JP2005007234A - Water purification measure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently remove nitrate nitrogen contained in ground water at a low cost. <P>SOLUTION: The subject purification measure 1 for a water source has a hollow space 2 at the inside by forming a water purification material so as to be a hollow cylindrical shape with a bottom. The purification measure 1 for the water source is produced with a water purification material having denitrification action and water permeability. Specifically, it can be produced by a method wherein lime, sulfur, and sulfur oxidizing bacteria are mixed, or a sludge solidified body in which cement-containing alkaline sludge is solidified by the solidification action of the cement, sulfur and sulfur oxidizing bacteria are mixed, or alkaline sludge containing cement being a hydraulic material, sulfur and sulfur oxidizing bacterial are mixed before the solidification of the alkaline sludge. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water purification jar that purifies groundwater contaminated mainly with nitrate nitrogen.
[0002]
[Prior art]
Recently, nitrate nitrogen has become a problem as a harmful pollutant contained in groundwater. Such problems are thought to be caused by the eutrophication of water quality by nitrogen and phosphorus in closed water areas such as lakes and rivers, and as a result, flowing into groundwater in the form of nitrate nitrogen.
[0003]
Nitrate nitrogen is a substance produced as a result of decomposition of nitrogen components in agricultural chemicals, herbicides, fertilizers, manure, etc. by microorganisms, but when nitrate nitrogen enters the body, it is reduced and nitrous acid is added. It changes to natural nitrogen and produces a substance called nitrosamine, which is a carcinogen, or causes so-called methemoglobinemia, which decreases the function of hemoglobin in the blood and causes oxygen deficiency, resulting in cyanosis. Has been pointed out.
[0004]
Therefore, nitrate nitrogen contained in groundwater must be removed in advance so that the concentration is less than the concentration that does not cause health damage.
[0005]
[Patent Document 1]
Japanese Unexamined Patent Publication No. 2000-232728
[0006]
[Patent Document 2]
Japanese Patent Laid-Open No. 10-113693
[0007]
[Patent Document 3]
JP-A-10-286590
[0008]
[Problems to be solved by the invention]
As a method of removing nitrate nitrogen contained in water, attempts have been made to reduce the nitrate nitrogen to nitrogen gas by a plant, and some have already been put into practical use.
[0009]
Here, as a method put into practical use in the plant, there are a sludge sludge method, a dual sludge method, a single sludge method, etc., all of which are hydrogen donors (usually, for reducing nitrate nitrogen in an intermediate step). Methanol) is required separately, or the addition of an alkaline agent that neutralizes the pH is required, and as a result, the reaction process becomes complicated. There was still room for improvement in processing at low cost.
[0010]
In addition to purifying groundwater contaminated with nitrate nitrogen, the development of technology to prevent such a situation from occurring in the first place has also been awaited.
[0011]
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a water purification jar that can efficiently remove nitrate nitrogen contained in groundwater at low cost.
[0012]
Another object of the present invention is to provide a water purification jar capable of preventing nitrate nitrogen produced from agricultural chemicals, herbicides, fertilizers, manure, etc. from penetrating into the ground and flowing into groundwater.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, a water purification jar according to the present invention is configured such that a hollow space is formed inside a water purification material having denitrification and water permeability as described in claim 1. It is made.
[0014]
Further, the water purification tank according to the present invention is arranged such that a water-permeable space is formed between the water purification material and a hollow inner surface of the water purification material, and the water-impermeable tube is filled with a filtering material in the water-impermeable tube. In addition, the lower part of the filter medium is communicated with the water guiding space.
[0015]
Further, as described in claim 3, the water purification paddle according to the present invention forms a solid water purification material having a denitrification action and water permeability and breathability, and a water pipe or A drain pipe is inserted.
[0016]
Moreover, the water purification pad according to the present invention is configured by mixing the water purification material with lime, sulfur and sulfur-oxidizing bacteria.
[0017]
Further, the water purification pad according to the present invention is configured by mixing the water purification material with alkaline waste mud containing hydraulic material, sulfur and sulfur-oxidizing bacteria before solidification of the alkaline waste mud. is there.
[0018]
Further, the water purification pad according to the present invention is a mixture of the water purification material, the waste sludge solidified by alkaline waste mud containing the hydraulic material solidified by the solidification action of the hydraulic material, and sulfur and sulfur-oxidizing bacteria. It is configured as follows.
[0019]
In the water purification tank according to the present invention, the water purification material having a denitrification action and water permeability is configured such that a hollow space is formed therein, or has a denitrification action and water permeability. In addition, a water purification material having air permeability is solidly formed, and a pumping pipe or a drain pipe is inserted into the water purification material.
[0020]
If it does in this way, nitrate nitrogen in water will be reduced to nitrogen gas by the denitrification action of a water purification material.
[0021]
For example, in the inventions according to claims 4 to 6, the water purification material contains sulfur and sulfur-oxidizing bacteria, and when the water purification material and water containing nitrate nitrogen come into contact with each other, Sulfur is oxidized by the enzyme activity of sulfur-oxidizing bacteria, and along with the oxidation reaction, the sulfur becomes an electron donor, and nitrate nitrogen in water is reduced to nitrogen gas.
