JP2002239559A - Method and apparatus for treating wastewater of water containing metal ion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover metal components from water containing metal ions which is used for washing products having plating solution adhering thereon and to clean the treatment liquid. SOLUTION: Copper hydroxide is generated by adding sodium hydroxide into treatment water W11 containing copper ions to prepare alkaline treatment water W12. The treatment water W12 is supplied to a floating filter medium type filter 100, and the copper hydroxide is separated. The separated copper hydroxide is drained by the net material 301 part of a draining-heating apparatus 300. The drained copper hydroxide is heated by the iron plate part 302 of the apparatus 300 to be converted into copper oxide. Fine (micron order) copper particles are obtained by reducing the copper oxide. The filtrate of the filter 100 is further filtered by a hollow fiber membrane filter 200 to be cleaned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating wastewater containing metal ions. The present invention, for example, removes a metal component from treated water, which contains metal ions by washing a plating product to which a plating solution has adhered, and collects the metal component, and also generates no sludge as industrial waste. It is possible to purify the treated water without causing the purification. In addition, the recovered metal becomes extremely fine particles on the order of microns and is an expensive resource.

[0002]

2. Description of the Related Art Improvement of wear resistance and corrosion resistance of products,
The product surface is plated for decoration. Of the plating methods, in wet plating such as electroplating and electroless plating (chemical plating), the product is immersed in a plating tank containing a plating solution, plated, and then the plated product is plated. And immerse the product in a washing tank containing water. Therefore, in the washing tank, the plating solution attached to the surface of the product is washed with water. The product whose plating solution has been washed with water is pulled up from the washing tank and dried. Generally, two washing tanks are prepared, and washing is performed twice.

[0003] Since the wastewater discharged from the washing tank contains a plating solution, it also contains ionized metals. The ionized metal is copper ion in copper plating, nickel ion in nickel plating, zinc ion in zinc plating, tin ion in tin plating, and chromium ion in chromium plating. Such wastewater cannot be discharged to the outside environment as it is, but must be discharged after purifying so that the metal ion concentration is lower than the concentration specified by the wastewater standard. For example, the emission standards for copper ions have changed with the times, but have become concentrations of about 1 ppm or less.

Here, a conventional waste water treatment apparatus for plating water will be described with reference to FIG. As shown in the figure, raw water (waste water) W discharged from the washing tank after washing the plating product with water
1 is temporarily stored in the raw water tank 1. In the case of copper plating, the raw water W1 contains copper ions.

The raw water W1 is sent to the neutralization tank 2. Neutralization tank 2
Is charged with sodium hydroxide (NaOH) and slaked lime (Ca (OH) ₂ ), and the raw water W1 becomes alkaline treated water W2.
Therefore, the copper ions react with the hydroxyl groups to form copper hydroxide, and the generated copper hydroxide can precipitate. At this time, a large amount of slaked lime is charged to accelerate the sedimentation speed, but the sedimentation speed is slow because the generated copper hydroxide particles are fine and fine. The amount of slaked lime is usually 5 to 10 times the amount required for all copper ions to react with hydroxyl groups. Since the amount of slaked lime is increased in this way, the generated copper hydroxide is attached to unreacted slaked lime and sedimentation is promoted. If slaked lime is not supplied, it becomes impossible to settle and separate the precipitate in the decanter 4 at the subsequent stage.

[0006] Even if a large amount of slaked lime is charged, the sedimentation speed is still insufficient. Therefore, the treated water W2 is sent to the coagulation tank 3, and the coagulation material (eg, polyaluminum chloride, aluminum sulfate, etc.) is added to the coagulation tank 3. I do. Then, the generated copper hydroxide particles are combined to increase the particle diameter, so that the sedimentation speed is increased.

The treated water W2 to which the coagulant has been added is sent to a decanter (liquid cyclone) 4 and supplied in a circumferential direction so as to form a vortex inside the decanter 4. Therefore, copper hydroxide 5 having a high specific gravity and slaked lime are supplied to the decanter 4
Settles below. Treated water W3 from which copper hydroxide 5 was separated
Is taken out from above the decanter 4 and the sand filter 6
Sent to Under the decanter 4, not only the copper hydroxide 5 but also a large amount of unreacted slaked lime is mixed and precipitated.

[0008] The treated water W3 is filtered by the sand filtration device 6,
The filtered treated water W4 is discharged outside. The concentration of copper ions contained in the treated water W4 is equal to or less than the concentration specified in the wastewater standard.

Copper hydroxide 5 deposited under the decanter 4
When the amount of slaked lime exceeds the specified amount, the deposited copper hydroxide 5 and slaked lime are sent to the filter press 7. In the filter press 7, the sediment in which the copper hydroxide 5 and the slaked lime are mixed is squeezed. The liquid W5 which has squeezed out and leaks contains a large amount of copper hydroxide and the like and cannot be discharged to the outside as it is. When squeezing is performed in this manner, the water is squeezed out, and the sludge 8 remains. The sludge 8 contains not only copper hydroxide but also a large amount of slaked lime and has a water content of about 70%, so that its bulk is large.

Since a large amount of sludge 8 is industrial waste containing copper hydroxide and slaked lime, the treatment is entrusted to an industrial waste disposal company at a disposal cost.

