JPS6320095A - Treatment for making waste photographic processing liquid harmless - Google Patents

Abstract

PURPOSE:To efficiently and inexpensively reduce COD without requiring skill for operation and to permit recovery of silver as well by treating a waste photographic processing liquid contg. a specific ratio of COD with an inorg. peroxide. CONSTITUTION:The waste photographic processing liquid which contains the waste liquid of a liquid fixer and/or liquid bleach fixer and, in some cases, contains the other waste liquids of a liquid developer, liquid bleacher, image stabilizing bath or multi-stage counter current rinse water, etc., and has >=1,000mg/l COD is treated with the inorg. peroxide (e.g., hydrogen peroxide). The waste photographic processing liquid preferably contains >=1,000mg/l thiosulfate or >=1,000mg/l iron salt. As a result, the COD can be efficiently decreased even with the concd. waste photographic processing liquid and the cost of the treatment is low. The equipment is simple and no skill is required for the operation. An additional convenience lies in the recovery of the silver in the form of silver sludge as the silver compd. in the waste liquid forms the precipitate having an excellent settling characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for rendering a photographic processing waste solution of color and black and white silver halide photographic materials into mute.

(Prior art) The photographic processing waste liquid of silver halide photographic light-sensitive materials has a high BOD.
(biological oxygen consumption), C0D (chemical oxygen consumption)
As such, it is necessary to reduce the amount of oxygen consumed (hereinafter simply referred to as COD) in order to reduce the load on sewage treatment plants and comply with regulations related to the Sewerage Law.

Many methods have been proposed and implemented to reduce the COD of photographic processing waste liquid. For example, microbial decomposition methods such as activated sludge treatment and trickling filter treatment, electrolytic oxidation methods that electrically oxidize COD contributing components, and ti! ; Injection of IH, hypochlorite or ozone gas! Chemical methods such as elemental oxidative decomposition and ozone oxidative decomposition, adsorption removal methods in which COD-6 components are adsorbed onto activated carbon or organic polymers and removed from the waste liquid, and COD contributing components are removed as residue by heating and evaporating the waste liquid. There are ways to start a novel that requires editing. The effectiveness of each method varies depending on the concentration, amount, composition, etc. of the waste liquid, so one stage of COD reduction suitable for each waste liquid is selected. For example, microbial decomposition methods require large equipment costs and cumbersome biological management, or are the cheapest option for large-scale effluents, while evaporation methods require high thermal energy consumption and This is an effective method when there are disadvantages such as the odor associated with the nozzle emission, or when the amount of waste liquid is small. Does the electrolytic oxidation method have disadvantages in terms of equipment costs, or does it have advantages in automation and labor saving?

For details, please refer to Iwano and Mizusawa's "Environmental Conservation and Wastewater Treatment"
(Basic silver halide photography for photography, Chapter 4.4, Coronasha 19
(Published in 1978), Iwano “Trends in Processing and Pollution Countermeasures” (Advances in Color Photography and Trends in Processing, 3ζt, Monthly 11 J Labosha 1)
974, line 11).

(Problem to be solved by IJ1) In recent years, the concentration of waste liquid has been relatively high, and the amount of liquid has been gradually increasing due to wood-type development processing. The results are not completely satisfactory, and further improvements are desired in terms of decomposition efficiency and equipment cost. Particularly in small-scale photo processing plants, there is a strong desire for an inexpensive C0DK reduction method that can be easily operated on the spot by workers without specialized skills. Furthermore, since it is difficult for small-scale MS factories to have silver recovery equipment, it would be even more valuable if silver recovery could be done at the same time as waste liquid treatment.

The present invention has been developed based on the above-mentioned background: 1. It is possible to efficiently reduce COD even with concentrated photographic processing waste liquid, 2. the processing cost is low, 2. the equipment is simple, and 3. no skill is required for operation. The purpose of this study is to establish a method for processing photographic processing waste liquid that is suitable for processing small volumes of waste liquid discharged from small-scale workshops.

Another object of the present invention is to establish a treatment method that can detoxify waste liquid and at the same time recover silver.

