JP6519934B2 - Metal material aggregation promoting layer, and water treatment apparatus using the same - Google Patents

Description

  The present invention relates to a metal material aggregation promoting layer for purifying water to be treated, and a water treatment apparatus using the same.

  BACKGROUND ART Conventionally, development of a water treatment apparatus for purifying water to be treated has been advanced. With regard to the water treatment apparatus, for example, those disclosed in the following Patent Document 1 can be mentioned.

JP 2007-99612 A

  The conventional water treatment apparatus as disclosed in Patent Document 1 is generally assumed to be used in an area where it is assumed that water purification is performed in a public water treatment facility.

  On the other hand, in emerging countries where social infrastructure has not been 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 a water treatment device in each home. In particular, there is a need to remove metal-related substances such as metal ions contained in the water to be treated by a water treatment apparatus installed at home. However, in order to remove metal-related substances from the water to be treated in a treatment time meeting household water demand, according to the principle of the conventional water treatment apparatus, it becomes necessary to provide a large reservoir.

  However, homes often do not have a space of a size suitable for installing a large water treatment apparatus. Therefore, in order to meet the above-mentioned needs, a water treatment device capable of sufficiently removing metal-related substances contained in water to be treated is required without providing a large-sized storage tank. Become. Therefore, there is a need for a water treatment apparatus that can efficiently remove metal-related substances contained in water to be treated in a small space.

  The present invention has been made in view of the problems of the prior art. And the object of the present invention is a metal material aggregation promoting layer capable of efficiently removing metal-related substances such as metal ions, metal particles, metal oxide particles and metal hydroxide particles, and It is providing the water treatment apparatus used.

In order to solve the said subject, the metal material aggregation promotion layer which concerns on the 1st aspect of this invention has a base material and the porous support layer provided in the surface of the base material. Furthermore, the metal material aggregation promoting layer contains at least one trivalent iron ion compound supported on the porous carrier layer and selected from the group consisting of Fe ₂ O ₃ , Fe ₃ O ₄ , Fe (OH) ₃ and FeOOH. It has adsorption particles.

  In a water treatment apparatus according to a second aspect of the present invention, water to be treated containing at least one metal-related substance selected from the group consisting of metal ions, metal particles, metal oxide particles and metal hydroxide particles flows It has a to-be-processed water flow path and an oxidizing agent supply part which supplies an oxidizing agent to to-be-processed water. Furthermore, the water treatment apparatus has the metal material aggregation promoting layer according to the first aspect, and causes the aggregation of the metal related material by adsorbing the metal related material contained in the water to be treated to the adsorption particles by the action of the oxidizing agent. It has a cohesion promoting part to promote.

FIG. 1: is a schematic diagram for demonstrating the whole structure of the water treatment apparatus which concerns on embodiment of this invention. FIG. 2 is a conceptual diagram for explaining the principle of water treatment in the water treatment apparatus according to the embodiment of the present invention. FIG. 3 is a cross-sectional view for explaining the structure of the metal material aggregation promoting layer according to the embodiment of the present invention. FIG. 4 shows that, in the aggregation promoting portion of the water treatment apparatus according to the embodiment of the present invention, trivalent iron ions are supported on the iron oxide or the iron hydroxide supported on the porous carrier by the oxidizing action of the oxidizing agent. It is a schematic diagram for demonstrating adsorb | sucking. FIG. 5: is a schematic diagram for demonstrating the whole structure of the water treatment apparatus of the other example which concerns on embodiment of this invention. FIG. 6: is a schematic diagram for demonstrating the whole structure of the water treatment apparatus which concerns on Embodiment 1 of this invention. FIG. 7: is sectional drawing for demonstrating the structure of the oxidizing agent supply part of the water treatment apparatus which concerns on Embodiment 1 of this invention, and a mixing part. FIG. 8 is a schematic view for explaining the overall structure of the water treatment apparatus according to Embodiment 2 of the present invention, showing that the water to be treated flows in the forward direction. FIG. 9 is a schematic view for explaining the entire structure of the water treatment apparatus according to Embodiment 2 of the present invention, showing that the water to be treated flows in the reverse direction. FIG. 10 is a schematic view for explaining the overall structure of the water treatment apparatus according to Embodiment 3 of the present invention. FIG. 11 is a schematic view for explaining the entire constitution of the water treatment apparatus in the embodiment. FIG. 12 is a graph showing the relationship between the concentration of iron remaining in the treated water and the concentration of chlorine introduced into the treated water in Example 2. FIG. 13 is a graph showing the relationship between the concentration of free chlorine remaining in treated water and the concentration of chlorine added to water to be treated in Example 2. FIG. 14 relates to Example 3, in the case where the flow rate of the water to be treated is 0.2 L / min, 0.5 L / min, 0.75 L / min, 1 L / min, 1.5 L / min, 2 mL / min. It is a graph which shows the relationship between the density | concentration of iron which remains in a treated water, and the amount of activated carbon which carry | supported the iron compound.

