JP6846656B2 - Water treatment equipment - Google Patents

Description

The present invention relates to a water treatment apparatus. More specifically, the present invention relates to a water treatment apparatus capable of efficiently purifying water to be treated.

Conventionally, the development of a water treatment device for purifying the water to be treated has been promoted. Examples of the water treatment apparatus include those disclosed in Patent Document 1. In Patent Document 1, a mesoporous carbon bead using a bead-shaped molded product of a phenolic resin as a precursor is used, and a water treatment catalyst in which a metal is supported in the mesopores of the mesoporous carbon bead is used. The actual waste water treatment device is disclosed.

JP-A-2007-99612

The conventional water treatment device as disclosed in Patent Document 1 is supposed to be used in an area where it is assumed that water is purified in a public water treatment facility.

On the other hand, in emerging countries where the social infrastructure is not well developed, there are many areas that do not have public water treatment facilities. In such areas, there is a need to purify water by installing water treatment equipment in each household. In particular, there is a need to remove metal-related substances such as metal ions and turbid components such as silica contained in the water to be treated by a water treatment device installed at home. However, according to the principle of conventional water treatment equipment, it is necessary to provide a large storage tank in order to remove metal-related substances and turbid components in a treatment time that meets the water demand of households.

However, ordinary households often do not have a space of a size suitable for installing a large water treatment device. Therefore, in order to meet the above-mentioned needs, it is necessary to have a water treatment device capable of sufficiently removing metal-related substances contained in the water to be treated to the required extent without providing a large storage tank. Become. Therefore, there is a demand for a water treatment device capable of efficiently removing metal-related substances and turbid components in a small space.

The present invention has been made in view of the problems of the prior art. An object of the present invention is to provide a water treatment apparatus capable of efficiently removing metal-related substances such as metal ions and turbid components such as silica.

In order to solve the above problems, the water treatment apparatus according to the aspect of the present invention includes at least one metal-related substance selected from the group consisting of metal ions, metal particles, metal oxide particles and metal hydroxide particles, and silica. And a water flow path to be treated to which water to be treated containing at least one of alumina and a turbid component is provided. Further, the water treatment apparatus includes an oxidant supply unit that supplies an oxidant to the water to be treated, and a coagulant supply unit that supplies a coagulant that agglomerates turbid components into the water to be treated. The water treatment apparatus is further supported by a base material, a porous carrier layer provided on the base material, and a porous carrier layer, and is composed of Fe ₂ O ₃ , Fe ₃ O ₄ , Fe (OH) _3, and Fe OOH. By providing an adsorbed particle containing at least one trivalent iron ion compound selected from the above, and a metal material aggregation promoting layer having the adsorbed particles, the metal-related substance contained in the water to be treated is adsorbed on the adsorbed particles by the action of an oxidizing agent. , It is provided with an aggregation promoting part that promotes aggregation of metal-related substances.

According to the present invention, it is possible to provide a water treatment apparatus capable of efficiently removing metal-related substances such as metal ions and turbid components such as silica.

It is a schematic diagram for demonstrating the whole structure of the water treatment apparatus which concerns on this embodiment. It is a conceptual diagram for demonstrating the principle of water treatment in the water treatment apparatus which concerns on this embodiment. It is sectional drawing for demonstrating the structure of the metal material agglutination promotion layer which concerns on this Embodiment. Explained that trivalent iron ions are adsorbed on iron oxide or iron hydroxide supported on a porous carrier by the oxidizing action of an oxidizing agent in the aggregation promoting portion of the water treatment apparatus according to the present embodiment. It is a schematic diagram for doing. It is a schematic diagram for demonstrating the whole structure of the water treatment apparatus of another example which concerns on this embodiment. It is a schematic diagram for demonstrating the whole structure of the water treatment apparatus which concerns on Embodiment 1. FIG. It is sectional drawing for demonstrating the structure of the oxidant supply part and the mixing part of the water treatment apparatus which concerns on Embodiment 1. FIG. It is a schematic diagram for demonstrating the whole structure of the water treatment apparatus which concerns on Embodiment 2, and is the figure which shows that the water to be treated flows in the forward direction. It is a schematic diagram for demonstrating the whole structure of the water treatment apparatus which concerns on Embodiment 2, and is the figure which shows that the water to be treated flows in the opposite direction. It is a schematic diagram for demonstrating the whole structure of the water treatment apparatus which concerns on Embodiment 3. It is a schematic diagram for demonstrating the whole structure of the water treatment apparatus in Example 1. FIG. It is a schematic diagram for demonstrating the whole structure of the water treatment apparatus in Example 2. FIG. It is a graph which shows the relationship between the turbidity of kaolin and the cumulative filtration flow rate in the treated water treated by the water treatment apparatus of Example 2. It is a graph which shows the relationship between the concentration of aluminum, and the cumulative filtration flow rate in the treated water treated by the water treatment apparatus of Example 2.

Hereinafter, the water treatment apparatus 100 of the present embodiment will be described with reference to the drawings. The dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios.

In the following embodiments, the term metal-related material is used. The metal-related substance means ^{one or more substances selected from the group consisting of metal ion M +} , metal particles M, metal oxide particles MO, and metal hydroxide particles MOH. The water W to be treated is at least one of metal ion M ⁺ , metal particles M, metal oxide particles MO, and metal hydroxide particle MOH, which are metal-related substances, and at least one of silica and alumina. It contains a turbid component containing.

Further, all of the metal-related substances such as metal ion M ⁺ , metal particles M, metal oxide particles MO, and metal hydroxide particles MOH are supported on the porous carrier, and the metal oxide particles and metal hydroxide are supported. It is adsorbed on at least one of the object particles. Therefore, in the present specification, metal oxide particles and metal hydroxide particles having a function of adsorbing metal-related substances are referred to as adsorbed particles.

As shown in FIG. 1, the water treatment apparatus 100 of the present embodiment includes water treatment channels 11, 12, and 13 through which the water to be treated W flows. A mixing unit 1 is connected between the water flow path 11 to be treated and the water flow path 12 to be treated. An agglutination promoting unit 2 is connected between the water flow path 12 to be treated and the water flow path 13 to be treated. The oxidant O is supplied to the mixing unit 1 from the oxidant supply unit 4, and the coagulant F is further supplied from the coagulant supply unit 5. The water W to be treated that has flowed out from the agglutination promoting unit 2 to the water flow path 13 to be treated is filtered by the filter unit 3 and reaches a faucet or the like as treated water via the supply flow path 14.