The above-mentioned example is an example in which the raw water W1 obtained by washing a copper-plated product with water is treated. By performing the same treatment as in the case of copper plating, a large amount of sludge containing nickel hydroxide, zinc hydroxide, tin hydroxide, chromium hydroxide and slaked lime is generated.

[0012]

As described above, in the conventional method, a large amount of sludge 8 is generated. In addition, since the sludge 8 is an industrial waste, the treatment must be entrusted to pay for the treatment, and a high treatment cost is required. Also, from the viewpoint of environmental protection, it has been desired to reduce the amount of sludge, and ideally not to generate sludge, but the prior art could not meet such a demand.

According to the present invention, it is possible to carry out a purification treatment while removing a metal component from wastewater containing metal ions and reusing it as a valuable metal without generating any sludge as industrial waste. It is an object of the present invention to provide a wastewater treatment method and a wastewater treatment device for treated water containing metal ions.

[0014]

According to a method of the present invention for solving the above-mentioned problems, at least one of sodium hydroxide and potassium hydroxide is added to treated water containing metal ions, and if necessary, furthermore, The coagulant is charged to generate a metal hydroxide, and the specific gravity is supplied to the floating filter medium type filtration device using a filter medium smaller than the specific gravity of the treated water, by supplying the treated water containing the metal hydroxide. Separating the treated water and the metal hydroxide, taking out the separated metal hydroxide, draining the water adhering to or penetrating the hydroxide, and heating the drained metal hydroxide In this way, the metal oxide is obtained by heating the frozen hydroxide of the drained metal, followed by heating.

Further, in the configuration of the apparatus of the present invention, treated water containing metal ions is supplied, at least one of sodium hydroxide and potassium hydroxide is charged, and a coagulant is charged as necessary. Thereby, a neutralization tank that generates a metal hydroxide, and when the treated water containing the metal hydroxide is supplied from the neutralization tank, a specific gravity is used which is smaller than the specific gravity of the treated water. A floating filter medium type filtration device for filtering treated water and separating a metal hydroxide, and a metal hydroxide is supplied from the floating filter medium type filtration device, and adheres or permeates to the metal hydroxide. A water draining device for draining water, and a heating device for supplying a metal hydroxide that has been drained by the water draining device and heating the metal hydroxide to obtain a metal oxide. That. If necessary, a refrigerating device for refrigerating the drained metal hydroxide is provided upstream of the heating device.

[0016]

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

FIG. 1 shows a first embodiment of the present invention.
1 shows a wastewater treatment apparatus according to an embodiment. As shown in the figure, raw water (waste water) W11 discharged from the washing tank after washing the plating product with water is temporarily stored in the raw water tank 11. In this example, the raw water W11 is obtained by washing a copper-plated product with water, and the raw water W11 contains copper ions.

The raw water W11 is sent to the neutralization tank 12. Sodium hydroxide is charged into the neutralization tank 12, and the raw water W11
Becomes alkaline treated water W12. Therefore, the copper ions react with the hydroxyl groups to form copper hydroxide (Cu (OH) ₂ ). Further, an aggregating material is charged into the neutralization tank 12 as needed. The coagulant may be polyaluminum chloride or aluminum sulfate, but is preferably an organic coagulant.
As the organic coagulant, for example, Gellannic F ₃ (Geranic) (product name manufactured and sold by Mitsubishi Corporation) is available.

Unlike the conventional case, slaked lime (Ca (OH) ₂ ) is not introduced. If slaked lime was added, the sedimentation speed would be faster, but the amount of impurities mixed into the recovered copper oxide would greatly reduce the commercial value, and a large amount of sludge would be generated. Because it cannot be achieved.

The treated water W12 containing copper hydroxide is sent to the floating filter medium type filtration device 100. Floating filter medium type filtration device 10
As “0”, “Oasis (trade name)” manufactured by Zenken Co., Ltd. is specifically adopted. The details of the floating filter medium type filtration device 100 will be described later, but the outline is as follows.

That is, the inner space of the filter tube 102 of the floating filter medium type filter apparatus 100 is filtered
4 and a collection chamber 105. A filter medium net 108 is stretched over the upper part of the filtration chamber 104, and the filter medium 1 is placed in the lower space of the filter medium net 108 in the filtration chamber 104.
06 is filled. The filter medium 106 is granular, has a specific gravity of less than 1, and floats when the treated water W12 is supplied. As a result, the floating filter media 106 are pressed against each other in a dense state, and a filter layer on the order of microns is formed by the filter media 106.

The filtration chamber 104 of the floating filter medium type filtration apparatus 100
The treated water W12 supplied to the lower space is filtered by passing upward through a filtration layer formed by the filter medium 106 from below to become treated water W13. The concentration of copper ions contained in the treated water W13 is equal to or lower than the concentration specified in the wastewater standard.

On the other hand, the copper hydroxide α is stirred in the lower space of the filtration chamber 104 where the filter medium 106 does not exist, and the grains grow, fall down and enter the recovery chamber 105. Since the recovery chamber 105 is separated from the filtration chamber 104 by the funnel member 103, the liquid in the recovery chamber 105 is quiet, and the copper hydroxide α is deposited on the lower part of the recovery chamber 105.