  Hereinafter, the water treatment apparatus 100 of the present embodiment will be described with reference to the drawings. In the following description, portions having the same function are denoted by the same reference numerals, and the description of the same function will not be repeated unless necessary.

In the following description of the embodiment, the term metal-related substance is used. The metal-related substance means one or more substances selected from the group consisting of metal ions M ⁺ , metal particles M, metal oxide particles MO, and metal hydroxide particles MOH. In addition, the water to be treated W contains at least one of metal ions M ⁺ , metal particles M, metal oxide particles MO, and metal hydroxide particles MOH, which are metal-related substances.

Also, metal oxide particles and metal hydroxides in which any of metal ions M ⁺ , metal particles M, metal oxide particles MO, and metal hydroxide particles MOH, which are metal-related substances, are supported on a porous support It is adsorbed to at least any 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 adsorption particles.

  As shown in FIG. 1, the water treatment apparatus 100 according to the present embodiment includes the to-be-treated water channels 11, 12, and 13 through which the to-be-treated water W flows. The mixing unit 1 is connected between the treated water flow passage 11 and the treated water flow passage 12. A cohesion promoting unit 2 is connected between the treated water flow path 12 and the treated water flow path 13. The oxidizing agent O is supplied to the mixing unit 1 from the oxidizing agent supply unit 4. The to-be-processed water W which flowed out to the to-be-processed water flow path 13 from the aggregation acceleration | stimulation part 2 is filtered by the filter part 3, and reaches via a supply flow path 14 a faucet etc. as treated water.

As shown in FIG. 2, in the water treatment apparatus 100, the to-be-treated water W containing the metal-related substance flows from the to-be-treated water channel 11 into the mixing unit 1. That is, the water to be treated W containing the metal ions M ⁺ , the metal particles M, the metal oxide particles MO, and the metal hydroxide particles MOH flows from the water to be treated channel 11 into the mixing part 1. In addition, in the metal-related substance contained in the to-be-processed water W, metal ion M ^<+> is a bivalent iron ion (Fe ^{< 2+ >} ) and a trivalent iron ion (Fe ^{< 3+ >} ), for example. The metal particles M are, for example, particles of iron (Fe). The metal oxide particles MO are, for example, particles 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 oxidizing agent supply unit 4 supplies the oxidizing agent O to the mixing unit 1. The mixing unit 1 is configured to mix the water to be treated W flowing through the water to be treated channel 11 and the oxidant O supplied from the oxidant supply unit 4. The to-be-processed water W which flowed out of the mixing part 1 flows in into the aggregation acceleration | stimulation part 2 via the to-be-processed water flow path 12. As shown in FIG.

  The oxidizing agent O causes the metal-related substance to oxidize in the water to be treated W. Specifically, when the metal-related substance is a divalent iron ion, it has an effect of oxidizing to a trivalent iron ion. Such an oxidant 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 in order to efficiently oxidize metal-related substances.

  As the oxidizing agent O, a chlorine-based agent is preferable, and in particular, one in which hypochlorous acid is generated inside the water to be treated W is 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 calcium hypochlorite, at least one of an exposed powder (30% available chlorine) and a highly exposed powder (70% available chlorine) can be used. As 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 using an injection method by a metering pump, so it can be particularly preferably used. In addition, since the inorganic highly exfoliated powder has a very high solubility in the water to be treated W, it can exhibit a high oxidation effect.

  As shown in FIG. 3, the aggregation promoting unit 2 includes the metal material aggregation promoting layer 200, and the metal material aggregation promoting layer 200 is treated water W to which the oxidizing agent O is added via the treated water flow path 12. Flows in. The metal material aggregation promoting layer 200 includes the base material 201 and the porous carrier layer 202 provided inside the base material 201.

  The substrate 201 holds the porous carrier layer 202 such that the water to be treated W flowing in from the water to be treated channel 12 permeates the porous carrier layer 202 and flows out from the water to be treated channel 13. As the base material 201, for example, a cylinder or a box having a space capable of holding the porous carrier layer 202 inside can be used. Moreover, as the base material 201, a frame which can hold the porous carrier layer 202 on the surface can be used. In the aggregation promoting unit 2 shown in FIG. 3, the water passage 12 is connected to the upper surface of the base material 201 in the metal material aggregation promoting layer 200, and the water passage 13 is connected to the lower surface of the base 201. . Then, the net 203 is provided so that the porous carrier C which is held in the inside of the base material 201 and which constitutes the porous carrier layer 202 does not flow into the water passage 13.

The porous carrier layer 202 includes a porous carrier C carrying 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 opening ratio that maintains the flow rate of the treated water W containing the oxidizing agent O at a certain level or more. In addition, the porous carrier C has sufficient surface area and adsorptivity to support the adsorbing particles A necessary for removing the metal-related substances M ⁺ , M, MO and MOH.

The adsorption particles A include at least one of metal oxide particles and metal hydroxide particles. Specifically, the adsorptive 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.

