JPH0947768A - Method for removing heavy metal and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively and selectively remove the heavy metal ions from the solution and also to reduce clogging of the packed layer by passing a solution contg. heavy metal ions in an upward stream through a packed layer packed with a redox solid phase material which is obtained by adsorbing and fixing a compound contg. a hydroquinone skeleton on a solid porous carrier. SOLUTION: In this method, a dilute solution of an overflow solution is supplied to an upper space section 5 in contact with the upper surface of a packed layer 4 that is packed with a redox solid phase material in the treatment vessel 8 from an overflow solution inflow port 1 while pressurizing the dilute overflow solution with a pump. The solution is passed downwardly from the upper surface of the packed layer 4 through the inside of the packed layer 4 and further, through a perforated plate 7 and reaches a silver sludge reservoir 3. Thereafter, the solution is passed through an conduit pipe 2 extending along the central line in the vertical direction of the vessel 8 and introduced to an outflow port 6 to supply the solution to a holding tank. On the other hand, the dilute overflow solution is also passed through the treatment vessel 8 in the completely reverse direction to the direction of this downflow process. Thus, even a packed column is prevented from being blocked and the redox solid phase material loaded can effectively be utilized and silver removal can effectively be performed.

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 removing heavy metal ions from a solution containing heavy metal ions. , A heavy metal ion removing method and a heavy metal ion removing apparatus capable of efficiently and selectively removing heavy metal ions at a constant removal rate for a long time, reducing the cost of the removing operation, simplifying the removing apparatus, and simplifying the operation Regarding

[0002]

2. Description of the Related Art A large amount of solutions containing heavy metal ions are generated as waste water in various industries. Particularly in the fields of electronic parts, automobiles, industrial catalysts such as industrial oxidation catalysts and reduction catalysts used for oxidation treatment of industrial exhaust gas, and fields such as the photographic industry, wastewater containing a large amount of valuable metal resources is discharged. From the viewpoint of resource recovery and environmental conservation, it has recently been emphasized to recover and reuse these precious metal resources. Most of these metals are contained in an aqueous medium such as an aqueous solution as a heavy metal ion or a heavy metal complex ion (hereinafter, the both are simply referred to as a heavy metal ion).

As a method for recovering these heavy metal ions, for example, (1) a method of producing a precipitate from an aqueous solution by an insoluble salt or reduction to separate impurities and metals, and (2) There are a method of adsorbing and collecting with an ion exchange resin or a chelate resin, and a method of (3) adsorbing and collecting with a redox resin. In the method (1), the metal recovery rate was poor. The methods (2) have the drawback that the selectivity is not so high when several kinds of heavy metal ions coexist, and is difficult to remove when the heavy metal ions form a complex. In the method (3), there is no practical method for directly alkylating or alkenylating quinones such as anthraquinone even in the case of producing a monomer as a raw material for producing a redox resin, such as monovinylanthraquinone. , Requires many steps and becomes very expensive. Further, when the monomer is used to polymerize with, for example, divinylbenzene, it has a drawback that it is unlikely to form beads, and a practical product has not been produced.

On the other hand, in fields such as the photographic industry, a large amount of waste water containing precious heavy metal resources such as silver is discharged. Conventionally, as a developing solution for a silver halide light-sensitive material (hereinafter, also referred to as a light-sensitive material), a color developing solution, a black and white developing solution, a bleaching solution,
A bleach-fixing solution, a fixing solution, a stabilizing solution, a rinsing solution, and in some cases, washing water in which these solutions are diluted with water and the like.

The used processing solution for the photosensitive material to be discharged always contains silver because the photosensitive member is made of silver halide. As such a used processing liquid,
Used fixing solutions and bleach-fixing solutions containing silver salts, washing water containing silver salts, stabilizing solutions and the like. However, in certain areas, the emission regulations of silver are strict, and in this case, it is required to remove silver from the used processing liquid.

Regarding the regulation of silver in industrial wastewater, silver is listed in the water quality environmental standards of many countries. It is listed as a target. Therefore, the removal of silver from used treated water, which occurs when the photosensitive material is washed with water, is a great concern in the art. In many areas, the emission control to silver sewage is about 1 to 5 mg / L, but depending on the area, 0.1 to 1.0 mg / L can be used without considering the current level of silver removal technology from wastewater. In reality, L level regulation has been put in place, and even the regulation of extreme regulation value of 0.01 to 0.1 mg / L has begun to be enforced.

Therefore, it is economically advantageous to efficiently recover silver from a used processing solution containing silver and to reuse the solution from which silver has been removed to reduce the amount of photographic processing waste solution. Not only that, but it is also being considered in some European and American countries because it can comply with regulations on the emission of silver into the environment.

Various methods have been researched and developed for the method of removing silver from the used processing solution in the photographic development processing. As such a method, from the viewpoint of economic efficiency,
The electrolytic recovery method and the metal replacement method were carried out, and the precipitation removal method using sodium sulfide was carried out at the final waste liquid treatment stage.
The desilvering ability by these is 100 mg / L in the electrolytic method,
The metal substitution method has a limit of 50 mg / L, and the sodium sulfide method can remove silver up to 0.1 mg / L. However, this technique is difficult to implement in the laboratory, let alone the solution after silver removal was not reusable.

Furthermore, a new desilvering technique that requires more strict regulation by law is required, and an adsorption method (not sodium sulfide) represented by the ion exchange resin method and a chemical precipitation agent that can be handled even in a small-scale developing laboratory are required. The sedimentation method using is also proposed for strict regulated areas. Theoretically, the ion exchange resin method can be sufficiently reduced to 0.1 mg / L or less. Furthermore, if you manage well without complicated operations, 0.5-
A silver removal level of 1.0 mg / L can be reached. However, at this desilvering level, the number of steps is increased, frequent backwashing is carried out to prevent channeling, and chemical washing is carried out to prevent water stains. Further, the most recently proposed method of using trimercaptotriazine as a chemical precipitating method is also capable of desilvering at a level of 0.5 mg / L (L. Hannen and A. Szembrot “A Practica
l Application of a Silver Recovery Method ”IS &
T International Symposium on Photofinishing Techno
logy, February 1994, at Atlanta, USA). However, even this method, which is the most advanced in terms of applicability, has drawbacks such as aging sedimentation for a long period of time, a large-scale device commensurate with the residence time, and the like, which require a solution.

Therefore, with the existing desilvering method, the desilvering ability is insufficient especially in areas where the silver regulation is strict, and it is difficult to reuse the processing solution after desilvering, and the equipment and operation There are many problems above. Therefore, there is a demand for the development of a simple and economical method which has a high silver removal capacity capable of complying with regulations in any region and can reduce the amount of waste liquid. In addition, the photographic development process is a color development lab, a minilab that miniaturizes it to provide development processing services in stores for small areas,
It is widely dispersed in various places in the urban area such as printing and plate making factories that perform photoengraving printing, hospitals and clinics that develop medical photographic sensitive materials such as X-ray films, and there are small-scale business establishments. Many. For this reason, the silver removal technology is desired to be labor-saving, simple and low-cost so as not to burden the developing operator. Not limited to the above-described silver-containing photographic processing solution, the prior art does not have an effective method for removing heavy metal ions from a solution containing heavy metal ions.

In European Patent No. 647721A, a redox solid phase body in which a compound having a hydroquinone skeleton capable of reducing heavy metal ions in an aqueous solution containing heavy metal ions to zero valence is carried on a solid porous carrier is used,
A method for removing heavy metal ions in an aqueous solution containing heavy metal ions, a method for producing the same, a metal ion treating agent capable of selectively separating heavy metal ions such as precious metal ions and complex ions thereof from the aqueous solution, and a method for producing the same. Disclosed. Further, in Japanese Patent Application No. 7-47558, a used processing solution in the development processing of a silver halide photosensitive material is
It was shown that silver in the liquid can be removed efficiently and selectively by treating with the redox solid phase.

The redox solid phase body in which the above-mentioned reducing compound is supported on a solid porous carrier is effective as a method for recovering heavy metal ions. However, the heavy metal deposited on the redox solid phase is easily oxidized, and therefore, when the redox solid phase is brought into contact with the heavy metal ion-containing solution, the heavy metal is oxidized by dissolved oxygen and redissolved as a heavy metal ion. In some cases, the redox solid-phase body could not exhibit the processing ability sufficiently. Further, since the redox solid phase body captures a large amount of heavy metal ions, when the heavy metal ion-containing solution is filled in a column or the like and the heavy metal ion-containing solution is treated, the column is clogged early in the treatment,
This necessitated frequent replacement of the redox solid phase. Therefore, the cost is significantly increased and the replacement work is complicated. Therefore, further than the above metal removal method,
There is a demand for an excellent method for removing heavy metal ions, which has a high metal recovery efficiency and can be stably treated for a long period of time.

[0013]

Therefore, the object of the present invention is to make the redox solid phase exhibit the heavy metal ion removing ability sufficiently, to reduce the clogging of the packed bed, to keep the processing rate constant for a long time, and to efficiently and efficiently. Heavy metal ions can be selectively removed,
It is an object of the present invention to provide a method for removing heavy metal ions, which can reduce the processing cost, simplify the processing equipment, and simplify the operation. Another object of the present invention is to provide a method for removing heavy metal ions, which eliminates the influence of various metals coexisting by pretreatment and can effectively remove the target heavy metal. Another object of the present invention is to provide a constant processing speed for a long time,
It is intended to provide a heavy metal ion removing device capable of stably performing metal removal treatment and capable of highly removing heavy metal ions. A further object of the present invention is to improve the efficiency of a photographic processing solution such as a used processing solution, which is produced in a large amount when a silver halide light-sensitive material is developed, with less clogging of a filling layer and at a constant processing speed for a long time. It is to provide a method for removing heavy metal ions, which can selectively and selectively remove silver ions, reduce the processing cost, simplify the processing equipment, and simplify the operation.

[0014]

The above-mentioned object of the present invention can be achieved by the constitution of the present invention described below. (1) Using a heavy metal ion removing device having a packed bed filled with a redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and fixed on a solid porous carrier, and the packed bed can be passed through in an upward flow A method for removing heavy metal ions, which comprises passing a solution containing heavy metal ions in an upward flow to selectively remove the heavy metal ions from the solution. (2) It has a packed layer filled with a redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and fixed on a solid porous carrier so as to have a hollow part, and water permeability is provided on the hollow part side and the outer peripheral side of the packed layer. Using a heavy metal ion removing device which is provided with a partition wall and is capable of passing liquid from the hollow portion side toward the outer peripheral side, a solution containing heavy metal ions is passed from the hollow portion side to the outer peripheral side of the packed bed. And selectively removing heavy metal ions from the solution.

(3) A packing layer filled with a redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and immobilized on a solid porous carrier, and a deaeration gas aeration means are provided.
Using a heavy metal ion removing device capable of flowing in a downward flow, while aerating deoxygenated gas from the lower part of the packed bed to above, a solution containing heavy metal ions is passed in a downward flow in the packed bed. A method for removing heavy metal ions, which comprises selectively removing heavy metal ions from the solution. (4) A compound having a hydroquinone skeleton is adsorbed and immobilized on a solid porous carrier, which has a packed bed filled with a redox solid phase body, and is previously reduced with a heavy metal ion removing device capable of passing in a downward flow. A solution containing heavy metal ions treated by at least one of treatment with a compound, metal substitution treatment and electrolysis treatment is passed through the packed bed in a downward flow to selectively remove heavy metal ions from the solution. A method for removing heavy metal ions, comprising:

(5) The method for removing heavy metal ions according to any one of (1) to (4) above, wherein the redox solid phase body has a particle shape. (6) Any one of the above (1) to (3), wherein the solution containing heavy metal ions is previously treated with at least one treatment of a reducing compound, a metal substitution treatment and an electrolysis treatment. The method for removing heavy metal ions according to one. (7) The solution containing heavy metal ions is a photographic processing solution containing silver ions.
The method for removing heavy metal ions according to any one of (4). (8) The method for removing heavy metal ions according to (7) above, wherein the photographic processing solution is a photographic processing solution containing at least a processing solution having fixing ability. (9) A heavy metal ion removing device having a packed bed filled with a redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and immobilized on a solid porous carrier, and the packed bed is allowed to flow in an upward flow. It has a packed layer filled with a solid phase body having a hollow part, and a water-permeable partition wall is provided on the hollow part side and the outer peripheral side of the packed layer, and liquid can be passed from the hollow part side to the outer peripheral side. A heavy metal ion removing device, a packed bed filled with the redox solid phase body, and a deaeration gas aeration means, and two or more of the heavy metal ion removing devices capable of passing in a downward flow are connected in series or A heavy metal ion removing device characterized by being connected in multiple parallels.