The floating filter medium type filtration device 100 has high filtration performance and excellent separation characteristics by employing the funnel member 103. For this reason, even if the sedimentation speed of the copper hydroxide contained in the treated water W12 is low, the separation of the copper hydroxide can be performed quickly and efficiently. For this reason, as described above, it is possible to eliminate the need for introducing slaked lime.

The treated water W13 filtered by the floating filter medium type filtration apparatus 100 can be discharged to the external environment as it is, but in the present embodiment, it is sent to the hollow fiber membrane type filtration apparatus 200 for further fine filtration. Can be As the hollow fiber membrane type filtration device 200, specifically, “Super Fine Filter (trade name)” manufactured by “ZENKEN” is used. The details of the hollow fiber membrane type filtration device 200 will be described later, but the outline is as follows.

That is, the hollow fiber membrane module 206 is disposed in the filtration tube 202 of the hollow fiber membrane type filtration device 200. The treated water W13 is supplied to the injection hole 20 of the injection pipe 207.
The gas is ejected from the approximate center of the hollow fiber membrane module 206 in the radial direction through 7a. Spouted treated water W13
Is filtered through the hollow fiber membrane module 206 to become clear treated water W14. Since the filtered treated water W14 is extremely clean, it can be reused as industrial water. Of course, when unnecessary, it can be discharged to the external environment.

Further, the contaminants 2 separated and deposited by filtration
When the accumulation amount of No. 10 exceeds a certain amount, this pollutant 2
10 is returned to the raw water tank 11 together with the treated water (this is indicated by a symbol W15).

On the other hand, when a certain amount of copper hydroxide α is deposited in the lower part of the recovery chamber 105 of the floating filter medium type filtration device 100,
This copper hydroxide α is treated with treated water together with a draining / heating device 30
Send to 0. The draining / heating device 300 is a device in which the draining device and the heating device are integrated.

In the draining / heating device 300, a plate-like net material 301 and an iron plate 302 are connected. And
The net material 301 and the iron plate 302 are arranged diagonally so that the net material 301 is located on the lower side and the iron plate 302 is located on the upper side. A water receiving tank 3 is provided below the net material 301.
The heater unit 304 is provided on the lower surface of the iron plate 302.

Above the net material 301 and the iron plate 302, a scraping device 305 is arranged. This scraping device 305 has a number of scrapers 305b arranged on the outer peripheral surface of a conveyor belt 305a. When the conveyor belt 305a rotates, the scraper 305
The b moves diagonally downward and diagonally upward while rubbing the upper surfaces of the net material 301 and the iron plate 302.

Therefore, when the copper hydroxide α and the treated water are sent to the upper surface of the net material 301, the copper hydroxide α is scraped up by the scraper 305b and slides on the upper surface of the net material 301. During this slide movement,
The moisture adhering to the surface of the copper hydroxide α and the moisture permeating the inside of the copper hydroxide α move downward by the action of gravity, fall from the copper hydroxide α, and pass through the net material 301. ,
It falls toward the water receiving tank 303. That is, the moisture that has adhered to and has penetrated the copper hydroxide α is drained. The water collected in the water receiving tank 303 is returned to the raw water tank 11.

The drained copper hydroxide α is further scraped up by the scraper 305b and slides on the upper surface of the iron plate 302. At this time, the iron plate 302 is heated to 320 ° C. or more by the heater unit 304. Then, when sliding on the upper surface of the iron plate 302, the copper hydroxide α is oxidized and copper oxide (CuO, Cu
₂ O) β. In this case, since the copper hydroxide α has been drained in advance, there is no need to heat and evaporate the water, and only the copper hydroxide α needs to be heated, so that the heating energy may be small. The temperature of the iron plate 302 is set to 320 ° C.
The reason is that copper hydroxide α is theoretically 320 °
This is because heating to C or more turns into copper oxide.

The heated copper oxide β is pushed out by the scraper 305 b at the upper end of the iron plate 302, falls, and is collected in the collection box 306. The recovered copper oxide β contains a large amount of a copper component, and becomes copper only by performing a reduction treatment. That is, the recovered copper oxide β is a copper raw material containing a copper component at a much higher concentration than copper ore, and is a raw material with high commercial value. To give a specific numerical example, about 10,000 kg of sludge is generated when 10,000 liters of treated water (raw water) containing 500 ppm of copper ions is treated by a conventional technique. However, according to the present invention, 7 kg of sludge is generated without generating sludge. Can be obtained, and the treated water can be purified.

It should be noted that since the recovered copper oxide has a particle size of 1 micron or less, the copper obtained by the reduction treatment has a very fine particle of micron order. It is. Such finely divided copper is extremely expensive as a catalyst material or a coating material. Normally, producing such fine copper requires a lot of labor and cost and is extremely expensive (for example, about 1,000 yen per gram). Incidentally, a copper lump is, for example, about 1,000 yen per kg. In the present invention,
From the treated water that becomes waste, it is possible to recover such expensive fine-particle copper, and it is not just a wastewater treatment, but it has an extremely excellent feature that it can produce rare and expensive fine metals. I have.

