JPH09248561A - Device for removing nitrate nitrogen and nitrite nitrogen in natural water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce nitrate nitrogen and nitrite nitrogen in a natural water to be used for drinking water up to the standard concentration with a simple constitution by providing a siliceous stone layer having a flow-in port and a flow-out port for the natural water respectively at the one end and another end and formed by heaping the chips of the siliceous stone between the flow-in port and the flow-out port. SOLUTION: The natural water flowing-in to the flow-in port 4 of a 1st filtration layer 2-1 from a natural water flow-in pipe line 12, after organic materials, fungi odor and the like are removed in an activated carbon layer, is made to flow-in to the siliceous stone layer 7 through a filter plate 6 to have a considerable amount of the nitrate and nitrite nitrogen adsorbed to the siliceous stone and removed. The natural water is further passed through a magnetite layer 9 magnetized by annular magnets 10, 11 through the filter plate 6 to be activated and to have the remaining nitrate and nitrite nitrogen removed. The natural water is successively passed through a 2nd filtration layer 2-2 and a 3rd filtration layer 2-3 and the concentration of nitrate and nitrite nitrogen in the natural water flowing-out from a flow-out port 5 is reduced to the desired value.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to river water, lake water,
The present invention relates to a device for removing nitrate nitrogen and nitrite nitrogen existing in natural water (excluding tap water) such as groundwater.

[0002]

2. Description of the Related Art Drinking water contains trace amounts of nitrate nitrogen and nitrite nitrogen. These are absorbed from the digestive system and taken into hemoglobin in the blood, and hemoglobin is oxidized to methemoglobin. When the concentration of methemoglobin in the blood is 10% or more, a condition in which oxygen supply is low, that is, methemoglobinemia is caused.
Methemoglobinemia is especially predisposed to infants. For this reason, the total amount of nitrate nitrogen and nitrite nitrogen is 10 m according to the water quality standards stipulated by the Water Supply Act and WHO drinking water guidelines.
It is specified as g / l or less.

At a water purification plant using natural water such as river water, lake water, groundwater, etc. as a tap water source, no particular method is currently adopted to reduce nitrate nitrogen and nitrite nitrogen.

[0004]

[Problems to be Solved by the Invention] Recently, agricultural land, orchards,
A large amount of nitrogen compounds tends to be supplied to natural water due to the increase of fertilizer application of nitrogen-based fertilizers in grasslands and the increase of soil infiltration treatment of domestic wastewater, and as a result, the nitrate nitrogen and nitrite nitrogen in natural water The total concentration also tends to increase, and in some places, the upper limit reference concentration of 10 mg / l is far exceeded and reaches several tens of mg / l.

There is currently no means for economically and effectively removing such high concentrations of nitrate and nitrite nitrogen. Therefore, in such a case, there is currently no way to deal with it other than to abandon the water source and move it to another place.

The present invention has been made in view of the above circumstances, has a simple structure and is therefore low in cost, and has nitrate nitrogen and nitrite properties in natural water used as drinking water such as tap water source or well water. It is an object of the present invention to provide a device capable of reducing nitrogen to a standard concentration.

[0007]

[Means for Solving the Problems] The present inventor, while carrying out experiments and research to achieve the above-mentioned object, passes natural water by mixing barley stone, which is a kind of quartz porphyry, alone or in combination with activated carbon. And, surprisingly, it was discovered that nitrate nitrogen and nitrite nitrogen in natural water were remarkably adsorbed and removed, and the present invention was reached.

That is, the apparatus for removing nitrate nitrogen and nitrite nitrogen in natural water according to the first aspect of the present invention, which achieves the object of the present invention, has natural water inlet and outlet at one end and the other end, respectively. And a barley stone layer in which fine pieces of barley stone are deposited is provided between the inflow port and the outflow port.

The apparatus according to the invention of claim 2 has an inlet and an outlet for natural water at one end and the other end, respectively.
Between the inflow port and the outflow port, an activated carbon layer in which granular activated carbon is deposited and a bakuhanishi layer in which fine particles of bakuhanishi are deposited are provided.

According to a third aspect of the present invention, there is provided a magnetite layer in which fine particles of magnetite ore are deposited on at least one of the upstream side and the downstream side of the barite stone layer and a magnet for magnetizing the magnetite layer is arranged. It is characterized by being installed.