The present inventors have diligently studied how to effectively use the redox solid phase body. As a result, there are various problems when the redox solid phase body used in the present invention is applied to the removal of heavy metals at a practical level, and the present invention has found means for solving them brilliantly. The redox solid phase strongly reduces heavy metal ions and deposits (captures) the metal reduction product on the surface of the redox solid phase, so that the heavy metal can be reduced and removed extremely efficiently. However, the heavy metal reduced and precipitated by the redox solid phase is reoxidized by the dissolved oxygen, so that it starts to dissolve again, and the capacity of the redox solid phase is apparently reduced. Further coexistence of impurities that facilitate redox, specifically, a metal complex that is more easily reduced than the heavy metal according to the present invention, such as an iron salt of ethylenediaminetetraacetic acid or a cobalt complex,
These are reduced, and the intended more valuable heavy metal is not reduced.

With respect to the above, in the ordinary column treatment method (when the water to be treated flows from the top to the bottom because no pump or the like is required), in order to prevent overflow of the water to be treated from above the column, and Due to downsizing, the upper interface between the water to be treated and the redox solid phase in the column is set to be somewhat lower than the upper end of the column. for that reason,
When the treated water is supplied from the upper part of the column, when the treated water reaches the treated water in the column or the upper interface of the redox solid phase body, air is entrained in the treated water and accompanied by bubbles, There was a problem that the precipitated heavy metal was reoxidized and melted again. As a result, all of the filled redox solid phase bodies could not exhibit the metal removal performance and became inefficient. Furthermore, when the water surface of the water to be treated in the column becomes equal to or lower than the upper interface of the redox solid phase, the redox solid phase directly contacts the air, and the heavy metal that has been reduced and deposited is oxidized by the air and flows downward. I will end up. In addition, the water surface of the water to be treated in the column may be adjusted to be higher than the upper interface of the redox solid phase body, but in this case,
For the adjustment, monitoring is required and manpower or adjusting means is required.

The above is a more serious problem. For example, in the photographic processing solution, especially in the color photographic processing solution, a bleaching solution is always present because a color image cannot be obtained unless the black color of the developed silver is removed by oxidizing and bleaching the developed silver. In this bleaching solution, an EDTA-Fe salt or the like is used as an oxidizing agent for oxidizing and bleaching developed silver.
Further, even in black and white processing, a reducing solution is used in order to partially oxidize and bleach the development to correct the image, and this reducing solution is a so-called oxidizing agent such as red blood salt and dichromate. Therefore,
Especially when applied to a photographic processing solution, the redox solid phase is consumed by these coexisting metals. For these reasons, the packed redox solid phase was ideally not used for removing all heavy metals (particularly noble metals), which was inefficient. On the other hand, the strong reducibility of the redox solid phase and heavy metal ions are deposited as a metal on the surface of the redox solid phase as a result of the reduction. , The heavy metal is deposited on the upper redox solid phase, and the weight is also increased (the specific gravity of the redox solid phase is about 1.0, whereas when the heavy metal is reduced and deposited, it is about 1.2 to 1.6). However, due to the increase in size and the increase in pressure, the packed bed was blocked at the upper part of the packed bed. As a result, the packed bed had to be exchanged while the redox solid phase material below the packed bed did not sufficiently act, which was extremely inefficient.

In the present invention, the heavy metal ion-containing solution is passed through the packed bed filled with the redox solid phase body in an upward flow, or is passed outward from the hollow portion of the packed bed having a hollow portion. Or a deoxygenated gas is aerated while passing a downward flow, or a solution containing a heavy metal ion that has been previously treated by a specific treatment is passed through a downward flow. The removal ability can be fully exerted. Further, according to the present invention, even when the redox solid phase body captures a large amount of metal on the surface during the treatment, the packed layer is less likely to be clogged, and the metal removal treatment is stably performed at a constant treatment speed for a long time. Is possible.

In the present invention, since heavy metal ions can be selectively removed and all the redox solid phase bodies packed in the packed bed can be used for metal reduction without waste,
It is possible to reduce the cost of the treatment without frequently changing the packed bed, and to realize the simplification of the treatment equipment and the convenience of the operation. In the present invention, “selectively removing heavy metal ions” means that various ions (eg, Ag, Fe, P) contained in a solution of interest are included.
t, Ni, Na, Mg, Ca) etc. to remove heavy metal ions.

In the present invention, the heavy metal ion-containing solution is passed through the packed bed filled with the redox solid phase body in an upward flow, or is passed outward from the hollow portion of the packed bed, or in advance. Even when a heavy metal ion-containing solution treated by a specific treatment is passed in a downward flow, the lower part of the packed bed,
It is preferable to aerate deoxygenated gas from the bottom. As a result, it is possible to further prevent the filling layer from being clogged due to size increase and weight increase due to precipitation of heavy metal on the surface of the redox solid phase body, and stable metal removal treatment can be performed at a constant treatment speed for a long time. .

In the present invention, the redox solid phase body is preferably in the form of particles. In the packed bed filled with the redox solid phase particles, the packed bed is particularly blocked by heavy metals and oxidized by air, so that the above-described effects of the present invention are more significantly exhibited.

In the present invention, the solution containing heavy metal ions to be used in the method for removing heavy metal ions of the present invention has been previously treated with at least one of treatment with a reducing compound, metal substitution treatment and electrolytic treatment. Is preferred. As a result, metal ions having a higher redox potential in the solution to a certain extent (for example, trivalent ions of iron with respect to silver) are removed, so that the solution can be applied even in a solution containing a high concentration of heavy metal ions, Alternatively, the treatment life of the packed bed filled with the redox solid phase body is extended, and the metal removal treatment can be stably performed for a longer time at a constant treatment speed.
Furthermore, various heavy metals other than the purpose of coexistence (for example, iron,
By reducing the valence of (cobalt, chromium) ions by pretreatment and making it in a state that cannot be reduced by the redox solid phase, the target valuable heavy metals (silver, gold, platinum, etc.) can be effectively removed, and the cost can be reduced. Can be realized. Furthermore, since the heavy metal ion concentration in the solution is lowered to some extent, the heavy metal ion concentration in the solution after the treatment can be remarkably lowered. Furthermore, the solution containing heavy metal ions is subjected to a treatment with a reducing compound, a metal substitution treatment and an electrolytic treatment in advance and then subjected to the heavy metal ion removal method of the present invention without being exposed to air. Is preferred. Further, it is preferable that the solution containing heavy metal ions is treated with at least one treatment of a reducing compound, a metal substitution treatment and an electrolytic treatment immediately before being subjected to the method for removing heavy metal ions of the present invention.

In the method for removing heavy metal ions by the packed bed filled with the redox solid phase body according to the present invention, the reductive At least one treatment of treatment with a compound, metal substitution treatment and electrolysis treatment makes the iron complex salt, cobalt complex salt, etc. low valence,
By reducing and separating silver by the treatment with the packed bed filled with the redox solid phase body, the target heavy metal removal efficiency can be remarkably increased, and the cost can be reduced.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The reducing compound in the treatment with the reducing compound is a reducing compound for removing dissolved oxygen from the heavy metal-containing solution, such as sulfite or hydroxylamine, and the heavy metal-containing solution. It means a reducing compound, such as hydrosulfite or borohalide, which makes a base metal such as iron mixed therein into a reductant to effectively carry out reductive precipitation of a noble metal.
As the metal substitution treatment, a method of ion substitution using a metal that is baser than heavy metal ions such as silver, for example, iron wool,
This is a method of replacing with a metal having a large metal surface such as aluminum wool and steel wool. The electrolytic treatment is a method of reducing and depositing on the electrode under a potential lower than that of a heavy metal such as silver. Specific methods for these are DA
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In the present invention, the heavy metal ion to be deposited is the equilibrium redox potential of the compound having a hydroquinone skeleton supported on a solid porous carrier (here,
Equilibrium redox potential refers to a redox potential when an oxidant and a corresponding reductant maintain an equilibrium state under operating conditions). A heavy metal ion having a higher metal ion-metal equilibrium redox potential. Is. That is, this corresponds to a heavy metal ion in which the heavy metal ion is reduced to a zero-valent heavy metal by the supported compound having a hydroquinone skeleton. In the present invention, the heavy metal ion may be a heavy metal ion forming a complex.

In the present invention, the heavy metal is preferably one having a smaller ionization tendency than copper, more preferably a noble metal, that is, a gold, silver or platinum group element,
Examples of the platinum group element include ruthenium, rhodium, palladium, osmium, iridium and platinum, and gold, silver, platinum, palladium and ruthenium are more preferable.
Especially, silver is preferable.

In the present invention, the solution containing heavy metal ions is preferably a photographic processing solution containing silver ions. Here, the photographic processing solution containing silver ions means a processing solution containing a silver salt eluted by the processing of a silver halide photosensitive material or a solution containing the processing solution. The solution containing heavy metal ions is more preferably a photographic processing solution containing at least a processing solution having fixing ability.
Here, the processing solution having a fixing ability means a used processing solution from the processing step after the bleaching treatment and the fixing processing, or the bleach-fixing treatment, or a used processing solution containing a bleaching agent having a fixing ability. It refers to a treatment liquid and a mixed liquid thereof. Depending on the case, it also includes the case where any of the above-mentioned treatment liquids is diluted with water. It may also include wash water diluted with a lot of water (for example, 50 times or more with water).

In the present invention, a used processing solution generated when a silver halide light-sensitive material (hereinafter also referred to as a light-sensitive material) is subjected to a development processing is brought into contact with a redox solid phase body to selectively remove silver ions. The silver ion in the used treatment liquid can be reduced to capture the silver ion selectively and efficiently, and the used treatment liquid from which silver has been removed can be recycled, and the silver ion can be highly removed. Therefore, it can be discharged to sewage as it is. The method of the present invention is particularly effective for a used processing solution generated when a color photosensitive material is subjected to development processing, and is particularly effective for a used processing solution containing a bleaching agent. The present invention may be directly applied to the used processing solution discharged from the development processing step, or may be applied to the collected processing solution after collecting the used processing solution discharged from a plurality of development processing steps. .

The redox solid phase used in the present invention reduces silver thiosulfate complex ion (silver thiosulfato complex ion) to produce metallic silver and thiosulfate ion, but does not reduce thiosulfate ion. Therefore, the desilvering process reduces the consumption of thiosulfate and maintains the fixing activity, and the processing solution obtained by the desilvering process can be reused. This effect is particularly remarkable when the redox solid phase is activated carbon carrying an anthrahydroquinone / anthraquinone redox compound.

The silver thiosulfate complex ion (also referred to as silver thiosulfato complex ion) in the present invention is represented by the compound having the chemical formula shown below. [Ag (S ₂ O ₃ ) ₂ ] ^3- or [Ag (S
₂ O ₃ ) ₃ ] ^5-

In the present invention, two or more of the packed beds filled with the redox solid phase body as described above are connected in multiple series or multiple parallels, and in some cases, a pressurizing means such as a pump or a deoxidizing gas is used. With the heavy metal ion removing device having an aeration means or the like, not only the metal removal treatment can be stably performed at a constant treatment speed for a long time, but also the heavy metal ions can be highly removed. Here, as the filling layer, a plurality of layers may be arranged vertically or a plurality of layers may be arranged horizontally. Further, the plurality of filling layers used may have the same structure or different structures. For example, a packed bed filled with the same redox solid phase body or a packed bed filled with different redox solid phase bodies may be used. Furthermore, similar effects can be obtained even if they are installed in parallel and sequentially switched.