(Means for Solving the Problems) The present inventors have conducted intensive research to overcome the drawbacks of the above-mentioned conventional methods, and as a result, the present inventors have developed a method of treating photographic processing waste liquid of silver halide photographic light-sensitive materials with hydrogen peroxide. The reaction rate when reducing COD depends on the type and concentration of compounds present in the waste liquid. In particular, the presence of thiosulfate in the waste liquid causes the decomposition reaction to proceed faster.
Contrary to expectations based on chemical common sense, the concentration of the 0DR component is higher or the reaction progresses more quickly.In other words, the overflow liquid from each tank is collected as is and is not diluted with washing water. The inventors have discovered that the oxidation reaction is fast, and that the presence of iron aminopolycarbonate-resistant salt in the waste liquid in addition to thiosulfate accelerates the oxidation reaction, and based on these findings, the present invention has been accomplished.

That is, the present invention provides a method for treating a photographic processing waste liquid having a COD of 0,000 layer g/cross or more, which is collected and recovered after being treated with an inorganic peroxide.

The photographic processing waste liquid to which the method of the present invention is applied refers to the waste liquid discharged when a silver halide photographic light-sensitive material is subjected to photographic processing such as development processing, fixed stone processing, bleach-fixing processing, image stabilization processing, washing processing, etc. The photographic processing waste liquid is preferably a fixing waste liquid or a bleach-fixing waste liquid, or other waste liquids, such as a developing waste liquid or a bleaching waste liquid, may be used, and it is reasonable to treat these by mixing them. In the case of a developing solution, it is advantageous for the mute processing if it contains thiosulfate or iron salt, which will be described later.

The composition of the photographic processing waste solution varies depending on the type of processing, but it usually contains thiosulfates and sulfites derived from the fixing solution or white fixing solution, and in some cases @IN agents such as alum.
pH buffering salts such as boric acid (11), acetate and complexing agents such as carboxylic acid derived from bleaching solutions and their iron(III)'A salts, alkali halides, ammonium halides, developing agents derived from developing solutions; Contains preservatives such as hydroxylamine and sulfites, and alkaline agents such as carbonates.

In the present invention, the photographic processing waste liquid is thiosulfate io0
0mg/u or more or iron 11! It is preferable if it contains looOmg/1 or more.

The COD of photographic processing waste liquid to which the method of the present invention is applied is 1000.
Must be 0mg/u or more, 2000mg
/l or more” is more preferable. C to which the method of the present invention can be applied
There is no particular restriction on the upper limit of OD, and it is applicable even to 120,011 g/m. Ordinary fixer and bleach-fixer are C
OD or higher than other liquid baths, depending on how you drink it mg/l
within the range of Therefore, the present invention is suitable for such high CO
In addition to the D value waste liquid, waste liquid from other tanks such as developer solution, bleach solution, and image stabilizing solution is also added, resulting in tens of thousands of units of waste water that do not have running water to wash and drain.
It can be effectively applied to waste liquid of COD of g/kg.

This is particularly advantageous as a waste liquid treatment method for minilabs that produce concentrated waste liquid because the conventional concept of kasumizu-ki-arai is not used.

The processing process for silver salt photographic materials consists of a combination of a development process, a desilvering process, and an auxiliary process. From the development process, color or black and white developing waste liquid is discharged, and from the desilvering process, in the case of processing color photographic materials, bleaching, fixing or bleach-fixing waste liquid;
Also, in black-and-white processing, waste fixing fluid is discharged. The auxiliary process is
Depending on the processing, waste liquids and washing wastewater from the image stabilizing bath, washing bath, adjustment bath, stop bath, etc. are discharged. In the present invention, since it is necessary to include a mixed liquid of these waste liquids as an object to be treated or to have a high COD contributing component, a large amount of washing waste water is excluded from the object to be treated. In addition, waste liquid can generally be included in the treatment target.

There are no particular restrictions on the silver halide photographic materials to be photographically processed, including color development method color photographic materials, silver dye bleaching photographic materials, such as color negative films for motion pictures and general use, color vapors, color rehearsal films, and There are vapor and black and white photographic materials, such as black and white medical X-ray film, photosensitive materials for printing plate making, microfilm, black and white negative film, and photographic paper.

