JPH0949832A - Silver detector, silver detecting method using it, and method for controlling desilvering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and accurately detect or measure silver by detecting the physical change of a redox solid-phase material adsorbed to a porous carrier having a hydroquinone skeleton caused by silver deposited on the material by reduction. SOLUTION: A silver detector 2 is constituted by filling a transparent container (column) made of glass, etc., and having a port for introducing waste water (containing silver ions) and another port for discharging the waste water with a redox solid-phase material prepared by adsorbing and immobilizing a compound having a hydroquinone skeleton to a porous solid carrier (for example, silicon dioxide, activated carbon, etc.). A reflecting optical photometer 22 is attached to the detector 2 and the silver deposited on the solid-phase material by reduction is detected by converting the physical change (color change) of the solid-phase material caused by the silver into an electric signal and outputting the electric signal. In addition, the silver is detected by visually checking the color change of the solid-phase material caused by the deposited silver without using the photometer 22. Therefore, the management and preparation of a reagent become unnecessary and the silver can be easily detected and measured without requiring skillfulness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to provide a silver detector and a silver detection method which are simple and capable of detecting or measuring silver with high accuracy.

[0002]

2. Description of the Related Art In recent years, from the standpoint of environmental protection, the regulations on the emission standards of silver ions that can be discharged into sewers are becoming stricter year by year. The treatment is performed to reduce it to about 1 ppm or less. As a method for removing silver, various methods such as adsorption removal by an ion exchange resin, reduction removal by electrolysis, metal displacement removal by steel wool, and precipitation removal by a liquid sulfur-containing linear polymer (JP-A-7-14)
No. 8492). Furthermore, the method described in Japanese Patent Application No. 7-47558 proposed by us reduces silver ions by a redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and immobilized on a solid porous carrier to obtain metallic silver. It is removed from the liquid, and this method has a very excellent silver removing ability. Further, such a redox solid phase capable of removing silver requires a replacement of the redox solid phase or regeneration of the silver removing ability by a regenerant because the silver removing ability is lowered when the amount of treatment exceeds the capacity. Become.

It is necessary to detect the presence or absence of deterioration of the silver removing ability quickly and simply in order to meet the strict silver emission standards, and several kinds of silver detectors have been known so far. ing. For example, Japanese Unexamined Patent Publication No. 6-186222 discloses a silver detector and method for detecting the presence or absence of silver in wastewater by utilizing the property that dithizone and silver form a complex to form a color.

The dithizone method described above enhances the detection sensitivity by accumulating a coloring component reactive with silver.

[0005]

However, the above-mentioned dithizone method has a high detection sensitivity by visual observation, and the silver 0.1 pp
The feature is that it can detect m or less, but the stability of dithizone is poor and it is troublesome to prepare a liquid just before use.
It requires time and skill. In addition, there is a method of detecting the silver ion concentration using a silver bromide electrode, or a method of crushing hypo with hydrogen peroxide and then adding a halogen to examine the amount of silver halide precipitates. No one can analyze silver for those who are skilled and have never been analyzed.

Furthermore, there is a need to know the level of silver removal after removing silver, a need to know the amount of silver present before removal of silver, and the silver removal device is automatically operated by detecting silver. Since there is a need for (control), a simple and accurate silver detector and silver detection method are desired. Therefore, the object of the present invention is similar to the dithizone method, which requires no management of reagents, no need for liquid preparation, is easy and easy to operate, requires no skill, and is capable of detecting accumulation of silver due to reactive adsorption of silver. Provided are a silver detector capable of detecting or measuring silver at a level equal to or higher than that of the dithizone method because it detects the accumulation of a color-change component (accumulation of reduced silver), a silver detection method using the same, and a control method of a silver removal device. That is.