The effect of this heavy metal ion removing device will be described by taking silver, which is preferable as a heavy metal, as an example. If only one packed bed is used, the liquid after the treatment is collected and the silver concentration is monitored, and when the silver concentration becomes high, the treatment is interrupted, the redox solid phase body is replaced, and the treatment is restarted. , Batch processing. As described above, continuous processing is possible by using the heavy metal ion removing device in which two or more are connected in multiple series or multiple parallel. That is, i) at least one of the heavy metal ion removing devices connected in series is made transparent so that the internal redox solid phase can be observed, and the internal redox solid phase is changed from (for example, black) to gray. When it changes to (silver), it is switched to the connected second heavy metal ion removing device. ii) A silver detector is provided in series or in parallel with the heavy metal ion removing device, and when the sensor changes by visual observation, it is switched to the connected second heavy metal ion removing device. iii) The silver detector is configured to automatically detect the replacement time of the heavy metal ion removing device, and the second heavy metal ion removing device is switched to based on the information based on this detection. These enable continuous processing without interrupting the processing. Further, in the case of iii) above, no human labor is required, which is simple.

Here, as a silver detector, Japanese Patent Laid-Open No. 6-1 is used.
The dithizone method described in Japanese Patent No. 86222 and other known methods such as a halogen titration method, an atomic absorption method, and a fluorescent X-ray method used in the analysis method may be used, or a small size filled with the redox solid phase body according to the present invention. A detector having an inflow port and an outflow port for the liquid to be treated may be used in the container (1) to detect the color change of the redox solid phase body due to the deposition of heavy metal such as silver.
In practice, a detector using a redox solid phase body is preferable considering that it can be attached to a silver removing device and used. A detector using this redox solid phase body can be used by connecting it in parallel to the packed bed or by connecting it in series to the liquid outlet of the packed bed.

Further, a packed bed filled with the at least one redox solid phase body, if necessary, a pressurizing means (means for pressurizing waste liquid with a pump or the like to make an upward flow), and an aeration means for deoxygenated gas. The heavy metal ion removing device has a fixing ability when the photosensitive material is continuously processed by an automatic developing machine for silver halide photosensitive materials installed in the photographic processing waste liquid part containing at least a processing solution having a fixing ability. It becomes possible to continuously remove the silver ions eluted in the liquid. Here, to install in a photographic processing waste liquid part containing at least a processing solution having a fixing ability means to install in series at a solution discharge port (overflow hole) from a processing bath containing a processing solution having a fixing ability. As a result, the liquid after the silver is removed can be discharged to the sewage after clearing the discharge regulation. Further, this treated waste liquid can be reused as a treatment liquid again by removing silver without causing deterioration of other components.

The method of the present invention is basically a redox solid phase body in which a solution containing heavy metal ions is passed through a packed bed filled with the redox solid phase body in an upward flow using a pressure pump or the like. A solution containing a heavy metal ion is passed from the hollow part of the packed layer filled with a hollow part to the outside of the packed layer, to the packed layer filled with the redox solid phase body,
A solution containing heavy metal ions is passed through in a downward flow while aerating with a deoxygenated gas from the bottom of the packed bed, a heavy metal ion-containing solution that has been treated in a specific process is passed in a downward flow, in advance. The heavy metal ion-containing solution treated by the specific treatment is passed through the above-described method in five modes. In the present invention, the upward flow refers to a flow in a direction substantially opposite to the direction of gravity, and specifically, is to flow the liquid upward at an angle of 30 degrees or more with respect to the horizontal, The angle is preferably 45 degrees or more, more preferably 6
It is 0 degrees or more. The downward flow indicates a flow in substantially the same direction as the direction of gravity, and specifically, it is a flow of liquid downward at an angle of 30 degrees or more with respect to the horizontal, and preferably the angle is It is 45 degrees or more, and more preferably 60 degrees or more.

The filling layer satisfies the above conditions,
Any structure may be used as long as the filled redox solid phase body can reduce and capture the heavy metal ions in the solution. Specific examples of the filling layer include those in which a container is filled with redox solid phase bodies of various forms. Examples of the container include a container capable of preventing the redox solid phase from migrating and easily contacting the heavy metal ion-containing solution. Specifically, at least a part thereof has a porous partition wall. Examples thereof include columns, cartridges, and the like (a column has a porous partition wall at least inside or outside the concentric circles). Other special forms are possible,
From the practical viewpoint, the above two are preferable. More preferably, a cartridge that can be easily replaced is preferable. The form of the filling layer may be any of a columnar shape such as a columnar shape and a prismatic shape, a spherical shape, a plate shape, a mortar shape, and a hollow cylindrical shape. The shape is preferably columnar or hollow cylindrical.

As a method for filling the redox solid phase body in the filling layer, it may be densely filled or may be filled with a certain gap. The filling layer having a hollow portion of the above aspect, the inside of the form of the filling layer has a hollow portion which is not filled with a redox solid phase so that a heavy metal-containing solution can be supplied, Any material can be used as long as it is provided with water-permeable partition walls on the hollow portion side and the outer peripheral side. For example, a hollow portion as a supply path for supplying the heavy metal ion-containing solution is provided inside a packed bed in the shape of a cylinder, a prism, a sphere, or the like. Preferably, the packed layer is provided with a hollow portion so that all of the heavy metal ion-containing solution to be treated is in uniform contact with the redox solid phase body. An example is one in which a hollow portion that is a supply path is provided along the axis. For example, the thing shown in FIG. 3 mentioned later is mentioned.

The size of the filling layer can be appropriately set depending on the type of liquid to be treated, its use, conditions and the like. For example, when processing a photographic processing solution containing silver, a compact one is preferable. Volume of packed bed (V)
Is V = S × L, where (S) is the cross-sectional area in the direction in which the water to be treated passes and (L) is the length of the packed bed. Here, L / S ≧ 1 is preferable, and L / S ≧ is more preferable.
3, particularly preferably L / S considering channeling prevention
≧ 5. In this case, since L / S ≧ 1 should be substantially obtained, the packed bed is partitioned by the partition plate in parallel with the flow direction of the liquid to be treated, and each partitioned chamber satisfies L / S ≧ 1. Including cases where

Specifically, for minilab, printing, and X-ray, L / S ≧ 5 and S = 50 cm ^{2 to} 500 c
m ² is preferable (L = 20 to 150 cm). For large labs, medium labs, and small labs, L / S without partition plate
It is preferable that ≧ 1 and L / S ≧ 5 when a partition plate is attached. Depending on the form, when L / S ≧ 1 or ≧ 3 is not satisfied, it is better to provide a partition plate. In the case of other waste liquids for producing electronic substrates, L / S ≧ 1. By doing so, 100% of the ability of the redox solid phase body can be exhibited. Further, the filling amount of the redox solid phase body with respect to the filling layer can be appropriately set.
Can be easily obtained from That is, it is 1 liter to 75 liters for an extremely small laboratory such as a minilab, and 50 to 2500 liters for a large to small laboratory. In the case of other waste liquids for producing electronic substrates, it is 100 to 5000 liters.

In the present invention, the treatment rate of the heavy metal ion-containing solution for the packed bed can be appropriately set depending on the size of the packed bed, the concentration of the heavy metal ions, the treatment temperature, the kind of the heavy metal ions and the like. Specifically, the SV value (abbreviation of Space Velocity, which is a measure of how many times the volume of the packed bed is treated per hour) is preferably 1 to 30, and more preferably 3 to 15.

In the present invention, the packed bed may be used as it is as a treatment tank, and a solution containing a heavy metal ion may be passed through the packed bed for processing, or at least one of the packed beds may be provided. The heavy metal ion-containing solution may be passed through a treatment tank provided with a container, a pipe and the like for treatment.

In the present invention, as the pressurizing means for passing the liquid in the upward flow, any pump can be used as long as it operates for a head difference of 0.5 to 3 m. For example, a chemical pump (eg, MO pump series manufactured by Iwaki Co., Ltd .; pump manufactured by Nikkiso Co., Ltd.) which is always used in the photo lab can be used. Other diaphragm pumps and plunger pumps can also be used.

In the present invention, as a method for aerating deoxygenated gas from the lower part of the packed bed, preferably the bottom of the packed bed, the volume (V) of the packed bed is V / 30 to 1 per minute.
The voltage is preferably set to 00V, more preferably V / 10
It is 3V. In this case, the treatment may be continuous or intermittent. The means is performed so that the above conditions are satisfied by various pumps. As the aeration means, any air feed pump that operates for a head difference of 0.5 to 3 m can be used. For example, a diaphragm pump or a mini-compressor pump, which is always used at a photo lab, can be used. Examples of the deoxygenated gas include nitrogen gas and deoxidized air. Deoxidized air passed through the developer or the used developer is preferred.

The redox solid phase material in the present invention means a supported material in which a compound having a hydroquinone skeleton is adsorbed and fixed on a solid porous carrier. This is a compound capable of reducing heavy metal ions to a zero-valent metal, and any compound can be used as long as it is a compound that is stably immobilized on a porous carrier by adsorption or the like. In a broad sense, the compound having a hydroquinone skeleton also includes a compound obtained by reducing a known quinone compound. Other examples include compounds obtained by reducing indigo and the like.

Examples of the compound having a hydroquinone skeleton include hydroquinone (1,4-dihydroxybenzene), naphthohydroquinone (1,4-dihydroxynaphthalene), anthrahydroquinone (9,10-dihydroxyanthracene), hydrogenated compounds thereof, and the like. And a hydroquinone compound selected from the substitution products of.

Examples of the substituent in the above-mentioned hydroquinone compound substitution product include an alkyl group, an alkenyl group, an alkoxyl group, a phenyl group, an alkylamino group,
Examples thereof include relatively hydrophobic substituents such as halogen groups. The carbon number of the alkyl group, alkenyl group and alkoxyl group is 1 to 60, practically 24 or less, and the alkyl group may be linear or branched. Further, as long as it does not hinder the object of the present invention, a sulfonic acid group, a sulfonic acid amide group, a substituent of these hydroquinone compounds,
Although a substituent containing a carboxyl group can be adopted, since the redox solid phase body of the present invention is used in an aqueous solution, it generally has a reducing substituent having a hydrophobic substituent which does not elute in the aqueous solution. Compounds are preferred.

The compounds having these substituents include
For example, 2-methylhydroquinone, 2-ethylhydroquinone, 2,3,5-trimethylhydroquinone, 2-methylnaphthohydroquinone, 2-ethylnaphthohydroquinone,
2-propylnaphthohydroquinone, 2-methylanthrahydroquinone, 2-ethylanthrahydroquinone, 2-
Alkylated hydroquinone compounds such as amylanthrahydroquinone, 2-t-butylanthrahydroquinone, 2- (4-methyl-pentyl) anthrahydroquinone; 2-
Alkenylated hydroquinone compounds such as (4-methyl-pentenyl) anthrahydroquinone; Alkoxylated hydroquinone compounds such as 1-methoxyanthrahydroquinone and 1,5-dimethoxyanthrahydroquinone; Phenyl-substituted hydroquinone compounds such as 2-phenylhydroquinone; 2-N , Alkylaminated hydroquinone compounds such as N-dimethylamino-anthrahydroquinone; halogenated hydroquinone compounds such as 2-chlorohydroquinone, 2,3-dichloronaphthohydroquinone, 1-chloroanthrahydroquinone, and 2-chloroanthrahydroquinone.

Hydrogenated compounds of hydroquinone compounds include 1,4-dihydro-9,10-dihydroxyanthracene, 1,2,3,4-tetrahydroanthrahydroquinone, 1,2,3,4,5,6,7. , 8-octahydroanthrahydroquinone and the like. Also, catechol, 4,4'-dihydroxybiphenyl (reduced form of diphenoquinone) and 1,4-dihydroxyanthracene,
Reducing compounds corresponding to polycyclic aromatic quinones such as 9,10-dihydroxyphenanthrene and a reductant of anthanthrone may also be mentioned.

As the compound having a hydroquinone skeleton, an anthrahydroquinone compound is preferable in terms of the redox potential.

In the present invention, examples of the anthrahydroquinone compound include anthrahydroquinone (9,10
-Dihydroxyanthracene) and its hydrogenated compounds and substituted products thereof.

Examples of the substituent in the substituent of the anthrahydroquinone compound include relatively hydrophobic substituents such as an alkyl group, an alkenyl group, an alkoxyl group, a phenyl group, an alkylamino group and a halogen group. The number of carbon atoms in the alkyl group, alkenyl group and alkoxyl group is 1 to 60, practically 24 or less, and the alkyl group may be linear or branched.