[0022]
Here, sulfur is oxidized by itself to become sulfuric acid, but is neutralized by alkali components in lime and alkaline waste mud. For example, sulfuric acid becomes neutral gypsum by neutralizing with calcium carbonate or calcium hydroxide in lime or alkaline waste mud. Therefore, it is possible to prevent the pH from being lowered by sulfuric acid and prevent the enzyme activity of sulfur-oxidizing bacteria from being lowered. In the case of alkaline waste mud, in the past, it had to be disposed of as industrial waste. However, according to the present invention, there is a remarkable effect that it can be effectively used as a raw material for detoxifying nitrate nitrogen.
[0023]
The problem of nitrate nitrogen contamination is already known in the field of microorganisms at the time of filing of the present application, and the possibility of using sulfur and sulfur-oxidizing bacteria as a method for denitrifying such nitrate nitrogen and sulfuric acid in limestone It is also known that can be neutralized.
[0024]
On the other hand, in the civil engineering and construction industry, a large amount of alkaline waste mud is generated by mud construction methods such as the underground continuous wall construction method, and its disposal becomes a big social problem, and groundwater contaminated with nitrate nitrogen is also removed. When it was used as a water source, development of economically feasible purification technology was awaited. In addition, development of a purification technology that prevents the contaminated water contaminated with nitrate nitrogen from penetrating into the ground and flowing into the groundwater has been awaited.
[0025]
The applicant is concerned with the above-mentioned problem and the social situation where sulfur is surplus in the desulfurization process in gasoline refining etc. As a result of conducting various research and development, we have obtained the above-mentioned new knowledge, and I will add it just in case that the knowledge is extremely significant in the industry.
[0026]
In order for the water purification material to have water permeability or water permeability and air permeability, for example, a method of adjusting components so as to cause cracking, or a method of forming a porous body by adding a foaming agent or the like can be considered. .
[0027]
Constructing the water purification material such that a hollow space is formed therein includes, for example, a case where the water purification material is formed in a bottomed cylindrical shape, and a case where the water purification material is formed in a solid shape. Including a solid cylindrical shape, a solid rectangular tube shape is included.
[0028]
In the configuration in which the water purification material is solidly formed and the pumping pipe or the drainage pipe penetrates the water purification material, the inside of the pumping pipe or the drainage pipe is communicated with the internal water-permeable space of the water purification material, and at the penetration point, It is desirable to provide a number of holes in the pumping pipe and drain pipe. The internal water permeable space mainly means fine cracks and voids.
[0029]
Here, in order to use the water purification tank according to claim 1, the water purification tank is buried near the ground surface so that the top opening of the water purification tank communicates with the atmosphere.
[0030]
In this case, the water purification tank can be used in two ways: a water source tank and an underground infiltration tank.
[0031]
That is, when the surrounding groundwater is contaminated with nitrate nitrogen and the groundwater is to be used as a water source, the water in the hollow space of the water source purification tank is pumped up.
[0032]
The water in the purification basin for the water source is one in which the surrounding ground water has permeated through the water purification material that constitutes the purification basin for the water source. The action occurs, and nitrate nitrogen contained in the groundwater is reduced to nitrogen gas, and the nitrogen gas is released to the atmosphere through the top opening of the water source purification tank. The pumped water can be used as water from which nitrate nitrogen has been removed.
[0033]
By the way, the environment where the surrounding groundwater is contaminated with nitrate nitrogen includes the environment where groundwater is stored by underground dams and the groundwater is contaminated.
[0034]
On the other hand, when contaminated water containing nitrate nitrogen generated from domestic wastewater, agricultural chemicals, herbicides, fertilizers, manure, etc. is to be infiltrated underground, such contaminated water is put into the hollow space of the underground infiltration septic tank.
[0035]
In this case, the contaminated water in the underground infiltration basin passes through the water purification material constituting the underground infiltration basin and flows out to the surrounding ground. Nitrification occurs, and nitrate nitrogen contained in the contaminated water is reduced to nitrogen gas, and the nitrogen gas is released to the atmosphere through the soil voids. The outflowed water eventually joins groundwater as water from which nitrate nitrogen has been removed.
[0036]
In the water purification tank according to claim 1, an impermeable pipe is disposed in the hollow space so that a water guide space is formed between the hollow inner surface of the water purification material and the impervious pipe is filled with a filter medium. In addition, when the lower part of the filter medium is communicated with the water conveyance space, the treated water from which nitrate nitrogen has been removed by the denitrification action flows through the water conveyance space when used as a water source purification tank, and enters the impermeable pipe. Water is once collected below the filled filter medium.
[0037]
Therefore, the treated water from which nitrate nitrogen has been removed passes through the filter medium from the bottom to the top during pumping, and it is possible to perform not only nitrate nitrogen but also necessary purification as clean water. .