  The aggregation promoting unit 2 receives the to-be-treated water W containing the oxidizing agent O from the to-be-treated water flow path 12. The aggregation promoting unit 2 adsorbs the metal-related substance contained in the water to be treated W to the adsorption particles A by the action of the oxidizing agent O. Thereby, the aggregation promoting unit 2 promotes aggregation of mixed particles composed of the metal oxide particles MO and the metal hydroxide particles MOH derived from the metal-related substance on the surface of the porous carrier C.

Specifically, as shown in FIG. 2, when the metal-related substance contained in the water to be treated W is iron ions, iron particles, iron oxides, and iron hydroxides, the oxidizing action of the oxidant O causes iron The ions are oxidized to trivalent iron ions (Fe ³⁺ ). The trivalent iron ion, the iron particles, the iron oxide, and the iron hydroxide are adsorbed on the surface of the adsorption particle A with the trivalent iron ion compound contained in the adsorption particle A serving as a core. As a result, on the surface of the adsorption particle A, the metal-related substance grows into an aggregate MDA composed of iron oxide particles having a diameter φ of 1 μm or more, iron hydroxide and the like. The trivalent iron ions are adsorbed to the adsorbing particles A, but the divalent iron ions (Fe ²⁺ ) contained in the water to be treated W are adsorbed to the surface of the activated carbon constituting the porous carrier C, Grow into aggregates MDA.

  Here, it is preferable that the metal which comprises the adsorption particle A, and the metal which comprises the metal relevant substance contained in the to-be-processed water W are the same elements. In this case, the adsorptive particles A are considered to have a high adsorptive effect on metal-related substances. However, the adsorptive particles A may be capable of adsorbing the metal-related substance in the water to be treated W. Therefore, the metal constituting the adsorbing particles A and the metal constituting the metal-related substance may not be the same element.

  The aggregate MDA aggregated on the surface of the porous carrier C is separated from the surface of the porous carrier C by the water flow of the water to be treated W as shown in FIG. Flow downstream with That is, the to-be-processed water W containing aggregate MDA flows into the filter part 3 from the aggregation acceleration | stimulation part 2 via the to-be-processed water flow path 13. FIG.

The filter unit 3 is provided downstream of the aggregation promoting unit 2 and captures the aggregate MDA that has flowed from the aggregation 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 the filter unit 3, the aggregates MDA can be removed from the water to be treated W. As a result, in the downstream of the filter unit 3, processed water from which the aggregates MDA of the metal ions M ⁺ , the metal particles M, the metal oxide particles MO, and the metal hydroxide particles MOH have been removed is generated. The treated water is supplied to the faucet via the supply channel 14.

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

As shown in (a) of FIG. 4, the water treatment device of the comparative example, the water to be treated W is an oxygen (O _2), containing no oxidizing agent O. When activated carbon is used as the porous carrier C, activated carbon has the property of easily adsorbing divalent iron ions (Fe ²⁺ ). Here, when divalent iron ions are oxidized in water to be trivalent iron ions (Fe ³⁺ ), the trivalent iron ions instantaneously combine with oxygen and change to particulate iron oxide. However, activated carbon is more difficult to adsorb iron oxide fine particles than iron ions, and as a result, trivalent iron ions often pass through the activated carbon without being adsorbed.

  Thus, although divalent iron ions are adsorbed to the porous carrier C, trivalent iron ions are combined with oxygen to form iron oxide particles of several nm level, and thus pass through the porous carrier C. It will In order to remove such iron oxide particles of several nm level, it is necessary to use a reverse osmosis membrane (RO membrane) or the like, which greatly increases the cost. In addition, although it is possible to coarsen iron oxide particles of several nm level using a coagulant, it is necessary to leave them for a long time for coarsening, so the removal efficiency is greatly reduced.

On the other hand, in the water treatment apparatus 100 of the present embodiment, as shown in (b) of FIG. 4, when the oxidizing agent O is supplied into the water to be treated W, divalent iron ions become trivalent iron ions. It is oxidized. Then, the trivalent iron ions are adsorbed to the adsorbing particles A present in the aggregation promoting unit 2. That is, the adsorbing 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. The trivalent iron ion in the water to be treated W has a high affinity to the trivalent iron ion compound in the adsorption particle A, so the trivalent iron ion compound becomes a nucleus and is adsorbed on the surface of the adsorption particle A . As a result, iron ions in the water to be treated W aggregate on the surface of the adsorption particles A, and aggregates MDA of iron oxide and iron hydroxide are generated. In addition, divalent iron ions that are not oxidized by the oxidizing agent O are adsorbed to the porous carrier C, and form adsorbed particles A and aggregates MDA present on the surface of the porous carrier C.

  Here, after the particle size of the aggregate MDA reaches a level of several μm, the aggregate MDA is detached from the surface of the adsorbent particle A. That is, iron ions in the water to be treated W aggregate on the surface of the adsorption particles A as aggregates MDA of iron oxide and iron hydroxide. And when aggregate MDA becomes several micrometers or more, it desorbs from the surface of adsorption particles A with the water flow of treated water W, and reaches filter part 3. However, since the aggregate MDA is several μm or more, it can be easily removed by sand filtration, for example, without using a reverse osmosis membrane.