Further, unless the object of the present invention is hindered,
A substituent containing a sulfonic acid group, a sulfonic acid amide group, or a carboxyl group can be adopted as a substituent of these anthrahydroquinone compounds. It is preferable to use a reducing compound having a hydrophobic substituent that does not elute.

Examples of the anthrahydroquinone compound having these substituents include 2-methylanthrahydroquinone, 2-ethylanthrahydroquinone, 2-amylanthrahydroquinone, 2-t-butylanthrahydroquinone, 2- (4-methylpentyl). Alkylated anthrahydroquinone compounds such as anthrahydroquinone; 2-
Alkenylated anthrahydroquinone compounds such as (4-methyl-pentenyl) anthrahydroquinone; Alkoxylated anthrahydroquinone compounds such as 1-methoxyanthrahydroquinone and 1,5-dimethoxyanthrahydroquinone; Phenyl-substituted anthrahydroquinone compounds such as 2-phenylanthrahydroquinone An alkylaminated anthrahydroquinone compound such as 2-N, N-dimethylaminoanthrahydroquinone; a halogenated anthrahydroquinone compound such as 1-chloroanthrahydroquinone and 2-chloroanthrahydroquinone.

Examples of the hydrogenated compound of the anthrahydroquinone compound include 1,4-dihydro-9,10-dihydroxyanthracene and 1,2,3,4-tetrahydroanthrahydroquinone. These compounds may be used alone or in combination of two or more.

In the present invention, as the anthrahydroquinone compound, anthrahydroquinone, the above-mentioned alkyl-substituted anthrahydroquinone, 1,4-dihydro-9,10-dihydroxyanthracene (1,4-dihydroanthrahydroquinone) or an alkyl-substituted compound thereof is used. Preferably 1,4-dihydro-9,10-
Dihydroxyanthracene is preferred.

In the present invention, examples of the solid porous carrier include carbon products such as silicon dioxide, activated carbon and activated carbon fibers, as well as hydrophobically prepared silicon dioxide and carbon particles such as activated carbon, for example, an aqueous solution of polytetrafluoroethylene. Emulsion processed products (JP-A-53-92981), organic synthetic polymer particles such as styrene divinylbenzene copolymer which is a so-called organic synthetic adsorbent, or molded products thereof can be mentioned. Particularly, activated carbon is available at a low price. Easy and preferable. In order to be suitably used for this porous carrier, the pore size is 5 angstroms or more, preferably 10 angstroms or more, the specific surface area per gram is 300 to 1,000 square meters for particles of silicon dioxide and synthetic polymer, carbon products, etc. Then, the specific surface area per gram is 1000
Square meters are the standard. The activated carbon may be in any form such as powder or pellet, spherical or crushed carbon. In the present invention, as the shape of the redox solid phase body, any of particle shape, plate shape, container shape and the like can be used. A plate-shaped material such as carbon fiber can be used, but in the present invention, a particle-shaped material is preferable as described above. Since carbon fiber is expensive, it leads to cost increase,
Not preferred.

The smaller the particle size of the pelletized, spherical or crushed charcoal of this porous carrier, the better the contact efficiency, but when filling the above packed bed and continuously treating an aqueous solution containing heavy metal ions. Since the liquid flow resistance will increase,
Generally, the particle size of the porous carrier is suitably 0.3 to 10 mm, more preferably 0.4 to 3 mm.

As the porous carrier used in the method of the present invention, in particular, particulate activated carbon is inexpensive and easy to handle,
In addition, the supporting rate is high, which is preferable.

In the present invention, as a method for preparing a redox solid phase body, in the case of a compound which is relatively stable in the process of carrying a compound having a hydroquinone skeleton (for example, a hydroquinone compound), its hydroquinone skeleton is usually used. The compound having can be used as it is. However, in the case where the compound having a hydroquinone skeleton is an unstable compound such as easily oxidized in the operation process of supporting, for example, a naphthohydroquinone compound or an anthrahydroquinone compound, an oxide corresponding to the compound having the above hydroquinone skeleton Preferred is a method of loading using, for example, a naphthoquinone compound or an anthraquinone compound. In this case, as the oxide, for example, compounds corresponding to hydroquinone, naphthohydroquinone and anthrahydroquinone are benzoquinone, naphthoquinone (1,4-naphthoquinone) and anthraquinone (9,10-anthraquinone), hydrogenated compounds thereof and the above-mentioned compounds. It is a quinone compound having a substituent.

In the present invention, the method for preparing the redox solid phase body is generally performed as follows. For example, as a batch method, in a solution prepared by dissolving a compound having a hydroquinone skeleton or an oxide thereof in a soluble organic solvent, it generally depends on the kind and solvent of the compound to be used, but generally at room temperature or higher. A compound having a hydroquinone skeleton or an oxidation thereof is obtained by adding a porous carrier and impregnating and adsorbing a compound having a hydroquinone skeleton or an oxide thereof into the porous carrier while stirring, distilling off an organic solvent and drying. It is possible to easily produce a supported product.
Further, if necessary, a solvent is added to the dried support to impregnate it, and then demineralized water is added to the mixture with stirring to stir the compound having a floating hydroquinone skeleton which is not adsorbed on the carrier or an oxide thereof. Can be removed and washed, and the supported material of the compound having a hydroquinone skeleton can be kept in a wet state as it is to prepare a redox solid phase in an aqueous solution. Further, a solid porous carrier moistened with a solvent is packed in a column in advance, and a solution in which a compound having a hydroquinone skeleton or an oxide thereof is dissolved is passed through and carried.
It can also be carried out by a washing method. On the other hand, a supported material obtained by using an oxide corresponding to a compound having a hydroquinone skeleton can be prepared as a similar redox solid phase body by a reduction treatment.

As a method for reducing a support using an oxide corresponding to a compound having a hydroquinone skeleton as a raw material, a method of reducing an ordinary quinone compound to a hydroquinone compound or the like can be adopted. For example, sodium dithionite (sodium hydrosulfite),
An aqueous solution of hydrosulfite such as potassium dithionite (potassium hydrosulfite) is preferably used, and a sulfite or a zinc-acid (or alkali) -based reducing agent is used depending on the type of other quinone compound. can do. In the case of reducing a quinone compound with sodium hydrosulfite, for example, a sodium hydrosulfite solution in a stoichiometric amount or more is used, and a support material carrying a quinone compound is fed batchwise under conditions of pH 10 or less.
Alternatively, it can be carried out by passing the solution through a column filled with the supported material and bringing it into contact with it.

The reaction formula of the reaction of reducing the anthraquinone compound to the anthrahydroquinone compound using sodium hydrosulfite is as shown in the following formula.

[0065]

Embedded image

As the above-mentioned organic solvent, any solvent capable of dissolving a necessary amount of the compound having a hydroquinone skeleton or an oxide thereof can be adopted. It is preferable to select a solvent that is easily supported by the carrier used. Examples of the organic solvent generally include alcohols such as methanol, ethanol, propanol, and isopropanol.

Generally, the concentration of the solution of the compound having a hydroquinone skeleton or its oxide is equal to or lower than its solubility and close to the saturated concentration. The amount of the compound having a hydroquinone skeleton or its oxide supported is not particularly limited and may be appropriately selected depending on the type of the solid porous carrier used, but is generally 0.01 to 2 mol / liter. Carrier, preferably 0.3-1.0 mol / liter-carrier. If the supported amount is small, the cost will be higher than that of the recovered metal, and even if the supported amount is too large, the amount that does not act on the heavy metal ions increases, so that the raw material is wasted.

As the method for producing the redox solid phase body of the present invention, a water-soluble salt of a compound having a hydroquinone skeleton, for example, a water-soluble salt of an anthrahydroquinone compound, is used in addition to the method of supporting it on a carrier using the above-mentioned organic solvent. A method may be mentioned in which a porous carrier is added to the aqueous salt solution, the anthrahydroquinone compound is adsorbed on the porous carrier, the porous carrier is separated, and then washed. The water-soluble salt of the anthrahydroquinone compound in the present invention is selected from, for example, alkali metal salts and ammonium salts. Examples of the alkali metal salt include sodium salt, potassium salt, lithium salt and the like. As the ammonium salt, a normal ammonium (NH ₄ ⁺ ) salt,
Alternatively, a quaternary ammonium salt such as tetramethylammonium salt, tetraethylammonium salt, tetrapropylammonium salt or tetrabutylammonium salt can be used. However, inexpensive sodium salts are usually used.

In particular, the aqueous disodium salt solution of the 1,4-dihydro-9,10-dihydroxyanthracene compound is obtained by the Diels-Alder reaction of naphthoquinone with the corresponding 1,3-butadiene compound.
The 4,4a, 9a-tetrahydroanthraquinone compound is easily reacted with an aqueous solution of an alkali metal hydroxide in an equivalent amount (2 times the mole of the quinone compound) or more, preferably 2 to 2.4 times the mole of the alkali metal hydroxide. Since it is obtained, it can be industrially advantageously obtained. The concentration of the aqueous solution of the alkali metal salt of the compound having a hydroquinone skeleton used in the method of the present invention (the concentration is represented by weight% in terms of quinone compound such as anthraquinone) is 1 to 23% (in the present specification, "%"). Indicates "wt%" unless otherwise specified.),
It is preferably 2 to 22%, the temperature of the adsorption treatment is usually normal temperature, and the adsorption time is 5 minutes to 5 hours, preferably 1
~ 4 hours.

The amount of these anthrahydroquinone compounds used varies depending on the type of the porous carrier, but is not particularly limited as long as it is not higher than the solubility of the compound, and the mother liquor obtained after the adsorption treatment is reconcentrated. It can be used for adsorption treatment by adjusting.

The adsorption treatment is usually carried out in a batch (batch type) by a method in which a container containing a porous carrier and an aqueous solution of an alkali metal salt of an anthrahydroquinone compound is gently rotated or left to stand to adsorb, or a porous column is packed in a packed column or the like. It is also possible to employ a continuous contacting method in which a porous carrier is pre-filled and an aqueous solution of an anthrahydroquinone compound is circulated and immersed while being immersed. Since the anthrahydroquinone compound used in the present invention is generally an extremely weak kind of acid, the salt is hydrolyzed even if the support carrying the alkali metal salt of the anthrahydroquinone compound is washed with an aqueous medium such as water. The alkali heavy metal ions can then be replaced with hydrogen ions. As this aqueous medium, an aqueous medium such as demineralized water and deionized water from which dissolved oxygen has been removed is preferable. In this cleaning treatment, the treatment with an aqueous acid solution is effective in reducing the amount of cleaning water or ensuring the replacement with hydrogen ions. The acid used for the washing treatment with the aqueous acid solution may be an organic or inorganic acid as long as it has an ability to liberate an alkali metal salt. Examples of the inorganic acid include sulfuric acid and hydrochloric acid, and examples of the organic acid include carboxylic acid such as acetic acid and sulfonic acid such as naphthalenesulfonic acid. The acid may be used in an amount such that the alkali heavy metal ion in the obtained supported material is sufficiently replaced with hydrogen ion, and is generally equal to or more than 20 equivalents of the adsorbed compound and its concentration is 0. ．
A 1-20% aqueous solution is used.

To carry out this method, the following procedure is generally performed. For example, a container is charged with a predetermined amount of a porous carrier, for example, granular activated carbon, degassed under reduced pressure, and further sufficiently subjected to nitrogen substitution treatment, and then a predetermined concentration of an alkali metal salt of an anthrahydroquinone compound in a nitrogen atmosphere. For example, the porous carrier is added to a predetermined amount of a disodium salt aqueous solution of 1,4-dihydro-9,10-dihydroxyanthracene having a predetermined concentration, and the mixture is contacted under reduced pressure and adsorbed for a predetermined time. This mixture is separated with a separator such as a centrifuge under a nitrogen atmosphere and washed with an aqueous medium such as deoxygenated deionized water, or washed with a dilute acid such as 5 to 10% sulfuric acid. Then, the obtained carrier (support) carrying the anthrahydroquinone compound is stored in demineralized water that has been sufficiently deoxygenated. The supported amount of the obtained supported substance varies depending on the type of the anthrahydroquinone compound, the concentration of the aqueous solution of the salt, and the type of the solid porous carrier, but for example, disodium 1,4-dihydro-9,10-dihydroxyanthracene. When using salt and granular activated carbon, it is about 0.3 to 1.0 mol / liter-carrier.