[0038]
In order to use the water purification pad according to claim 3, it is embedded near the ground surface so that the internal ventilation space of the water purification material constituting the water purification pad communicates with the atmosphere. The internal ventilation space means mainly fine cracks and voids like the internal water permeable space, and may also serve as the internal water permeable space.
[0039]
In this case, the water purification tank can be used in two ways, as in the case of claim 1, a water source cleaning tank and an underground infiltration tank.
[0040]
That is, when the surrounding groundwater is contaminated with nitrate nitrogen and the groundwater is to be used as a water source, the water in the internal permeable space of the water source purification tub is pumped through the pumping pipe.
[0041]
In this way, as in the invention according to claim 1, the denitrification action described above occurs in the water permeation step, nitrate nitrogen contained in the groundwater is reduced to nitrogen gas, and the nitrogen gas is water purification. It is released to the atmosphere through the internal ventilation space of the material. The pumped water can be used as water from which nitrate nitrogen has been removed.
[0042]
On the other hand, if you want to infiltrate contaminated water containing nitrate nitrogen generated from domestic wastewater, pesticides, herbicides, fertilizers, manure, etc., the internal permeable space in the water purification material through the drainage pipe To send.
[0043]
If it does in this way, like the invention concerning Claim 1, denitrification occurs in a water permeation process, nitrate nitrogen contained in polluted water will be reduced into nitrogen gas, and such nitrogen gas will be Released to the atmosphere through the internal ventilation space. The outflowed water flows out to the surrounding ground as water from which nitrate nitrogen has been removed, and eventually joins the groundwater.
[0044]
The water purification material may have any denitrification action and water permeability, or any water quality purification material having a denitrification action and water permeability and air permeability. Thus, the composition containing sulfur and sulfur-oxidizing bacteria is preferable.
[0045]
For example, a mixture of lime, sulfur and sulfur-oxidizing bacteria, and alkaline waste mud containing hydraulic material solidified by solidifying action of the hydraulic material, and sulfur and sulfur-oxidizing bacteria It is conceivable that the mixture is constituted by mixing alkaline waste mud containing hydraulic material, sulfur and sulfur-oxidizing bacteria before solidifying the alkaline waste mud. In addition, what is necessary is just to add suitably the enzyme active substance required for the enzyme activity of the sulfur oxidation bacterium which catalyzes sulfur oxidation reaction, for example, a carbon source or organic substance as needed. For example, charcoal, wood, sugarcane residue, waste material, and the like can be considered.
[0046]
Hydraulic materials include cement and lime.
[0047]
Alkaline waste mud containing hydraulic materials is mainly for waste mud produced by underground wall construction methods and mud construction methods such as shields, but for the convenience of transportation, hydraulic materials are added for the purpose of solidification. The waste mud is not limited to the waste mud produced by the muddy water method as long as it is alkaline. The solidifying action of the hydraulic material mainly means a hydration reaction by cement.
[0048]
In addition, when water purification material is constituted by mixing alkaline waste mud containing hydraulic material, sulfur and sulfur oxidation bacteria before solidification of alkaline waste mud, sulfur oxidation bacteria catalyze the oxidation reaction of sulfur. Therefore, it takes a number of days until the microbial activity becomes high, and even if it is added to the alkaline waste mud, the alkaline waste mud solidifies before the oxidation reaction of sulfur starts. Therefore, there is almost no concern that sulfur is oxidized when the water purification structure is constructed.
[0049]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a water purification tank according to the present invention will be described with reference to the accompanying drawings. Note that components that are substantially the same as those of the prior art are assigned the same reference numerals, and descriptions thereof are omitted.
[0050]
(First embodiment)
[0051]
FIG. 1 is a cross-sectional view showing a water purification tank according to the present embodiment. As shown in the figure, the water source purification pad 1 as the water purification pad according to the present embodiment is configured such that a hollow space is formed in the water purification material.
[0052]
As shown in the figure, the water source purification tub 1 has a hollow space 2 inside by forming a water purification material so as to have a bottomed hollow cylindrical shape.
[0053]
The water source purification tub 1 may be manufactured with a water purification material having a denitrification action and water permeability, but can be specifically manufactured by the following three methods.
[0054]
(I) The purification jar 1 for water sources is comprised by mixing lime, sulfur, and sulfur oxidation bacteria.
[0055]
In this case, a mold that can be formed into a cylindrical shape with a bottom is manufactured in advance, and the lime, sulfur, and sulfur-oxidizing bacteria described above are mixed and added together with water to be solidified. At the time of solidification, water permeability is ensured by appropriately adopting known techniques such as intentionally generating cracks or adding a foaming agent to form a porous structure.
[0056]
(Ii) The water purification slag 1 is constituted by mixing the waste sludge solidified by the solidification action of the cement with alkaline waste sludge containing cement, and sulfur and sulfur-oxidizing bacteria.
[0057]
In this case, a mold that can be formed into a cylindrical shape with a bottom is manufactured in advance, and the solidified sludge and the sulfur and sulfur-oxidizing bacteria described above are charged therein and a solidifying agent for solidifying them, such as cement milk. May be added and solidified. At the time of solidification, water permeability is ensured by appropriately adopting known techniques such as intentionally generating cracks or adding a foaming agent to form a porous structure.