As shown in FIG. 2, in the water treatment apparatus 100, the water to be treated W containing a metal-related substance flows from the water flow path 11 to be treated into the mixing unit 1. As the water to be treated W, water or rainwater pumped from a water source such as a well, a river or a pond can be used, and as described above, a metal-related substance and a turbid component such as silica and alumina are contained. In the metal-related substance contained in the water W to be treated, the metal ion M ⁺ is a divalent iron ion (Fe ²⁺ ) and a trivalent iron ion (Fe ³⁺ ). The metal particles M are iron (Fe) particles. The metal oxide particle MO is a particle of iron oxide (FeO, Fe ₂ O ₃ , Fe ₃ O ₄ ). The metal hydroxide particles MOH are particles of iron hydroxide (Fe (OH) ₂ , Fe (OH) ₃ , FeO (OH)).

The oxidant supply unit 4 supplies the oxidant O to the mixing unit 1. The mixing unit 1 is configured to mix the water W to be treated flowing through the water flow path 11 to be treated and the oxidant O supplied from the oxidant supply unit 4. The water to be treated W that has flowed out of the mixing section 1 flows into the aggregation promoting section 2 via the water flow path 12 to be treated.

The oxidizing agent O causes an oxidizing action on the metal-related substance in the water W to be treated. Specifically, when the metal-related substance is a divalent iron ion, it has an action of oxidizing the trivalent iron ion. Such an oxidizing agent O preferably contains ozone or chlorine. Ozone and chlorine can be easily added to the water to be treated W and can be preferably used because they efficiently oxidize metal-related substances.

As the oxidizing agent O, a chlorine-based agent is preferable, and one in which hypochlorous acid is generated inside the water to be treated W is particularly preferable. As the oxidizing agent O, at least one selected from the group consisting of sodium hypochlorite, calcium hypochlorite and chlorinated isocyanuric acid can be used. As the calcium hypochlorite, at least one of bleaching powder (effective chlorine 30%) and highly bleaching powder (effective chlorine 70%)) can be used. As the chlorinated isocyanuric acid, at least one selected from the group consisting of sodium trichloroisocyanurate, potassium trichloroisocyanurate, sodium dichloroisocyanurate, and potassium dichloroisocyanurate can be used. Among these, sodium hypochlorite is a liquid and can be quantitatively added to the water to be treated W by using an injection method using a metering pump, so that it can be particularly preferably used. Further, since the inorganic highly bleached powder has a very high solubility in the water to be treated W, it can exhibit a high oxidizing action.

As shown in FIG. 3, the agglutination promoting section 2 includes a metal material agglutination promoting layer 200, and the water W to be treated to which the oxidizing agent O is added flows into the metal material agglutination promoting layer 200 via the mixing section 1. .. The metal material aggregation promoting layer 200 includes a base material 201 and a porous carrier layer 202 provided inside the base material 201.

The base material 201 holds the porous carrier layer 202 so that the water W to be treated that has flowed from the water flow path 12 to be treated permeates the porous carrier layer 202 and flows out from the water flow path 13 to be treated. As the base material 201, for example, a tubular body or a box body having a space capable of holding the porous carrier layer 202 inside can be used. Further, as the base material 201, a frame body capable of holding the porous carrier layer 202 on the surface can be used. In the aggregation promoting portion 2 shown in FIG. 3, the water flow path 12 to be treated is connected to the upper surface of the base material 201 in the metal material aggregation promoting layer 200, and the water flow path 13 to be treated is connected to the lower surface of the base material 201. .. A net 203 is provided so that the porous carrier C, which is held inside the base material 201 and constitutes the porous carrier layer 202, does not flow out into the water flow path 13 to be treated.

The porous carrier layer 202 contains a porous carrier C that carries adsorption particles A on its surface. As the porous carrier C, at least one selected from the group consisting of activated carbon, silica, ceramics and zeolite can be used. The porous carrier C has an aperture ratio that maintains the flow velocity of the water to be treated W containing the oxidizing agent O at a certain level or higher. Further, the porous carrier C has a sufficient surface area and adsorptivity for supporting the adsorbed particles A required for the aggregation of ^{the metal-related substances M +, M, MO and MOH.}

The adsorbed particles A include at least one of metal oxide particles and metal hydroxide particles. Specifically, the adsorbed particle A contains at least one trivalent iron ion compound selected from the group consisting of _{Fe 2} O ₃ , Fe ₃ O ₄ , Fe (OH) _{3 and FeOOH.}

The agglutination promoting unit 2 receives the water to be treated W containing the oxidizing agent O from the water flow path 12 to be treated. Then, the aggregation promoting unit 2 adsorbs the metal-related substance oxidized by the action of the oxidizing agent O to the adsorbed particles A. As a result, the aggregation promoting unit 2 promotes aggregation of mixed particles composed of metal oxide particles MO derived from metal-related substances and metal hydroxide particles MOH on the surface of the porous carrier C.

Specifically, as shown in FIG. 2, when the metal-related substances contained in the water to be treated W are iron ions, iron particles, iron oxide, and iron hydroxide, iron is produced by the oxidizing action of the oxidizing agent O. The ions are oxidized to trivalent iron ions (Fe ^3+). Then, the trivalent iron ions, iron particles, iron oxides and iron hydroxides are adsorbed on the surface of the adsorbed particles A with the trivalent iron ion compound contained in the adsorbed particles A as a nucleus. As a result, on the surface of the adsorbed particles A, the metal-related substance grows into aggregate MDA composed of iron oxide particles having a particle diameter of 1 μm or more, iron hydroxide and the like. The trivalent iron ions are adsorbed on the adsorbed particles A, but the divalent iron ions (Fe ²⁺ ) contained in the water to be treated W are adsorbed on the surface of the activated carbon constituting the porous carrier C and aggregated. It grows into a thing MDA.