When polyaluminum chloride or aluminum sulfate is used as the coagulant, a small amount of aluminum is contained in the copper oxide β, but there is no problem if copper and aluminum are separated during the reduction treatment. . When an organic coagulant is used as the coagulant, it is preferable that the copper oxide β does not contain other metal components.

In the example of FIG. 1, sodium hydroxide is charged into the neutralization tank 12, but potassium hydroxide may be charged. Also, both may be input.

Further, the same treatment is applied to raw water containing nickel ions, zinc ions, tin ions, and chromium ions. By performing such treatment, nickel oxide, zinc oxide, tin oxide, and chromium oxide which are fine particles, which are raw materials having commercial value, can be obtained.
The heating temperature of the heating device is 380 for nickel oxide.
° C or higher, 390 ° C or higher for zinc oxide, 400 ° C or higher for tin oxide, and 45 ° C for chromium oxide.
0 ° C. or higher.

[Modification] In the example of FIG. 1, the draining device and the heating device are integrated into a draining / heating device. However, both devices may be configured as separate devices. In addition, as the draining device, a belt conveyor having a net-shaped belt is adopted, copper hydroxide α and treated water are placed on the net-shaped belt, and the belt is moved. It may be made to drain. Alternatively, an inclined plate may be prepared, copper hydroxide α and treated water may be placed on the plate, and the treated water may be drained by flowing down the treated water. Further, draining may be performed using the principle of a centrifuge. In addition, draining may be performed by adding copper hydroxide α and treated water to a net-shaped “bar”.

In the example of FIG. 1, one floating filter medium type filtering apparatus 100 is used, but two large and small floating medium filter apparatuses can be used. The metal-containing hydroxide and treated water filtered and separated by the first-stage large floating filter medium-type filtration apparatus are further filtered and separated by the second-stage small floating filter medium-type filtration apparatus. Alternatively, the hydroxide containing metal and the treated water filtered and separated by the floating filter medium type filtration device may be sent to a draining device.

[Second Embodiment] Next, a main part of a wastewater treatment apparatus according to a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the first embodiment shown in FIG.
Instead of the draining / heating device 300 in the embodiment, a draining device 400, a refrigeration device 500, and a heating device 600 shown in FIG. 2 are employed, and the configuration of other parts is the same as that of the first embodiment. It is. Therefore, in the second embodiment, the draining device 400, the freezing device 500, and the heating device 600 will be described, and the description of the configuration of the other parts will be omitted.

In the drainer 400, the net material 401 is arranged obliquely, and a water receiving tank 402 is arranged below the net material 401. Above the net material 401, a scraping device 403 is arranged. This scraping device 403 has a large number of scrapers 403b arranged on the outer peripheral surface of a conveyor belt 403a. When the conveyor belt 403a rotates, the scraper 403
The b moves diagonally downward and diagonally upward while rubbing the upper surface of the net material 401.

Therefore, when the copper hydroxide α and the treated water are sent to the upper surface of the net material 401, the copper hydroxide α is scraped up by the scraper 403b and slides on the upper surface of the net material 401. During this slide movement,
The moisture adhering to the surface of the copper hydroxide α and the moisture permeating the inside of the copper hydroxide α move downward by the action of gravity, fall from the copper hydroxide α, and pass through the net material 401. ,
It falls toward the water receiving tank 402. That is, the moisture that has adhered to and has penetrated the copper hydroxide α is drained. The water collected in the water receiving tank 402 is returned to the raw water tank 11.

The drained copper hydroxide α is supplied to a refrigeration unit 50
0 is supplied. In the refrigeration apparatus 500, a concave-shaped refrigerant storage unit 502 having a hollow inside is disposed inside a concave-shaped heat insulating material 501. Refrigerant storage unit 5
Inside 02, a refrigerant 503 in which ethylene glycol is mixed at a ratio of 30% and water at a ratio of 70% is injected, and a cooling pipe 504 for cooling the refrigerant 503 is arranged. This cooling pipe 50
4, a coolant at about −10 ° C.
3 is cooled to -5 ° C to -10 ° C. The upper surface is covered with a heat-insulating lid 506.

Then, the drained copper hydroxide α is supplied and stored in a space surrounded by the refrigerant storage section 502 and the lid 506. After a certain period of storage, copper hydroxide α, which is a hydrate gel, is frozen, and the contained water freezes. In other words, the water that has penetrated into the copper hydroxide α collects into ice crystals, and the crystal part of the water (ice) and the copper hydroxide α
Is separated and mixed.

When frozen in this way, the frozen copper hydroxide α is supplied to the heating device 600. The heating device 600 has an iron plate 601 which is formed in a disk shape and rises from a peripheral portion toward the center.
A heater 602 is provided on the lower surface of the iron plate 601. A cylindrical mesh member 603 is arranged on the periphery of the iron plate 602. The iron plate 601, the heater 602, and the mesh member 603 are supported on the upper surface of a water receiving tank 605 via a heat insulating material 604. Further, a stirring member 606 is arranged above the iron plate 601.