[0058]
(Iii) The alkaline waste mud containing cement, which is a hydraulic material, and sulfur and sulfur-oxidizing bacteria are mixed before the alkaline waste mud is solidified to constitute the water source purification tub 1.
[0059]
In this case, a mold that can be formed into a bottomed cylindrical shape is manufactured in advance, and the alkaline waste mud described above, sulfur and sulfur-oxidizing bacteria are mixed and charged therein, and solidified. At the time of solidification, water permeability is ensured by appropriately adopting known techniques such as intentionally generating cracks or adding a foaming agent to form a porous structure.
[0060]
In the production methods (i), (ii), and (iii) described above, an enzyme active substance, such as a carbon source or an organic substance, necessary for the enzyme activity of sulfur-oxidizing bacteria that catalyze the oxidation reaction of sulfur is used as necessary. What is necessary is just to add suitably. For example, charcoal, wood, sugarcane residue, waste material, and the like can be considered.
[0061]
In order to catalyze the sulfur oxidation reaction by sulfur-oxidizing bacteria, it takes time until the microbial activity becomes high. Therefore, when sulfur and sulfur-oxidizing bacteria are mixed and solidified in lime or alkaline waste mud, In combination with the consumption of water in the hydration reaction, there is almost no concern that the microbial activity is increased and sulfur is oxidized until the water source purification tank 1 is completed.
[0062]
By the way, after installation, since groundwater permeates into the internal water-permeable space of the water purification material constituting the water source purification tub 1, sulfur-oxidizing bacteria oxidize sulfur in the internal water-permeable space and sulfur is Nitrate nitrogen contained in groundwater as an electron donor is reduced and converted to nitrogen gas. Moreover, since the sulfuric acid produced by the oxidation of sulfur is neutralized with an alkaline component derived from lime or cement, the enzyme activity of sulfur-oxidizing bacteria does not decrease.
[0063]
Moreover, in the case of the manufacturing method of (ii) and (iii) which uses alkaline waste mud, the mixing ratio of alkaline waste mud and sulfur should just be set to 50-90: 50-10 by weight ratio, for example.
[0064]
The alkaline waste mud that is the raw material should use the waste mud generated by underground continuous wall construction. In continuous underground wall construction, when excavating the ground, in order to prevent the excavated hole wall from collapsing, excavation is carried out while putting muddy water as a stabilizing liquid in the excavation hole. Replace and collect the stable solution while placing.
[0065]
Although this spent stable liquid becomes waste mud, it is replaced and recovered with underwater concrete, so cement is mixed in the waste mud, and therefore, such waste mud becomes alkaline waste mud. Yes.
[0066]
In order to use the water source purification pad 1 manufactured in this way when the surrounding ground water is contaminated with nitrate nitrogen and wants to use the ground water as a water source, as shown in FIG. It is buried near the ground surface of the ground 4 so that the top opening 3 of the gutter 1 communicates with the atmosphere, and the pumping pipe 5 is disposed in the hollow space 2.
[0067]
The embedding depth of the water source purification tub 1 is set to such a depth that the water level of the hollow space 2 of the water source purification tub can be lowered by lowering the water level of the hollow space than the surrounding groundwater level.
[0068]
Here, if the underground water level is low and the embedding depth of the water source purification tub 1 is deepened, and therefore the head is increased, a pump is installed at the bottom of the water source purification basin 1, and the pump It is only necessary to connect the pumping pipe 5 to the pump to pump the water on the ground.
[0069]
In the water source purification tub 1 installed in this manner, the surrounding groundwater will flow through the water purification material constituting the water source purification tub 1 and flow into the hollow space 2. The nitrate nitrogen in the groundwater is reduced to nitrogen gas by the denitrification action of the purification material.
[0070]
That is, when the water purification material that constitutes the water source purification tank 1 and the groundwater containing nitrate nitrogen come into contact, sulfur in the water purification material is oxidized by the enzyme activity of the sulfur-oxidizing bacteria, and accompanying the oxidation reaction. The sulfur becomes an electron donor, and nitrate nitrogen contained in the ground water is reduced to nitrogen gas, and the nitrogen gas is released to the atmosphere through the top opening of the water source purification tub 1. The pumped water can be used as water from which nitrate nitrogen has been removed.
[0071]
Here, as described above, the sulfuric acid produced by the sulfur oxidation is neutralized by the alkali component in the lime or alkaline waste mud, and the sulfuric acid becomes neutral gypsum. Therefore, it can prevent that pH decreases with sulfuric acid and the enzyme activity of sulfur oxidation bacteria falls.
[0072]
As described above, according to the water source purification pad 1 according to the present embodiment, when the water purification material and the groundwater containing nitrate nitrogen come into contact with each other, sulfur in the water purification material is oxidized by the enzyme activity of the sulfur-oxidizing bacteria. Along with the oxidation reaction, the sulfur becomes an electron donor, and nitrate nitrogen in the groundwater is reduced to nitrogen gas.