Examples of inorganic peroxides used in the present invention include:
Examples include hydrogen peroxide, persulfates, hypochlorites, ozone, etc., with hydrogen peroxide being particularly preferred.

The method of the present invention is carried out by adding an inorganic peroxide to a photographic processing waste solution, mixing the mixture as appropriate, and then allowing the mixture to stand for a predetermined period of time or stirring.

The inorganic peroxide may act as necessary depending on the COD of the waste liquid. For example, in the case of hydrogen peroxide, the pure hydrogen peroxide is 16/
34 (weight ratio) is available for releasable oxygen, which is consumed to reduce the COD of waste fluid. Hydrogen peroxide has a stoichiometric amount of 0.
It is preferable to use 4 to 1.1 mol. In the case of hydrogen peroxide, any concentration can be used, but in terms of availability, a 3% aqueous solution (commonly known as oxidol) or a 30 to 35% aqueous solution (strong oxytol) is convenient. Furthermore, it is important to ensure safe handling of thick materials, such as those with a thickness of 90%, although they may be troublesome, but of course they should be used with caution. However, in terms of workability and efficiency, a concentration of 30 to 35% is appropriate. If the COD of photographic processing waste liquid is high, 3% oxytol is also effective. In short, it is best to use the hydrogen peroxide solution to the extent that it does not cause any major disadvantage due to dilution.

In the case of IJI that has not yet occurred, the treatment may be carried out at room temperature, or if the mixture is mixed, the entire liquid becomes warm due to the reaction, which tends to promote oxidation. The time required for the reaction is the same as that of normal color development processing waste liquid and black and white development processing waste liquid (both of which are COD tens of thousands of times a day).
l), it only takes about 5 minutes. 1 as necessary
It would be even more reliable if the delay was extended to about 00 minutes.

After adding hydrogen peroxide and stirring if necessary, the resulting precipitate settles and can be separated by decantation, filtration, or a combination thereof. This precipitation separation method has an advantage over the conventional sulfidation sorter method in that the filtrate can be safely discharged.

The waste liquid after treatment is discharged to the sewer after checking the water quality if necessary (normally, once the appropriate conditions are determined, there is no need to check) because the COD IJ is sufficiently low.

(effect) Color intensification method using hydrogen peroxide (West German patent l.

No. 813.920, JP-A-52-13335.

In JP-A-55-127555, etc.), hydrogen peroxide is added to the color developer, but this intensifier has a short lifespan compared to general color developers, or even if the development correction is insufficient. It has sufficient stability to be used as a power fluid. As can be seen from this example, although hydrogen peroxide has a high oxidation potential, it is known that the rate of oxidation reaction against organic substances such as developer waste liquid components is generally slow.

On the other hand, in the unfired Ij1, (a) COD', Xi
'The reaction rate is fast when the concentration of the donor component is high (b) The presence of thiosulfate accelerates the oxidation reaction (c) The iron/aminopolycarboxylic acid complex salt accelerates the reaction. The reason for this is unknown, or it is thought that there is an effect of accelerating the decomposition reaction due to the temperature increase due to the heat of reaction, or that the redox cycle of iron ions plays a catalytic role in reducing COD.

(Effects of the Invention) According to the 11th method, photographic processing waste liquid with high COD can be efficiently treated with simple operation without requiring any manual intervention, and it is especially useful for small-scale photographic processing waste liquid plants, especially with specialized technology. It can be easily carried out by a worker without requiring any additional training.

Furthermore, advantageously, in the method of the present invention, the silver compounds in the waste liquid interact with hydrogen peroxide and thiosulfate to form a precipitate with excellent sedimentation properties, so that complex precipitation such as coagulation and sedimentation is avoided. It is possible to recover silver sludge in the form of silver sludge without any processing operations.

The method of the present invention is suitable for small-scale development locations where it is disadvantageous to have dedicated industrial wastewater treatment equipment, and for development locations in offices and stores where piping is difficult to install.

