JPH04268000A - Treatment method for photograph treatment waste-water - Google Patents

Abstract

PURPOSE:To keep biological treatment stable for a long duration even in the case of high concentration and make waste-water harmless at high treatment efficiency by carrying out discomposition in aerobic condition with active sludge containing photosynthesis bacteria. CONSTITUTION:Photosynthesis bacteria is cultured in a fundamental culture medium under anaerobic condition and then mixed with active sludge and aerated. Raw waste-water is added to the resulting active sludge, the sludge together with treated water is transferred to a precipitation tank, and the supernatant liquid and the sludge are separated. The precipitated sludge is returned to an aeration tank and the supernatant liquid is discharged. In this way, aerobic discomposition is carried out by the active sludge containing photosynthesis bacteria and thus wast-water containing COD in high concentration can be treated stably and efficiently.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to a method for detoxifying photographic processing waste fluid, and more specifically to a method for biologically treating photographic processing waste fluid containing high concentrations of reducing inorganic sulfur compounds and organic compounds. It is related to.

0002

[Prior Art] Photographic processing waste liquid contains many types of inorganic and organic compounds and is highly concentrated, giving high COD (chemical oxygen demand) and BOD (biological oxygen demand). , cannot be discharged into rivers as is. Therefore, many purification treatment methods have been studied.

[0003] Conventionally, the activated sludge method (Japanese Patent Publication No. 55-49559, Japanese Patent Application Laid-open No. 1983-1983) has been used as a method for treating photographic processing waste liquid.
2353, etc.), evaporation method (Japanese Patent Application Laid-Open No. 49-89347)
(Japanese Patent Publication No. 56-33996, etc.), electrolytic oxidation method (Japanese Patent Publication No. 49-119458, Japanese Patent Publication No. 53-43478, etc.), ion exchange method (Japanese Patent Publication No. 51-37704, Japanese Patent Publication No. 53-383, etc.) ), reverse osmosis method (JP-A-50-2246
No. 3, etc.), chemical treatment method (JP-A-53-12152,
Japanese Patent Publication No. 57-37396, Japanese Patent Publication No. 61-241746
(e.g.) are known, but each has the following drawbacks.

[0004] The electrolytic oxidation method requires high equipment costs and the electrodes are easily contaminated. The ion exchange method and reverse osmosis method can quickly become unusable when dealing with concentrated photographic waste liquids because the resin and membrane become fatigued. Furthermore, chemical treatment methods using hydrogen peroxide, persulfates, perhalogenates, halous acid, and hypohalous acid are known, but none of these treatments can be used for photographic waste liquid with a high COD concentration. It is extremely inefficient and always results in the use of more drugs than necessary.

[0005] Regarding the activated sludge method, the initial BOD of waste liquid
, sufficient treatment cannot be achieved unless the COD value is adjusted to 3000 ppm or less, and since photographic processing waste liquid contains high concentrations of inorganic and organic compounds, it requires dilution with a large amount of water, and the capacity of the equipment is limited. The drawback is that it becomes too large.

A method of oxidizing thiosulfate-containing liquids using sulfur-oxidizing bacteria is also known, but this treatment method can only be applied to photographic fixing waste liquid, which is a part of photographic processing waste liquid.

Furthermore, a method for treating photographic processing waste liquid using photosynthetic bacteria in an anaerobic manner is disclosed in Japanese Patent Application Laid-Open No. 52-109759,
There is a method disclosed in Japanese Patent Application Laid-Open No. 52-145330. This method requires a large amount of light energy and is disadvantageous in terms of cost.Since it is processed anaerobically, the sulfur component in the photographic waste liquid turns into hydrogen sulfide, and organic acids are generated, resulting in bad odors. It has the disadvantage of being

[0008]

[Problems to be Solved by the Invention] In recent years, as demands for environmental protection have increased, the photographic processing waste liquid technology described above is insufficient, and further improvements are strongly desired. Therefore, an object of the present invention is to provide a method that can be made harmless at low cost and at a high processing rate. Another object is to provide a method that allows biological treatment to maintain a stable state for a long period of time even at high concentrations. Another object is to provide a method that can be rendered harmless at a high processing rate without emitting harmful gases or bad odors.

[0009]

[Means for Solving the Problems] As a result of various studies, the present inventors have found that the object of the present invention can be effectively achieved by using the following means. That is, a method in which photographic processing waste liquid is aerobically decomposed using activated sludge containing photosynthetic bacteria.

The present invention will be explained in detail below.

The photosynthetic bacteria used in the present invention are purple non-sulfur bacteria, such as Rhodobacter capsulatus (Rh
Rhodobacter capsulatus) Rhodobacter sphaeroides
sphaeroides). In the present invention, not only these bacteria but also other photosynthetic bacteria can be used.