[0007]

The above-mentioned objects of the present invention can be achieved by the following constitutions (1) to (7). (1) A transparent container having an inlet and an outlet for a silver ion-containing liquid is 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 silver is added to the redox solid phase body. A silver detector characterized by detecting silver ions by the physical change of the redox solid phase due to the reduction and precipitation of. (2) The silver detector of (1) above is provided with a measuring device that changes a physical change of the redox solid phase due to reduction and deposition of silver onto the redox solid phase into an electric signal, and a change in the electric signal of the measuring device. A silver detector characterized by detecting silver ions by. (3) A silver detection method characterized in that the silver detector of (1) is used to visually detect silver ions for discoloration of the redox solid phase due to reduction and deposition of silver on the redox solid phase. (4) A silver detection method characterized in that the silver detector of (2) above is used to measure an integrated concentration of silver ions in a silver-containing waste liquid by a change in an electric signal of the measuring device. (5) A control method characterized in that the silver removal apparatus is controlled by a change in an electric signal of a measuring device, using the method of (4). (6) The silver detector of (1) or (2) above is provided in parallel with or in series behind the silver removing device for the photographic processing waste liquid, and the silver removing capability of the silver removing device is reduced. A method for detecting silver, which comprises detecting the outflow of silver ions into wastewater. (7) The silver detector of (1) or (2) above is provided in parallel with or in series behind the silver removing device for the photographic processing waste liquid, and the silver removing capability of the silver removing device is reduced. A control method comprising detecting the outflow of silver ions into waste water and controlling the apparatus.

Further, the preferred embodiments are as follows (8) to (1
Shown in 1). (8) A sub-flow channel having a cross-sectional area of 1/10 to 1/1000 of the flow passage is provided in the silver removing device in parallel to the flow passage of the silver removing device for photographic processing waste liquid, and the sub-flow passage is provided with the sub-flow passage. (1) or the silver detector according to (2) above is installed, and an increase in the silver ion concentration in the wastewater due to a decrease in the silver removing ability of the silver removing device is detected by the silver detector. . (9) The silver removing device is provided with a sub-flow passage having a flow passage cross-sectional area of 1/10 to 1/1000 in parallel with the flow passage of the silver removing device for the photographic processing waste liquid, and the sub-flow passage is provided with the sub-flow passage. By installing the silver detector of (1) or (2) above, it is possible to detect the increase in the silver ion concentration in the wastewater due to the reduction of the silver removal capacity of the silver removing device by the silver detector and control the device. Characteristic control method. (10) The silver detector of (1) or (2) above is provided in series in the rear of the flow path of the photographic processing waste liquid silver removing device to reduce the silver removing ability of the silver removing device. A method for detecting silver, which comprises detecting the outflow of silver ions into the accompanying wastewater. (11) The silver detector of (1) or (2) above is provided in series with the silver removal device for photographic processing waste liquid in the rear of the flow path of the device to reduce the silver removal capability of the silver removal device. A control method characterized by detecting the outflow of silver ions into the accompanying wastewater and controlling the device.

[0009]

In the silver detector of the present invention, when the redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and fixed on a solid porous carrier, silver is reduced and deposited, for example, when the porous carrier is activated carbon, Silver is detected by utilizing the change of color from black to gray. Other physical changes,
For example, optical changes (including spectroscopic changes), electromagnetic changes, acoustic and ultrasonic changes, and weight changes can be used. Among them, the preferable physical change is an optical change. The optical change can be seen in reflected light (transmitted light) using ordinary tungsten light, halogen lamp light, laser light, LED light, or the like. In the electromagnetic change, a change in impedance generated from a coil using a high frequency magnetic field may be used, or a non-magnetic metal depositor (ET-305, 308, 110) manufactured by Keyence Corporation may be used. Further, a weight scale can be used for a weight change, and a metal detector (made by OMRON) can be used for a sound wave or an ultrasonic wave change.

The redox solid phase has a property of reducing silver ions to be deposited on the redox solid phase, and before the reduction and precipitation of silver ions, for example, when the porous carrier is activated carbon, it is black. Therefore, when silver ions are reduced and deposited, it becomes gray. The color change may be detected visually, for example, or using a measuring device that changes a physical change such as reflectance into an electric signal.

In the case of visual detection, redox solid phase bodies filled in a transparent container, for example, when the porous carrier is activated carbon, silver is detected by observing the color change from black to gray. As a measuring instrument that changes a physical change into an electric signal, for example, when using a reflection optical photometer, a transparent container filled with a redox solid phase body is further provided with a reflection optical photometer,
Silver is detected by the reflectance value associated with the color change from black to gray due to the deposition of silver on the redox solid phase due to the reduction of silver ions. In this case, the integrated silver concentration can be accurately detected.