As described above, the adsorptive 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 adsorbent particles A contain at least one of Fe (OH) ₃ and FeOOH. Fe (OH) ₃ and FeOOH have a particularly high affinity to trivalent iron ions, which facilitates formation of aggregates MDA, and metal-related substances can be efficiently removed from the water W to be treated It becomes.

When the water W to be treated contains particles of iron hydroxide (Fe (OH) ₃ ), iron oxide (Fe ₂ O ₃ ), and iron (Fe), iron hydroxide , Iron oxide and iron particles pass through the porous carrier C. However, since the adsorption particles A can also adsorb particles of iron hydroxide, iron oxide and iron, they can be removed as aggregates MDA.

  The water to be treated W may contain, in addition to iron, arsenic, manganese, silica, alumina or the like as a metal-related substance. Silica and alumina deteriorate water quality as suspended components. However, since these metal-related substances can be aggregated on the surface of the adsorbing particles A in a form of being caught by iron ions, it becomes possible to form and remove the aggregates MDA with iron.

  According to the water treatment apparatus 100 of this embodiment, the to-be-processed water W which contains iron ion with an oxidizing agent is allowed to pass through the porous support layer 202 in which the adsorption particle containing a trivalent iron ion compound exists in high density. Thereby, divalent iron ions are adsorbed on the surface of the porous carrier C. Further, trivalent iron ions are adsorbed to particles of iron oxide or particles of iron hydroxide as adsorption particles A attached to the surface of the porous carrier C. As a result, on the surface of the porous carrier C, aggregation of the metal-related substance is promoted. According to this, regardless of the valence number of iron ions contained in the water to be treated W, it is possible to remove iron ions to a required extent.

  The whole structure of the water treatment apparatus 100 in the other example of this embodiment is demonstrated using FIG. As shown in FIG. 5, in the water treatment apparatus 100 of another example, the oxidant O contains chlorine. The oxidizing agent O containing chlorine can promote the aggregation of the metal-related substance as described above and can sterilize the water to be treated W. Moreover, in the water treatment apparatus 100 of the other example, the fiber material of iron is installed in the mixing part 1. Thereby, iron ions and iron particles are supplied to the water to be treated W in the mixing section 1. Iron particles may be changed to particles of iron ions, particles of iron oxide, and particles of iron hydroxide in the water to be treated W.

Generally, in the environment where the water treatment apparatus 100 is used, raw water to be treated water W is a metal-related substance, such as metal ions M ⁺ , metal particles M, metal oxide particles MO, and metal hydroxide particles MOH Contains at least one of 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, the oxidizing action of the chlorine and the metal material aggregation promoting layer 200 make it possible to use raw water to trivalent iron ions, iron particles, iron oxide particles, and iron hydroxides. The particles can be removed. The divalent iron ions are removed from the raw water by the adsorptive action of the porous carrier C.

  On the other hand, the raw water to be treated water W may hardly contain any of iron ions, iron particles, iron oxide particles, and iron hydroxide particles. As mentioned above, metal related substances other than iron such as arsenic, manganese, silica, alumina are aggregated and removed on the surface of the adsorption particle A in the form of being caught by iron ions, and therefore the raw water does not contain iron. May make it difficult to remove these metal-related substances. Therefore, it is preferable to intentionally add iron to the water to be treated W to facilitate 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, divalent iron ions and trivalent iron ions are dissolved in the water to be treated W by the reaction between iron fiber material and chlorine. Further, in the water to be treated W, particles of trivalent iron ions, particles of iron, particles of iron oxide, and particles of iron hydroxide are adsorbed to the adsorption particles A in the metal material aggregation promoting layer 200. Also in this case, the adsorptive 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.

  The water treatment apparatus 100 according to another example of the present embodiment positively uses iron fiber material, iron particles, iron oxide particles, iron oxide particles, and iron hydroxide particles to the water to be treated W. It is added. Thereby, on the surface of the adsorption particle A, the aggregation of iron oxide particles and iron hydroxide particles is intentionally promoted to remove metal-related substances other than iron such as arsenic, manganese, silica, and alumina. It becomes possible.

  According to the water treatment apparatus 100 of the other example of the present embodiment described above, metal-related substances are removed from the water to be treated W to the required extent 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 the removal of metal-related substances can be improved. Further, it is possible to remove fine particles from the water to be treated W by utilizing the dissolution of the fiber material of iron into the water to be treated W as iron ions.

  Hereinafter, the concrete composition of water treatment equipment 100 of this embodiment is explained.

(Embodiment 1)
The water treatment apparatus 100 of Embodiment 1 is demonstrated using FIG.6 and FIG.7. As shown in FIG. 6, in the water treatment apparatus 100 of the first embodiment, the aggregation promoting unit 2 and the filter unit 3 are provided in one storage tank 10. And the to-be-processed water flow path 13 is provided in the storage tank 10, and is a boundary part of the aggregation promotion part 2 and the filter part 3 in the storage tank 10. As shown in FIG.

