of carbonization of charcoal can be obtained.

Then, by performing the above pre-processing,
Removal of heavy metals and the like contained in the water to be purified can be performed in advance, and biological purification by the first and second treatments can be effectively performed. Therefore, when the present water purification method is applied to rivers into which industrial wastewater flows in addition to household wastewater, it is possible to remove heavy metals and the like by performing the above pretreatment in addition to removing organic compounds. become.

The second invention according to the water purification apparatus for carrying out the first invention is characterized in that the charcoal after the carbonization treatment is mainly acidic or acidic to weak base within a carbonization temperature range of 300 ° C. to 1400 ° C. Low-temperature carbonized charcoal tank filled with low-temperature carbonized charcoal carbonized in a low-temperature region, and charcoal after carbonization within the above-mentioned carbonization temperature range shows stronger basicity than the low-temperature carbonized charcoal A high-temperature carbonized charcoal tank filled with high-temperature carbonized charcoal that has been carbonized in a high-temperature region, and the low-temperature carbonized charcoal tank is disposed at an upstream position with respect to the flow path of the water to be purified. A high-temperature carbonized charcoal tank is disposed at a position downstream of the low-temperature carbonized charcoal tank adjacent to the low-temperature carbonized charcoal tank so that water to be purified passes through the low-temperature carbonized charcoal tank and the high-temperature carbonized charcoal tank in order. Make it a specific matter Than it is.

Here, the above-mentioned "low-temperature charcoal charcoal tank" or "high-temperature charcoal charcoal tank" partitions the flow path by a partition wall through which water can flow at predetermined intervals in the flow direction. Filling with low-temperature charcoal or high-temperature charcoal, or forming a container with water-permeable wall material,
It may be formed by filling low-temperature charcoal or high-temperature charcoal in this container and unitizing it. Examples of the above-mentioned "partition wall" or "wall material" include various wire meshes, metal plates with punched holes, expanded metals, and the like. In addition, what is necessary is just to form similarly to the above also in the "mixed charcoal tank" or the "charcoal tank for heavy metal adsorption" mentioned later.

In the second aspect of the present invention, a plurality of sets of a low-temperature charcoal charcoal tank on the upstream side for performing the first treatment and a high-temperature charcoal charcoal tank on the downstream side for performing the second treatment are formed. May be alternately arranged in the direction of. Also,
The mixed charcoal tank filled with a mixture of charcoal carbonized in the low-temperature region and charcoal carbonized in the high-temperature region passes through the mixed charcoal tank so that the water to be purified that has flowed out of the most downstream high-temperature charcoal tank passes through. The mixed charcoal tank may be disposed adjacent to the tank at a downstream position thereof to perform the final treatment.

In the second invention, an air supply means for supplying air (aeration) to at least the water to be purified in the low-temperature charcoal charcoal tank may be provided. As such an air supply means, for example, a sprinkler is provided above the low-temperature charcoal charcoal tank to spray shower water on the water surface, or a pipe for aeration is provided inside or below the low-temperature charcoal charcoal tank. May be blown out. Further, as the air supply means, for example, a low-temperature charcoal charcoal tank is provided such that a head is provided by a weir or the like above the low-temperature charcoal charcoal tank so that the water to be purified falls on the upper surface of the low-temperature charcoal charcoal tank by the above-mentioned head difference. The air supply may be performed by entraining the air by the falling water. Furthermore, even without providing the active air supply means as described above, the air supply means is constituted by utilizing the degree of filling of charcoal into the charcoal tank and the air entrained by the natural flow of the water to be purified. Is also good.
In this case, as the air supply means, as described in the first invention, a gap exists between the charcoals, and the filling degree is set to such an extent that the charcoal can move each other by the action of buoyancy. The entrained air may be diffused between the charcoals together with the flow by the force of the flow to make contact between each charcoal and the air. In order to make it easy to actively entrain air, for example, an obstacle or the like in which natural rocks are piled up is installed in the stream of the water to be purified before flowing into the low-temperature charcoal charcoal tank, and the stream is slightly turbulent. What should I do?