Further, the correlation between the value of the absorbance or the gradual change of the color due to the discoloration of the redox solid phase and the product of the concentration of silver in the waste liquid and the amount of the waste liquid treated (total silver amount). By obtaining the relationship, it is possible to easily determine the presence or absence of the silver removing ability of the silver removing device and the duration time, and to estimate the time when the silver removing device needs maintenance, which reduces the work.

Further, by controlling the operation of the desilvering device based on the information of the silver detector, automation and labor can be saved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. The silver detector of the present invention comprises an inlet and an outlet for introducing and discharging a waste liquid, and a filling section for filling a redox solid phase body. The filling part is a transparent container having a light transmittance of 90% or more such as glass, transparent vinyl chloride, and transparent plastic such as acryl when utilizing optical change or spectroscopic change, and its shape is Those having a certain volume such as a cylindrical shape and a rectangular parallelepiped shape are preferable, and examples thereof include a column shape, a column shape, and a prism shape. The size of these filling portions is preferably about 10 to 600 ml in volume, and when used in combination with a silver removing device, it is 1/1 of the channel cross-sectional area of the removing device.
10 to 1/1000 is preferable. Further, the silver detector may be provided with a scale on the surface of the transparent container so as to suit the intended use. This is not the case when using other physical changes.

As shown in FIG. 5, a silver detector for detecting silver by using a reflection optical photometer is 1 / g of a glass column (a).
A reflection optical photometer 22 is installed in parallel to a flat surface 21 obtained by heating with a burner at 10 places and processing so that the upper portion becomes flat as shown in (b). The incident angle from the light source and the reflection angle from the plane 21 are 6 with respect to the horizontal plane.
It is preferably 0 ° or more, and the incident angle and the reflection angle are preferably the same. As the reflective optical photometer 22, any commercially available reflectometer can be used. For example, a handy gross checker manufactured by HORIBA, Ltd. can also be used. Also, if you have a light source and a light receiver, install it in the column,
It can be used if reflection measurement is possible.

As a method for detecting silver by using a silver detector, the methods shown in FIGS. 1 to 4 can be mentioned. Each drawing will be described below. The desilvering device used in each figure is not particularly limited, and all desilvering devices can be used, and the silver detector may or may not have a reflection optical photometer. You can use either of the vessels. FIG.
Is a silver removing device 1 and a silver detector 2 along the flow direction of the waste liquid.
Are sequentially provided in series. According to this method, when the waste liquid flowing into the desilvering device 1 is discharged from the device 1 after the desilvering process, it is confirmed that the silver concentration is below the environmental standard and that the silver removing capability of the desilvering device is detected to be low. can do.

FIG. 2 shows that the flow path of the silver removing apparatus 1 is provided with a sub flow path of 1/10 to 1/1000 of the sectional area of the flow path,
A silver detector is provided in this sub-channel. That is, the silver removing device 1 and the silver detector 2 are provided in parallel. As the usable silver removing apparatus 1, a silver removing apparatus using a redox solid phase body described later, a silver removing apparatus using an ion exchange resin, or a silver removing apparatus in which a column or the like is filled with steel wool is preferable. I can give you. When such parallel installation is performed, data on the correlation between the degree of stepwise color change of the silver detector or the change in the value of the reflection optical photometer due to the color change and the concentration of silver in the waste liquid are obtained in advance. This makes it possible to predict the limit of the silver removal capacity of the silver removing device 1 or to predict the total amount of silver processed from the start of processing. Further, if a reflection photometer is provided, the operation of the desilvering device can be controlled based on this information, so the maintenance of the desilvering device becomes easy and the working efficiency is improved. Furthermore, it eliminates the need to analyze the silver in the liquid after desilvering by the conventionally used fluorescent X-ray or atomic absorption method, and enables real-time silver analysis, and the device is inexpensive and can be installed anywhere in the device. Can be used. Further, it is not necessary to constantly monitor the presence or absence of the silver removing ability during the operation of the silver removing device, and automatic control such as replacement of the silver removing device (for example, replacement of turret) becomes possible. Also, since the duration of silver removal ability can be predicted,
The unexpected event that the concentration of silver in the wastewater exceeds the standard disappears.