Here, it is preferable that the metal constituting the adsorbed particles A and the metal constituting the metal-related substance contained in the water to be treated W are the same element. In this case, the adsorbed particles A can efficiently adsorb metal-related substances. However, the adsorbed particles A only need to be able to adsorb metal-related substances in the water to be treated W. Therefore, the metal constituting the adsorbed particles A and the metal constituting the metal-related substance may be different elements.

When the aggregate MDA aggregated on the surface of the porous carrier C has a certain size or more, for example, the particle size becomes 1 μm or more, it is separated from the surface of the porous carrier C by the water flow of the water to be treated W, and the water to be treated W It flows downstream with. That is, the water W to be treated containing the agglomerate MDA flows from the agglutination promoting unit 2 to the filter unit 3 via the water flow path 13 to be treated.

The filter unit 3 is provided downstream of the agglutination promoting unit 2 and captures the agglutination MDA that has flowed from the agglutination promoting unit 2 together with the water to be treated W. In the present embodiment, the filter unit 3 is a sand filtration unit. According to this filter unit 3, the agglomerated MDA can be removed from the water W to be treated. ^{As a result, treated water from which the metal ion M +} , the metal particles M, the metal oxide particles MO, and the aggregate MDA of the metal hydroxide particles MOH have been removed is generated downstream of the filter unit 3. The treated water is supplied to the faucet via the supply flow path 14.

Next, with reference to FIG. 4, focusing on the removal of iron ions in the water to be treated W, the difference between the water treatment device 100 of the present embodiment and the water treatment device of the comparative example will be described.

As shown in FIG. 4A, in the water treatment apparatus of the comparative example, the water to be treated W contains oxygen (O ₂ ) but does not contain the oxidizing agent O. When activated carbon is used as the porous carrier C, the activated carbon has a property of easily adsorbing ^{divalent iron ions (Fe 2+).} Here, when the divalent iron ion is oxidized in water ^{to become a trivalent iron ion (Fe 3+} ), the trivalent iron ion instantly combines with oxygen and changes into fine iron oxide. However, since activated carbon is more difficult to adsorb iron oxide fine particles than iron ions, as a result, trivalent iron ions often pass through the activated carbon without being adsorbed.

In this way, the divalent iron ions are adsorbed on the porous carrier C, but the trivalent iron ions combine with oxygen to form iron oxide particles at the level of several nm, so that they pass through the porous carrier C. I will end up. In order to remove such iron oxide particles at a level of several nm, a reverse osmosis membrane (RO membrane) or the like must be used, which greatly increases the cost.

On the other hand, in the water treatment apparatus 100 of the present embodiment, as shown in FIG. 4B, when the oxidizing agent O is supplied into the water to be treated W, the divalent iron ions become trivalent iron ions. It is oxidized. Then, the trivalent iron ion is adsorbed by the adsorbed particles A existing in the agglutination promoting portion 2. That is, the adsorbed particles A contain at least one trivalent iron ion compound selected from the group consisting of _{Fe 2} O ₃ , Fe ₃ O ₄ , Fe (OH) _{3 and FeOOH.} Since the trivalent iron ion in the water to be treated W has a high affinity with the trivalent iron ion compound in the adsorbed particle A, the trivalent iron ion compound becomes a nucleus and is adsorbed on the surface of the adsorbed particle A. .. As a result, iron ions in the water to be treated W aggregate on the surface of the adsorbed particles A, and an aggregate MDA of iron oxide or iron hydroxide is generated. Further, the divalent iron ions that have not been oxidized by the oxidizing agent O are adsorbed on the porous carrier C, and the adsorbed particles A existing on the surface of the porous carrier C and the aggregate MDA are generated.

Here, after the particle size of the agglomerated MDA reaches a level of several μm, the agglomerated MDA is desorbed from the surface of the adsorbed particles A. That is, the iron ions in the water to be treated W aggregate on the surface of the adsorbed particles A as aggregates MDA of iron oxides and iron hydroxides. When the aggregate MDA becomes 1 μm or more, it is separated from the surface of the adsorbed particles A by the water flow of the water to be treated W and reaches the filter unit 3. However, since the aggregate MDA is 1 μm or more, it can be easily removed by sand filtration or the like without using a reverse osmosis membrane.

As described above, the adsorbed particles A preferably contain at least one trivalent iron ion compound selected from the group consisting of _{Fe 2} O ₃ , Fe ₃ O ₄ , Fe (OH) _{3 and FeOOH.} However, it is more preferable that the adsorbed particles A _{contain at least one of Fe (OH) 3 and FeOOH.} Since Fe (OH) ₃ and FeOOH have a particularly high affinity for trivalent iron ions, agglomerates MDA are likely to be formed, and metal-related substances can be efficiently removed from the water to be treated W. It becomes.

If the water to be treated contains iron hydroxide (Fe (OH) ₃ ), iron oxide (Fe ₂ O ₃ ), and iron (Fe) particles, the iron hydroxide , Iron oxide and iron particles are not easily adsorbed on the porous carrier C. However, since the adsorbed particles A can also adsorb iron hydroxides, iron oxides, and iron particles, they can be removed as aggregates MDA.

As described above, the treated water W composed of water or rainwater pumped from a water source such as a well, river or pond may contain turbid components such as silica and alumina in addition to metal-related substances. is there. Since a part of such a turbid component can be aggregated on the surface of the adsorbed particles A in a form of being caught in the metal-related substance, the aggregate MDA can be formed and removed together with the metal-related substance. However, since the turbid component in the water to be treated W has a particle size of several nm, it may not be sufficiently removed only by the action of the aggregation promoting portion 2. Therefore, as shown in FIG. 1, the water treatment apparatus 100 includes a coagulant supply unit 5 that supplies a coagulant F that agglomerates turbid components to the water to be treated W.

The coagulant supply unit 5 supplies the coagulant F to the mixing unit 1. The mixing unit 1 is configured to mix the water to be treated W flowing through the water flow path 11 to be treated and the coagulant F supplied from the coagulant supply unit 5. That is, the mixing unit 1 is configured to mix the flocculant F and the oxidizing agent O supplied from the oxidizing agent supply unit 4. The order of adding the flocculant F and the oxidant O to the water W to be treated is not particularly limited, and the oxidant O may be added after the flocculant F is added, or the flocculant F is added after the oxidant O is added. Alternatively, the flocculant F and the oxidizing agent O may be added at the same time.