Further, in relation to the degree of filling, low-temperature charcoal or high-temperature charcoal, especially low-temperature charcoal,
Granular, lump or flaky charcoal of 50 mm to 50 mm, or rod-like charcoal with a diameter of 5 cm to 25 cm and a length of about 5 cm to 100 cm, and put the charcoal in a tank such as a low-temperature charcoal charcoal tank or a high-temperature charcoal charcoal tank. 4 of its internal volume
It is preferable to fill at a coarse filling degree such that the volume ratio is about 0% to 80%. As a result, initially, the water floats in the tank due to buoyancy and absorbs water, and the specific gravity is almost 1.0.
In response to the flow of the water to be purified, the water moves repeatedly forward, backward, left, right, up, down, and turns, turns, and inverts, and the contact between the water to be purified and the charcoal is promoted. The water to be purified is agitated, causing a turbulent state in each tank. The occurrence of the turbulent state also promotes the contact between the air and the charcoal. In addition, by enabling the free movement of each charcoal, if the water to be purified is river water, even if a situation such as heavy rainfall temporarily increases mud on the surface of each charcoal The mud placed on the surface of each charcoal sinks downward due to the upside down movement of each charcoal, and the occurrence of clogging and the like on each charcoal surface can be effectively prevented. Note that the above description is the same in the first invention.

Further, the "flow path" according to the second aspect of the present invention.
Is a natural river or an artificial waterway, and the low-temperature charcoal charcoal tank and the high-temperature charcoal charcoal tank are immersed in flowing water flowing through the natural river or artificial waterway, or are disposed with only the upper end protruding from the water surface. I just need. In addition, you may employ | adopt a culvert or a pipe-shaped closed space as said "flow path." At this time, it is preferable to arrange each charcoal tank so that sunlight or artificial light is preferably incident on the low-temperature charcoal charcoal tank and the high-temperature charcoal charcoal tank, or at least on the high-temperature charcoal charcoal tank. In the case of a natural river or an artificial waterway, at least the upper part of the high-temperature charcoal charcoal tank may be opened to expose to sunlight, and in the case of a closed space such as the culvert described above, the high-temperature charcoal charcoal tank Irradiation of artificial light ranging from infrared rays to visible rays to ultraviolet rays may be performed from above. And, when the above is opened to be exposed to sunlight, the upper end of each charcoal tank is protruded from the water surface to be exposed and exposed to the atmosphere, thereby maintaining and promoting life activity of microorganisms by light, Promotion of supply and diffusion of oxygen into water and promotion of oxidation by air and oxygen in water are effectively achieved.

The definitions of the "low temperature range" and the "high temperature range" which are the carbonization temperature ranges in the second invention are the same as those in the first invention, and therefore the description is omitted.

In the case of the second aspect, the low-temperature charcoal charcoal filled in the low-temperature charcoal charcoal tank forms a low-temperature charcoal charcoal layer, and the high-temperature charcoal charcoal filled in the high-temperature charcoal charcoal tank causes the high-temperature charcoal charcoal layer. Is formed. Then, the first treatment in the first invention is performed in the low-temperature charcoal charcoal tank, and the second treatment in the first invention is performed in the high-temperature charcoal charcoal tank. Also, by combining the low-temperature charcoal charcoal tank and the high-temperature charcoal charcoal tank as one set and disposing a plurality of sets in series in the flow direction, the first processing and the second processing in the first invention can be performed. Can be repeated a plurality of times. As described above, in the case of the second invention, the water purification method of the first invention can be specifically and reliably implemented.