The frozen copper hydroxide α is supplied onto the iron plate 601. At this time, the iron plate 601 is heated to 320 ° C. or higher by the heater unit 602, and the copper hydroxide α is stirred by the stirring member 606. In this way, the moisture (ice) mixed in the frozen copper hydroxide α is heated and evaporated, and moisture is removed from the copper hydroxide α. At this time, since the crystal part of the water (ice) and the crystal part of the copper hydroxide α are separated, the water can be efficiently evaporated in a short time. In other words, when the copper hydroxide α in the gel state is heated, it takes time to completely heat and dry the water that has penetrated into the inside, but the copper hydroxide α The water separated from the crystal part is easily heated and dried because it is easily exposed to heat. In addition, a part of the water melted from the ice flows on the surface of the iron plate 601 from the central portion to the peripheral portion, passes through the mesh member 603, falls, and drops in
Collect at 5. The water collected in the water receiving tank 605 is the raw water tank 1
Returned to 1.

The heated and dried copper hydroxide α is further heated to copper oxide β. When all the copper hydroxide α supplied on the iron plate 601 becomes copper oxide β, the copper oxide β is recovered. The recovered copper oxide β is fine particles and contains a large amount of a copper component, and becomes copper which has become fine particles only by performing the reduction treatment. That is, the recovered copper oxide β is a copper raw material containing a copper component at a much higher concentration than copper ore, and is a raw material with high commercial value.

[Explanation of Floating Filter Type Filtration Apparatus] Here, the detailed structure of the floating filter type filtering apparatus 100 will be described with reference to FIG. The filtration tube 10 of the floating filter medium type filtration device 100
Numeral 2 is installed (attached and arranged) with its axis oriented along the up-down direction, and its upper end surface and lower end surface are closed. In this filter tube 102, treated water W
12 are supplied.

A funnel member 103 is disposed at substantially the center of the inside of the filter tube 102 in the vertical direction.
3, the internal space of the filtration tube 102 is
4 and a lower collection chamber 105. Funnel member 1
Reference numeral 03 denotes a conical surface whose opening area is reduced toward the bottom, and a lower end is a lower end opening 103a. Through this lower end opening 103a, the filtration chamber 10
4 communicates with the collection chamber 105. The funnel member 10
Numeral 3 is formed of a mesh member, and the mesh diameter thereof is smaller than the particle diameter of a filter medium 106 described later.

A net 107 for the closing member is stretched over the filtration chamber 104 at a position close to the funnel member 103, and a position above the net 107 for the closing member in the filtration chamber 104 (a position near the upper end face of the filter cylinder 102). ), A filter medium net 108 is stretched. Moreover, the filter medium net 10
The mesh diameter of 8 is significantly smaller than the mesh diameter of the closing member net 107.

A space below the filter medium net 108 in the filtration chamber 104 is filled with a granular filter medium 106. As the filter medium 106, fine styrene foam particles, resin particles, or inorganic material particles having a specific gravity smaller than 1 (for example, a specific gravity of about 0.1) are employed. In addition, the particle size of the filter medium 106 is, for example, 0.3 mm to 3 mm, which is larger than the mesh diameter of the filter medium net 108 and smaller than the mesh diameter of the closing member net 107.

Between the funnel member 103 and the closing member net 107 in the filtration chamber 104, a spherical closing member whose size (diameter) is larger than the mesh diameter of the closing member net 107 or the opening diameter of the lower end opening 103a. 109 are arranged. The specific gravity of the closing member 109 is smaller than 1 and the filter medium 1
06 (for example, when the specific gravity is 0.1%).
3 to 0.9). For this reason, when the treated water is supplied into the filtration tube 102, the closing member 109 floats and comes into contact with the closing member net 107, and when the treated water is discharged from the inside of the filtration tube 102, the closing member 109 descends ( (Sedimentation) to close the lower end opening 103a of the funnel member 103.

The stirring rod 110 is rotatably attached to the filter cylinder 102 so as to extend in the axial direction of the filter cylinder 102. A stirring blade 110a is attached to a portion of the stirring rod 110 located in the filtration chamber 104. Then, when the handle 110b provided at the upper end of the stirring rod 110 is rotated, the stirring rod 110 is rotated, whereby the stirring blade 110a is rotated to stir the filter medium 106.

The filtering device 10 having such a configuration
In the lower space of the space of the filtration chamber 104, the pump P
Is connected to the supply pipe 111, and the filtration chamber 10
A discharge pipe 112 is connected to an upper space of the space 4 and a drain pipe 113 provided with a drain valve 113a is connected to a lower space of the space of the collection chamber 105.

When the treated water is not supplied to the filtration device 100, the filter medium 106 is in the filtration chamber 104 with a certain gap between the individual filter mediums. Further, the closing member 107 sinks to close the lower end opening 103a of the funnel member 103. As described above, since the lower end opening 103a is closed by the closing member 107 and the mesh diameter of the funnel member 103 is smaller than the particle diameter of the filter medium 106,
The filter medium 106 does not fall to the lower recovery chamber 105 side. In FIG. 3, the filter medium 106 is drawn “sparsely” for the sake of illustration, but the filter medium 106 is actually present in a dense state.

When performing the filtration treatment, the treated water W12 is supplied to the filtration chamber 104 via the pump P and the supply pipe 111 with the drain valve 113a closed. Then, the treated water W12 fills the inside of the filtration tube 102 and flows upward in the filtration chamber 104 from below.