For example, in addition to waste fluid discharged from small-scale color labs commonly called minilabs as mentioned above, waste fluids used for research experiments at universities and other research institutes, small-scale developing equipment for commercial use, hospitals, and clinics. X-ray processing equipment, developing machines built into office microsystems, printer processors for office microsystems used for microrecording and retrieval of documents, reader printers (e.g. Michael ■, manufactured by Fuji Photo Film Co., Ltd.), color It is possible to detoxify liquid waste from color hard copy printer processors that use vapor, as well as coin machine type processors used to create ID photos.

(Examples) Next, the present invention will be explained in more detail based on examples.

When measuring the COD value in the examples, there is a problem in that although hydrogen peroxide should be considered to have a COD of 0 from an environmental chemical point of view, the COD value comes out as positive due to the measurement method. Therefore, COD full! In the determination, first, the remaining hydrogen peroxide was determined by iodometry, and the hydrogen peroxide was removed by adding sodium sulfite corresponding to that amount, and then the COD was determined.

Alternatively, instead of determining the COD value, the amount of iodine consumed was determined. In the Examples, either or both of these were used depending on the experimental content.

Example 1 Commercially available photographed multilayer color negative film Super HR
-100, HR-Zoo, HR-200, Super HR
-400, HR-400, HR-1600 (hereinafter referred to as two-sided product name, manufactured by Fuji Photo Film Co., Ltd.), VR-100, VR-4
00, VR-1000 (all trade names, manufactured by Eastman Kodak Company).

5R-100, 5R-400, 5R-1600, 5RG
-100 (all trade names, manufactured by Konishiroku Photo Industry Co., Ltd.) were weighed and mixed without particular classification, and sequentially processed using a Fuji Mini Lab 23S color negative film Brosse v-cer.

Table 1 shows the treatment steps, treatment temperature, surface spacing, and replenishment.

Table 1 The processing liquid used in each step is as follows.

(Color developer) Tank liquid Replenisher diethylenetriaminepentaacetic acid 3.0g 3.0g Sodium sulfite 4.0g 4.4g Potassium carbonate
30.0g 32.0g Potassium bromide
1.4g 0.7g Potassium iodide 1.3
■g □Hydroxylamine sulfate I'! ! 2.4g 2.6g 4-(N-ethyl-N-β-hydroxyethylamino)-2-methylaniline sulfate 4.5g Add 5.0g water 1.0 liters 1.0 liters pH 1o, oo
10.20 (Bleach solution) Tank solution Replenisher ethylenecyaminetetraacetic acid ferric ammonium y 100.0g llo, 0g ethylenediaminetetraacetic acid disodium trilam salt 8. Og 10.0g ammonium bromide 150.0g 175.0g ammonium nitrate 8.0g lo, 0g aqueous ammonia (28
%) 7. Od 4.0rllil! Add water, 1.0 liters, 1.0 liters pH 6,05,
7 (Fixer) Tank liquid Replenisher Disodium ethylenediaminetetraacetate 2.0g 4.4g Sodium sulfite 16.0g 7.0g Anunim thiosulfate aqueous solution (70%) 200.0n1 240d Sodium sulfite 4.0g 12.2g Ammonia water □ Add 10.0 surizu
1.0 reading 1.0 sentence pH 7,37,5 (stable liquid) Tank liquid Replenisher formalin O, Olmol 0.015■ [
Fuji Trywell 5.0 5.0 suri Ethylenediaminetetraacetic acid disodium 2501g 250g Add water 1. OR1,0 sentence After the above process, collect the overflow liquid discharged from the processor, add 30% hydrogen peroxide to it, leave it to stand, and after 10 minutes, decant to calculate J:, COD of clear liquid, and I2 consumption. The amount and silver content were measured. The results are shown in Table 2. The content of iron(III) thiosulfate and aminopolycarboxylic acid complex salt in each overflow liquid is as follows:
They were 0.22 mol/l and 15 g/l, respectively.

From the results in the table above, it can be seen that CO
It can be seen that D (decomposition rate was 99.0%) and that silver was also effectively separated and recovered by precipitation.

In this experiment, the reason why an iodine consumption meter was used instead of all COD determination was to take into consideration that if hydrogen peroxide remained, it would affect the COD value.