FIG. 3 shows a silver removing device 3 arranged in parallel.
1 to 33, the silver detectors 21 to 23 are respectively provided in series behind the waste liquid flow path, and an automatic switching cock 81 for switching the waste liquid flow path is provided. In this method, first, the waste liquid flow path is made to flow into the silver removal device 31 to perform silver removal processing, and the limit of the silver removal capability of the silver removal device 31 is determined by visual observation of the degree of color change of the silver detector 21 or by a reflection optical photometer. Value is detected, and based on the detection data, the automatic switching cock 81 switches the waste liquid flow path to the silver removing device 32 and continues the processing. Similarly, the limit of the silver removing ability of the silver removing device 32 is detected by the silver detector 22, and the flow path is switched to the silver removing device 33 by the automatic switching cock 81. When a plurality of silver removing devices are provided in parallel in this way, it is possible to perform maintenance of the silver removing device having a reduced silver removing ability with a margin.

In FIG. 4, a desilvering device 1a and a silver detector 2a are provided in parallel, and a desilvering device 1b and a silver detector 2b are provided in parallel with the desilvering device 1a and the silver detector 2a. Yes, the flow path is switched by the automatic switching cocks 4a and 4b. By doing so, it is not necessary to constantly monitor the desilvering device by automatically switching the direction of the waste liquid flow path depending on the degree of deflection or discoloration of the stylus of the reflection optical photometer of the silver detector.

The redox solid phase material in which the compound having a hydroquinone skeleton, which can be used in the present invention, is adsorbed and immobilized on a solid porous carrier will be described in detail below.

The redox solid phase material in the present invention refers to 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 the silver thiosulfate complex ion to a zero-valent silver 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) and 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, unless the object of the present invention is hindered,
Although a substituent containing a sulfonic acid group, a sulfonic acid amide group, or a carboxyl group can be adopted as a substituent of these hydroquinone compounds, since the redox solid phase body of the present invention is used in an aqueous solution, it is generally used. Is preferably a reducing compound having a hydrophobic substituent that does not elute in an aqueous solution.

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 view 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, as the solid porous carrier, carbon products such as silicon dioxide, activated carbon, activated carbon fiber, etc., as well as hydrophobically prepared silicon dioxide, carbon particles such as activated carbon, for example, aqueous solution of polytetrafluoroethylene are used. Examples include emulsion processed products (Japanese Patent Laid-Open No. 53-92981), organic synthetic polymer particles, for example, so-called organic synthetic adsorbents such as styrene divinylbenzene copolymers or molded products thereof. In particular, activated carbon is inexpensive and available. 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.

The smaller the particle size of pellets, spheres or crushed charcoal of this porous carrier, the better the contact efficiency, but when packed in a column or the like and continuously treated with an aqueous solution containing silver ions. In general, 0.3 to 2.5 mm is suitable for activated carbon because it has a high liquid resistance. The particle size of the redox solid phase body used in the silver detector is 0.05 to 3 mm in diameter, preferably 0.08 to 1 m.
m.

The size of the redox solid phase material is preferably 1/10 to 1/1000 of the diameter of the column used.

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 (eg, a hydroquinone compound etc.) in the process of carrying a compound having a hydroquinone skeleton, the 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.

As the oxide in this case, for example, compounds corresponding to hydroquinone, naphthohydroquinone and anthrahydroquinone are benzoquinone, naphthoquinone (1,4-naphthoquinone) and anthraquinone (9,10-anthraquinone) and hydrogenated compounds thereof. And a quinone compound having the above-mentioned 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 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 of reducing the supported material 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.

[0044]

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As the organic solvent, any one can be used as long as it can dissolve a required amount of the compound having a hydroquinone skeleton or its oxide, and the solubility and the solubility in the compound having a hydroquinone skeleton or its oxide. 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.

In general, the concentration of the solution of the compound having a hydroquinone skeleton or its oxide is preferably less 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.

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, an aqueous solution 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. As the alkali metal salt,
Examples thereof include sodium salt, potassium salt, lithium salt and the like. As the ammonium salt, usual ammonium (N
H ₄ ⁺ ) salts or quaternary ammonium salts such as tetramethylammonium salt, tetraethylammonium salt, tetrapropylammonium salt or tetrabutylammonium salt. 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.

In the adsorption treatment, in a batch (batch type), a container containing a porous carrier and an aqueous solution of an alkali metal salt of an anthrahydroquinone compound is usually slowly rotated or allowed to stand to adsorb, or a packed column or the like is used for permeation. 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.