When the treated water is supplied to the filter cylinder 102 in this manner, as shown in FIG.
Rises into a dense state in which the individual filter media 106 are pressed tightly. For this reason, a very firm filtration layer is formed by the filter medium 106, and filtration on the order of microns is possible. The closing member 109 also floats and contacts the closing member net 107, so that the lower end opening 103a of the funnel member 103 is opened.

The treated water is filtered by flowing through the filter medium 106 from below to above. The filtered treated water is sent to the hollow fiber membrane type filtration device 200 via the discharge pipe 112.

As the filtering operation is continued, copper hydroxide α adheres to the filter medium 106 as shown in FIG. Especially filter media 1
The copper hydroxide α adheres to the lower surface of the substrate 06. The copper hydroxide α accumulates and grows, and forms a lump. Some of the copper hydroxide α naturally peels off from the lower surface of the filter medium 106 and falls down by its own weight. In addition, during the filtering operation, the handle 110b is turned to rotate the stirring blade 110a, and the filter medium 106 is rotated.
Also, the copper hydroxide α is peeled off and falls downward. The copper hydroxide α that has dropped downward passes through the closing member net 107 having a large mesh diameter, and further moves downward along the surface of the funnel member 103 to form a lower end opening 103a.
Pass into the collection chamber 105 and settle. In this case, since the mesh diameter of the closing member net 107 is large, it does not hinder the drop of the copper hydroxide α. In addition, a part of the copper hydroxide α passes through the mesh of the funnel member 103 and the collection chamber 105.
Some may enter and precipitate.

Since treated water is supplied to the filtration chamber 104, a turbulent flow is generated, and peeling and growth of the copper hydroxide α are likely to occur.
On the other hand, the collection chamber 105 is filtered by the funnel member 103 to form the filtration chamber 10.
4, the treated water is almost stationary in the collection chamber 105. Therefore, the collection room 1
The copper hydroxide α that has fallen to 05 is settled and deposited.
In addition, since the funnel member 103 has a conical surface whose opening area is reduced as it goes downward, the collection chamber 1
The copper hydroxide α moved to 05 does not return to the filtration chamber 104 side. As a result, even during the filtration operation,
The filter medium 106 can efficiently separate and remove the treated water and the copper hydroxide α.

When a large amount of copper hydroxide α settles and accumulates in the collection chamber 105 by performing the filtration operation, the supply of the treated water is stopped, the drain valve 113a is opened, and the copper hydroxide precipitated in the collection chamber 105 is opened. α is sent to the draining / heating device 300 together with the treated water.

[Explanation of Hollow Fiber Membrane Filter] Next, the detailed structure of the hollow fiber membrane filter 200 will be described with reference to FIG. As shown in FIG.
02 is installed (attached and arranged) with its axis oriented along the vertical direction. A funnel member 203 is disposed inside the filter tube 202, and the funnel member 203 divides the internal space of the filter tube 202 into an upper filtration chamber 204 and a lower recovery chamber 205. Funnel member 203
Has a conical surface in which the opening area is reduced toward the bottom, and has a lower end opening 203a at the lower end. Through this lower end opening 203a, the filtration chamber 204
And the collection chamber 205 communicate with each other.

The filtration chamber 204 contains the hollow fiber membrane module 2
Reference numeral 06 is disposed in a state of extending in the vertical direction. This hollow fiber membrane module 206 has a large number (several hundred to several thousand)
The upper side of the hollow fiber membrane 206a is bound and restrained by the holder 206b, while the lower side is free. The lower end surface of each straw-shaped hollow fiber membrane 206a is sealed, and the upper end surface is an open end surface.

The hollow fiber membrane module 206 is
When the treated water W13 is injected into the filter chamber 2, the filtration chamber 2
It spreads out in 02 inside. This is the hollow fiber membrane module 2
This is because 06 is simply bundled at the upper end and the lower end is free. Further, by making the inner diameter of the filtration tube 202 1.5 to 3.0 times the diameter of the upper end of the hollow fiber membrane module 206, the hollow fiber membrane module 206 This is because it is configured to allow a natural spread in a shape. Although the details will be described later, the treated water W1 is moved from the radial center position of the hollow fiber membrane module 206 outward in the radial direction.
3 is ejected so that the hollow fiber membrane module 206 is positively spread in a bundle.

The injection pipe 207 penetrates the bottom surface of the filter tube 202 and has a central lower end opening 20 of the funnel member 203.
3a extends in the axial direction through a gap, and the upper part is inserted into the center position (radial center position) of the hollow fiber membrane module 206. The portion of the injection pipe 207 inserted into the hollow fiber membrane module 206 has
07a and 207b are formed. Outlet 207a,
A plurality (about four) 207b are formed in the circumferential direction. In addition, the ejection holes 207a and 207b are located at a position P1 which is 1/3 from the upper end of the hollow fiber membrane module 206,
It is arranged between a position P2 and 2/3 from the upper end. The treated water W13 is mixed with the bubbling air A1,
The pressure is fed into the injection pipe 207, and the ejection holes 207a, 20
7b is ejected along the radial direction and injected into the filtration chamber 204.

A backwash chamber 208 is formed on the upper surface of the filter tube 202. In the backwash chamber 208, treated water W14 obtained by filtering the treated water W13 by the hollow fiber membrane module 206 is provided.
Is temporarily stored. A pipe L1 in which a valve V1 and a valve V2 are interposed is connected to the backwash chamber 208.