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

  In the first embodiment, the mixing unit 1 and the oxidant supply unit 4 are integrated. The mixing unit 1 includes a mixed oxidation tank 23 having a lid 22. The oxidizing agent supply unit 4 is a tablet-like chlorine-based drug 24 itself as the oxidizing agent O installed in the mixing unit 1. In the mixing unit 1, fibrous iron 25 that supplies iron ions and iron particles to the water to be treated W is disposed together with a tablet-like chlorine-based drug 24.

  As shown in FIG. 7, in the mixing section 1, the water to be treated W is blown out from the water to be treated channel 11 to the space 21 in the mixed oxidation tank 23. Thereafter, the water to be treated W contacts the tablet-like chlorine-based drug 24 and the fibrous iron 25 installed at the lower part of the mixed oxidation tank 23. Thus, the tablet-like chlorine-based drug 24 and the fibrous iron 25 supply the oxidizing agent O and iron ions and iron particles to the water to be treated W.

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

  As described above, in the first embodiment, the chlorine-based agent 24 and the fibrous iron 25 are disposed close to each other in the mixed oxidation tank 23. Therefore, iron ion, iron, iron oxide and iron hydroxide are easily eluted from iron 25 by the effect of the chlorine-based drug 24, and an oxidant O for the water to be treated W, as well as iron ion, iron and iron oxide And iron hydroxide can be efficiently added. Also, as described above, even if the raw water to be treated water W contains almost no iron ions, iron, iron oxides, and iron hydroxides, the water treatment apparatus 100 of Embodiment 1 is used. Iron can be intentionally added to the water W to be treated. As a result, it becomes possible to remove metal-related substances other than iron such as arsenic, manganese, silica and alumina.

Second Embodiment
The water treatment apparatus 100 of Embodiment 2 is demonstrated using FIG.8 and FIG.9. The water treatment apparatus 100 further includes a flow path switching valve 50 and a drainage port 17. The flow path switching valve 50 is connected to the treated water flow path 12 and the supply flow path 14. The mixing unit 1 and the flow path switching valve 50 are connected by the treated water flow path 12 a. The flow path switching valve 50 and the storage tank 10 are connected by the treated water flow path 12 b. Moreover, the storage tank 10 and the flow path switching valve 50 are connected by the supply flow path 14a. The flow path switching valve 50 and the faucet 16 are connected by the supply flow path 14 b. The flow path switching valve 50 is also connected to the drainage 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 flows in the forward direction X from the aggregation promoting portion 2 to the filter portion 3 shown in FIG. 8 and the water to be treated W shown in FIG. It switches with the state of flowing in the reverse direction Y toward the promotion unit 2. In the case of the flow in the forward direction X, as shown in FIG. 8, the water to be treated W has the mixing part 1, the flow path switching valve 50, the aggregation promoting part 2, the filter part 3, the flow path switching valve 50, and the faucet Flow through 16 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 mixed in the mixing part 1, the flow path switching valve 50, the filter part 3, the aggregation promoting part 2, the flow path switching valve 50, and drainage. It flows through the mouth 17 in this order.

  The drainage port 17 is positioned downstream of the aggregation promoting unit 2 in a state where the water to be treated W flows in the reverse direction Y, and discharges the water to be treated W to the outside. Therefore, according to the water treatment apparatus 100, it is possible to backwash the filter unit 3. In addition, at the time of backwashing of the filter unit 3, the adsorbing particles A adhering to the filter unit 3 are adsorbed by the adsorbing particles A adsorbed by the aggregation promoting unit 2. As a result, the ability of the adsorbed particles A of the aggregation promoting unit 2 can be recovered.

  Here, the aggregation promoting unit 2 has a porous carrier C containing, for example, a group of particles, and the filter unit 3 has a sand filtering unit containing, for example, a group of sand grains. The density of the group of particles in the aggregation promoting section 2 is smaller than the density of the group of sand grains in the filter section 3. Therefore, in the water in the storage tank 10, the group of particles of the aggregation promoting unit 2 is positioned above the group of sand grains of the filter unit 3. Further, a group of particles forming the aggregation promoting unit 2 and a group of sand grains forming the filter unit 3 are deposited so as to line up in the vertical direction. Therefore, the water treatment apparatus 100 can be miniaturized. In addition, even if the filter unit 3 is backwashed, the group of particles forming the aggregation promoting unit 2 and the group of sand particles forming the filter unit 3 naturally maintain their mutual arrangement by gravity.

A group of sand grains constituting the filter unit 3 is, for example, manganese sand. And the density of manganese sand is 2.57-2.67 g / cm ³ . The manganese deposition amount of manganese sand is 0.3 mg / g or more. However, the filter part 3 may be formed of general filtration sand (2.5 g / cm ³ ). In addition, the density of the porous carrier C containing a group of particulates 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. It is 2.2 g / cm ³ in the case of silica and 0.7 g / cm ³ in the case of ceramics.