The pH of the flocculant F is about 3.5, and when a chlorine-based agent is used as the oxidizing agent O, it is preferable to mix them so that they do not come into direct contact with each other. That is, when these are added to the water to be treated at the same time, the acidic flocculant F may decompose the oxidizing agent O to generate chlorine gas. Therefore, the oxidant supply unit 4 may be provided upstream of the water flow path to be treated, and the coagulant supply unit 5 may be provided downstream of the water flow path to be treated to make it difficult for the acidic flocculant F and the oxidant O to come into direct contact with each other. preferable.

In the coagulant supply unit 5, the method of adding the coagulant F is not particularly limited. When the coagulant F is a liquid, it can be quantitatively added to the water to be treated W by using an injection method using a metering pump. When the coagulant F is a powder, it can be added to the water to be treated W as a powder by using a feeder or the like.

The aggregating agent F is not particularly limited as long as it can agglomerate turbid components and produce particles that can be filtered by the filter unit 3, that is, particles having a particle size of 20 μm to 50 μm. As the coagulant F, at least one of an inorganic coagulant and an organic coagulant can be used. The inorganic flocculant is preferably at least one of an iron-based inorganic flocculant and an aluminum-based inorganic flocculant. As the iron-based inorganic flocculant, at least one selected from the group consisting of ferrous sulfate, ferric sulfate, ferric chloride, polyferric sulfate, and polysilica-iron flocculant can be used. As the aluminum-based inorganic flocculant, at least one of polyaluminum chloride (PAC) and aluminum sulfate (sulfate band) can be used. As the organic flocculant, at least one selected from the group consisting of a cationic synthetic polymer flocculant, an anionic synthetic polymer flocculant, and a nonionic synthetic polymer flocculant can be used. Among these, it is preferable to use an inorganic flocculant as the flocculant F, and it is more preferable to use an iron-based inorganic flocculant. The iron-based inorganic flocculant can be preferably used because there is less concern about health hazards than the aluminum-based inorganic flocculant.

The amount of the flocculant F added to the water to be treated W is not particularly limited as long as it is possible to agglomerate the turbid component into particles that can be filtered by the filter unit 3. For example, when the flocculant F is an inorganic flocculant, it is preferable to add the flocculant F so that the concentration of the flocculant F with respect to the water to be treated W is 1 to 5 ppm.

In the water treatment apparatus 100, when the coagulant F is added to the water to be treated W by the coagulant supply unit 5, the turbid components dispersed in the water to be treated W are aggregated and aggregated by the action of the coagulant F. Generate things. At this time, metal-related substances may be incorporated into the agglomerates together with silica and alumina which are turbid components. Then, the agglomerates formed by agglutinating the turbid components reach the agglutination promoting portion 2 via the water flow path 12 to be treated. Most of the aggregates of the turbid component pass through the aggregation promoting portion 2 as they are, but some of the aggregates may aggregate together with the metal-related substance and be incorporated into the aggregate MDA.

Then, the agglutination component agglutination and the metal-related substance agglutination MDA flowing out from the agglutination promotion section 2 flow into the filter section 3 via the water flow path 13 to be treated. Since the particles of the turbid component aggregate and the metal-related substance aggregate MDA are coarsened, they can be easily captured by the filter unit 3 and removed from the water to be treated W. As a result, treated water from which agglomerates of turbid components and agglutinates of metal-related substances MDA have been removed is generated downstream of the filter unit 3, and the treated water passes through the supply flow path 14. Is supplied to the faucet.

As described above, the water treatment apparatus 100 of the present embodiment has the treated water channels 11, 12, and 13 through which the treated water W containing the metal-related substance and the turbid component containing at least one of silica and alumina flows. Be prepared. The metal-related substance is at least one selected from the group consisting of metal ions, metal particles, metal oxide particles, and metal hydroxide particles. Further, the water treatment apparatus 100 includes an oxidant supply unit 4 that supplies the oxidant O to the water W to be treated, and a coagulant supply unit 5 that supplies the coagulant F that agglomerates the turbid component into the water W to be treated. To be equipped. Further, the water treatment apparatus 100 has a metal material aggregation promoting layer 200, and promotes aggregation of the metal-related substance by adsorbing the metal-related substance contained in the water to be treated W on the adsorbed particles A by the action of the oxidizing agent. The aggregation promoting unit 2 is provided. The metal material aggregation promoting layer is supported on the base material 201, the porous carrier layer 202 provided on the base material, and the porous carrier layer, and is supported on Fe ₂ O ₃ , Fe ₃ O ₄ , Fe (OH) _3, and Fe OOH. It has adsorbed particles A containing at least one trivalent iron ion compound selected from the group consisting of.

In the water treatment apparatus 100, when the metal-related substances contained in the water to be treated W are iron ions, iron particles, iron oxides, and iron hydroxides, the porous carrier layer 202 in which adsorbed particles are present at a high density , The water to be treated W containing iron ions is passed together with the oxidizing agent. As a result, divalent iron ions are adsorbed on the surface of the porous carrier C. Further, trivalent iron ions are adsorbed on iron oxide particles or iron hydroxide particles as adsorbed particles A adsorbed on the surface of the porous carrier C. As a result, aggregation of metal-related substances is promoted on the surface of the porous carrier C. Further, the turbid component contained in the water to be treated W is also aggregated by the action of the flocculant F. Therefore, iron ions can be removed regardless of the valence of iron ions contained in the water to be treated W, and in addition, turbid components can be efficiently removed.

Further, the porous carrier layer 202 preferably contains activated carbon. Since activated carbon has a high specific surface area, it can support adsorbed particles at a high concentration. Further, since the activated carbon adsorbs divalent iron ions, the divalent iron ions in the water to be treated W can be easily removed.