A pipe L2 provided with a valve V3 is connected to an upper portion of the filtration chamber 204. A pipe L3 provided with a valve V4 is connected to a lower portion of the recovery chamber 205.

In the filtering apparatus 200 having the above-described configuration, when performing the filtering operation, the valves V2 and V3 are opened, the valves V1 and V4 are closed, and the treated water W13 and the bubbling air A1 are injected. Pipe 20
And pump it into 7. Then, air A1 for bubbling
The treated water W13 mixed with the jets 207a and 207b
And is injected into the filtration chamber 204 in the radial direction.

When the treated water W13 is thus injected and supplied, the filtration chamber 204 and the collection chamber 205 connected to the filtration chamber 204 are filled with the treated water W13. The treated water W13 passes through each hollow fiber membrane 206a from the outer peripheral side to the inner peripheral side, and the treated water W in which contaminants are filtered.
14 enter the internal space of each hollow fiber membrane 206a. The treated water W14 is sent from the outlet end face of the hollow fiber membrane module 206 to the backwashing chamber 208, where it is temporarily stored, sent to the pipe L1, and discharged through the pipe L1. The filtration operation is performed in this manner. Note that bubbles generated by the bubbling air A1 are discharged through the pipe L2.

In such a filtration operation step, the hollow fiber membrane module 206 is spread in a lump. Moreover, since the treated water W13 is jetted outward from the radial center position of the hollow fiber membrane module 206 in the radial direction, the hollow fiber membrane module 206 is positively spread in a collective manner. Therefore, a gap is formed between the individual hollow fiber membranes 206a constituting the hollow fiber membrane module 206, and the treated water W1
3 can sufficiently spread to the inside of the hollow fiber membrane module 206 (central part in the radial direction), and effectively utilize all the hollow fiber membranes 206a from the outer peripheral part to the central part of the hollow fiber membrane module 206. Can be filtered. For this reason,
The filtration efficiency is improved.

Furthermore, since the treated water W13 is jetted from the radial center position of the hollow fiber membrane module 206 toward the outside in the radial direction, the hollow fiber membranes 206a spread in a bundle
Can be continuously shaken. As described above, since each hollow fiber membrane 206a can be continuously shaken and vibrated by the jet flow of the treated water W13, the attached matter (contaminated matter) 210 temporarily attached to the outer peripheral surface of the hollow fiber membrane 206a is removed. Is peeled off from the outer peripheral surface of the hollow fiber membrane 206a.

Further, bubbles generated by the bubbling air A1 are also blown out from the jet holes 207a and 207b. The bubbles that have been blown out in this way float in the filtration chamber 204, so that the treated water W
13 is vibrated, and the vibration also causes the hollow fiber membrane 206
attached matter (contaminated matter) 210 temporarily attached to the outer peripheral surface of a
Is peeled off and removed.

Thus, the deposit 210 attached to the outer peripheral surface of the hollow fiber membrane 206a can be removed during the filtration operation. For this reason, the filtration operation time can be lengthened,
Continuous filtration operation can be performed for a long time.

The removed contaminants 210 are treated water W13
Since the treated water W13 in the filtration chamber 204 is turbulent, it gradually sinks downward due to the specific gravity difference. The contaminated matter 210 that has settled moves downward along the funnel member 203, and further through the lower end opening 203a.
Fall into 5.

Since the recovery chamber 205 is separated from the filtration chamber 204 by the funnel member 203 except for the lower end opening 203a, the treated water W13 in the recovery chamber 205 does not become turbulent, and becomes almost stationary. ing. Therefore, the contaminants 210 that have fallen into the collection chamber 205 accumulate on the bottom of the collection chamber 205. Further, since the lower end opening 203a is narrow, the contaminants 210 entering the collection chamber 205 do not return to the filtration chamber 204 side.

As described above, since the contaminants 210 that have been removed and entered the collection chamber 205 do not return to the filtration chamber 204, the removed adherents 210 adhere again to the outer peripheral surface of the hollow fiber membrane 206a. Can be prevented.

When the filtration operation is repeated and a large amount of contaminants 210 accumulates in the collection chamber 205, the supply of the treated water W13 is temporarily stopped. Then, the valve V4 is opened. Then, together with the treated water W13 in the collection chamber 205, the contaminant 2
10 can be returned to the raw water tank 11 via the pipe L3.

[0078]

As described above in detail with the embodiments, in the present invention, treated water containing metal ions, for example, treated water containing metal ions due to washing of a plating product with water, is completely treated with sludge. Purification treatment can be performed without any generation. Moreover, the metal can be recovered as a valuable resource as a metal oxide.

Conventionally, sludge was generated, so that the disposal cost of the sludge was required. However, in the present invention, useful metal oxide can be produced, and this metal oxide can be reused as a resource or sold as a product. be able to. As described above, according to the present invention, not only sludge is not generated at all, but also a metal oxide having commercial (economic) value can be obtained. The metal obtained by reducing the recovered metal oxide is extremely fine (micron order), and is extremely useful as a catalyst material or a coating material.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a wastewater treatment device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a wastewater treatment device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a floating filter medium type filtration device used in the embodiment of the present invention.