In the case where the water to be purified contains a heavy metal compound such as industrial wastewater, the above second invention is further provided with a heavy metal adsorption charcoal tank filled with heavy metal adsorption charcoal. The charcoal tank for heavy metal adsorption is disposed at the most upstream position of the flow path so that the water to be purified after passing through the charcoal tank for heavy metal adsorption flows into the low-temperature charcoal charcoal tank. What is necessary is just to perform the above-mentioned pre-processing. In this case, the object to be adsorbed by the charcoal for heavy metal adsorption, the temperature range of the carbonization temperature thereof, and the like are the same as those described in the first invention, and therefore, detailed description is omitted.

[0036]

As described above, according to the water purification method of the first invention, biological stepwise purification similar to the self-purifying action of a river can be artificially realized. . This makes it possible to significantly improve the purification function as compared to a case where the purification target water is simply contacted with multiple charcoal layers carbonized at the same carbonization temperature in multiple stages, and the purification target water containing organic wastewater is reliably obtained. Can be purified. When this method is applied to a river, in addition to the above-described self-cleaning action inherent in a river, the self-cleaning action can be enhanced and promoted. In addition, even when the present method is applied to an artificial flow path or pipe, the water to be purified can be surely purified by the stepwise purification.

Moreover, clogging caused by sludge of charcoal, which is a carrier of microorganisms, can be reliably prevented by adopting the above-described stepwise purification, and the purification function can be maintained for a long period of time to replace charcoal layers. The labor can be reduced as much as possible.

Further, according to the water purification apparatus of the second invention, the first invention can be concretely and reliably implemented, and the effect of the water purification method can be reliably obtained. become.

[0039]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 2 shows a water purification apparatus according to a first embodiment of the present invention. In the first embodiment,
The river water 2 that is provided for the natural river 1 as a flow channel
Is the water to be purified. In FIG. 2, 3, 3
Is a low-temperature charcoal charcoal tank, 4 and 4 are high-temperature charcoal charcoal tanks, 5 is a mixed charcoal tank, and 6 is a charcoal tank for heavy metal adsorption.

As the above-mentioned natural river 1, a river in which household wastewater or industrial wastewater flows in upstream of the place where the present water purification device is installed is selected. The present water purification device is applied to a case including a heavy metal compound.

The above four types of charcoal tanks 3, 4 in total
Reference numerals 5 and 6 denote a charcoal tank 6 for heavy metal adsorption, a low-temperature charcoal charcoal tank 3, a high-temperature charcoal charcoal tank 4, a low-temperature charcoal charcoal tank 3, a high-temperature charcoal charcoal tank 4, and a mixed charcoal from the upstream to the downstream of the natural river 1. The tanks 5 are arranged in series in this order. Each charcoal tank 3, 4,
5 and 6, the upstream and downstream sides (left and right sides in FIG. 2) extend in a direction (river width direction) orthogonal to the flow direction (upstream and downstream direction) of the river water 2 and flow through the natural river 1. And a charcoal 31, which is filled with a specific carbonization temperature between the partition walls 7, which are adjacent to each other on the upstream and downstream sides.
41 and 61 are formed.

The low-temperature charcoal charcoal tank 3 has a low-temperature charcoal charcoal layer 32 formed by filling low-temperature charcoal 31 carbonized at a temperature of, for example, about 500 ° C. between partition walls 7 on both the upstream and downstream sides. The high-temperature carbonized charcoal tank 4 is similarly formed by filling a high-temperature carbonized charcoal layer 42 between the partition walls 7 by filling a high-temperature carbonized charcoal 41 carbonized at a temperature of, for example, about 800 ° C. The mixed charcoal tank 5 is filled with the low-temperature charcoal 31 and the high-temperature charcoal 41 mixed in an arbitrary ratio (for example, 1: 1) between the two partition walls 7, 7. The mixed charcoal layer 52 is formed. Further, the charcoal tank 6 for heavy metal adsorption is filled with charcoal for heavy metal adsorption carbonized at a temperature of, for example, about 1000 ° C. between the same partition walls 7, 7 as above to form a charcoal layer 62 for heavy metal adsorption. It is a thing. As the form of each of the charcoals 31 and 41, various shapes such as a bar, a piece, a lump, and a grain can be adopted in relation to a wall material described later which forms the partition wall 7. In addition, the above-described filling is preferably performed so that a gap is left between the individual charcoals such that the river water 2 can pass through, and preferably, the charcoal becomes a floating state due to the buoyancy of the water, moves in the tank by the force of the flow, and becomes a solar cell. It may be performed to such an extent that light reception of light or the like or contact promotion by diffusion of oxygen in the atmosphere and water is achieved.