[0011]

[Function] Bakuhanishi is a kind of quartz porphyry, which is a mixture of white part, transparent quartz part, green part and brown part. Its chemical composition is about 70% silicic anhydride (SiO ₂ ) and aluminum oxide ( Al ₂ O ₃ ) about 14% as a main component, and magnesium oxide (MgO), potassium oxide (K ₂ O), sodium oxide (Na ₂ O), calcium oxide (CaO), ferrous oxide (FeO), It contains ferric oxide (Fe ₂ O ₃ ), compounded water adhering water (H ₂ O), titanium oxide (TiO ₂ ), phosphoric anhydride (P ₂ O ₅ ), and manganese oxide (MnO). It is known that the water that has passed through the crushed pieces of barley stone is less likely to rot and has the effect of elution of minerals that are beneficial to health into the water. For these reasons, barley stone is used at home. However, it has not been known so far that barley stone has a significant effect of adsorbing nitrate nitrogen and nitrite nitrogen in natural water, and natural water such as water purification plants is treated as a tap water source. There is no example of using barite stone to remove nitrate nitrogen and nitrite nitrogen in a facility.

The present invention has been used only to the extent that it is conventionally used to taste delicious water at home, and is a major pollutant of tap water currently used in barley rice stone, which has hardly been omitted industrially. It is a use invention based on the discovery that there is a novel use for adsorbing and removing the problematic nitrate nitrogen and nitrite nitrogen remarkably remarkably, and it is used as tap water or as well water It is extremely useful for purifying natural water and makes a great contribution to society. That is, even a water source that had to be abandoned as an unsuitable tap water source due to its high concentration of nitrate nitrogen and nitrite nitrogen is used as a respectable water source by adopting the removal device of the present invention. Because you can.

In the present specification, "natural water" means water that is untreated or in the process of being used as a source of drinking water such as river water, lake water, tap water such as ground water, or well water source, Does not include tap water supplied as potable water after completion of all water purification treatment including chlorination.

According to the first aspect of the present invention, natural water is passed through the boiled stone layer to remarkably adsorb and remove nitrate nitrogen and nitrite nitrogen in the natural water, and the total concentration thereof is desired to be a reference concentration or the like. The concentration can be reduced.

According to the second aspect of the present invention, by passing natural water through the activated carbon layer and the barley stone layer, nitrate nitrogen and nitrite nitrogen in natural water can be remarkably adsorbed and removed. It is also possible to remove organic substances, other impurities, musty odor, and the like.

According to the third aspect of the invention, the removal of nitrate nitrogen and nitrite nitrogen is further promoted by passing natural water through the magnetite layer magnetized by the magnet.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows one embodiment of the present invention. A nitrate nitrogen and nitrite nitrogen removing apparatus 1 comprises three filtration tanks 2 having the same structure, which are cascade-connected by a pipe line 3.

Each of the filtration tanks 2 is formed in a cylindrical shape whose upper and lower sides are closed and has a lid portion 2a and a bottom portion 2b. The lid portion 2a has a natural water inlet 4 and the bottom portion 2b has a natural water outlet. Have five. A filter plate 6 such as a non-woven fabric filter is provided in three stages in the up-down direction in the filtration tank 2. Granular activated carbon, barley stone particles, and magnetite fine particles are placed from above in a space partitioned by these filter plates 6. The pieces are respectively filled and deposited to form an activated carbon layer 7, a barley stone layer 8 and a magnetite layer 9.

The filter plates 6 above and below the magnetite layer 9,
Ring magnets 10 and 11 shown in FIG. 3 are placed on the magnet 6, and the magnetite layer 9 is magnetized by the lines of magnetic force.
The respective annular magnets 10 and 11 are positioned so that their respective positions coincide with each other in the vertical direction, and the respective directions of the magnetic lines of force of the respective annular magnets 10 and 11 coincide with each other, and in particular, they are opposite to the flow of water. It is arranged so that the lines of magnetic force coincide with the flow of water.

Due to the arrangement of the annular magnets 10 and 11, the magnetic lines of force of the annular magnets 10 and 11 are coupled to each other to reinforce each other, and in particular, upward, that is, along the flow of water and in the opposite direction, it is uniform and strong. A magnetic field is formed to strongly magnetize the entire magnetite layer 9.

As shown in FIG. 3, the annular magnets 10 and 11 have the shape of a disc having an opening 12 at the center, and the outer diameter, inner diameter and thickness of the annular magnets 10 and 11 are the dimensions of the filtration tank 2 and the strength of the required magnetic field. And the amount of water to be treated are taken into consideration and set to an appropriate value. Further, in the present embodiment, each annular magnet is composed of a single annular magnet, but instead of this, each of the annular magnets 10 and 11 has two large and small annular magnets 10a and 10b (as shown in FIG. 4). 1
1a, 11b) may be arranged coaxially.