The anthrahydroquinone compound used in the present invention is generally an extremely weak acid, and therefore even if the carrier carrying the alkali metal salt of the anthrahydroquinone compound is washed with an aqueous medium such as water, the salt can be treated. Can be hydrolyzed to replace its alkali metal ions 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 metal ion in the obtained support is sufficiently replaced with hydrogen ion. Generally, the amount of the acid is not less than the equivalent of the adsorbed compound, 20
The amount is equal to or less than the equivalent, and an aqueous solution having a concentration of 0.1 to 20% is used.

The method is generally carried out as follows. 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, and at the first time, it is converted into 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 converts silver ions in a silver ion-containing solution such as a used processing solution discharged from a photographic processing step into a zero-valent metallic silver by a redox reaction, and the redox solid phase body is formed on the redox solid phase body. It can be precipitated and recovered.

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

The method of passing the liquid through the column is not particularly limited, and a usual method can be used, and a method such as an upward flowing method or a downward flowing method can be appropriately adopted.

The treatment conditions of the silver ion-containing liquid in the present invention are not particularly limited as long as the pH of the liquid to be treated is influenced by the coexisting anions, but the silver ions are stably present in the aqueous solution. However, usually 4 to 1
A wide range of 2, preferably 4.5 to 11 is adopted.

The concentration of silver ions in the silver ion-containing solution is not particularly limited as long as it is dissolved, and may be low or high. Generally, it is 0.1 to 30000 ppm, preferably 5 to 20000 ppm, and the treatment temperature is generally 10 to 10.
It is performed at 70 ° C, usually 20 ° C to 60 ° C.

Further, in the present invention, at least silver thiosulfate to be recovered is used by using two or more kinds 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 a complex ion and selectively separating it from other metal ions such as iron contained in the treatment liquid can be adopted. For example, it is possible to remove iron trivalent ions and the like in the first half and reduce and remove silver by the second half.

That is, a plurality of packed layers filled with a redox solid phase body in which two or more kinds of compounds having hydroquinone skeletons having different equilibrium redox potentials are supported on a solid porous carrier are filled with equilibrium redox potentials. Arranged in series in ascending order, the used treatment liquid containing at least silver thiosulfate complex ion is brought into contact with the packed layer, and the trivalent ion of coexisting iron is divalent by utilizing the difference in reducing power. It is also possible to use a treatment method comprising effectively capturing the silver thiosulfate complex ion as a zero-valent metal by reducing it in advance. 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.

The redox solid phase material that can be used in the present invention is described in more detail in Japanese Patent Application No. 5-32304.
5, Japanese Patent Application No. 6-280769 and Japanese Patent Application No. 6-29522
It is described in each publication of No. 1.

[0064]

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) 10 ml of a redox solid phase body having a particle size of 0.8 mm was placed in a transparent column having a diameter of 15 mm, and a silver negative concentration unknown (a silver concentration was x ppm) made by Fuji Photo Film Co., Ltd. Flushing wastewater of FNcp-600 (the treating agent was the color negative treating agent CN-16 manufactured by Fuji Photo Film Co., Ltd., and the wastewater of the final washing machine was used) was treated. Flow velocity (S
When V) was treated with 1.7 and the treatment amount (BV) was treated with 60 BV, the color changed from black to gray in a visual state.

From this fact, it is found that there is silver in the washing wastewater, and the maximum amount of redox solid phase is 3 g / 10 ml.
Since it has the ability to reduce the amount of silver, reversely estimate the amount of silver in the washing wastewater as follows. By capturing silver by the redox solid phase on the column tip side (that is, the part near the inlet where the washing wastewater is injected),
The solid phase body gradually changed to gray, but it could be easily confirmed by visual observation when 30 mg of silver ions flowed.

In the above processing, the silver detector is 60 BV
The fact that the color changed from black to gray at. Since the volume of the column is 10 ml, the treated liquid is 6
It becomes 00 ml (60 × 10 = 600 ml). From this, the following relational expression holds. x (mg / liter) × 0.6 (liter) = 30 mg x = 30 / 0.6 = 50 (ppm) That is, the silver concentration in the waste liquid treated by the desilvering device is about 50 p.
Expected to be pm.