The size of the charcoal tanks 3, 4, 5, 6 in the flow direction, that is, the two partition walls 7,
In the interval of 7, the water to be purified is each charcoal layer 32, 42, 52, 6
It is preferable to have a predetermined length (for example, 2 m or more in the case of a relatively gentle flow) so that the contact with the charcoal tank 2 can be maintained for a certain period of time, for example, about 30 minutes. The size in the depth direction of 3, 4, 5, and 6 (the depth of the partition wall 7) is at least a predetermined depth within a range in which the growing light beam from the sun ray or the like can exert an effect in water at least in the high-temperature charcoal charcoal tank 4. (For example, 0.5 m or more and 6 m or less).

If each partition wall 7 has a gap through which water can pass and the gap is set to a size that can hold various charcoals 31 and 41 in place, metal or wood is used. Various wall materials can be used regardless of the material used. For example, a wire mesh or the like may be fixed by a frame member such as a support, or a partition wall having a self-supporting rigidity such as a punched metal or an expanded metal having a large number of holes may be installed. 7 may be formed.

A shower head 8 as an air supply means is disposed above each of the low-temperature charcoal charcoal tanks 3.
Aerating treatment is performed by spraying water in a shower shape on the water surface at the upper surface position of No. 2.

The charcoal tank 6 for adsorbing heavy metals at the most upstream position
A screen or the like for blocking relatively large floating dust or the like may be provided at a position upstream of the screen.

In the case of the first embodiment, even if the river water 2 contains organic wastewater or a heavy metal compound, the river water 2 is first subjected to a pretreatment in the charcoal tank 6 for heavy metal adsorption. By this pretreatment, the heavy metal compound is adsorbed and removed by the charcoal layer 62 for heavy metal adsorption.
Next, biological stepwise purification is performed on the river water 2 from which the heavy metal compounds have been removed. That is, the first treatment by the low-temperature charcoal charcoal tank 3 and the second treatment by the high-temperature charcoal charcoal tank 4 are alternately repeated twice for the river water 2, and finally, the treatment by the mixed charcoal charcoal tank 5 is performed. . This allows
Organic compounds are removed and water purification is performed. At this time, the aeration of the low-temperature carbonized charcoal tank 3 promotes the growth of aerobic fungi.

If the natural river water 1 does not cause the inflow of heavy metal compounds such as industrial wastewater, the installation of the charcoal tank 6 for adsorbing heavy metals is not necessary and may be omitted. Good.

<Second Embodiment> FIG. 3 shows a water purification apparatus according to a second embodiment. In the second embodiment, the water 12 to be purified is dropped on the upper surface of the low-temperature carbonized charcoal tank 3 with a drop, thereby performing aeration treatment on the water 12 to be purified contained in the low-temperature carbonized charcoal layer 32. It was done.
In the second embodiment, components having the same configuration as in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and a detailed description thereof will be omitted. For one combination of the low-temperature charcoal charcoal tank 3 on the upstream side and the high-temperature charcoal charcoal tank 4 on the downstream side, one weir 13 is provided at an upstream position of the low-temperature charcoal charcoal tank 3,
Discharge port 13 of weir 13 against the upper surface of low-temperature carbonized charcoal tank 3
The water 12 to be purified falls from a. The flow path 11 in the second embodiment may be a natural river or an artificial flow path in a water treatment plant.