[0073]
Therefore, nitrate nitrogen contained in groundwater can be efficiently removed at low cost, and the water flowing into the hollow space 2 of the water source purification tub 1 becomes treated water from which nitrate nitrogen has been removed. By pumping this to the ground, it can be effectively used as a water source.
[0074]
On the other hand, sulfur is oxidized by itself to become sulfuric acid, but since it is neutralized by the alkaline component in the alkaline waste mud, it prevents the pH from being lowered by sulfuric acid and the enzymatic activity of sulfur-oxidizing bacteria from being reduced. Can do.
[0075]
In addition, since alkaline waste mud has a high phosphorus adsorption capacity, the water purification material constituting the water source purification tank 1 according to the present embodiment has not only the action of purifying nitrate nitrogen but also the action and effect of adsorbing and removing phosphorus. Have.
[0076]
In addition, according to the water source purification pad 1 according to the present embodiment, it is possible to effectively use alkaline waste mud that has been conventionally disposed as industrial waste as a raw material for detoxifying nitrate nitrogen. Has a remarkable effect.
[0077]
Moreover, according to the water purification tank 1 which concerns on this embodiment, the sulfur which tends to be surplus in the desulfurization process in gasoline refining etc. can also be used effectively.
[0078]
Although not particularly mentioned in this embodiment, when the concentration of nitrate nitrogen contamination is high, the pumped water is not used immediately, but instead is permeated into the ground via the water source tail purifier 1. By repeating the procedure of pumping up water, it is possible to reliably purify high-concentration groundwater contaminated areas.
[0079]
By the way, if the pumping energy in that case is covered by electric energy converted from natural energy such as wind power generation, it is possible to construct an environmental restoration system that can be self-sufficient in terms of energy.
[0080]
(Second Embodiment)
[0081]
In the first embodiment, the water purification material is configured so that a hollow space is formed therein, and the water purification column 1 is used. However, instead of this configuration, the water purification material has a denitrification action and is permeable and breathable. It is good also as a structure which formed the water quality purification material which has solid.
[0082]
FIG. 2 shows this embodiment as a second embodiment. As can be seen from the figure, the water purification tub 1a as the water purification tub according to the present embodiment has a solid water purification material and has a water pump 11 inserted into the water purification material.
[0083]
The purification jar 1a for water source may be manufactured with a water purification material having a denitrification action and water permeability and breathability, but specifically, it is manufactured by the following three methods almost similar to the first embodiment. can do.
[0084]
(I ') The water source purification waste 1a is constituted by mixing lime with sulfur and sulfur-oxidizing bacteria.
[0085]
In this case, if a mold that can be formed into a solid cylindrical shape is manufactured in advance, the pumping pipe 11 is previously disposed therein, and then the lime, sulfur, and sulfur-oxidizing bacteria described above are mixed with water and solidified. Good.
[0086]
If it does in this way, the pumping pipe 11 will be connected to the internal water-permeable space of a water purification material, and it will become possible to pump the water which permeate | transmitted this water purification material.
[0087]
It is desirable to provide a large number of water-permeable holes 12 in the pumping pipe 11 inserted into the water purification material.
[0088]
In solidification, water permeability and air permeability are ensured by appropriately adopting known techniques such as intentionally cracking or adding a foaming agent to form a porous structure.
[0089]
(Ii ′) The water source purification tub 1a is formed by mixing the waste sludge solidified by the solidification action of the alkaline waste sludge containing cement with sulfur and sulfur-oxidizing bacteria.
[0090]
In this case, a mold that can be formed into a solid cylindrical shape is manufactured in advance, and the pumping pipe 11 is previously disposed therein, and then the above-described waste mud solidified body, sulfur, and sulfur-oxidizing bacteria are added to the mold. A solidifying agent for solidification, for example, cement milk, may be additionally charged and solidified. In solidification, water permeability and air permeability are ensured by appropriately adopting known techniques such as intentionally cracking or adding a foaming agent to form a porous structure.
[0091]
(Iii ') The water source purification waste 1a is constituted by mixing alkaline waste mud containing cement, which is a hydraulic material, and sulfur and sulfur-oxidizing bacteria before the alkaline waste mud is solidified.
[0092]
In this case, a mold that can be formed into a solid cylindrical shape is manufactured in advance, the pumping pipe 11 is previously disposed therein, and then the above-described alkaline waste mud, sulfur and sulfur-oxidizing bacteria are mixed and charged and solidified. Just do it. In solidification, water permeability and air permeability are ensured by appropriately adopting known techniques such as intentionally cracking or adding a foaming agent to form a porous structure.
[0093]
In order to use the water source purification tub 1a thus manufactured when the surrounding ground water is contaminated with nitrate nitrogen and wants to use the ground water as a water source, as shown in FIG. It is buried near the ground surface of the ground 4 so that the internal ventilation space of the water purification material constituting the ridge 1a communicates with the atmosphere.