A natural water inflow conduit 12 is connected to the natural water inflow port 4 of the first filtration tank 2-1 of this apparatus, while a natural water outflow pipe is connected to the natural water outflow port 5 of the third filtration tank 2-3. Road 1
4 are connected. The outlet 5 of the first filtration tank 2-1 is the inlet 4 of the second filtration tank 2-2, and the outlet 4 of the second filtration tank 2-2 is the third filtration tank 2-3. Are connected by an inflow port 4 and a pipe line 3, respectively.

Next, the operation of this device will be described.

The first filtration tank 2 from the natural water inflow conduit 12
The organic water and other impurities, mold odor, etc. are removed from the natural water flowing into the inflow port 4 of -1 in the activated carbon layer, and nitrate nitrogen and nitrite nitrogen are also removed to a small extent.

Next, natural water flows through the filter plate 6 and into the lower boiled stone layer 8, where a considerable part of nitrate nitrogen and nitrite nitrogen is adsorbed by the boiled stone and removed from the natural water. It

Natural water further flows into the lower magnetite layer 9 through the filter plate 6. Ring magnets 10 and 11
The natural water passing through the magnetite layer 9 magnetized by is activated and at the same time, a considerable part of the nitrate nitrogen and the nitrite nitrogen remaining therein is adsorbed by the magnetite ore fragments and removed from the natural water. To be done.

Natural water flowing out of the first filtration tank 2-1 is further filtered in the second filtration tank 2-2 and the third filtration tank 2
-3 through the above process, the nitrate nitrogen and the nitrite nitrogen in the water are adsorbed and removed through the above-mentioned process to gradually decrease, and the natural water in the natural water flowing out from the outlet 5 of the third filtration tank 2-3 is discharged. The concentrations of nitrate nitrogen and nitrite nitrogen have been reduced to the desired concentrations (eg 10 mg / l or less).

In the above example, three filtration tanks 2 having the same structure are used, but instead, only one filtration tank is used,
The amounts of activated carbon, barley stone, and magnetite to be filled inside may be the total amounts for the three filtration tanks of the above example, and large magnets may be used.

As the magnet for magnetizing the magnetite layer, another magnet may be used instead of the annular magnet (10, 11) in the above example. For example, as shown in FIG. 5, in a disk-shaped plastic plate 15 provided with a large number of fine water holes (not shown) on the entire surface, the central angle on a concentric circle centered on the center of the plate is 120.
It is also possible to use one in which three disk-shaped magnets 17 are housed in the three housing holes 16 formed at positions equally divided by three degrees. However, if the annular magnets (10, 11) shown in FIG. 3 or FIG. 4 used in the above embodiment have the same magnetic field strength as the magnets shown in FIG. It is the most preferable because it has good removal efficiency of nitrogen and nitrite nitrogen.

FIG. 2 shows another embodiment of the present invention, in which a nitrate nitrogen and nitrite nitrogen removing apparatus 20 is provided with a filter tank 22 formed in a cylindrical shape whose upper and lower sides are closed, The filtration tank 22 has a cover 22a with an inlet 24 for natural water.
The bottom 22b has an outlet 25 for natural water. A filter plate 26 such as a non-woven fabric filter is provided in the filtration tank 22.
Is provided, and the pieces of barley stone are filled and accumulated in the central space partitioned by the filter plates 26 to form the layer of barley stone 28.

In this embodiment, the function of the barley stone layer 28 is almost the same as that of the embodiment of FIG.

FIG. 6 shows another embodiment of the present invention, in which the nitrate nitrogen and nitrite nitrogen removing device 30 is provided with a cylindrical filtration tank 32 whose upper and lower sides are closed. The filtration tank 32 has a lid portion 32a with an inlet 34 for natural water.
The bottom 32b has a natural water outlet 35. A filter plate 36 such as a non-woven fabric filter is provided in the filtration tank 32.
Is provided, and granular activated carbon is filled in the upper space partitioned by the central filter plate 36, and fine particles of barley stone are filled and accumulated in the lower space to form the activated carbon layer 37 and the barley stone layer 38, respectively. ing.

In this embodiment, the functions of the activated carbon layer 37 and the barley stone layer 38 are almost the same as those of the embodiment of FIG. Comparing the embodiment of FIG. 2 or FIG. 6 with the embodiment of FIG. 1, the embodiment of FIG. 1 with a magnetized magnetite bed for the same volume of filter tank is more suitable for nitrate nitrogen and nitrogen nitrite. The removal rate is high. Therefore, in order to achieve the same removal rate as that of the embodiment of FIG. 1 according to the embodiment of FIG. 2 or FIG. 6, the activated carbon and barley stone used by increasing the volume of the filter tank or by increasing the number of filter tanks to be connected. Need to increase the amount of.