More specifically, two weirs 13, 13 are formed in the flow path 11 at predetermined intervals in the upstream and downstream directions, and a charcoal tank 6 for heavy metal adsorption is provided upstream of the upstream weir 13. On the other hand, between the upstream weir 13 and the downstream weir 13, a first low-temperature charcoal charcoal tank 3 and a first high-temperature charcoal charcoal tank 4 are provided.
The second low-temperature charcoal charcoal tank 3, the second high-temperature charcoal charcoal tank 4, and the mixed charcoal tank 5 are disposed in this order downstream of the downstream weir 13. Then, in the first low-temperature carbonized charcoal tank 3 immediately below the upstream weir 13, the water 12 to be purified that has passed through the heavy metal adsorption charcoal layer 62 of the heavy metal adsorption charcoal tank 6 is caused to fall through the discharge port 13a,
Further, in the second low-temperature charcoal charcoal tank 3 immediately below the downstream weir 13, the water to be purified that has passed through the high-temperature charcoal charcoal layer 42 of the first high-temperature charcoal charcoal tank 4 is caused to fall through the discharge port 13 a.

<Third Embodiment> FIG. 4 shows a water purification apparatus according to a third embodiment of the present invention. In the third embodiment,
The low-temperature charcoal charcoal tank 3 and the high-temperature charcoal charcoal tank 4 and the like are constituted by charcoal units 23 and 24. In the case where the flow path 21 is a river having a relatively wide river width or an artificial flow path as the flow path 21 It is suitably applied to a case where a water purification device is relatively easily installed. Also in the case of the present embodiment, the same reference numerals are given to the components having the same configuration as the first embodiment, and the detailed description thereof will be omitted.

The charcoal units 23 and 24 are made of, for example, a container 25 made of the same wall material as the partition wall 7 of the first embodiment, such as a wire mesh, and the inside of the container 25 is filled with low-temperature charcoal 31 or 41. The low-temperature carbonized charcoal layer 32 or the high-temperature carbonized charcoal layer 42 is formed. As an example of the size of the charcoal units 23 and 24, it is preferable to set the dimension in the depth direction to about 0.8 to 1.5 m in consideration of convenience of handling. Then, a predetermined number of charcoal units 23 and 24 may be stacked in the depth direction in accordance with the depth of the flow path in which this is installed.

The low-temperature carbonized charcoal tank 3 is formed by arranging a plurality of charcoal units 23 accommodating the low-temperature charcoal charcoal layer 32 so as to partition the flow path 21 in the width direction. The charcoal tank 4 has a high-temperature carbonized charcoal layer 42.
The charcoal unit 24 accommodating the flow channel 21 is
Are formed by arranging a plurality of parts so as to partition in the width direction. At this time, the respective charcoal units 23 and the respective charcoal units 24 are arranged in a staggered manner in plan view, whereby the two charcoal units 2 adjacent in the width direction are arranged.
3 and 23, and both charcoal units 24 and 24
The gap between them is not arranged in a straight line in the flow direction of the purification target water 22.

In the case of the third embodiment, the charcoal unit 2
By previously forming the predetermined number of charcoal units 23 or 24 with respect to the flow path 21, the low-temperature charcoal charcoal tank 3 or the high-temperature carbonization tank irrespective of the width of the flow path 21. The charcoal tank 4 can be easily installed and formed, and labor for forming the water purification device can be saved. The purification target water 22 flowing down from the upstream side first contacts the low-temperature charcoal charcoal layer 32 of the low-temperature charcoal charcoal tank 3 to perform the first treatment, and then contacts the high-temperature charcoal charcoal layer 42 of the high-temperature charcoal charcoal tank 4. Upon contact, the second processing is performed, and this is repeated.

It should be noted that also in the third embodiment, the first
When the charcoal tank 6 for heavy metal adsorption or the mixed charcoal tank 5 described in the embodiment is provided, the charcoal unit 23,
The unit may be formed as in unit 24.