Further, the water treatment device 100 is provided downstream of the agglutination promoting unit 2, and is a filter unit that filters the agglutination MDA of the metal-related substance and the agglutination of the turbid component that have flowed from the agglutination promoting unit 2 together with the water to be treated W. It is preferable that 3 is further provided. As a result, the filter unit 3 can remove the aggregate MDA of the metal-related substance and the aggregate of the turbid component from the water W to be treated. As a result, it is possible to generate water from which aggregates of metal-related substances MDA and aggregates of turbid components have been removed. The particle size of the aggregate MDA of the metal-related substance and the aggregate of the turbid component captured by the filter unit 3 is preferably 20 μm to 50 μm. When the particle size of the agglomerates is within this range, the filtered sand can be used as the filter unit 3, so that filtration can be performed at low cost. When measuring the particle size of the aggregate MDA of the metal-related substance and the aggregate of the turbid component, the measuring method is not particularly limited, but the measurement can be performed by, for example, a laser diffraction / scattering method.

In FIG. 1, the coagulant supply unit 5 is connected to the mixing unit 1, but the present invention is not limited to this mode. That is, when it takes time for the turbid component to be coarsened by the action of the coagulant F, it is preferable that the coagulant supply unit 5 is connected to the mixing unit 1. As a result, the agglomerates can be coarsened while the water to be treated W passes through the water flow path 12 to be treated and the agglutination promoting portion 2, so that agglomerates having a particle size of 20 μm to 50 μm can be easily obtained. However, when the coagulant F is used so that the coarsening of the turbid component can be performed in a very short time, the coagulant F is not limited to the mixing unit 1, and the water flow path 12 to be treated, the coagulation promoting part 2, and the water flow path 13 to be treated The coagulant supply unit 5 may be connected to any of the above.

Next, the overall configuration of the water treatment apparatus 100 in another example of the present embodiment will be described with reference to FIG. In the water treatment apparatus 100 of another example, the oxidant supply unit 4 and the coagulant supply unit 5 are connected to the mixing unit 1, the oxidant O is supplied from the oxidant supply unit 4, and the coagulant supply unit 4 is supplied. The flocculant F is supplied from 5. And the oxidizing agent O contains chlorine. As described above, the chlorine-containing oxidizing agent O can promote the aggregation of metal-related substances and sterilize the water to be treated W. Further, in the water treatment apparatus 100 of another example, the iron fiber material is installed in the mixing unit 1. As a result, in the mixing unit 1, iron ions and iron particles are supplied to the water to be treated W. Some iron particles change into iron ions, iron oxide particles, and iron hydroxide particles in the water W to be treated.

Generally, in an environment in which the water treatment apparatus 100 is used, the raw water to be treated water W is composed of metal ions M ⁺ , metal particles M, metal oxide particles MO, and metal hydroxide particles MOH as metal-related substances. Contains at least one of them. For example, the raw water contains at least one of iron ions, iron particles, iron oxide particles and iron hydroxide particles. In this case, in the water treatment apparatus 100, as described above, due to the oxidizing action of chlorine and the metal material aggregation promoting layer 200, trivalent iron ions, iron particles, iron oxide particles, and iron hydroxides are produced from the raw water. Particles can be removed. Further, the divalent iron ion can be removed from the raw water by the adsorption action of the porous carrier C.

On the other hand, the raw water to be the water to be treated W may contain almost no iron ions, iron particles, iron oxide particles, or iron hydroxide particles. As described above, metal-related substances other than iron, such as arsenic and manganese, are agglomerated and removed on the surface of the adsorbed particles A in the form of being caught in iron ions. Metal-related substances may be difficult to remove. Therefore, it is preferable to intentionally add iron to the water W to be treated to facilitate the removal of these metal-related substances. In the water treatment apparatus 100 shown in FIG. 5, a fiber material for supplying iron to the water to be treated W is provided in the mixing unit 1.

In the example shown in FIG. 5, the reaction between the iron fiber material and chlorine causes divalent iron ions and trivalent iron ions to dissolve in the water to be treated W. Further, in the water to be treated W, trivalent iron ions, iron particles, iron oxide particles, and iron hydroxide particles are adsorbed by the adsorbed particles A in the metal material aggregation promoting layer 200. Also in this case, the adsorbed particle A contains at least one trivalent iron ion compound selected from the group consisting of _{Fe 2} O ₃ , Fe ₃ O ₄ , Fe (OH) _{3 and FeOOH.}

The water treatment apparatus 100 of another example of the present embodiment positively produces iron ions, iron particles, iron oxide particles, and iron hydroxide particles from the iron fiber material with respect to the water W to be treated. It is added. As a result, it is possible to intentionally promote the aggregation of iron oxide particles and iron hydroxide particles on the surface of the adsorbed particles A, and to remove metal-related substances other than iron such as arsenic and manganese.

According to the water treatment apparatus 100 of another example of the present embodiment described above, metal-related substances are removed from the water to be treated W to the extent required without providing a large storage tank by the oxidizing action of chlorine. can do. Therefore, according to the water treatment apparatus 100, the space efficiency of removing metal-related substances can be improved. Further, fine particles can be removed from the water to be treated W by utilizing the fact that the iron fiber material dissolves into the water to be treated W as iron ions.

Hereinafter, a specific configuration of the water treatment device 100 of the present embodiment will be described.

(Embodiment 1)
The water treatment apparatus 100 of the first embodiment will be described with reference to FIGS. 6 and 7. As shown in FIG. 6, in the water treatment apparatus 100 of the first embodiment, the agglutination promoting unit 2 and the filter unit 3 are provided in one storage tank 10. The water flow path 13 to be treated is provided in the storage tank 10 and is a boundary portion between the aggregation promoting portion 2 and the filter portion 3 in the storage tank 10.

A pump P1 is provided in the water flow path 11 to be treated. The pump P1 sends the water to be treated W from a well or the like to the mixing unit 1. In the storage tank 10, the water W to be treated that has flowed out from the mixing unit 1 flows into the storage tank 10 from the upper part of the storage tank 10 via the water flow path 12 to be treated. In the storage tank 10, the water to be treated W flows down from above to below. At this time, the water W to be treated that flows down passes through the agglutination promoting unit 2 and the filter unit 3. After that, the treated water flows out from the lower part of the storage tank 10 and is supplied to the faucet via the supply flow path 14.