(Embodiment 3)
The water treatment apparatus 100 of the third embodiment will be described with reference to FIG. The water treatment apparatus 100 further includes a reducing agent adsorption unit 18 provided in the for-treatment water flow path 11 upstream of the mixing unit 1 and adsorbing ammonia as a reducing agent contained in the for-treatment water W. Therefore, it can suppress that the oxidizing agent O in the mixing part 1 is consumed for the oxidation of the ammonia in the to-be-processed water W. FIG. The reducing agent adsorbing unit 18 is a zeolite that contains sodium ions and adsorbs ammonia in the water to be treated W by replacing the sodium ions with ammonium ions in the water to be treated W.

  The water treatment apparatus 100 includes a regeneration solution supply unit 19 that regenerates the ammonia adsorption effect of zeolite. The regeneration solution supply unit 19 causes the reducing agent adsorption unit 18 to adsorb new sodium ions by supplying a regeneration solution containing sodium chloride to the zeolite. Thereby, the adsorption effect of ammonia by the reducing agent adsorption unit 18 can be maintained.

  Hereinafter, the present embodiment will be described in more detail by way of examples, but the present embodiment is not limited to these examples.

Example 1
First, as described below, an iron compound as adsorption particles was supported on activated carbon as a porous carrier. First, 300 mL of activated carbon was placed in a cylindrical processing tank with an inner diameter of 50 50 mm and a capacity of 1 L. The activated carbon used had a particle diameter Φ of 0.5 mm to 2.3 mm. Next, water containing 0.7 ppm of divalent iron ions and sodium hypochlorite solution are continuously passed through the activated carbon in the cylindrical treatment tank, and the activated carbon, water and hypochlorous acid are contained in the treatment tank. The sodium solution was in good contact. The water flow rate of water was 6 L / min, and the injection amount of 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 load the iron compound on the activated carbon.

  Next, using the activated carbon carrying an iron compound, obtained as described above, a water treatment apparatus shown in FIG. 11 was produced. And in order to confirm the iron removal performance of a metal material aggregation promotion layer, comparison with a prior art was performed. As prior art, after promoting iron aggregation with an oxidizing agent to make grain growth, it compares with high-speed filtration which filters with filtration sand.

  A comparative experiment was conducted using the water treatment apparatus shown in FIG. A cylindrical container with an inner diameter 50 of 50 mm and a capacity of 1 L was used for the aggregation promoting unit and the sand filtration tank. Then, 100 mL of filtration gravel (Φ 2 to 4 mm) and 300 mL of activated carbon carrying an iron compound were placed in the inside of the container, to prepare a coagulation promoting portion provided with a metal material coagulation promoting layer. The filtration gravel used had a particle diameter Φ of 2 mm to 4 mm. Furthermore, 100 mL of filtration gravel and 300 mL of manganese sand (Φ 0.35 mm) were placed in the inside of the container to prepare a sand filtration tank. The filtration gravel used had a particle diameter Φ of 2 mm to 4 mm, and the manganese sand used that having a particle diameter Φ of 0.35 mm.

  Then, as shown in FIG. 11, the aggregation promoting unit is disposed on the upstream side of the sand filtration tank using the treated water flow path, and on the upstream side of the aggregation promoting unit, a feed pump of raw water as treated water, oxidation The metered dose injection mechanism of the agent was provided. As the oxidizing agent, a sodium hypochlorite solution having a chlorine concentration of 10,000 ppm was used. A bypass line (BL) was provided between the hypochlorous acid injection mechanism and the aggregation promoting part, and between the aggregation promoting part and the sand filtration tank. The volume of BL is 1 L, and the total volume is made to be the same regardless of whether it passes through the flow path of BL or the aggregation promoting unit.

  As an experiment item, a total of four ways were performed consisting of a combination of the presence or absence of the aggregation promoting part and the presence or absence of the chlorine supply. The high speed filtration which is the prior art corresponds to the case where there is no aggregation promoting part and chlorine as an oxidizing agent is present. Moreover, the filtration using the aggregation promoting part according to the present embodiment corresponds to the case where there is an aggregation promoting part and there is chlorine. As raw water, water with an iron concentration of 0.72 ppm was used, and the raw water flow rate was 1 L / min. In the case of chlorine supply, the input was controlled to be 30 ppm.

  Table 1 shows the concentration of iron contained in each treated water. The iron concentration was 0.47 ppm in the high-speed filtration (with no aggregation promoting portion and with chlorine), which is the prior art. This is because some iron particles grow due to the effect of chlorine and are filtered by the sand filtration unit, but it is a result of insufficient grain growth time, that is, the capacity of the former stage of the sand filtration tank to perform sufficient iron removal it is conceivable that.