[0057]

Example: Carbonization temperature of charcoal when cedar wood (sapwood; sapwood) is powdered and this cedar powder is carbonized as a carbonized material;
The relationship with the pH value of the charcoal after carbonization was measured by a test. The result is shown in FIG.

FIG. 5 shows that as the carbonization temperature increases from the start of the carbonization treatment, the pH value increases and the acidity gradually changes from basic to basic. As a specific correlation between the carbonization temperature and the pH value, a carbonization temperature of 300 ° C. indicates a little less than pH 6, a carbonization temperature of 400 ° C. shows a pH 6, and a carbonization temperature of 500 slightly exceeds pH 7, and a carbonization temperature of 550 ° C. shows almost a pH of 8. Will be shown. And carbonization temperature 600 ° C
In the range of -900 ° C, the pH is in the range of 8-9, and at a carbonization temperature of 1000 ° C, the pH is slightly lower, and at a carbonization temperature of 1,100 ° C, the peak value of pH11 is higher (pH 11.2). Then, at a carbonization temperature of 1200 ° C. and a pH of less than 10,
The pH value gradually decreases, such as a carbonization temperature of 1300 ° C. and a pH of slightly over 9;
3).

Therefore, in the case of this test example, the carbonization temperature 3
It shows a pH of 6 to 8 in the range from 00 ° C or 400 ° C to slightly lower than 600 ° C (less than 600 ° C),
It will exhibit a pH value higher than pH 8 in the range of the carbonization temperature of 00 ° C.

FIG. 6 shows another test example (wooden composite material research result report, edited and issued by the Woody Composite Material Technology Research Association, March 31, 1998) as a reference example. In this reference example, too, cedar wood was selected as a carbonized material, and the relationship between carbonization temperature and pH was measured.

According to FIG. 6, at a carbonization temperature of 300 ° C., p
H5 strong, carbonization temperature 400 ° C, pH6 weak, carbonization temperature 5
PH 6 is shown at 00 ° C. Further, when the carbonization temperature is between 550 ° C. and 600 ° C. and the pH exceeds 7, the carbonization temperature is 60 ° C.
Shows pH 7.5 at 0 ° C, carbonization temperature 650 ° C-700 ° C
During this period, the pH exceeds 8 and the pH rises to a little over 8 at a carbonization temperature of 700 ° C. And the carbonization temperature 700 ° C to 1000 ° C
In the range of pH 8 to 10 is shown.

Accordingly, in the case of this reference example, pH 6 to 8 is shown when the carbonization temperature is in the range of about 400 ° C. to about 700 ° C. (less than 700 ° C.).
It will show a pH value higher than 8.

When FIG. 6 is compared with FIG. 5 described above, the tendency that the pH value gradually changes from acidic to basic as the carbonization temperature increases is the same, but the carbonization temperature and the pH value are both the same. In the specific correlation, there is a slight shift between the two. This means that while the specific correlation changes depending on the type of tree, the same correlation may cause a slight shift in the specific correlation due to the difference in the place of production, age, or site used as a carbonized material even for the same tree type. Conceivable.

For this reason, the carbonization temperature range for obtaining the low-temperature carbonized charcoal or the high-temperature carbonized charcoal of the present invention is specified by measuring the relationship between the carbonization temperature and the pH value of a specific carbonized material used for carbonization in advance. There is a need.

In order to clarify the difference in characteristics between the low-temperature carbonized charcoal and the high-temperature carbonized charcoal, a low-temperature range of 400 to 700 ° C. is set as the carbonization temperature.
PH value when the high temperature range is 0 ° C to 900 ° C,
Table 1 shows a comparison of each item of the pore distribution, specific surface area, adsorption power, and cell size of the honeycomb structure.

[0066]

[Table 1]

[0067]

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing the self-cleaning action of a natural river.

FIG. 2 is a schematic view showing the water purification device of the first embodiment in a longitudinal sectional state.