As a precaution, in order to confirm the accuracy of the silver detector of the present invention, when the silver concentration in the waste liquid is measured by the atomic absorption method, the silver concentration is 51 ppm, which shows that the accuracy is good.

(B) Further, a graph showing the relationship between the density, the reflectance of the reflection optical photometer, and the density can be prepared as follows, and the silver density of the unclear dark waste liquid can be measured from the graph. . The gloss reflection optical photometer was faced to the column used in (a) as shown in FIG. 6 (a), and the reflected light was measured. The measurement result is shown in the graph of FIG.
The vertical axis of the graph represents the reflectance of reflected light, and the horizontal axis represents 10
The amount of silver adsorbed on the ml column is shown.

That is, from the graph, when the amount of reduced silver is 30 mg / 10 ml with respect to 10 ml of the column, it is about 7%, 30%.
It becomes about 30% at 0 mg / 10 ml and 33% thereafter. In the straight line portion of this slope, the amount of silver reduced and adsorbed is obtained by measuring the reflectance with a reflectometer, and as a result, the processing amount (B
If V) is known, silver in the treated wastewater is required.

For example, the silver concentration xppm different from (a)
The concentration of silver in the wash waste water when the reflectance of exactly 15% is obtained when 100 liters of (x mg / liter) wash waste water is treated is calculated. At this time, 100 mg of silver was reduced and adhered to the surface of the redox solid phase body from FIG.
The total amount of silver passed through the column is 100 mg.

Therefore, x (mg / liter) × 100
(Liter) = 100 (mg) (* x is the concentration of waste mercury), and x = 100/100 = 1 (mg / liter) (1
ppm). Furthermore, in order to confirm the accuracy, the waste liquid was measured for silver by an atomic absorption method to find that it was 0.9 ppm, which was almost the same as the value measured for the silver concentration using the silver detector of the present invention.

(Example 2) 10 ml of redox solid phase body having a particle diameter of 0.2 mm was placed in a transparent column of φ5 mm, and silver 50 p
The pm-containing washing wastewater was treated. When the SV was 1.7 and the throughput was 60 BV, about 1/10 of the column length of 50 cm was changed from black to gray. Column length of 5 for 1800 BV
About 0/3 of 0 cm turned from black to gray. In this way, the gray part gradually grew in the flow velocity direction according to the treatment amount.

When this is calculated in detail, at the column 1/10, (1) the redox solid phase body becomes 1 ml and the maximum is about 300.
This means that mg of silver was reduced and adsorbed. (It can be seen visually from its 1/10 level.) (2) On the other hand, the silver in the treated wastewater will be silver 50 mg / liter x 10 ml x 60 BV = 30 mg, which will appear black to gray by human eyes. . That is, if the column is lengthened, the total amount of silver in the treated wastewater can be roughly analyzed. Further, when the 1800 BV process is performed, the gray portion has advanced to about 1/3 of the column length.

In this case, the silver content in the treated wastewater is 50 mg.
/ Liter × 10 ml × 1800 BV = 900 mg. Approximately 1/3 of the column length is 3 ml of redox solid phase
Thus, silver will be reduced and adsorbed up to 900 mg. 3
If it advances more than cm, it means that the color changed from black to gray while reducing and adsorbing up to the approximate maximum adsorption amount.

That is, in the beginning, the forward part where the color changes from black to gray advances in a somewhat ambiguous manner, but it is 3 at φ5 mm.
It can be seen that when the distance exceeds cm, the color changes from black to gray, which is almost the same as the theory. Therefore, by examining the length of the discoloration from black to gray, the total amount of silver treated with wastewater can be predicted. If this can be predicted, the silver concentration in the waste liquid can be predicted if the processed amount is obtained with a meter or a measuring cup.

From this, it is possible to predict the time when the maintenance of the silver removing device should be performed by previously correlating the correlation between the silver concentration and the amount of processing and the degree of advance of the gray portion in the flow velocity direction. Becomes In other words, if this silver depositor is installed in front of a silver removal device (here, an electrolysis device is used) as shown in FIG. 1, if the column 1 also turns from black to gray, it means that the silver removal device has failed. Become.