In the first embodiment, the mixing unit 1 and the oxidizing agent supply unit 4 are integrated. Specifically, as shown in FIG. 7, the mixing unit 1 includes a mixing oxidation tank 23 having a lid portion 22. The oxidant supply unit 4 is the tablet-shaped chlorine-based agent 24 itself as the oxidant O installed in the mixing unit 1. In the mixing section 1, a tablet-shaped chlorine-based chemical 24 and a fibrous iron 25 that supplies iron ions and iron particles to the water to be treated W are installed. As shown in FIG. 6, the coagulant supply unit 5 is connected to the mixing unit 1, and the coagulant F is supplied from the coagulant supply unit 5, but the illustration is omitted in FIG. 7.

As shown in FIG. 7, in the mixing section 1, the water W to be treated is blown out from the water flow path 11 to be treated into the space 21 in the mixed oxidation tank 23. After that, the water to be treated W comes into contact with the tablet-shaped chlorine-based chemical 24 installed in the lower part of the mixed oxidation tank 23 and the fibrous iron 25. As a result, the tablet-shaped chlorine-based agent 24 and the fibrous iron 25 supply the oxidizing agent O, iron ions, and iron particles to the water W to be treated.

Since the tablet-shaped chlorine-based chemical 24 and the fibrous iron 25 are captured by the net 26 provided in the path from the mixed oxidation tank 23 to the water flow path 12 to be treated, the water flow path 12 to be treated downstream is captured. It will not be washed away. As the chlorinated agent 24, it is preferable to use chlorinated isocyanuric acid, for example, sodium dichloroisocyanurate or sodium trichloroisocyanurate is more preferable, and sodium trichloroisocyanurate is particularly preferable. Since sodium trichloroisocyanurate has low solubility in water, when used as a tablet-like chlorine-based drug 24, a small amount of the drug can be continuously added for a long period of time.

As described above, in the first embodiment, the chlorine-based chemical 24 and the fibrous iron 25 are arranged in close proximity to the mixed oxidation tank 23. Therefore, due to the effect of the chlorine-based agent 24, iron ions, iron, iron oxides and iron hydroxides are easily eluted from the iron 25, and the oxidant O and iron ions, iron, iron oxides and iron with respect to the water to be treated W are easily eluted. It becomes possible to efficiently add the hydroxide. Further, as described above, even when the raw water to be the water to be treated W contains almost no iron ions, iron, iron oxides, and iron hydroxides, the water treatment apparatus 100 of the first embodiment is used. Therefore, iron can be intentionally added to the water to be treated W. As a result, it becomes possible to remove metal-related substances other than iron such as arsenic and manganese.

(Embodiment 2)
The water treatment apparatus 100 of the second embodiment will be described with reference to FIGS. 8 and 9. The water treatment device 100 further includes a flow path switching valve 50 and a drain port 17. The flow path switching valve 50 is connected to the water flow path 12 to be treated and the supply flow path 14. The mixing unit 1 and the flow path switching valve 50 are connected by a water flow path 12a to be treated. The flow path switching valve 50 and the storage tank 10 are connected by a water flow path 12b to be treated. Further, the storage tank 10 and the flow path switching valve 50 are connected by a supply flow path 14a. The flow path switching valve 50 and the faucet 16 are connected by a supply flow path 14b. The flow path switching valve 50 is also connected to the drain port 17. The flow path switching valve 50 is a so-called five-way valve.

The flow path switching valve 50 has a state in which the water to be treated W shown in FIG. 8 flows in the forward direction X from the aggregation promoting unit 2 toward the filter unit 3, and the water to be treated W shown in FIG. 9 is aggregated from the filter unit 3. The state of flowing in the opposite direction Y toward the promotion unit 2 is switched. In the case of the flow in the forward direction X, as shown in FIG. 8, the water W to be treated contains the mixing unit 1, the flow path switching valve 50, the aggregation promoting unit 2, the filter unit 3, the flow path switching valve 50, and the faucet. 16 flows in this order. In the case of the flow in the reverse direction Y, as shown in FIG. 9, the water to be treated W is the mixing unit 1, the flow path switching valve 50, the filter unit 3, the aggregation promoting unit 2, the flow path switching valve 50, and the drainage. It flows through the mouth 17 in this order.

The drain port 17 is positioned downstream of the agglutination promoting unit 2 in a state where the water to be treated W flows in the opposite direction Y, and discharges the water to be treated W to the outside. Therefore, according to the water treatment device 100, the filter unit 3 can be backwashed. Further, during the backflow cleaning of the filter unit 3, the adsorbed particles A adhering to the filter unit 3 are adsorbed by the adsorbed particles A adsorbed by the agglutination promoting unit 2. As a result, the ability of the adsorbed particles A of the agglutination promoting unit 2 can be restored.

Here, the agglutination promoting unit 2 has, for example, a porous carrier C containing a group of granules, and the filter unit 3 has, for example, a sand filtering unit containing a group of sand particles. The density of the granules of the group of the agglutination promoting portion 2 is smaller than the density of the sand grains of the group of the filter portion 3. Therefore, in the water in the storage tank 10, the granules of the group of the agglutination promoting portion 2 are deposited above the sand grains of the group of the filter portion 3. Further, a group of granules constituting the agglutination promoting portion 2 and a group of sand grains constituting the filter portion 3 are deposited so as to be arranged in the vertical direction with each other. Therefore, the water treatment device 100 can be miniaturized. Further, even if the filter unit 3 is backwashed, the group of granules constituting the agglutination promoting unit 2 and the group of sand particles constituting the filter unit 3 naturally maintain their arrangement with each other due to gravity.

The group of sand grains constituting the filter unit 3 can be, for example, manganese sand. The density of manganese sand is 2.57 to 2.67 g / cm ³ , and the amount of manganese adhered to manganese sand is 0.3 mg / g or more. However, the filter unit 3 may be formed of general filtered sand (2.5 g / cm ^3). The density of the porous carrier C containing a group of granules constituting the aggregation promoting portion 2 is, for example, 0.5 g / cm ³ in the case of activated carbon and 0.9 to 1.1 / cm ^{3 in the case of zeolite.} In the case of silica, it is 2.2 g / cm ³ , and in the case of ceramics, it is 0.7 g / cm ³ .