The thus obtained support composed of 1,4-dihydro-9,10-dihydroxyanthracene / activated carbon is used, for example, in a silver thiosulfate complex ion, in the first time to give another anthrahydroquinone compound. In comparison, it is particularly preferable in that it exhibits a silver ion capturing efficiency of 2 to 5 times.

The redox solid phase body of the present invention can convert heavy metal ions contained in a heavy metal ion-containing solution into a zero-valent metal by a redox reaction, and can be captured and collected on the redox solid phase body.

The redox solid phase material which can be used in the present invention is described in detail in Japanese Patent Application No. 5-323045,
It is described in Japanese Patent Application No. 6-280769 and Japanese Patent Application No. 6-295221.

The treatment conditions of the liquid to be treated in the present invention are influenced by the coexisting anions, but the pH of the liquid to be treated is not particularly limited as long as the heavy metal ions are stably present in the solution. However, a wide range of 0-12, preferably 0-11, is usually adopted.

The concentration of heavy metal ions in the solution is not particularly limited as long as it is dissolved, and may be low or high.
Generally 0.1 to 30000 ppm, preferably 5 to 2
0000 ppm, and the treatment temperature is generally 10 to 70
C., usually 20.degree. C. to 60.degree.

The redox solid phase used in the present invention has the ability to be reduced in the case of treating a solution containing heavy metal ions, that is, the redox solid phase which has passed through is treated with an anthraquinone compound as described above. Methods for reducing anthrahydroquinone compounds, for example, reduction with sodium hydrosulfite aqueous solution, and other reductions such as nascent hydrogen (for example, zinc and hydrochloric acid or alkaline aqueous solution) capable of reducing the anthraquinone compound of the present invention to anthrahydroquinone compound After the reduction treatment is carried out again by the method, the solution containing the heavy metal ion is treated again, and although there are some differences depending on the kind of the supported hydroquinone skeleton compound, the heavy metal ion is repeatedly reduced for a considerable number of times to precipitate the heavy metal ion. Can be captured.

A general method for reducing a redox solid phase exhibiting a breakthrough oxidation type (quinone type) is as follows, after the breakthrough redox solid phase is usually washed with demineralized water or the like. By performing the reduction treatment, it is possible to repeatedly treat the heavy metal ion-containing aqueous solution with this redox solid phase body. This washing treatment may be performed in an amount capable of displacing the solution containing the remaining heavy metal ions, and generally 2 times or more the volume of the redox solid phase body is sufficient.

Further, in the present invention, at least silver thiosulfate to be recovered is used by using two or more types of redox solid phase bodies in which compounds having hydroquinone skeletons having different equilibrium redox potentials are supported on a solid porous carrier. A method of treating a used treatment liquid containing complex ions and separating it from other metal ions such as iron contained in the treatment liquid can be adopted. For example, it is possible to remove trivalent iron and the like in the first half and reduce and remove silver in the latter half. That is, a plurality of packed layers filled with a redox solid phase body in which two or more compounds having hydroquinone skeletons having different equilibrium redox potentials are supported on a solid porous carrier are connected in series in descending order of equilibrium redox potential. And the used treatment solution containing at least silver thiosulfate complex ion is brought into contact with the packed layer, and the coexisting iron trivalent ion is reduced in advance to divalent by utilizing the difference in reducing power. By doing so, a treatment method comprising effectively capturing the silver thiosulfate complex ion as a zero-valent metal can also be used. The packed bed of the redox solid phase body can be implemented by, for example, an apparatus that forms a single container (column) in which two layers are formed above and below, or an apparatus that forms separate containers in series.

In the present invention, the combination of the compound having a hydroquinone skeleton and the heavy metal ion can be determined by the respective equilibrium redox potentials. For example, when the compound is hydroquinone, it captures noble metal ions and palladium ions as heavy metal ions, but does not capture copper ions. When the compound is 2-ethylanthrahydroquinone, it also captures noble metal ions and copper ions as heavy metal ions. By using the packed bed using the former compound first and combining the packed bed using the latter compound, the noble metal ion and the copper ion can be selectively separated and captured. By this method, the precipitation of a plurality of heavy metal ions occurring in a single packed bed can be recovered without contaminants. The conditions for carrying out a plurality of packed beds are the same as the above except that a plurality of packed beds are used.

The metal-captured redox solid phase body uses a carrier capable of burning an organic synthetic adsorbent, activated carbon or the like. In the case of an expensive metal such as a noble metal, the metal-captured redox solid phase body is used. For example, it can be easily recovered as a noble metal by incineration. This incineration method
It is not particularly limited, and any type can be used as long as it can recover precious metals from incineration residues such as a rotary incinerator such as a rotary kiln and a crucible type incinerator. Further, if the captured metal is dissolved and recovered by an acid such as nitric acid, this recovery method can also be adopted.

In the present invention, the heavy metal ion-containing solution to be applied can be suitably applied to heavy metal ion aqueous solutions discharged from various industries, particularly noble metal-containing wastewater from industries handling precious metals. For example,
Wastewater containing gold or silver ions or complex ions discharged from electronic parts processing plants, wastewater containing ions or complex ions such as palladium, ruthenium and platinum discharged from the catalyst manufacturing industry, processing of photographic materials Examples include photographic processing solutions containing silver ions or silver complex ions generated from Particularly, in the present invention, it is preferably used for a photographic processing solution containing silver ions or silver complex ions.

When the method of the present invention is applied to a photographic processing solution containing a silver ion or a silver complex ion, a used processing solution having a fixing ability, containing a bleaching solution, a bleaching process and a fixing process, or a bleach-fixing process. By treating the used treatment solution from the treatment step after the treatment with the redox solid phase, the silver salt contained in the treatment solution or the washing water is concentrated as the reductant on the redox solid phase, and the redox solid phase is condensed. It is preferable to separate and remove silver from the silver to recover the silver. It is recovered in the redox solid phase in the reduced state, ie in the form of metallic silver. In the present invention, the following advantages can be obtained by recovering silver as described above.

First, the redox solid phase body of the present invention has an extremely large silver capture capacity (for example, 300 g / liter).
Since the carrier, the redox-based support material, and the by-products other than reduced silver are not incorporated on the top, silver can be recovered as an extremely pure metal. When settling out as silver sulfide, by-products such as sulfur and iron compounds are incorporated and the silver concentration is reduced, which reduces the silver recovery efficiency. Further, in connection with the above, the recovery of silver from the redox solid phase has an advantage that the load of separating and removing impurities such as sulfur is small. Also, unlike incineration from silver salt, there is little outflow of silver to the atmosphere when heated strongly. For transport to the silver recovery site, it is easy to transport in a concentrated state to the redox solid phase body. When silver is recovered from the redox solid phase body on which silver is deposited as described above, activated carbon is preferable as the carrier.

As a specific method for recovering silver from the redox solid phase body using activated carbon as the carrier, the following methods (1) to (4) are preferable. The activated carbon containing silver in a concentrated state is incinerated, and the activated carbon is oxidized and vaporized to separate the silver from the activated carbon. Generally, when a residue containing silver is treated in an incinerator, silver is a metal having a relatively low boiling point, so that it easily scatters and disappears in the atmosphere. Especially in general industrial waste incinerators,
Air supply is sufficient (outlet oxygen concentration is 6 to 8%), flame temperature is 900 to 1000 ° C, and the scattering of silver is remarkable.
In the case of the above method, the silver concentrated in the redox solid phase body is relatively less scattered and lost, probably because it is deposited on the metal. Activated carbon containing silver in a concentrated state is subjected to dry distillation to heat-melt the silver and separate it from the activated carbon. When the silver concentrated in the redox solid phase is recovered by a carbonization device as described in, for example, US Pat. It is possible to recover silver.

Activated carbon containing silver in a concentrated state is put into a silver melting furnace and heated and melted at 600 ° C. or higher, and the activated carbon is separated by oxidation and vaporization. In this method, the concentration of silver in the redox solid phase is high, and since coexisting activated carbon is high-purity carbon, it can be directly charged into a melting furnace to take out silver in a molten state from the bottom of the furnace. I knew I could do it.
With this method, pre-steps such as silver precipitation and concentration in the silver recovery step and dehydration can be omitted, and there are great economic merits. Activated carbon containing silver in a concentrated state is treated with an oxidizing acid aqueous solution, for example, nitric acid aqueous solution to oxidize and extract silver as silver ions for separation. This is a non-destructive method of recovering silver concentrated on the redox solid phase of the present invention,
When redox solid phase containing silver is treated with an oxidizing liquid, for example, dilute nitric acid, silver dissolves into silver nitrate and is released from activated carbon. This solution is electrolytically purified to recover silver salt. . Since the oxidized redox solid phase material is still supported on the activated carbon, it can be reused after being reduced and activated by the method described above.

In the present invention, the silver concentration in the treatment liquid may be measured by a silver detecting means, and the redox solid phase replacement time may be determined according to the product of the concentrations. As the silver detecting means, it is preferable to use the value of the potential of the silver sulfide electrode as a measure of the silver concentration. For example, those described in JP-A-6-27623 can be mentioned. This allows
Even if the silver concentration in the waste liquid fluctuates, it is possible to always perform good silver removal treatment and continuous treatment. In the present invention, when the treated processing solution obtained by processing the color sensitive material and the redox solid phase body are brought into contact with each other to be processed, the silver concentration of the processed water becomes 1
It can be 0 ppm or less, usually 0.001-1 ppm. Similarly, for waste water discharged from an electronic parts processing plant, the gold concentration is 1 ppm or less, usually 0.001 to 0.
1ppm, silver 10ppm or less, usually 0.001-1
ppm. Similarly for the wastewater from the catalyst factory, if it is palladium or platinum, it will be 1 ppm or less. When the method of the present invention is used for a used processing solution after the bleaching treatment and the fixing treatment, or the processing step after the bleach-fixing treatment,
The desilvered water after desilvering may be reused, for example, as water for dissolving the fixing agent or the fixing bleaching agent.

The method of the present invention is preferably used for a photographic processing solution containing silver ions or silver complex ions generated during the development processing of black-and-white light-sensitive materials and color light-sensitive materials. Hereinafter, the color photosensitive material will be mainly described. Bleaching and fixing,
Or, the used processing liquid from the processing step after the bleach-fixing treatment has conventionally relied on the above-mentioned ion exchange resin technology, the membrane technology by the reverse osmosis membrane or the ultrafiltration membrane, and in comparison with them, as described above. Needless to say, there are merits in equipment cost and running cost.

The method of the present invention comprises a bleaching treatment and a fixing treatment,
Or a used processing solution having a relatively dilute salt concentration, such as a used processing solution from a processing bath after bleach-fixing processing, a used processing solution containing a bleaching agent and having a fixing ability. It can be applied to a silver-containing photographic processing solution which has a high salt concentration (100 times or more as compared with the former) and has a significantly different surface corrosion action or surface coating action.

Using the redox solid phase material of the present invention, silver in the processing solution having fixing ability is removed to make it reusable, and the regenerated solution is returned to the processing solution having fixing ability. Has excellent characteristics in the following points. As described above, the method of the present invention can efficiently remove silver without decomposing a compound having a fixing ability and can be reused, so that the life of the regenerating solution is long and the stability of the solution is good. . Further, as compared with the electrolytic recovery method, no power consumption is required and no power cost is required.

Furthermore, when the used processing solution processed by the method of the present invention is regenerated and reused, the processed photographic material has no stain generation or residual color. Possibly, the accumulation of salts is low in the process of regeneration, which may bring about such an effect. By removing the silver salt contained in the used processing liquid and reusing it, the amount of replenishment can be reduced and the amount of waste liquid can be reduced. Low replenishment and reuse are means for reducing the amount of waste liquid, and either may be selected, or both may be selected at the same time, depending on the conditions of the place of development processing.

In the present invention, the amount of replenishment can be further reduced by returning the desilvered liquid to the processing liquid having the fixing ability together with a new replenishing liquid in an amount equal to or less than the amount of the regenerating liquid. A low replenishment system that can significantly reduce the amount of waste liquid can be achieved. In the present invention, when the used processing solution after desilvering is returned to the processing tank having the fixing ability, the processing solution may be returned in the whole amount or a part thereof. Here, when part of the treatment liquid is returned, since the remaining treatment liquid contains almost no silver, it can be discharged as it is to sewage or the like.