When the desilvering device is a column packed with redox solid phase bodies, the silver removing capability of the column desilvering device is lost. Fig. 2 (Here, Japanese Patent Application No. 7-4755 is used as a silver removing device.
When the Noredox solid phase bodies described in No. 8 are packed in a column and used in parallel as shown in (1), 1/100 of the wastewater flows parallel to the column as a silver detector. If the redox solid phase of the column as a silver detector is set to 1/100 of the redox solid phase of the desilvering device, when the entire column as the silver detector becomes gray, the desilvering is performed. This is when the redox solid phase of the device is out of processing capacity. Therefore, the redox solid phase body of the desilvering device is exchanged immediately before the column as the silver detector becomes entirely gray. By doing this, silver will not exceed the specified value even if the government agency suddenly checks the wastewater.

As shown in FIG.
1000 is made to flow in parallel to the column as a silver detector, and the redox solid phase body of the column as a silver detector is made 1/100 with respect to the redox solid phase body of the silver removal device. Compared with this, when up to 1/10 of the length of the column as the silver detector becomes gray, the redox solid phase body of the desilvering device is replaced.

That is, the maintenance (replacement) time of the silver removal device can be predicted.

(Example 3) 1 of the glass column of Example 2
At the position of / 10, it was heated with a burner as shown in FIG. A reflection optical photometer was installed so as to be parallel to this plane. The reflection optical photometer used is a handy type gloss checker IG-320 /
Model 310; incident angle 60 °, light receiving angle 60 °, light source LED (8
80 nm) Photodetector Silicon diode manufactured by Horiba.

At first, the value of the reflection optical meter was almost zero, but the needle shook out after about 6000 BV water flow treatment. By combining this information with the flow meter, the silver accumulated at 1/10 of the silver detector can be read. Specifically, the needle was shaken when 6000 BV of wash water containing 5 ppm of silver was passed. That is, it was expected that the needle would shake when 30 mg of silver was reduced and precipitated per 1 ml of the column as a silver detector, but in reality, since the silver was thin, it was deposited according to the theory of the maximum reduced deposition amount, and thus it worked as calculated. It will be.

That is, silver 5 mg / liter × 10 ml × 6
00BV = silver 30 mg / redox solid phase body 1 ml. From this, it can be seen that when the redox column is used as a silver detector, silver is reduced and deposited accurately (according to theory) by using as thin a silver-containing wastewater as possible.
Further, when using a silver-containing wastewater having a high silver concentration, it is important to make the flowing speed as slow as possible (to reduce SV). Alternatively, if the column is made as long as possible and the detection part is installed at a place far from the inlet, reduction precipitation according to the theory will occur. Moreover, by doing so, the change from black to gray increases, so that the cheapest reflection optical photometer can be used.

It is also possible to flatten the entire upper surface of the glass column of Example 2 and move the photometer on the glass column to perform photometry. That is, when the photometer was moved to the position of 2/10, the needle was shaken when further processed at 6000 BV. If the photometer is placed 2/10 from the beginning, the needle will shake at about 12000 BV.

When the same procedure was repeated thereafter, the needle shook in the same manner.
Therefore, (desired amount of treated wastewater) * (silver concentration) = constant silver can be removed by previously setting a photometer at that position when silver is removed.

Example 4 The concentration of the liquid to be treated can be estimated by measuring the treatment amount and the gray column length as in Example 2. For example, if the 50 cm column is all gray when processing 1 liter,
The silver reduced and precipitated by the redox solid phase at this time is 3000 mg. From this, assuming that the silver concentration in the waste liquid is xmg / liter (xppm) and the treatment amount is 1 liter, the column length y of the redox solid phase body is now y.
If it becomes gray at the position of / 10, the silver reduced and attached during that period is 3000 mg × (y / 10).

That is, x mg / liter × 1 liter = 3000 mg × (y /
10) x = 300y. From this, when the length of y is obtained, the concentration (ppm) of silver in the waste liquid can be obtained.