(Embodiment 3)
The water treatment apparatus 100 of the third embodiment will be described with reference to FIG. The water treatment device 100 is provided in the water flow path 11 to be treated upstream of the mixing unit 1, and further includes a reducing agent adsorbing unit 18 for adsorbing ammonia as a reducing agent contained in the water W to be treated. Therefore, it is possible to prevent the oxidizing agent O in the mixing unit 1 from being consumed due to the oxidation of ammonia in the water to be treated W. In the reducing agent adsorbing unit 18, a zeolite containing sodium ions and adsorbing ammonia in the water to be treated W can be used by substituting the sodium ions with the ammonium ions in the water to be treated W.

The water treatment device 100 includes a reclaimed liquid supply unit 19 that regenerates the ammonia adsorption effect of zeolite. The regenerating liquid supply unit 19 supplies a regenerating liquid containing sodium chloride to the zeolite to adsorb new sodium ions to the reducing agent adsorbing unit 18. As a result, the effect of adsorbing ammonia by the reducing agent adsorbing unit 18 can be maintained.

Hereinafter, the operation of the water treatment device in the present embodiment will be described in more detail with reference to Examples, but the present embodiment is not limited to these Examples.

[Example 1]
In Example 1, the iron removal performance of the metal material agglutination promoting layer was confirmed by using the water treatment apparatus shown in FIG.

First, an iron compound as adsorbed particles was supported on activated carbon as a porous carrier. Specifically, first, 300 mL of activated carbon was placed in a cylindrical treatment tank having an inner diameter of Φ50 mm and a capacity of 1 L. The activated carbon used had a particle size of 0.5 mm to 2.3 mm. Next, water containing 0.7 ppm of divalent iron ions and a sodium hypochlorite solution are continuously passed through the activated carbon inside the cylindrical treatment tank, and the activated carbon, water and hypochlorite are continuously passed through the treatment tank. The sodium solution was in good contact. The flow rate of water was 6 L / min, and the injection amount of the sodium hypochlorite solution was quantitatively controlled so that the free chlorine concentration in the treatment tank was maintained at 5 ppm. The water and sodium hypochlorite solution were injected for 10 hours to support the iron compound on the activated carbon.

Next, the water treatment apparatus shown in FIG. 11 was produced using the activated carbon supporting the iron compound obtained as described above. Then, in order to confirm the iron removal performance of the metal material agglutination promoting layer, a comparison with the prior art was performed. As a prior art, it was compared with high-speed filtration in which iron was promoted to aggregate with an oxidizing agent to grow grains, and then filtered with filtered sand.

The comparative experiment was carried out using the water treatment apparatus shown in FIG. A cylindrical container having an inner diameter of 50 mm and a capacity of 1 L was used for the agglutination promoting portion and the sand filtration tank. Then, 100 mL of filtered gravel and 300 mL of activated carbon carrying an iron compound were placed inside the container to prepare an agglutination promoting portion provided with a metal material agglutination promoting layer. The filtered gravel used had a particle size of 2 mm to 4 mm. Further, 100 mL of filtered gravel and 300 mL of manganese sand (Φ0.35 mm) were placed inside another cylindrical container to prepare a sand filter tank. The filtered gravel used had a particle size of 2 mm to 4 mm, and the manganese sand used had a particle size of 0.35 mm.

Then, as shown in FIG. 11, the agglutination promoting part is arranged on the upstream side of the sand filtration tank using the water flow path to be treated, and the raw water supply pump as the water to be treated and the oxidation are placed on the upstream side of the agglutination promoting part. A fixed-quantity injection mechanism for the agent was provided. As the oxidizing agent, a sodium hypochlorite solution having a chlorine concentration of 10000 ppm was used. A bypass line BL was provided between the hypochlorous acid injection mechanism and the agglutination promoting part, and between the agglutination promoting part and the sand filtration tank. The capacity of the bypass line is 1 L, and the total capacity is the same regardless of which flow path of the bypass line or the aggregation promoting portion is passed.

As experimental items, a total of four types including the presence / absence of the agglutination promoting portion and the presence / absence of chlorine supply were performed. High-speed filtration, which is a conventional technique, corresponds to the case where there is no agglutination promoting portion and chlorine as an oxidizing agent is present. Further, the filtration using the agglutination promoting portion according to the present embodiment corresponds to the case where there is an agglutination promoting portion and there is chlorine. As the raw water, water having an iron concentration of 0.72 ppm was used, and the raw water flow rate was set to 1 L / min. When chlorine was supplied, the input amount was controlled to be 30 ppm.

Table 1 shows the iron concentration contained in each treated water. In the conventional high-speed filtration (without agglutination promoting part, with chlorine), the iron concentration was 0.47 ppm. This is because some iron grows in grains due to the effect of chlorine and is filtered by the sand filter, but the time for grain growth, that is, the capacity of the previous stage of the sand filter tank, is insufficient for sufficient iron removal. it is conceivable that.

On the other hand, when the agglutination promoting part was used in front of the sand filtration tank (with the agglutination promoting part and with chlorine), the iron concentration was 0.16 ppm, and it was confirmed that the iron removal performance was improved. It is considered that this is a result of the agglutination promoting part accelerating the agglutination of iron and the amount of iron filtered increased, and the effect of the agglutination promoting part on the iron removal treatment was confirmed. In addition, even when only the agglutination promoting part was used (with the agglutination promoting part and without chlorine), the iron concentration decreased slightly, and the effect of accelerating the grain growth of the agglutination promoting part alone was confirmed.

As described above, by providing the aggregation promoting portion of the present embodiment upstream of the sand filtration tank, iron grain growth is accelerated as compared with the case where only the oxidizing agent is used, and the iron removal performance by filtration is significantly improved. It was confirmed that.

[Example 2]
In Example 2, the water treatment apparatus 300 shown in FIG. 12 was used to confirm the removal performance of the turbid component by the metal material aggregation promoting layer and the flocculant.

As shown in FIG. 12, the water treatment device 300 includes a storage tank 310. As the storage tank 310, a cylindrical container having an inner diameter Φ of 100 mm and a length of 500 mm was used. On the upstream side of the inside of the storage tank, an agglutination promoting unit 302 made of activated carbon carrying an iron compound obtained in Example 1 was arranged, and on the downstream side, a filter unit 303 was arranged. In the filter section 303, manganese sand having a particle size of 0.35 mm, gravel having a particle size of 2 to 4 mm, and gravel having a particle size of 4 to 8 mm were laminated in this order from the aggregation promoting portion side. In the storage tank 310, the capacity of the agglutination promoting unit 302 was set to 400 mL. The volume of manganese sand in the storage tank 310 was 1400 mL, the volume of gravel having a particle size of 2 to 4 mm was 500 mL, and the volume of gravel having a particle size of 4 to 8 mm was 500 mL.