  On the other hand, in the case where the aggregation promoting part was used before the sand filtration tank (aggregation promoting part present, with chlorine), the iron concentration was 0.16 ppm, and it was confirmed that the iron removal performance was improved. This is considered to be the result of the aggregation promoting part accelerating the aggregation of iron and the amount of filtered iron being increased, and the effect on the iron removal treatment of the aggregation promoting part was confirmed. In addition, even when only the aggregation promoting part was used (aggregation promoting part present, without chlorine), the iron concentration slightly decreased, and the grain growth acceleration effect in the aggregation promoting part alone was also confirmed.

  As described above, by providing the aggregation promoting unit of the present embodiment upstream of the sand filtration tank, iron particle growth is accelerated more than when only the oxidizing agent is used, and iron removal performance by filtration is significantly improved. That was confirmed.

Example 2
As described in Example 1, it has been confirmed that grain growth of iron is further accelerated by using an oxidizing agent (chlorine) in the iron removal treatment using the aggregation promoting portion. Next, in order to investigate the necessary amount of chlorine, the input chlorine concentration is changed to 10 ppm, 20 ppm, 30 ppm and 40 ppm using the water treatment apparatus of Example 1, and evaluation of iron concentration and free chlorine concentration in the resulting treated water is performed. went. As in Example 1, the amount of activated carbon carrying an iron compound was 300 mL, and the flow rate of water to be treated was 1 L / min.

  As shown in FIG. 12, when the input chlorine amount was 30 ppm or more, the iron concentration in the treated water decreased to about 0.2 ppm. Since the water quality standard of iron in Japan is 0.3 ppm or less, it is possible to remove iron to the water quality that satisfies it. Moreover, as shown in FIG. 13, it was confirmed that the free chlorine concentration in the treated water sharply increases when the input chlorine amount is 30 ppm or more. From these results, it was found that in the present example, when the free chlorine is at a predetermined concentration (2 to 5 ppm) or more, the grain growth effect in the aggregation promoting portion can be more exhibited.

  Here, decomposition of ammonia, organic matter, and the like contained in the water to be treated can be considered as factors that consume chlorine other than iron oxidation. It is known that the raw water used in this example contains an ammonia component, and it is considered that most of the input chlorine is consumed for the oxidation of the ammonia component. It is assumed that the water quality of the raw water treated by the water treatment apparatus of the present embodiment differs depending on the case, such as the place where it is installed, and the content of the organic matter and the like is not constant. Therefore, the amount of input chlorine needs to be adjusted each time according to the quality of the raw water to be treated.

[Example 3]
In Example 3, the influence of the flow rate of the water to be treated and the amount of the activated carbon carrying the iron compound on the performance of the aggregation promoting portion was examined. First, an aggregation promoting portion in which the amount of activated carbon supporting iron compound is 50 mL, 100 mL, 200 mL, and 300 mL, respectively, was produced, and the water treatment apparatus of Example 1 was obtained using each aggregation promoting portion. And the flow rate of 0.2 L / min, 0.5 L / min, 0.75 L / min, 1 L / min, 1.5 L / min, 2 mL / min of raw water with an iron concentration of 0.72 ppm in the water treatment device. The water was passed through to check the iron removal performance. FIG. 14 shows the relationship between the concentration of iron remaining in the treated water and the amount of activated carbon carrying the iron compound at each flow rate. The concentration of chlorine introduced into the water to be treated was 40 ppm.

  As shown in FIG. 14, it can be seen that the iron concentration in the treated water can be reduced even if the flow rate of the water to be treated is changed in all of the activated carbon amounts of 50 mL, 100 mL, 200 mL and 300 mL. In particular, when the amount of activated carbon was 50 mL and 100 mL, good iron removal results were obtained at each flow rate. With regard to the flow rate, the best iron removal performance was exhibited when the amount of activated carbon was 100 mL and 0.75 L / min. The difference in iron removal performance shown in FIG. 14 is considered to be the result of consumption of chlorine into the activated carbon, and the flow rate of the water to be treated and the amount of activated carbon are within the range where the above-mentioned free chlorine concentration can be maintained. It is considered preferable to adjust.

  As described above, it can be seen that although there is a fixed relationship between the amount of activated carbon and the flow rate of water to be treated with respect to the iron removal performance, iron removal can be effectively achieved by using the aggregation promoting portion. In addition, although the raw water with an iron concentration of about 0.72 ppm is used in this experiment, it is assumed that if the iron concentration in the raw water is different, the result in FIG. It is necessary to design the water treatment system according to the actual raw water specifications.

  Hereinafter, the characteristic configurations of the metal material aggregation promoting layer and the water treatment apparatus according to the present embodiment and the effects obtained thereby will be described.

(1) The metal material aggregation promoting layer 200 includes the base material 201 and the porous carrier layer 202 provided on the base material 201. Furthermore, the metal material aggregation promoting layer 200 is supported by the porous carrier layer 202, and is 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. Containing adsorbed particles. According to such a configuration, the metal-related substances M ⁺ , M, MO, and MOH contained in the water to be treated W can be adsorbed and aggregated on the surface of the adsorption particles. As a result, the particle size of the metal-related substance aggregate MDA becomes a few μm level, so it is possible to easily separate from the water to be treated W and to reduce the concentration of the metal-related substance contained in the water to be treated W Become.