* Y = distance from column tip x = silver concentration in wastewater ppm = mg / liter

(Preliminary Experiment) 10 g of redox solid phase material was placed in 1 liter of silver-containing waste liquid, and after stirring with a stirrer, 30
After allowing to stand for a minute, after standing, all of these liquids were poured onto a filter paper to separate the redox solid phase body by filtration, and after drying, the surface reflection was measured with the reflection optical photometer of Example 3. At this time, the amount of reflected light (precipitation value) was measured by changing the concentration of silver in the waste water. The measured values of the silver concentration in the waste liquid and the reflection concentration are summarized below. Silver concentration in the waste liquid Reflected light metering (light intensity relative value) 0.03ppm 0.03 0.10ppm 0.07 0.30ppm 0.13 1.00ppm 0.25 3.00ppm 0.40 10.00ppm 0.42 From the data, the amount of the reflected light of the redox solid phase body is approximately temporarily increased at 0.03 to 3.0 ppm of silver, and quantification is also observed. Thus, when used successfully, the redox solid phase has the potential to be used in silver detectors.

[0089]

EFFECTS OF THE INVENTION The present invention eliminates the need for reagent management, liquid preparation,
Provided are a silver detector and a silver measuring method which are easy and easy to operate, require no skill, and can detect the accumulation of silver due to reductive precipitation and detect or measure silver at a level equal to or higher than that of the dithizone method. be able to.

Furthermore, the following (1) and (2) can be predicted. That is, the silver-capturing ability (zmg) of the redox solid phase substance in the column is unique and constant, and the silver concentration (xx) in the waste liquid (x
(mg / liter), and the treated amount (y liter), this product corresponds to the silver capturing ability of the redox solid phase. z = x (mg / liter) × y (liter) Therefore, as shown in (i) and (b) of Example 1, if the treated amount y liter is known, the silver concentration in the waste liquid can be obtained.

X = z / y (mg / liter) From this fact, the silver content of the water to be treated can be predicted by observing (1) the treatment amount (treatment amount passing through the silver detector) and the color change of the column. (2) Since the total amount of reduced silver is known, if this is combined with a silver removing device, a failure or deterioration of the silver removing device can be detected. If silver detectors are used in parallel, it is possible to predict when the desilvering device will be damaged.

[Brief description of drawings]

FIG. 1 illustrates one embodiment showing a preferred method of using a silver detector.

FIG. 2 illustrates one embodiment showing a preferred method of using a silver detector.

FIG. 3 illustrates one embodiment showing a preferred method of using a silver detector.

FIG. 4 illustrates one embodiment showing a preferred method of using a silver detector.

FIG. 5 is a preferred embodiment in which a reflection optical photometer is installed in the silver detector used in the example.

FIG. 6 is a graph showing the reflectance of reflected light and the amount of silver deposited on a silver detector in the example.

[Explanation of symbols]

 1 Silver removal device 2 Silver detector 22 Reflective optical photometer 81 Automatic switching cock

Front page continued (72) Inventor Tatsuya Sakurai 1-2, Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Kawasaki Chemical Industry Co., Ltd. Kawasaki Chemical Industry Co., Ltd.

Claims (7)

[Claims] 1. A redox solid phase body in which a compound having a hydroquinone skeleton is adsorbed and fixed on a solid porous carrier is filled in a transparent container having an inlet and an outlet for a silver ion-containing solution, and a redox solid phase body is formed. A silver detector characterized by detecting silver ions by the physical change of the redox solid phase body due to the reductive precipitation of silver. 2. The silver detector according to claim 1 is provided with a measuring device for converting a physical change of the redox solid phase due to reductive deposition of silver onto the redox solid phase into an electric signal, A silver detector characterized by detecting silver ions by changes. 3. A silver detection method, which comprises using the silver detector of claim 1 to visually detect silver ions for discoloration of the redox solid phase due to reductive deposition of silver on the redox solid phase. 4. A silver detection method comprising using the silver detector according to claim 2 and measuring an integrated concentration of silver ions in a silver-containing waste liquid by a change in an electric signal of the measuring device. 5. A method for controlling a desilvering device according to claim 4, wherein the desilvering device is controlled by a change in an electric signal of a measuring instrument. 6. A silver detector according to claim 1 or 2 is provided in parallel with or in series to the silver removing device for photographic processing waste liquid, and the silver removing capability of the silver removing device is lowered. A method for detecting silver, which comprises detecting the outflow of silver ions into wastewater. 7. A silver detector according to claim 1 or 2 is provided in parallel with or in series to the silver removing device for photographic processing waste liquid, and the silver removing capability of the silver removing device is reduced. A control method comprising detecting the outflow of silver ions into waste water and controlling the apparatus.