Then, as shown in FIG. 12, the coagulant supply unit 305 is arranged on the upstream side of the storage tank 310 using the water flow path to be treated, and the raw water as the water to be treated is supplied to the upstream side of the coagulant supply unit 305. A pump P and an oxidizing agent supply unit 304 were provided. A flow meter for measuring the flow rate of raw water was installed on the upstream side of the raw water supply pump P. As the raw water, water to which kaolin was added at a concentration of 0.1 g / L was used. A sodium hypochlorite solution was used as the oxidizing agent supplied from the oxidizing agent supply unit 304. Further, as the coagulant supplied from the coagulant supply unit 305, liquid polyaluminum chloride having a concentration of 11% was used.

Using such a water treatment device 300, the removal performance of kaolin, which is a turbid component, was confirmed. Specifically, raw water to which kaolin was added at a concentration of 0.1 g / L was flowed using a supply pump P at a flow rate of 2.3 L / min (linear velocity 17.6 m / h). Then, the oxidant was added to the raw water from the oxidant supply unit 304 using the supply pump P. At this time, the amount of the oxidizing agent added was adjusted so that the chlorine concentration was 10 ppm. Further, the coagulant was added to the raw water from the coagulant supply unit 305 using the supply pump P.

The raw water containing the oxidizing agent and the flocculant reached the storage tank 310 and passed through the agglutination promoting section 302 and the filtering section 303 in this order to obtain treated water. Then, the turbidity of kaolin contained in the treated water after passing through the storage tank 310 was measured. The measurement result is shown in FIG. In the graph of FIG. 13, the vertical axis represents the turbidity of kaolin contained in the treated water (unit: Nephelometric Turbidity Unit (NTU)), and the horizontal axis represents the cumulative filtration flow rate of raw water. FIG. 13 also shows the measurement result of the turbidity of kaolin when the storage tank 310 excluding the agglutination promoting unit 302 is used.

As shown in FIG. 13, it can be seen that when the coagulant and the coagulation promoting portion are used in combination, the amount is less than 5 NTU, which is the WHO standard. In addition, when the agglutination promoting part was not used, the cumulative filtration flow rate was ^{about 10 m 3} / m ² and the turbidity increased, whereas when the agglutinating agent and the agglutination promoting part were used together, the turbidity increased to 20 m. ^It can be seen that the increase in turbidity can be suppressed to about 3 / m ^2. That is, by using the agglutination promoting portion, the turbid component coarsened by the agglutinating agent is taken into the metal-related substance and easily forms the agglutinating MDA, so that the turbid component can be efficiently removed. Become. Since the turbidity of the raw water before the treatment to which kaolin was added at a concentration of 0.1 g / L is 100 NTU, it can be seen that the turbidity can be significantly reduced by using the agglutinating agent and the agglutination promoting portion together.

Furthermore, the concentration of aluminum contained in the treated water after passing through the storage tank 310 was also measured. This aluminum is derived from a flocculant, and if the treated water contains aluminum, there are concerns about health hazards. The measurement result is shown in FIG. In the graph of FIG. 14, the vertical axis represents the concentration of aluminum contained in the treated water, and the horizontal axis represents the cumulative filtration flow rate of raw water. As shown in FIG. 14, it can be seen that when the flocculant and the agglutination promoting portion are used in combination, the dose is less than 0.2 mg / L, which is the WHO standard. In addition, when the agglutination promoting part was not used, the cumulative filtration flow rate ^{increased at about 10 m 3} / m ² , whereas when the agglutinating agent and the agglutination promoting part were used in combination, 20 m ³ It can be seen that the increase in concentration can be suppressed even if it exceeds / m ^2. From this, it can be seen that the outflow of the agglutinating agent can be suppressed by using the agglutination promoting portion.

Although the contents of the present embodiment have been described above, it is obvious to those skilled in the art that the present embodiment is not limited to these descriptions and various modifications and improvements can be made.

2 Agglutination promotion part 3 Filter part 4 Oxidizing agent supply part 5 Coagulant supply part 100 Water treatment device 200 Metal material Coagulation promotion layer 201 Base material 202 Porous carrier layer A Adsorption particles C Porous carrier F Coagulant O Oxidizing agent W Treated water

Claims (5)

Water to be treated containing at least one metal-related substance selected from the group consisting of iron ions, iron particles, iron oxide particles and iron hydroxide particles and a turbid component containing at least one of silica and alumina flows. Water flow path to be treated and
An oxidant supply unit that supplies an oxidant to the water to be treated,
A coagulant supply unit that supplies a coagulant that agglomerates the turbid component to the water to be treated,
At least selected from the group consisting of a base material, a porous carrier layer provided on the base material, and Fe ₂ O ₃ , Fe ₃ O ₄ , Fe (OH) _{3, and Fe OOH supported on the porous carrier layer.} By providing an adsorbed particle containing a kind of trivalent iron ion compound and a metal material aggregation promoting layer having the adsorbed particle, the metal-related substance contained in the water to be treated is adsorbed on the adsorbed particle by the action of the oxidizing agent. , The aggregation promoting part that promotes the aggregation of the metal-related substance, and
A water treatment device. The water treatment apparatus according to claim 1, wherein the adsorbed particles _{contain at least one of Fe (OH) 3 and FeOOH.} The water treatment apparatus according to claim 1 or 2, wherein the porous carrier layer contains activated carbon. The water treatment apparatus according to any one of claims 1 to 3, wherein the flocculant is at least one of an iron-based inorganic flocculant and an aluminum-based inorganic flocculant. Claim 1 further includes a filter unit provided downstream of the agglutination promoting unit and filtering the agglutination of the metal-related substance and the agglutination of the turbid component flowing from the agglutination promoting unit together with the water to be treated. 4. The water treatment apparatus according to any one of 4.

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