The solution containing the heavy metal ion to be used in the present invention is typically photographic industry (for example,
There is some liquid discharged from the processing room). Examples of the liquid include a fixing liquid, a bleach-fixing liquid, washing water, a rinse liquid, and a stabilizing liquid. Further, these liquids may be used alone or as a mixture, or may be mixed with a developing solution or a bleaching solution. These photographic processing liquids contain various components.

The silver salt in the used processing solution is generally dissolved in the form of thiosulfate complex salt. In addition to the above, the used treatment liquid is a non-complexed thiosulfate ion, ammonium ion, carbonate ion, alkali metal ion, sulfate ion, aluminum ion, boric acid or its salt, EDTA or its related chelating agents, and their chelates. It contains complex salts of agents and iron ions, and halides. The silver halide in the light-sensitive material is dissolved by the fixing solution, and the silver ion forms a complex salt with anions such as S ₂ O ₃ ²⁻ and SO ₃ ²⁻ .

Even when a used treating solution containing an iron complex salt is treated by the method of the present invention, some of the redox solid phase may be consumed by the iron complex salt, which is relatively disadvantageous. Still, it is more effective than conventional silver removal methods. For example, in the case of electrolytic recovery, the reduced iron complex salt returns to the oxidized state by contact with air, and the redox cycle works, so the degree of inefficiency is large and the decomposition of the treatment liquid component also accompanies practicality. Is subject to considerable restrictions. The metal displacement method using steel wool is less likely to cause inefficiency due to reoxidation than the electrolysis method, but care must be taken to prevent air contact in order to prevent it. When the method of the present invention is applied to a used processing solution such as a fixing solution or a bleach-fixing solution, as described above, the deterioration of the solution due to air oxidation and increase of undesired accumulation occurring during the reproduction is small, and therefore, the recycling The rate can be kept high.

As the bleaching agent used in the processing solution having bleaching ability, aminopolycarboxylic acid iron (III) complex, persulfate, bromate, hydrogen peroxide, red blood salt and the like can be used. The polycarboxylic acid iron (III) complex can be most preferably used. The ferric iron complex salt used may be added as a complexed iron complex salt in advance and dissolved, and the complex forming compound and the ferric iron salt (for example, ferric sulfate, ferric chloride, odor, etc. A complex salt may be formed in a liquid having a bleaching ability by coexisting with ferric chloride, iron (III) nitrate, ammonium iron (III) sulfate, etc.).

As a compound forming a ferric complex salt in a liquid having a bleaching ability, ethylenediaminetetraacetic acid (E
DTA), 1,3-propanediaminetetraacetic acid (1,3-
PDTA), diethylenetriaminepentaacetic acid, 1,2-cyclohexanediaminetetraacetic acid, iminodiacetic acid, methyliminodiacetic acid, N- (2-acetamido) iminodiacetic acid,
Nitrilotriacetic acid, N- (2-carboxyethyl) iminodiacetic acid, N- (2-carboxymethyl) iminodipropionic acid, β-alaninediacetic acid, 1,4-diaminobutanetetraacetic acid, glycol etherdiaminetetraacetic acid, N -(2
-Carboxyphenyl) iminodiacetic acid, ethylenediamine-N- (2-carboxyphenyl) -N, N ', N'
-Triacetic acid, ethylenediamine-N, N'-disuccinic acid,
1,3-diaminopropane-N, N'-disuccinic acid, ethylenediamine-N, N'-dimalonic acid, 1,3-diaminopropane-N, N'-dimalonic acid and the like can be mentioned, but not limited to these. Not something.

The fixing agent component in the bleach-fixing solution or the fixing solution is
Known fixing agents, ie, thiosulfates such as sodium thiosulfate and ammonium thiosulfate; sodium thiocyanate,
Thiocyanates such as ammonium thiocyanate; ethylenebisthioglycolic acid, 3,6-dithia-1,8-
It is a water-soluble silver halide dissolving agent such as a thioether compound such as octanediol, a mesoionic compound and thioureas, and these can be used alone or as a mixture of two or more. Further, a special bleach-fixing solution containing a combination of a fixing agent described in JP-A-55-155354 and a large amount of a halide such as potassium iodide can be used. Preference is given to using thiosulfates, especially ammonium thiosulfate and sodium thiosulfate. The bleach-fixing solution or fixing solution of the present invention preferably contains a sulfite (or bisulfite or metabisulfite) as a preservative.

The bleach-fixing solution and fixing solution include sulfites (eg, sodium sulfite, potassium sulfite, ammonium sulfite) and bisulfites (eg, ammonium bisulfite, sodium bisulfite, potassium bisulfite) described above as preservatives. In addition to containing a sulfite ion-releasing compound such as metabisulfite (eg, potassium metabisulfite, sodium metabisulfite, ammonium metabisulfite),
Aldehydes (benzaldehyde, acetaldehyde, etc.), ketones (acetone, etc.), ascorbic acids, hydroxylamines, etc. can be added as necessary.

Further, a bleaching solution, a bleach-fixing solution and a fixing solution may be added with a buffering agent, a fluorescent whitening agent, a chelating agent, a defoaming agent, an antifungal agent and the like, if necessary.

In the present invention, the used processing solution after desilvering processing may be reused. In order to prevent unevenness of water droplets when the photosensitive material after processing is dried,
Various surfactants can be included. Among these, it is preferable to use a nonionic surfactant, and an alkylphenol ethylene oxide adduct is particularly preferable. Octyl, nonyl, dodecyl and dinonylphenol are particularly preferable as the alkylphenol, and 8 to 14 are particularly preferable as the number of moles of ethylene oxide added.
Further, it is also preferable to use a silicon-based surfactant having a high defoaming effect.

Various chelating agents may be contained in the wash water and / or the stabilizing solution. Preferred chelating agents include aminopolycarboxylic acids such as ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, N, N, N'-.
Trimethylenephosphonic acid, diethylenetriamine-N,
Examples thereof include organic phosphonic acids such as N, N ′, N′-tetramethylenephosphonic acid, and hydrolyzates of maleic anhydride polymers described in European Patent 345,172A1.

The automatic developing machine for silver halide light-sensitive materials which can be used in the present invention is provided with the above-mentioned single or plural heavy metal removing device of the present invention in series with the discharge port of the processing bath having fixing ability. Those are preferable. The discharge port of a processing bath having a fixing ability contains at least 1 part of the fixing component when brought in from a processing bath containing at least 1 part of the fixing liquid component or a pre-bath in a color or black and white automatic developing machine. Means the outlet of the processing bath. Normally, this outlet is located 50 to 150 cm from the floor surface. Therefore, when liquid is passed through the packed bed in an upward flow, the height of this outlet is used to remove the liquid in the treatment bath. It is preferable to provide the height of the uppermost portion of the filling tank in the apparatus to be installed lower than that of the interface. As a result, the liquid can be passed without providing the pressurizing means.

A processing solution having a fixing ability can be continuously supplied to the packed bed to precipitate heavy metal ions such as silver ions. Preferably, a plurality of packed beds are installed in a cartridge form in series, the liquid to be treated is passed through the first packed bed, and the liquid thus obtained is further passed through the second packed bed, and another Similarly, the packed bed is sequentially passed. Further, when it is time to replace the first packed bed, the packed bed is replaced with a new packed bed, and the new packed bed is used as the final packed bed. The first packed bed after replacement becomes the second packed bed before, the second packed bed after replacement becomes the third packed bed before, and so on. It is preferable to use a format that raises. Specific examples include those shown in FIGS. 5 and 6. As a result, the efficiency of removing heavy metal ions such as silver ions is remarkably improved, stable treatment can be performed, and the redox solid phase used is not wasted.

The automatic developing machine (also referred to as a developing machine) which can be used in the method of the present invention includes a roller conveying type automatic developing machine, a conveying type automatic developing machine using a timing belt and a leader, and a conveying type automatic developing machine using a sprocket and a leader. Machines are preferred, and among these, JP-A-60-191257 and 60-
It is preferable to have the photosensitive material conveying means described in JP-A Nos. 191258 and 60-191259. As described in the above-mentioned JP-A-60-191257, such a conveying means can remarkably reduce the carry-in of the treatment liquid from the front bath to the rear bath, and is highly effective in preventing the performance deterioration of the treatment liquid. Such an effect is particularly effective for reducing the processing time in each step and reducing the replenishing amount of the processing solution.

[0107]

EXAMPLES The present invention will be specifically described below with reference to examples, but the contents of the present invention are not limited thereto. Example 1 A color negative light-sensitive material prepared according to Example 1 described in JP-A-6-347964 was prepared by Fuji Photo Film Co., Ltd.
Treatment using the color negative treatment agent CN-16X manufactured by K.K. Simulated water washing)
A silver removal test by a silver removal method using a column packed with the following redox solid phase bodies was performed up to 0 to 3000 BV. However, in both the case where the diluting liquid is supplied by a downward flow method that is supplied from above the column and the case where the diluting liquid is supplied by an upward flow method that is pressurized by a pump from the lower part of the column and is supplied. Compared.

[Preparation of Redox Solid Phase Body in which 1,4-Dihydro-9,10-dihydroxyanthracene (hereinafter referred to as DDA) is Supported on Activated Carbon] (Supporting DDA) Coal-based activated carbon manufactured by Mitsubishi Chemical Co., particle size 0.4 to 0.
8 mm) 700 ml (400 g) was collected and demineralized water 90
0 ml was added and the nitrogen substitution treatment was repeated under reduced pressure to replace the oxygen in the activated carbon pores with nitrogen, and then 2 under a nitrogen atmosphere.
A disodium salt of DDA having a concentration of 2% by weight (hereinafter, "%" represents "% by weight" unless otherwise specified) (hereinafter, the disodium salt of DDA is referred to as "DDAN".
The concentration of AN is expressed as the concentration converted to anthraquinone. Approximately 1000 ml of the aqueous solution of 1) was added and adsorbed under reduced pressure for 4 hours. This mixture was suction-filtered under a nitrogen atmosphere, and the obtained filter cake was subjected to a nitrogen substitution treatment to demineralized water 50.
It was washed with 0 ml, washed with 700 ml of 10% sulfuric acid aqueous solution, and washed again with 500 ml of deionized water subjected to nitrogen substitution treatment. The redox solid phase body obtained by supporting the obtained DDA on activated carbon was transferred to a sample bottle, filled with deionized water subjected to nitrogen substitution treatment, and stored. Then, by the same method, the amount of redox solid phase required for the following examples was prepared.

(Measurement of Adsorption Amount of Redox Solid Phase Body) 10 ml of the redox solid phase body obtained above was sampled and extracted with a mixed solvent of acetone / methanol using a Soxhlet extractor, followed by toluene solvent. Extracted in
After eluting the anthrahydroquinone compound adsorbed on the activated carbon, these solvents were distilled off, the weight of the remaining compound was measured, and the adsorption amount was calculated in terms of anthraquinone. This adsorption amount was 0.85 mol per liter of activated carbon. 30 ml of the redox solid phase body (particle size 0.35 to 1.15 mm) prepared above is 30 mm in diameter and 300 in height.
The column was packed in a mm column, and 10 liters of the overflow solution diluted 100-fold with water without dissolved oxygen was passed at a space velocity (SV) of 10 (1 / hr) to remove silver. It was Processing amount (BV) and space velocity (S
The relationship of V) was evaluated.

The results are shown in FIG. As shown in FIG. 1, when the liquid was passed in a downward flow, the SV started to decrease from the 1500 BV treatment, and the column was almost clogged by the 3000 BV treatment. On the other hand, at least 3000 BV when the liquid flows upward
Up to this point, the SV value could be treated without changing, and silver was uniformly deposited on the entire redox solid phase body in the packed bed. Therefore, it is understood that stable treatment is possible by passing the liquid in the upward flow. Also, when observing the column that passed through in a downward flow, the redox solid phase body packed in the upper part of the column (the part of about 60% from the uppermost part) became silver due to silver deposition, and the size was remarkably large. Was becoming. It is considered that this is the cause of the blockage of the column.