[0094]
The burial depth of the water source purification tub 1a is determined by pumping water that has permeated through the internal water permeable space of the water purification material constituting the water source purification basin so that the water level of the internal water permeable space is higher than the surrounding groundwater level. The depth should be as low as possible.
[0095]
In the purification basin 1a for the water source installed in this way, the surrounding groundwater will permeate the water purification material constituting the purification basin and flow into the internal permeable space. The nitrate nitrogen in the groundwater is reduced to nitrogen gas by the denitrification action of the material.
[0096]
That is, when the water purification material that constitutes the water source purification tank 1a and the groundwater containing nitrate nitrogen come into contact, sulfur in the water purification material is oxidized by the enzyme activity of the sulfur-oxidizing bacteria, and accompanying the oxidation reaction. The sulfur becomes an electron donor, and nitrate nitrogen contained in the groundwater is reduced to nitrogen gas. The nitrogen gas passes through the internal ventilation space of the water purification material constituting the water source purification tank 1a. Is released. The pumped water can be used as water from which nitrate nitrogen has been removed.
[0097]
The internal water-permeable space and the internal air-permeable space are shared by a cracked portion and a void portion in the water purification material.
[0098]
Since the configuration, operation, and effect not particularly described in the present embodiment, including the description regarding the microbial activity and alkaline waste mud, are the same as those in the first embodiment, the description thereof is omitted here.
[0099]
(Third embodiment)
[0100]
In the first embodiment, the water purification material is configured so as to form the hollow space 2 therein, and the water source purification tub 1 is used. However, instead of this configuration, the water purification material is filtered into the hollow space 2 as shown in FIG. The material 24 may be arranged.
[0101]
FIG. 3 shows this embodiment as a third embodiment. As can be seen in the figure, the water source purification pad 1b as the water purification pad according to the present embodiment is similar to the first embodiment by forming the water purification member so as to have a bottomed hollow cylindrical shape. However, in this embodiment, a water-impermeable tube 23 is disposed in the hollow space 2 so that a water guide space 22 is formed between the hollow inner surface 21 and filtered in the water-impermeable tube. The material 24 is filled, and the lower part of the filter material is communicated with the water guide space 22.
[0102]
Here, the filter medium 24 can be configured by laminating, for example, a carbide layer, a sand layer, a carbide layer, and a gravel layer in the impermeable pipe 23 in this order. The lower end is penetrated.
[0103]
Since the water purification tub 1b may be manufactured in the same manner as in the first embodiment, the description thereof is omitted here. Moreover, since the installation method (relative depth relationship with the groundwater level) is the same as that of the first embodiment, the description thereof is omitted here.
[0104]
In the water source purification basin 1b installed in this way, the surrounding ground water will permeate the water purification material of the water source purification basin 1, and the denitrification described in the first embodiment in this water permeation step. An action occurs, and nitrate nitrogen contained in groundwater is reduced to nitrogen gas. By the way, if the water guide space 22 is communicated with the atmosphere, the nitrogen gas is smoothly released into the atmosphere through the water guide space.
[0105]
On the other hand, the treated water from which nitrate nitrogen has been removed by the denitrification action flows down the water guide space 22 and is once collected below the filter medium 24 filled in the impermeable pipe 23.
[0106]
Therefore, the treated water from which nitrate nitrogen has been removed will surely pass through the filter medium 24 from the bottom to the top during pumping, and may be purified not only for nitrate nitrogen but also as clean water. It becomes possible.
[0107]
Since the other operational effects have already been described in the first embodiment, the description thereof is omitted here.
[0108]
(Fourth embodiment)
[0109]
FIG. 4 is a cross-sectional view showing the water purification tank according to the present embodiment. As shown in the figure, the underground infiltration purification basin 41 as the water purification basin according to the present embodiment is configured such that a hollow space is formed inside the water purification material.
[0110]
As shown in the figure, the underground infiltration basin 41 has a structure having a hollow space 42 by forming a water purification material so as to have a bottomed hollow cylindrical shape.
[0111]
The underground infiltration purification tank 41 may be manufactured with a water purification material having a denitrification action and water permeability. Specifically, (i), (ii), (iii) described in the first embodiment. 3). Note that the details are redundantly described, and thus the description thereof is omitted here.
[0112]
When the contaminated water containing nitrate nitrogen generated from daily wastewater, agricultural chemicals, herbicides, fertilizers, manure, etc. is to be infiltrated underground using the thus produced underground infiltration slag 41, FIG. As shown in FIG. 2, the top opening 43 of the underground infiltration purifier 41 is buried near the ground surface of the ground 4 so as to communicate with the atmosphere, and the drain pipe 45 is disposed in the hollow space 42.
[0113]
In the underground infiltration basin 41 installed in this way, the contaminated water in the underground infiltration basin will flow through the water purification material and flow out to the surrounding ground. Denitrification occurs, and nitrate nitrogen contained in the contaminated water is reduced to nitrogen gas.