In the embodiment of FIG. 1, the magnetite layer is provided on the downstream side of the bakuhanishi layer, but it may be provided on the upstream side of the bakuhanishi layer, or on both the upstream side and the downstream side. May be.

In addition, in the embodiment of FIG. 1, FIG. 2 or FIG. 6, a filter layer made of other material such as a sand layer or a ceramic layer is added to remove various impurities in natural water other than nitrate nitrogen and nitrite nitrogen. May be.

In the embodiment of FIGS. 1 and 6, each layer is contained in one filtration tank 2 or 32.
You may make it accommodate each layer separately in a separate container, and connect these containers sequentially by a pipeline.

In the apparatus shown in FIG. 1, each cylindrical filtration tank 2 has an inner diameter of 150 mm, a length of 1,000 mm, and an inlet 4 and an outlet 5 of 13 mm in diameter.
Activated carbon, barley stone and magnetite were filled so that the activated carbon layer 7 occupies 40%, the barley stone layer 8 occupies 40% and the magnetite layer 9 occupies 20% in the volume. The annular magnets 10 and 11 have the shape shown in FIG. 3 and have an outer diameter of 100 mm and an inner diameter of 50.
A ferrite annular magnet having a thickness of 8 mm and a thickness of 8 mm was used.

Natural water (groundwater) having a total concentration of nitrate nitrogen and nitrite nitrogen of 48.4 mg / l as water to be treated
At a flow rate of 10 to 20 liters per minute from the natural water inflow conduit 12 to the filtration tanks 2-1, 2-2, 2-3 in this order and discharged from the natural water outflow conduit 14. A sample of the treated natural water was taken from the water intake provided in the pipeline 3 on the downstream side of the outlet 5 of each filtration tank, and the total concentration of nitrate nitrogen and nitrogen nitrite was stipulated by the law concerning water quality standards. It measured by the method. As a result, the total concentration of nitrate nitrogen and nitrite nitrogen after passing through the respective filtration tanks 2-1, 2-2, 2-3 was 35.6 mg / l, 12.5 mg / l, respectively, and was not detected. It was found that the passing standard concentration of 10 mg / l or less can be completely achieved.

[0039]

As described above, according to the invention described in claim 1, by passing natural water through the barley stone layer, nitrate nitrogen and nitrite nitrogen in natural water are remarkably adsorbed and removed, The total concentration can be reduced to a desired concentration such as a reference concentration.

According to the second aspect of the present invention, nitrate nitrogen and nitrite nitrogen in natural water can be adsorbed and removed remarkably by passing through the activated carbon layer and the barley stone layer. Other impurities and musty odor can also be removed.

According to the third aspect of the invention, the removal of nitrate nitrogen and nitrite nitrogen is further promoted by passing natural water through the magnetite layer magnetized by the magnet.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an embodiment of the present invention.

FIG. 2 is a diagram schematically showing another embodiment of the present invention.

3 is a perspective view showing an example of an annular magnet used in the embodiment shown in FIG. 1. FIG.

FIG. 4 is a perspective view showing another example of an annular magnet.

FIG. 5 is a perspective view showing another example of a magnet.

FIG. 6 is a diagram schematically showing still another embodiment of the present invention.

[Explanation of symbols]

 2,20,30 Filtration layer 3 Pipe line 4,24,34 Natural water inlet 5,25,35 Natural water outlet 6,26,36 Filter plate 7,27,37 Activated carbon bed 8,28,38 Boiled stone bed 9 Magnetite Layer 10, 11 Current magnet

Claims (3)

[Claims] 1. An inlet and an outlet of natural water are provided at one end and the other end, respectively, and between the inlet and the outlet,
An apparatus for removing nitrate nitrogen and nitrite nitrogen in natural water, which is provided with a layer of boiled stone on which fine pieces of boiled stone are deposited. 2. An inlet and an outlet of natural water are provided at one end and the other end, respectively, and between the inlet and the outlet,
An apparatus for removing nitrate nitrogen and nitrite nitrogen in natural water, characterized in that an activated carbon layer on which granular activated carbon is deposited and a barley stone layer on which pieces of barley stone are deposited are provided. 3. A magnetite layer in which fine particles of magnetite ore are deposited is provided on at least one of an upstream side and a downstream side of the bourneite layer, and a magnet for magnetizing the magnetite layer is provided. The apparatus according to 1 or 2.