Further, the silver concentration in the liquid after the desilvering process of the above-mentioned method of passing the liquid through the upward flow was measured by the atomic absorption method. The silver concentration after removal of silver was 0.02 ppm. Moreover, since the treated liquid did not decompose the components and the silver concentration was almost 0, it could be reused as a dilution liquid of the kit.

In other words, from the above results, it is possible to prevent the blockage of the column by effectively passing the liquid containing silver ions in the upward flow, and to effectively use the packed redox solid phase,
It turns out that silver can be effectively removed.

Example 2 The light-sensitive material of the above Example 1 was prepared by using a solution having the following processing solution composition.
The solutions were treated in the following treatment steps to bring them into running equilibrium.

(Processing step) Process Processing time Processing temperature Replenishment amount ^* Tank capacity Color development 3 minutes 5 seconds 37.6 ° C. 15 ml 17 liter Bleach 50 seconds 38.0 ° C. 5 ml 5 liter Fixing (1) 50 seconds 38.0 ° C-5 liters Fixing (2) 50 seconds 38.0 ° C 5 ml 5 liters Stable (1) 30 seconds 38.0 ° C-3.5 liters Stable (2) 20 seconds 38.0 ° C-3 liters stable (3) 20 seconds 38.0 ° C. 15 milliliters 3 liters Dry 1 minute 30 seconds 60 ° C. * Replenishment amount per 35 mm width of photosensitive material 1.1 m (equivalent to 24 Ex. 1 bottle)

The stabilizing solution is a countercurrent system from (3) to (2) to (1) and the fixing solution is from (2) to (1), and the overflow solution of the bleaching solution is introduced into the fixing bath (1). Then, the overflow solution of the stabilizing solution was introduced into the fixing bath (2).
The amount of developing solution brought into the bleaching process, the amount of bleaching solution brought into the bleach-fixing (fixing (1)) step, the amount of bleach-fixing (fixing (1)) bringing into the fixing (2) step, and fixing (2) The amount of the liquid brought into the washing step is 2.5 ml, 2.0 ml per 35 mm width of the photosensitive material and 1.1 m, respectively.
It was 2.0 ml and 2.0 ml. The crossover time is 6 seconds in all cases, and this time is included in the processing time of the previous step. Open area 120 cm ² in the color developing solution in the processing machine, 120 cm ² in the bleaching solution, the other processing solutions was about 100 cm ^2.

The composition of the processing liquid is shown below. (Color developer) Tank liquid (g) Replenisher (g) Diethylenetriaminepentaacetic acid 2.2 2.2 Catechol-3,5-disulfonic acid disodium 0.3 0.3 1-Hydroxyethylidene-1,1-diphosphone Acid 2.0 2.0 Sodium sulfite 3.9 5.5 Potassium carbonate 37.5 39.0 N, N-bis (2-sulfoethyl) hydroxylamine disodium 2.0 2.0 Potassium bromide 1.4 -Potassium iodide 1.3 mg-hydroxylamine sulfate 2.4 3.6 2-methyl-4- [N-ethyl-N- (β-hydroxyethyl) amino] aniline sulfate 4.5 6.8 Water In addition 1.0 liter 1.0 liter pH (adjusted with potassium hydroxide and sulfuric acid) 10.05 10.21

(Bleaching Solution) Tank Solution (g) Replenishing Solution (g) 1,3-Diaminopropanetetraacetic Acid Ferric Ammonium Ammonium Hydrochloride 113 170 Ammonium Bromide 70 105 Ammonium Nitrate 14 21 Glutaric Acid 93 140 Add Water 1.0 liter 1.0 liter pH [prepared with aqueous ammonia] 4.6 4.2

(Fixing (1) Tank Liquid) A 15:85 (volume ratio) mixture of the above bleaching tank liquid and the following fixing (2) tank liquid. (PH 7.0)

(Fixing Solution (2)) Tank Solution (g) Replenishing Solution (g) Ammonium Sulfite 19 57 Ammonium Thiosulfate Aqueous Solution (700 g / L) 280 mL 840 mL Imidazole 15 45 Ethylenediaminetetraacetic Acid 15 45 Water was added to add 1. 0 liter 1.0 liter pH [prepared with aqueous ammonia and acetic acid] 7.4 7.45

(Stabilizing Solution) Common to Tank Solution and Replenishing Solution (Unit: g) Sodium p-toluenesulfinate 0.03 Polyoxyethylene-p-monononylphenyl ether (Average degree of polymerization: 10) 0.2 1,2-benzo Isothiazolin-3-one 0.05 Ethylenediaminetetraacetic acid disodium salt 0.05 1,2,4-Triazole 1.3 1,4-Bis (1,2,4-triazol-1-ylmethyl) piperazine 0.75 Add water to 1.0 liter pH 8.5

Instead of the 100-fold dilution of the overflow liquid of Example 1, a 100-fold dilution of the overflow liquid (silver concentration is And the dilution procedure was almost the same as in Example 1), and the silver removal treatment was performed in the same manner as in Example 1 in the upward flow. It was possible to process up to 3000BV, but 18
From around 00BV, the silver concentration of the processed liquid is 0.7pp
It became m level, and the silver removal treatment liquid could not be discharged into the sewage in the area where the silver regulation was strict. At this time, 1 mM of hydrosulfite was added to 1 liter of a 100-fold diluted overflow solution under N ₂ (nitrogen) atmosphere,
When processed in the same manner, the silver concentration of the desilvered solution up to 2800 BV was 0.02 ppm. Therefore, the desilvered solution could be discharged into the sewage.

Example 3 A silver ion removing process was performed in the same manner as in Example 1 except that the heavy metal ion removing device shown in FIG. 2 was used instead of the column used in Example 1 above. In the device of FIG.
As indicated by the arrow in the middle, while being pressurized by a pump, a 100-fold dilution of the overflow liquid in Example 1 was transferred from the overflow liquid inlet 1 to the upper surface of the packed bed 4 of the redox solid phase body inside the processing tank 8. It is supplied to the upper void portion 5 in contact therewith. The liquid passes through the inside of the packed bed 4 from the upper surface of the packed bed 4 downward, passes through the perforated plate 7 and reaches the silver sludge pool 3. After that, it is guided to the outlet 6 through the conduit 2 located at the center of the processing tank 8 in the vertical direction, and is supplied to the holding tank. Two kinds of experiments were conducted, a method using the conventional downward flow (A) and a method in which the overflow liquid is passed in a direction completely opposite to the above, that is, an upward flow method (B). However, the packing layer 4 has a capacity of 25 liters and a cross-sectional area of 70.
At 0 cm ² , the filling amount of the redox solid phase body was 20 liters, and SV = 2.

Similar to the first embodiment, the relationship between the throughput (BV) and the space velocity (SV) was evaluated by the methods (A) and (B). As a result, as in the first embodiment, in the method of (A),
When the packed bed 4 is treated with 450 BV, it begins to become clogged. 2
Processing became impossible at the processing of 500 BV. On the other hand, in the method (B), even if the treatment was performed at 3500 BV, the liquid could be passed at a completely constant flow rate, and silver was uniformly deposited on the entire redox solid phase body in the packed bed. Therefore, it is understood that stable treatment is possible by passing the liquid in the upward flow. In addition, when observing the column passed through in a downward flow, the redox solid phase body packed in the upper part of the column (the part of about 30% from the uppermost part) became silver due to the deposition of silver, and had a significantly large size. Was becoming. It is considered that this is the cause of the blockage of the column. Also, the upper part 10 of the packed bed
The percentile changed from gray to black and the redox solid phase at the top 10% did not contribute to silver removal. Therefore, the redox solid phase has a silver ion reduction and deposition ability of 90.
Only%. In addition, in the method of passing the liquid through the above-mentioned upward flow, the gray-black change in the upper 10% of the packed bed did not occur, and all of the redox solid phase bodies worked effectively.
Therefore, it was found that 100% was effectively used in the upward flow, but only 90% of its capacity was used in the downward flow. The overflow liquid of Example 2 was used as the liquid to be treated instead of the 100-fold diluted liquid of the overflow liquid of Example 1 above. Hydrosulfite was added as a pretreatment in the same manner as in Example 2 above, and after the silver removal treatment, the silver in the liquid after treatment was 0.02 ppm when examined by an atomic absorption method.
It was able to be discharged into the sewage.

That is, from the above results, it is possible to prevent the blockage of the column and effectively use the packed redox solid phase body by passing the liquid containing the silver ions in the upward flow.
It turns out that silver can be effectively removed.

Example 4 Silver ions were deposited in the same manner as in Example 1 except that the heavy metal ion removing device shown in FIG. 3 was used in place of the column used in Example 1 above. In the apparatus shown in FIG. 3, as shown by the arrow in FIG.
CN-16X N3X overflow solution at 100
The double dilution liquid is supplied from the overflow liquid inlet 1 to the void portion 5 inside the packed bed. The liquid passes through the inside of the packed bed 4 from the side surface of the packed bed 4 of the redox solid phase body toward the center of the packed bed 4 through the porous membrane 7 and has a conduit part 2 ′ having a liquid passage hole as a hollow part. To reach. After that, it is led to the outlet 6 through the conduit 2 ′ located at the longitudinal center of the packed bed,
Supplied to holding tank. Two types of experiments, the conventional method (A) from the outside to the inside direction, and the method of passing the overflow liquid in the opposite direction from the above, that is, the liquid passage method from the hollow portion to the outside of the packed bed (B) I went.
However, the packed bed 4 has an inner diameter of 15 mm (conduit section 2 ') and an outer diameter of 2
The length of the major axis was 00 mm, the length of the major axis was 200 mm, the filling amount of the redox solid phase body was 6 liters, and SV = 3.

Similar to the first embodiment, the relationship between the throughput (BV) and the space velocity (SV) was evaluated by the methods (A) and (B). As a result, as in the first embodiment, in the method of (A),
When the packed bed 4 was processed at 1500 BV, it was clogged and could hardly be processed. On the other hand, in the method (B), 32
Even when treated with 00BV, the liquid could be passed at a completely constant flow rate. Therefore, it can be seen that stable treatment is possible by passing the liquid through the method (B). Further, when observing the column passed through by the method of (A), the redox solid phase body packed in both side surfaces of the packed bed (a portion of about 20% from the outermost side) becomes gray due to silver deposition, and has a size. Was significantly larger. It is considered that this is the cause of the blockage of the column.

Further, the silver concentration in the liquid after the desilvering treatment of the method of passing the liquid by the method (B) was measured by the atomic absorption method. The silver concentration after removal of silver was 0.07 ppm. Moreover, since the treated liquid had no decomposition of components and the silver concentration was almost 0, it could be reused.

That is, from the above results, it is possible to prevent the blockage of the column and effectively use the packed redox solid phase body by passing the liquid containing silver ions from the inside to the outside of the packed bed. It turns out that the silver can be effectively removed.

Example 5 The same photosensitive material as in Example 1 was used, the following processing solutions and processing methods were used, and an automatic processor equipped with the heavy metal ion removing device shown in FIG. 4 was manufactured by Fuji Photo Film Co., Ltd. Made FNCP4
Processing was carried out using a color negative processing agent CN-16 manufactured by Fuji Photo Film Co., Ltd. using an automatic developing machine for color negative which was modified from OB. In this process, the overflow solution (silver ion concentration;
4600 ppm) of 100-fold diluted solution was continuously fed to the apparatus shown in FIG. In FIG. 4, the treatment tank 8 is a packed bed 1.
4 and the packed bed 15. First, a 100-fold diluted solution of the overflow solution of the fixing solution is supplied to the packed bed 14 of the redox solid phase body from the upper part, and is passed through the packed bed 14 in a downward flow, and is passed through a passage in the lower part of the packed bed 14. It is introduced into the packed bed 15. The packed bed 14 was aerated with deoxygenated air 13 from the bottom of the packed bed 14. Air is passed by the air pump 10 into 10 liters of the waste liquid 11 of the developing solution, which is the overflow solution from the developing bath of the automatic developing machine, filled in the deoxidizing tank 16 to obtain the deoxidized air 13. The deoxygenated air 13 thus obtained is passed through the air supply path 12 to fill the packed bed 1
4 is supplied. The overflow solution of the fixer that has reached the packed bed 15 passes through the packed bed 15 in an upward flow as shown by the arrow, and is discharged from the upper part of the packed bed 15. Here, the packing layers 14 and 15 each have a capacity of 7 liters and a cross-sectional area of 2
At 00 cm ² , the filling amount of the redox solid phase body was 6 liters, and SV = 3.5. Aeration rate of deoxygenated air is 2
It was liter / minute.