In addition, the stable baths 1 and 2.3 in this example are three-stage countercurrent type water-saving type washing, and for comparison, baths 1.2 and 2.3 are
An experiment was also conducted in which washing was performed normally with water and the stabilizing bath was used only for the third bath.

When the water volume is 320@/m and 170/m,
The COD in all mixed waste liquids was 8100 tag/1.
The COD was 12,100 mg/l, and when hydrogen peroxide (30%) was added at 57 and 85 times per hour, corresponding to their COD, and left to stand for 10 minutes, analysis was performed.
The values of D were 1400 g/kg and 800 mg/kg, and the decomposition rates were 82% and 94%, respectively. In other words, these two
It was found that there was a large difference in the decomposition rate between the two levels.

Example 2 Prints were printed from color negatives on commercially available color paper (Fuji Color Paper 02 type, manufactured by Fuji Photo Film Co., Ltd.) and processed using a Fuji Mini Lab 233 paper processor. Treatment [about 1 hour] is as shown in Table 3.

Table 3: The rinsing bath was a three-stage wash from rinse 3 to rinse 1.

Details of the processing solutions used in the color development process and bleach-fixing process are as follows.

(Color developer) Tank liquid Replenisher water 800 units 800
dDiethylenetriaminepentavinegar Pl#3.0g 3.0g Sodium sulfite: lOg 2.3g Potassium bromide
0.3g □Potassium carbonate 30.0
g 25.0g N-Ethyl-N- (β-methanesulfonamidoethyl) -3-methyl-4-aminoaniline sulfate 5゜5g 7.5g Hydroxylamine sulfate 4.0g 4.5g Optical brightener (Stilbene system) 1. Add 1.5g of water and adjust the pH with OH at 1.0 or 1.0 times pH 10,8011,20 (bleach-fix solution) Tank solution Replenisher Wood 400 Print 40
0 ammonium thiosulfate (70%) 150n 300
dSodium sulfite 18g 36gEthylenediaminetetraacetic acid iron (m)Ammonium 55g 110gEthylenecyaminetetraacetic acid 5g Add 10g water and mix i, o 1.0 sentencespH 6,756,
30 (Rinse liquid) Tank liquid Replenisher l-Hydroxyethylidene-1,1-diphosphonic acid (6 (1%) 2.5 times 2.5 ml
Ammonia water (28%) 1. aml 1.
Add 8n ice 1.0 sentence 1.0nKO
pH 7.07.0 The replenishment amounts of the color printing solution, color fixing solution, and rinsing solution were 160, 60, and 200, respectively, per rn' of photographic paper.

The overflow waste liquid generated by this treatment was collected in the same amount as the waste liquid, and 30% hydrogen peroxide solution was added to it as shown in Table 4, and 10 minutes later, it was decanted. The hm solution was sampled to measure the amount of iodine consumed and the amount of silver. The results are shown in Table 4.

In addition, thiosulfate and aminocarboxylic acid iron (m)ti! The content of each is 0
．． 1 iol/exchange, 8 g/exchange.

Table 4 (Unit: rag/cross) In this case, the rinsing process following the deep mountain fixing process was changed to a normal type water washing at 42H20/m' in the same manner as in Example 1. There are 150 spaces (
The decomposition rate was 87%), the COD reduction rate was slow, the silver sludge collection efficiency was poor, and the amount of waste liquid was about 20 times larger, making it difficult to handle.

Example 3 The Fushi Mini Lab 23, which is a combination of the negative processor, printer, and paper processor of Examples 1 and 2, was operated under strict control to develop various color negatives of the southern limit and print them on Fushi Color Paper 02 type. To the resulting overflow liquid (COD 23000 rubbing/crossing, aminopolycarboxylic acid iron (m) salt 10 g/liter), 220 ml of 30% hydrogen peroxide solution was added per liquid, and after 10 minutes, the supernatant liquid was decanted. The samples were separated and analyzed, and the results shown in Table 5 were obtained. From the results in the same table, it can be seen that similar to Example 1.2, in the case of the negative and paper combination system, it is possible to process the waste liquid all at once without having to distinguish between sources.