[0114]
That is, when the water purification material constituting the underground infiltration purification tank 41 and the contaminated water containing nitrate nitrogen come into contact, sulfur in the water purification material is oxidized by the enzyme activity of the sulfur-oxidizing bacteria, and the oxidation reaction is performed. Along with this, the sulfur becomes an electron donor, nitrate nitrogen contained in the contaminated water is reduced to nitrogen gas, and the nitrogen gas is released to the atmosphere through the soil gap. The outflowed water eventually joins groundwater as water from which nitrate nitrogen has been removed.
[0115]
Here, as described above, the sulfuric acid generated by the sulfur oxidation is neutralized by the alkaline component in the lime or alkaline waste mud, and the sulfuric acid becomes neutral gypsum. Therefore, it can prevent that pH decreases with sulfuric acid and the enzyme activity of sulfur oxidation bacteria falls.
[0116]
As described above, according to the underground infiltration basin 41 according to the present embodiment, when the water purification material and the contaminated water containing nitrate nitrogen come into contact with each other, sulfur in the water purification material is converted into the enzyme activity of the sulfur-oxidizing bacteria. In the oxidation reaction, the sulfur becomes an electron donor and nitrate nitrogen in the contaminated water is reduced to nitrogen gas.
[0117]
Therefore, nitrate nitrogen contained in the contaminated water can be efficiently removed at low cost, and the water flowing out from the hollow space 42 of the underground infiltration purifier 41 is treated with the treated water from which nitrate nitrogen has been removed. Therefore, there is no possibility of contaminating the groundwater even if it joins the groundwater.
[0118]
On the other hand, sulfur is oxidized by itself to become sulfuric acid, but since it is neutralized by the alkaline component in the alkaline waste mud, it prevents the pH from being lowered by sulfuric acid and the enzymatic activity of sulfur-oxidizing bacteria from being reduced. Can do.
[0119]
In addition, since alkaline waste mud has a high adsorption capacity for phosphorus, the water purification material constituting the underground infiltration purification tank 41 according to the present embodiment has an effect of adsorbing and removing phosphorus as well as a purification action of nitrate nitrogen. Also have.
[0120]
Moreover, according to the underground infiltration purification tank 41 according to the present embodiment, it is possible to effectively use alkaline waste mud that has been conventionally disposed as industrial waste as a raw material for detoxifying nitrate nitrogen. It has a remarkable effect.
[0121]
Moreover, according to the water purification tank 41 which concerns on this embodiment, the sulfur which tends to be excessive in the desulfurization process in gasoline refining etc. can also be used effectively.
[0122]
(Fifth embodiment)
[0123]
In the fourth embodiment, the water purification material is configured so as to form a hollow space therein, and the underground osmosis purification basin 41 is used. However, instead of such a configuration, it has a denitrification action and has water permeability and ventilation. It is good also as a structure which formed the water quality purification material which has property solidly.
[0124]
FIG. 5 shows this embodiment as a fifth embodiment. As can be seen from the figure, the underground infiltration basin 41a as the water purification basin according to the present embodiment has a solid water quality purification material and a drain pipe 51 penetrating into the water quality purification material.
[0125]
The underground infiltration basin 41a may be manufactured from a water purification material having a denitrification action and water permeability and air permeability. Specifically, substantially the same as in the fourth embodiment, the following three methods are used. Can be manufactured.
[0126]
(I ′) The underground permeation purifier 41a is configured by mixing lime with sulfur and sulfur-oxidizing bacteria.
[0127]
In this case, if a mold that can be formed into a solid cylindrical shape is manufactured in advance, a drain pipe 51 is previously disposed therein, and then the above-described lime, sulfur, and sulfur-oxidizing bacteria are mixed with water and solidified. Good.
[0128]
In this way, the drain pipe 51 communicates with the internal water permeable space of the water purification material, and the contaminated water that has flowed in through the drain pipe 51 is made to permeate the water purification material and then flows out to the surrounding ground. It becomes possible to make it.
[0129]
It is desirable to provide a large number of water permeable holes 12 in the drain pipe 51 penetrating into the water purification material.
[0130]
In solidification, water permeability and air permeability are ensured by appropriately adopting known techniques such as intentionally cracking or adding a foaming agent to form a porous structure.
[0131]
(Ii ′) The underground osmosis purification waste 41a is formed by mixing the waste sludge solidified by the solidification action of the alkaline waste sludge containing cement with sulfur and sulfur-oxidizing bacteria.
[0132]
In this case, a mold that can be formed into a solid cylindrical shape is manufactured in advance, and the drain pipe 51 is previously disposed therein, and then the above-described waste mud solidified body, sulfur, and sulfur-oxidizing bacteria are added to the mold. What is necessary is just to add solidifying agent for solidifying, for example, cement milk, and to solidify. In solidification, water permeability and air permeability are ensured by appropriately adopting known techniques such as intentionally cracking or adding a foaming agent to form a porous structure.
[0133]
(Iii ') The underground infiltration slag 41a is configured by mixing alkaline waste mud containing cement, which is a hydraulic material, and sulfur and sulfur-oxidizing bacteria before solidifying the alkaline waste mud.