Similar to Example 1, the relationship between the throughput (BV) and the space velocity (SV) was evaluated. As a result, in the same manner as in Example 1, this method was able to pass the liquid at a completely constant flow rate even after the treatment of 5000 BV. Therefore, it can be understood that stable treatment is possible by passing the liquid in a downward flow and aerating with deoxygenated air. However, since the silver concentration in the waste liquid is high,
After 800BV, the silver concentration in the treated liquid is 0.6p
It has become pm. Therefore, although the packed bed was not blocked, it was necessary to replace the redox solid phase body every 750 BV. If this condition is satisfied and processed, the silver concentration becomes 0.
It was possible to clear less than 1 ppm, and it was possible to discharge it to sewage.

That is, from the above results, it is possible to prevent the blockage of the column by passing a liquid containing silver ions in a downward flow and aerating with deoxygenated air, and the packed redox solid phase is effective. You can see that it can be effectively used for silver removal.

Example 6 Color negative developing machine FNCP manufactured by Fuji Photo Film Co., Ltd.
An automatic developing machine obtained by modifying the -300 (the overflow liquid from the color developing tank of the developing machine flows into the deoxidizing tank 16 shown in FIG. 4 and appropriately overflows from the deoxidizing tank 16 (not shown). (The structure was modified so that the overflow liquid from the final washing tank of FIG. 4 entered from above the packing layer 14 in FIG. 4), and a developing agent CN-16 processing agent for color negative manufactured by Fuji Photo Film Co., Ltd. The above-mentioned overflow liquid was processed according to FIG. 4 in the same manner as in Example 5 while processing the same photosensitive material as in Example 1. The silver ion concentration in the overflow solution in the above washing tank was 46 ppm. Silver concentration in processing solution up to 2000BV is 0.02pp
However, because of Fe ions (EDTA-Fe (III), 40 ppm as Fe) contained in the overflow solution, the capacity of the redox solid phase body (capable of capturing 300 g / L, up to 6000 BV at 46 ppm) About 1
Only / 3 worked.

Therefore, in FIG. 4, the device for supplying the deoxidized air (the air introduction passage 12 to the deoxidized tank 16) is removed so that the deoxidized air is not aerated. Instead, first, the overflow liquid in the final washing tank is replaced. Was passed through a steel wool column (850 g) manufactured by Eastman Kodak Co. in advance to divalently reduce the existing EDTA-Fe (III), and then the liquid was not exposed to the air and the packed bed in FIG. It was fed above 14 and processed in downflow. Then, up to 6000 BV, the silver concentration in the treatment liquid was 0.02 ppm, which sufficiently cleared the silver wastewater regulation, so that it could be drained as it was.

When the treatment was performed without passing through the steel wool and without deoxidizing treatment, no clogging occurred, but after treating about 100 tons of washing water, the silver concentration of the treating solution was 0.3 ppm. I could not clear the regulation. Further, when the washing water was treated up to about 150 tons, the concentration became 0.7 ppm and the capacity was remarkably lowered. As a result,
After fixing water washing wastewater containing EDTA-Fe salt was previously treated with steel wool to reduce Fe (III) to Fe (II),
By flowing the packed redox solid phase into the filling tank in a downward flow, the packed redox solid phase is mixed with iron (I
II) It can be effectively used without being consumed by ions and can be effectively desilvered.

Example 7 Heavy metal ion removal having four cartridge type packing layers (columns) shown in FIGS. 5 and 6 in place of the heavy metal ion removal apparatus shown in FIG. 4 installed in the automatic processor in Example 5 A metal removal experiment was performed in the same manner as in Example 5 except that the treatment was performed using the apparatus. In this process, the overflow solution of the fixing solution which has reached the running equilibrium was continuously fed to the apparatus shown in FIG. FIG. 5 is a conceptual diagram showing the flow direction of the overflow liquid, and FIG. 6 is a conceptual diagram showing the mutual positional relationship of the packed layers installed in the automatic processor. As shown in FIG. 5, the overflow solution of the above-mentioned fixing solution is introduced from the lower part of the column 21 into the column 2 of the redox solid phase body.
1 under the pressure of a pump, and the column 21 in an upward flow.
The liquid was passed through, and the permeated liquid was allowed to flow out from the upper part of the column 21. Next, the effluent was supplied to the column 22 under pressure by a pump, and the column 22 was passed through in the same manner in the upward flow. Thereafter, in the columns 23 and 24 as well, the liquid was passed through in an upward flow as in the above. Here, each of the columns 21 to 2
4, the overflow liquid is passed, and the deoxidized air obtained by deoxidizing the overflow liquid of the color developer in the form of the deoxidizing tank 13 shown in FIG. 4 is aerated at a rate of 3 liters / minute. did.

As shown in FIG. 6, the columns 21 to 24 are concentrically arranged on the turntable 25, and the turntable is rotated 90 degrees to the right in FIG. 5 with the center of the turntable 25 as the axis of rotation. By doing so, the position of each column is 1 in the direction of rotation.
It is installed so that it is accurately displaced from each other. In addition, each column is a cartridge, and the piping is removable. As a result, the column that has reached the replacement time can be removed at any time and replaced with a new column. In the present embodiment, the first column 21 comes to the replacement time first and is replaced with a new column, and the replaced new column is rotated to the right by rotating the rotary table 25 to the fourth column.
Column as well as column 22,
The column 23 was arranged as the second column, and the column 24 was arranged as the third column. After that, the column was replaced and the column was rearranged in the same manner. Here, columns 21 to
The diameter of 24 was 50 mm and the height was 80 cm, the filling amount of the redox solid phase body was 1.5 liters, and SV = 4.

The time to replace the column was determined by the silver detector 26 attached to the tip of the silver removing device. Here, the silver detector 26 is filled with the redox solid phase body in a transparent container and has a liquid inlet and a liquid outlet. Container volume 20
The fill volume in ml was 19 ml. The silver detector 26 was visually evaluated from the outside. It was replaced when the color of the redox solid phase changed from black to silver gray. The first column 21 has 5
Since it was time to replace the column after time treatment, the column was replaced and the column was rearranged. This treatment was continuously performed for 20 hours, and the silver removal effect, SV value, and silver deposition level of the redox solid phase material in the column were evaluated.

Further, the silver concentration in the waste water after the desilvering treatment by the method of passing through the above system was measured by the atomic absorption method.
The silver concentration after removal of silver was stable at 40 ppm or less during the treatment (0.03 ppm as an average value). Moreover, the treated liquid did not decompose the components and the silver concentration was reduced to 1/100 or less, so that it could be reused. Further, the SV value was stable and hardly changed during the treatment. The redox solid phase in the exchanged column had a large amount of silver deposited on the whole and turned into gray.

That is, from the above results, it is possible to stably process a liquid containing silver ions at a high silver removal level and for a long period of time by connecting the apparatus of the present invention in multiple series.

[0140]

EFFECTS OF THE INVENTION According to the present invention, the ability of the redox solid phase to remove heavy metal ions is fully exerted, and clogging is reduced.
It is possible to provide a heavy metal ion removal method capable of efficiently and selectively removing heavy metal ions at a constant processing rate for a long time, reducing the processing cost, simplifying the processing equipment, and simplifying the operation. , It is possible to efficiently and selectively remove silver ions from photographic processing solutions such as used processing solutions that are generated in large quantities when developing silver halide light-sensitive materials with little clogging and at a constant processing speed for a long time. Another object of the present invention is to provide a method for removing heavy metal ions, which can reduce the processing cost, simplify the processing equipment, and simplify the operation.
On the other hand, it is possible to provide a heavy metal ion removing device capable of performing stable metal removal treatment at a constant treatment rate for a long time and highly capable of removing heavy metal ions. Further, it is possible to provide an automatic developing machine capable of continuously and easily removing heavy metal ions such as silver ions from a processing solution having a fixing ability, which is produced in a large amount when a silver halide light-sensitive material is developed.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a flow rate and a throughput in the method of the present invention.

FIG. 2 is a diagram showing one embodiment of a heavy metal ion removing apparatus relating to the method of the present invention.

FIG. 3 is a diagram showing one embodiment of a heavy metal ion removing apparatus relating to the method of the present invention.

FIG. 4 is a diagram showing one embodiment of a heavy metal ion removing apparatus relating to the method of the present invention.

FIG. 5 is a conceptual diagram showing an aspect of the device of the present invention.

FIG. 6 is a conceptual diagram showing one embodiment of the device of the present invention.

[Explanation of symbols]

 1 overflow inlet 2 conduit 2 conduit with 2'through hole 3 silver sludge reservoir 4 packed bed of redox solid phase 5 upper gap 6 treated liquid outlet 7 porous membrane 8 treatment tank 10 air pump 11 developer Waste liquid 12 Air introduction path 13 Deoxygenated air 14 Packed bed 15 Packed bed 16 Deoxygenation tank 21-24 Column 25 Turntable 26 Silver detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuya Sakurai, 1-2 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Kawasaki Chemical Industry Co., Ltd. No. 2 Kawasaki Chemical Industry Co., Ltd.

Claims (9)

[Claims] 1. A heavy metal ion removing device having a packed bed filled with a redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and fixed on a solid porous carrier, and capable of passing through the packed bed in an upward flow. A method for removing heavy metal ions, which comprises using a solution containing heavy metal ions in an upward flow to selectively remove the heavy metal ions from the solution. 2. A packed layer filled with a redox solid phase body having a compound having a hydroquinone skeleton adsorbed and fixed to a solid porous carrier so as to have a hollow portion, and the hollow portion side and the outer peripheral side of the filled layer. Using a heavy metal ion removing device which is provided with a water-permeable partition wall and which allows liquid to pass from the hollow portion side toward the outer peripheral side, a solution containing heavy metal ions is passed from the hollow portion side to the outer peripheral side of the packed bed. A method for removing heavy metal ions, which comprises liquefying and selectively removing heavy metal ions from the solution. 3. A heavy metal which has a packed bed filled with a redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and immobilized on a solid porous carrier, and an aeration means for deoxygenated gas, and which can flow in a downward flow. A solution containing heavy metal ions is passed through the packed bed in a downward flow while aerating deoxygenated gas from the lower part to the upper part of the packed bed using an ion removing device to selectively select the heavy metal ions from the solution. A method for removing heavy metal ions, characterized in that 4. A heavy metal ion removing device having a packed bed filled with a redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and immobilized on a solid porous carrier and capable of passing in a downward flow, is previously prepared. A solution containing heavy metal ions treated by at least one of treatment with a reducing compound, metal substitution treatment and electrolytic treatment is passed through the packed bed in a downward flow to selectively select heavy metal ions from the solution. A method for removing heavy metal ions, which comprises removing the heavy metal ions. 5. The method for removing heavy metal ions according to claim 1, wherein the redox solid phase body has a particle shape. 6. The solution containing a heavy metal ion is previously treated by at least one of a treatment with a reducing compound, a metal substitution treatment and an electrolytic treatment. The method for removing heavy metal ions according to the item 1. 7. The method for removing heavy metal ions according to claim 1, wherein the solution containing heavy metal ions is a photographic processing solution containing silver ions. 8. The method for removing heavy metal ions according to claim 7, wherein the photographic processing liquid is a photographic processing liquid containing at least a processing liquid having fixing ability. 9. A heavy metal ion removing device having a packed bed filled with a redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and immobilized on a solid porous carrier, and the packed bed can be passed through in an upward flow. The redox solid phase body has a filling layer filled so as to have a hollow portion, water-permeable partition walls are provided on the hollow portion side and the outer peripheral side of the filling layer, and the redox solid phase body is passed from the hollow portion side toward the outer peripheral side. A heavy metal ion removing device capable of liquid flow, a packed bed filled with the redox solid phase body, and an aeration means for deoxidizing gas, and two or more of the heavy metal ion removing devices capable of passing liquid in a downward flow are provided in series. A heavy metal ion removal device characterized by being connected in series or in parallel.