Example 4 The 3-tank rinsing process in Example 2 was changed to a 3-tank rinsing process, and cascade rinsing with io, Q/rn' water distribution was performed. Everything else was the same as in Example 2, and 30% hydrogen peroxide solution was added to the overflow liquid from the developing tank and bleach-fixing tank using the method of Example 2.
Added 30 yn[i/b. The treated effluent achieved reduced iodine consumption and copper removal as shown in Table 6 below.

Example 5 Documents were continuously recorded on microfilm using Michael ■ (trade name, Fuji Photo Film Co., Ltd. tA), a microfilm printer processor used for document management in offices and libraries. This processing liquid tank has the following composition.

(Processing process) Development 10 seconds fixing 10 seconds rinsing (1) 10 seconds rinsing (2) 10 seconds drying 10 seconds (Developing@) Sodium sulfite 80g 1-phenyl-3-pyrazolidone 0.5g hydroquinone
30g sodium carbonate - water 11!47
g Sodium hydroxide 12g Benzotriazole 0.4g Add water
1 sentence (Fixer) Ammonium thiosulfate 135g Boric acid
7g sodium acetate
log sodium metabisulfite
Add 5g of sodium sulfite and 6g of water.After continuous use for 1 month, renew the developer and fixer tank liquid and add 3g to the old armpit.
300 rubs of 0% hydrogen peroxide solution was added per solution, and after standing for 10 minutes, the supernatant liquid was analyzed and the following results were obtained.

“tFIA 5fFWk N m @ E゛, +,, Zo・Procedure 7 City Official Book (Section 9:,) 1 ■ 10 month 31st, 1985 Commissioner of the Patent Office Mr. Kuro Hl Akio 1, Indication of the case 1986 Patent Application No. 164516 2, Title of the invention: Method for detoxifying photographic processing waste liquid 3, Relationship with the person making the amendment case Patent applicant address: 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name (52)
0) Fuji Photo Film Co., Ltd. Representative: Minoru Ohnishi 4, Agent address: 6, 7th floor, Midoriya 2nd Building, 3-7-3 Shinbashi, Minato-ku, Tokyo 105 Subject of amendment: ``Detailed Description of the Invention'' in II. ” Column 7, Contents of amendment (1) 1!1 “As a liquid” on page 16, line 7 of the detailed description
is corrected to "in liquid".

(2) In the same page of the same book, "preferable" will be corrected to "has a large effect on".

(3) In lines 8 to 9 of the same page of the same book, “etc. may be” is changed to “
Is it effective for other people?'' is corrected.

(4) Correct r2000mg/4J on page 7, line 8 of the same book to "r20000g/bun."

(5) "Mini lab" in line 18 on the same page of the same book has been corrected to "water-saving mini lab."

(6) In the 7th line of the 11th page of the same book, ``It has been done, but this'' has been corrected to ``It has been done, this.''

(7) “4mi” in the 12th line from the bottom of page 25 of the same book is changed to “
I will correct it to 8 sentences.

(8) r in the iodine consumption row of Table 6, page 27 of the same book
Correct 601500J to r61500J.

(9) Correct "Michael■" in line 11 from the bottom of the same page of the same book to "Michael■".

(that's all)

Claims (5)

[Claims] (1) COD (chemical oxygen consumption) is 10,000 mg/
1. A method for treating photographic processing waste liquid, which comprises treating the photographic processing waste liquid with an inorganic peroxide. (2) The scope of the patent claims that the photographic processing waste solution includes a waste solution of a fixer and/or a bleach-fix solution, and optionally includes other waste solutions such as a developer, a bleach, an image stabilizing bath, or multi-stage countercurrent washing water. The method for treating photographic processing waste liquid according to item 1. (3) The method for treating photographic processing waste liquid according to claim 1, wherein the inorganic peroxide is hydrogen peroxide. (4) The method for treating photographic processing waste liquid according to claim 1, wherein the photographic processing waste liquid contains thiosulfate. (5) Generating sludge containing silver from photographic processing waste liquid,
A method for treating photographic processing waste liquid according to claim 1, which collects and recovers silver.