(2) The adsorptive particles contain at least one of Fe (OH) ₃ and FeOOH. Fe (OH) ₃ and FeOOH have high affinity to metal-related substances and can be easily adsorbed, which makes it possible to efficiently form aggregates MDA of metal-related substances.

(3) The porous carrier layer 202 contains activated carbon. Since activated carbon has a high specific surface area, it can support adsorptive particles at a high concentration. In addition, since activated carbon adsorbs divalent iron ions, it is possible to easily remove divalent iron ions in the water to be treated.

(4) The water treatment apparatus 100 includes the treated water flow paths 11, 12, 13, the oxidant supply unit 4, and the aggregation promotion unit 2. The to-be-treated water flow paths 11, 12, 13 are to be treated including at least one metal-related substance selected from the group consisting of metal ions M ⁺ , metal particles M, metal oxide particles MO, and metal hydroxide particles MOH. Water W flows. The oxidizing agent supply unit 4 supplies the oxidizing agent O to the water to be treated W. The aggregation promotion part 2 has a metal material aggregation promotion layer 200, and promotes aggregation of the metal-related substance by adsorbing the metal-related substance contained in the water to be treated W to the adsorption particles A by the action of the oxidizing agent O. .

  According to said structure, the to-be-processed water W containing the aggregate MDA of the metal oxide particle which adsorb | sucked the metal related substance flows out out of the aggregation promotion part 2. As shown in FIG. Therefore, if the aggregate MDA is captured by the filter unit 3 provided downstream of the aggregation promoting unit 2, more metal-related substances can be removed from the water to be treated W. Therefore, the space efficiency of the removal of the metal related substance from the to-be-processed water W can be improved.

(5) The oxidant O may contain ozone or chlorine. According to this, both sterilization of the to-be-processed water W and promotion of aggregation of a metal related material can be performed.

(6) The water treatment apparatus 100 further includes the filter unit 3 provided downstream of the aggregation promoting unit 2 and filtering the aggregate MDA of the metal-related substance that has flowed from the aggregation promoting unit 2 together with the water to be treated W Is preferred. According to this, the filter portion 3 can remove the aggregate MDA of the metal-related substance from the water to be treated W. As a result, it is possible to generate water from which the aggregates MDA of metal-related substances are removed.

  The entire contents of Japanese Patent Application No. 2015-116729 (filing date: June 9, 2015) and Japanese Patent Application No. 2015-176427 (filing date: September 8, 2015) are incorporated herein by reference.

  Although the contents of the present embodiment have been described above according to the examples, the present embodiment is not limited to these descriptions, and it is obvious to those skilled in the art that various modifications and improvements are possible. is there.

  According to the present invention, the space efficiency of the removal of one or more metal-related substances selected from the group consisting of metal ions, metal particles, metal oxide particles, and metal hydroxide particles can be improved.

2 Coagulation promoting part 3 Filter part 4 Oxidizing agent supply part 11, 12, 13 Treated water flow path 100 Water treatment device 200 Metal material cohesion promoting layer 201 Base material 202 Porous carrier layer A Adsorbed particles MDA Aggregate O Oxidizing agent W Covered Treated water

Claims (3)

A treated water flow path through which treated water containing at least one metal-related substance selected from the group consisting of iron ions, iron particles, iron oxide particles and iron hydroxide particles flows;
An oxidant supply unit for supplying an oxidant containing chlorine to the water to be treated;
Base material, porous carrier layer including porous carrier comprising a group of particles provided on the substrate, supported on the porous carrier, Fe ₂ O ₃ , Fe ₃ O ₄ , Fe (OH) ₃ and the adsorbent particles containing at least one trivalent iron ionic compound selected from the group consisting of FeOOH, and a coagulation promoting portion which have a metallic material aggregation promoting layer having,
A filter unit provided downstream of the aggregation promoting unit, comprising a sand filtration unit including a group of sand grains, and filtering the aggregates of the metal-related substance that has flowed from the aggregation promoting unit with the water to be treated;
A storage tank in which the aggregation promoting unit and the filter unit are provided;
Have
The aggregation promoting portion promotes aggregation of the metal-related substance by adsorbing the metal-related substance contained in the water to be treated to the adsorption particles by the action of the oxidizing agent, and then the metal-related substance is released. Draining the treated water containing an aggregate of the adsorbed metal oxide particles,
The particle diameter of the aggregate that has flowed out of the aggregation promoting portion is larger than the particle diameter of the metal-related substance that has flowed into the aggregation promoting portion,
The water treatment device, wherein a density of a group of particles in the aggregation promoting portion is smaller than a density of a group of sand grains in the filter portion. The water treatment apparatus according to claim 1, wherein the adsorption particles contain at least one of Fe (OH) ₃ and FeOOH.   The water treatment device according to claim 1, wherein the porous carrier layer comprises activated carbon.

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