FIG. 3 is a schematic diagram showing a water purification device according to a second embodiment in a longitudinal sectional state.

FIG. 4 is a schematic diagram illustrating a water purification device according to a third embodiment in a planar state.

FIG. 5 is a view showing a test example of a relationship between a carbonization temperature and a pH value.

FIG. 6 is a diagram showing a reference example of the relationship between the carbonization temperature and the pH value.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Natural river (flow path) 2 River water (purification target water) 3 Low-temperature charcoal charcoal tank 4 High-temperature charcoal charcoal tank 5 Mixed charcoal tank 6 Charcoal tank for heavy metal adsorption 8 Shower head (air supply means) 11, 21 Channel 12, 22 Water to be purified

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D003 AA12 AB02 AB08 AB09 BA01 BA02 BA03 BA04 BA07 CA03 CA07 DA01 DA14 DA18 DA19 DA21 DA30 EA01 EA14 EA19 EA25 EA38 FA01 FA02 4D024 AA05 AB16 BA03 BC01 CA01 DB10 DB15 4D037 AA05A CA01 CA07

Claims (8)

[Claims] 1. A low-temperature carbonized charcoal layer filled with low-temperature carbonized charcoal which is carbonized in a low-temperature region where charcoal after carbonization mainly exhibits acidity within a carbonization temperature range of 300 ° C. to 1400 ° C. A first treatment in which water is brought into contact with the water to be purified after the first treatment, that the charcoal after the carbonization treatment is basic within the above-mentioned carbonization temperature range and shows a stronger basicity than the low-temperature carbonized charcoal; A second treatment of contacting a high-temperature carbonized charcoal layer filled with high-temperature carbonized charcoal carbonized in a high-temperature region. 2. The water purification method according to claim 1, wherein a cycle comprising the first processing and the second processing is repeated a plurality of times. 3. The method according to claim 1, wherein water to be purified is brought into contact with a mixed charcoal layer obtained by mixing and filling charcoal carbonized in a low-temperature region and charcoal carbonized in a high-temperature region. A water purification method, wherein a final treatment is performed. 4. A low-temperature carbonized charcoal tank filled with low-temperature charcoal charcoalized in a low-temperature region where charcoal after carbonization is mainly acidic in a carbonization temperature range of 300 ° C. to 1400 ° C., A high-temperature carbonized charcoal tank filled with high-temperature charcoal that has been carbonized in a high-temperature region in which the charcoal after carbonization is basic within the carbonization temperature range and has a higher basicity than the low-temperature carbonized charcoal. The low-temperature charcoal tank is disposed at an upstream position with respect to the flow path of the water to be purified, while the high-temperature charcoal tank is adjacent to the low-temperature charcoal tank at a downstream position of the low-temperature charcoal tank. A water purification apparatus, wherein the water to be purified is configured to sequentially pass through the low-temperature charcoal charcoal tank and the high-temperature charcoal charcoal tank. 5. The method according to claim 4, wherein a plurality of sets of the low-temperature charcoal charcoal tank on the upstream side and the high-temperature charcoal charcoal tank on the downstream side are arranged alternately from the upstream side to the downstream side. Characterized water purification device. 6. The mixed charcoal tank according to claim 4 or 5, further comprising a mixed charcoal tank filled with a mixture of charcoal carbonized in a low-temperature region and charcoal carbonized in a high-temperature region. A water purification device, which is disposed adjacent to and downstream of the high-temperature charcoal charcoal tank so that water to be purified flowing out of the high-temperature charcoal charcoal tank on the side passes therethrough. 7. A water purification apparatus according to claim 4, further comprising an air supply means for supplying air to at least purification target water passing through the low-temperature charcoal charcoal tank. . 8. The high-temperature charcoal tank according to any one of claims 4 to 7, wherein the channel is a natural river or an artificial waterway, and at least the high-temperature charcoal tank can receive sunlight or artificial light. Water purifier characterized by being arranged as follows.