FIG. 4 is a configuration diagram showing a hollow fiber membrane type filtration device used in the embodiment of the present invention.

FIG. 5 is a configuration diagram showing a conventional wastewater treatment device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Raw water tank 12 Neutralization tank 100 Floating filter medium type filtration apparatus 200 Hollow fiber membrane type filtration apparatus 300 Draining / heating apparatus 301 Net material 302 Iron plate 303 Water receiving tank 304 Heater unit 305 Scooping device 306 Collection box 400 Drainage device 401 Net material 401 402 Water receiving tank 403 Raising device 500 Refrigeration device 501 Insulation material 502 Refrigerant storage unit 503 Refrigerant 504 Cooling pipe 505 Refrigerator 506 Lid 600 Heating device 601 Iron plate 602 Heater unit 603 Netting member 604 Heat insulating material 605 Water receiving device 606 Stirring member α Copper hydroxide β Copper oxide

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B01D 63/02 C02F 1/44 K C02F 1/44 1/54 K 1/54 C22B 7/00 G C22B 3/44 B01D 29/08 520B 7/00 540A C22B 3/00 Q F term (reference) 4D006 GA07 HA01 KA01 KB13 KB14 MA01 PB08 4D015 BA22 BB05 CA20 DA04 DA06 DB01 EA15 EA35 FA02 FA17 4D038 AA08 AB65 AB67 AB68 AB69 AB72 AB79 4 AA07 AB04 AB06 AC05 AC08 4K001 AA08 AA09 AA19 AA24 AA30 BA21 CA02 DB22 EA06

Claims (8)

[Claims] Claims: 1. A filter medium having a specific gravity smaller than the specific gravity of treated water, wherein at least one of sodium hydroxide and potassium hydroxide is charged into treated water containing metal ions to generate a metal hydroxide. The treated water containing the metal hydroxide is supplied to the floating filter medium type filtration device used to separate the treated water and the metal hydroxide, and the separated metal hydroxide is taken out and hydroxylated. A method for draining treated water containing metal ions, comprising draining water adhering to or penetrating an object and heating a hydroxide of the drained metal to obtain a metal oxide. 2. A treatment water containing metal ions, wherein at least one of sodium hydroxide and potassium hydroxide,
The coagulant is charged to generate metal hydroxide, and the treated water containing the metal hydroxide is supplied to a floating filter medium type filtration device using a filter medium having a specific gravity smaller than the specific gravity of the treated water. To separate the treated water from the metal hydroxide, take out the separated metal hydroxide, drain the water adhering to or infiltrating the hydroxide, and heat the drained metal hydroxide A metal oxide, thereby obtaining a metal oxide. 3. The treated water containing metal ions according to claim 1, wherein the drained hydroxide is frozen, and the frozen hydroxide is heated to obtain a metal oxide. Wastewater treatment method. 4. A neutralization tank for producing metal hydroxide by supplying treated water containing metal ions and supplying at least one of sodium hydroxide and potassium hydroxide, When the treated water containing the metal hydroxide is supplied from the neutralization tank, a floating filter medium that separates the metal hydroxide while filtering the treated water using a filter medium having a specific gravity smaller than the specific gravity of the treated water. A type filtration device, a metal hydroxide is supplied from the floating filter material type filtration device, and a drainage device that drains moisture adhering to or infiltrating the metal hydroxide, and a metal that is drained by the drainage device And a heating device for supplying metal hydroxide and obtaining a metal oxide by heating the metal hydroxide. 5. A neutralization tank for producing metal hydroxide by supplying treated water containing metal ions and supplying at least one of sodium hydroxide and potassium hydroxide, When the treated water containing the metal hydroxide is supplied from the neutralization tank, a floating filter medium that separates the metal hydroxide while filtering the treated water using a filter medium having a specific gravity smaller than the specific gravity of the treated water. A type filtration device, a metal hydroxide is supplied from the floating filter material type filtration device, and a drainage device that drains moisture adhering to or penetrating the metal hydroxide, and a metal that is drained by the drainage device And a refrigerating device for refrigerating the hydroxide of the metal, and supplying the hydroxide of the metal frozen by the refrigerating device to heat the frozen hydroxide of the metal. Yo Wastewater treatment device in the process water containing metal ions; and a heating device to obtain a metal oxide. 6. The wastewater treatment apparatus according to claim 4, wherein a coagulant is further charged into the neutralization tank. 7. The method of claim 4 or claim 5, or claim 6.
In the above, the floating filter medium type filtration device is disposed inside the filtration tube in a shape in which the opening area is narrowed downward as the direction of the axis is set along the vertical direction, A funnel member for partitioning the inside of the filter tube into an upper filtration chamber and a lower recovery chamber, a filter material net stretched over the funnel member in the filtration chamber, A wastewater treatment apparatus for treated water containing metal ions, wherein the apparatus is filled with a granular filter medium having a specific gravity of less than 1 while being filled in a space below the filter medium net. 8. The method according to claim 4, wherein the treated water filtered by the floating filter medium type filtration device is filtered by a hollow fiber membrane type filtration device using a hollow fiber membrane. Drainage treatment equipment for treated water containing metal ions.