[0134]
In this case, a mold that can be formed into a solid cylindrical shape is manufactured in advance, and a drain pipe 51 is previously disposed therein, and then the alkaline waste mud described above, sulfur and sulfur-oxidizing bacteria are mixed and charged and solidified. Just do it. In solidification, water permeability and air permeability are ensured by appropriately adopting known techniques such as intentionally cracking or adding a foaming agent to form a porous structure.
[0135]
When the contaminated water containing nitrate nitrogen generated from domestic wastewater, agricultural chemicals, herbicides, fertilizers, manure, etc. is to be infiltrated underground using the underground infiltration slag 41a thus manufactured, FIG. As shown in Fig. 4, the water purification material constituting the underground infiltration purification tank 41a is buried near the ground surface of the ground 4 so as to communicate with the atmosphere.
[0136]
The embedding depth of the underground infiltration purification tank 41a is set to such a depth that the water level of the internal permeable space of the contaminated water flowing in through the drain pipe 51 can be made higher than the surrounding underground water level.
[0137]
In the underground osmosis purification basin 41a installed in this way, the contaminated water will permeate the water purification material constituting the purification basin and flow out to the surrounding surrounding ground. The nitrate nitrogen in the contaminated water is reduced to nitrogen gas by the denitrification action of the purification material.
[0138]
That is, when the water purification material constituting the underground infiltration purification tank 41a and the contaminated water containing nitrate nitrogen come into contact, sulfur in the water purification material is oxidized by the enzyme activity of the sulfur-oxidizing bacteria, and the oxidation reaction is caused. Along with this, the sulfur becomes an electron donor, nitrate nitrogen contained in the contaminated water is reduced to nitrogen gas, and this nitrogen gas is an internal ventilation space of the water purification material constituting the underground infiltration purification tank 41a. Is released to the atmosphere via And the water which flowed out to the surrounding ground will join groundwater as the water from which nitrate nitrogen was removed.
[0139]
The internal water-permeable space and the internal air-permeable space are shared by a cracked portion and a void portion in the water purification material.
[0140]
Since the configuration, operation, and effect not particularly described in the present embodiment, including the description on the microbial activity and alkaline waste mud, are the same as those in the fourth embodiment, description thereof is omitted here.
[0141]
【The invention's effect】
As described above, according to the water purification plant according to the present invention, when the water purification material comes into contact with groundwater or contaminated water containing nitrate nitrogen, sulfur in the water purification material is oxidized by the enzyme activity of the sulfur-oxidizing bacteria. At the same time, with the oxidation reaction, the sulfur becomes an electron donor, and nitrate nitrogen in the ground water or contaminated water can be reduced to nitrogen gas to purify the ground water or contaminated water.
[0142]
[Brief description of the drawings]
1A and 1B are views of a water purification tank according to a first embodiment, wherein FIG. 1A is a vertical cross-sectional view, and FIG. 1B is a horizontal cross-sectional view along the line AA.
2A and 2B are views of a water purification tank according to a second embodiment, wherein FIG. 2A is a vertical cross-sectional view, and FIG. 2B is a horizontal cross-sectional view along the BB line direction.
FIGS. 3A and 3B are views of a water purification tank according to a third embodiment, wherein FIG. 3A is a vertical cross-sectional view, and FIG. 3B is a horizontal cross-sectional view along the direction of line CC.
FIGS. 4A and 4B are views of a water purification tank according to a fourth embodiment, wherein FIG. 4A is a vertical cross-sectional view, and FIG. 4B is a horizontal cross-sectional view along the DD line direction.
5A and 5B are views of a water purification tank according to a fifth embodiment, wherein FIG. 5A is a vertical cross-sectional view, and FIG.
[Explanation of symbols]
1,1a, 1b Water source purification tank (water purification tank)
2,42 hollow space
4 ground
5, 11, 25 Pumped pipe
22 Water transfer space
23 Impervious pipe
24 Filter media
41, 41a Underground seepage purification tank (water purification tank)
45,51 Drain pipe

Claims (6)

A water purification tank comprising a water purification material having a denitrification action and water permeability so that a hollow space is formed therein. An impervious pipe is disposed in the hollow space so that a water guide space is formed between the hollow inner surface of the water purification material, and the water impervious pipe is filled with a filter medium. The water purification tank according to claim 1, which is communicated with a space. A water purification jar characterized by solidly forming a water purification material having denitrification action and water permeability and breathability, and having a water pump or a drain pipe penetrated into the water purification material. The water purification jar according to any one of claims 1 to 3, wherein the water purification material is configured by mixing lime, sulfur, and sulfur-oxidizing bacteria. 4. The water purification material according to claim 1, wherein alkaline waste mud containing a hydraulic material, sulfur and sulfur-oxidizing bacteria are mixed before solidification of the alkaline waste mud. 5. Water purification jar. 4. The water purification material according to claim 1, wherein alkaline waste mud containing a hydraulic material is solidified by a solidified action of the hydraulic material, and sulfur and sulfur-oxidizing bacteria are mixed. The water purification tank according to any one of the above.

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