[0012] Photosynthetic bacteria can be cultured in the basic medium shown below by irradiating light anaerobically.
[Basic medium] KH2 PO
4
0.8g Mg
SO4 ・7H2 O
0.2g Na
Cl
0.1g
CaCl2 ・6H2 O
0.05g
NH4Cl
0.5g
Na-propionte
5.0g
NaHCO3
0.5g
Yeast extract
0.1g
add water
1 liter
pH
6.8-7.0

00
13] Typical light sources for culturing photosynthetic bacteria include sunlight, tungsten incandescent lamps, halogen-filled tungsten incandescent lamps, xenon discharge lamps, and arc discharge lamps.
Those with long wavelengths are preferred.

The energy density of the irradiated light is approximately 1 μw/
cm3 or more, preferably about 100μw/
cm3 to about 1 W/cm3.

Activated sludge is produced by using sewage sludge, industrial wastewater treatment sludge, or other sludge as a seed sludge, and adding reducing inorganic sulfur compounds, such as thiosulfates, sulfites, organic compounds, and nutrients, such as phosphates, to the seed sludge. A solution containing magnesium, calcium, etc. is provided as a nutrient source, and the plants are grown under aerobic conditions. Note that the pH at this time is preferably 6 to 8. The bacteria that make up activated sludge are mainly bacteria and ciliates, including the genus Zoogloea and Pseudomonas.
Genus, Achromobacter Genus, Flavob
There are the genus acterium.

[0016] The thiosulfate root (S2O3
2-) is decomposed into sulfuric acid radicals (SO42-), and most organic compounds are decomposed into carbon dioxide.
The above seed sludge contains a group of sulfur-oxidizing bacteria [Thiobacillus thioparus].
), Thiobacillus neapolitanius (Thioba
cillus neapolitans), Thiobacillus novelus
The activated sludge is dominated by

[0017] It is preferable that the photosynthetic bacteria be mixed with activated sludge in which sulfur-oxidizing bacteria are the dominant species, and aeration (hereinafter referred to as air aeration) be continued for 1 to 2 days without providing a nutrient source. Furthermore, p at this time
H is preferably 6 to 8. The pH may be adjusted using dilute sulfuric acid or an alkali (eg, sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate). When air aeration is carried out in this manner, photosynthetic bacteria are incorporated into activated sludge flocs in which sulfur-oxidizing bacteria are the dominant species. Here, flocs are aggregates of bacteria. Therefore, in the present invention, activated sludge is preferably a sludge in which sulfur-oxidizing bacteria are the dominant species.

[0018] Furthermore, it is preferable to add phosphorus, magnesium, calcium, etc. as nutrients to the waste liquid. Phosphorus is added to phosphates (e.g., KH2PO4, K2HPO4, NaH2PO) to contain 0.5% to 3% of the COD value.
It is preferable to perform the treatment after adding 4.2H2O, Na2HPO4), as this stabilizes the biota.

The treatment temperature may be any temperature at which photosynthetic bacteria are biologically active, and is approximately 0° to 45°, preferably 5°
° to 40 °C, more preferably 10 °C to 40 °C.

Next, the processing steps of the present invention will be explained with reference to the drawings. FIG. 1 shows an example of the processing steps. First, photosynthetic bacteria are cultured in a basic medium under anaerobic light conditions, and then mixed with activated sludge and subjected to air aeration for one day. Light irradiation is performed by sunlight during the day and by tungsten incandescent lamps, etc. at night. Raw wastewater is added to the activated sludge. At this time, as nutritional salts, phosphoric acid is added in an amount of about 3% based on COD, and small amounts of Mg and Ca are added. Treatment is at pH 6
It is preferable to carry out the reaction between 8 and 8 in order to preserve the biota, and the adjustment is carried out using dilute sulfuric acid or sodium hydroxide solution. The residence time of the waste liquid is approximately 2 days.The treated water and sludge are transferred to a sedimentation tank, and the supernatant liquid and sludge are separated. The settled sludge is returned to the aeration tank. This supernatant liquid is discharged, and it is preferable to further perform activated sludge treatment on this supernatant liquid, since this improves the efficiency of removing organic matter. It is also desirable to decolorize by treatment with activated carbon or ozone.

[0021] Through the activated sludge treatment in which the photosynthetic bacteria in the above treatment process are dominated by sulfur-oxidizing bacteria, reducing sulfur compounds such as thiosulfates are completely converted to sulfate groups, and organic compounds are also purified by 70 to 85%. It was found that the purification efficiency improved with further acclimatization.

The photographic processing waste liquid applied to the present invention has photographic processing liquid components as its main components.
In addition to materials added to photographic processing solutions, reaction products such as oxidized developing agents, sulfates, and halides produced during photographic processing, and trace amounts of gelatin dissolved from photosensitive materials,
Contains ingredients such as surfactants.

Photographic processing solutions include color processing solutions, black and white processing solutions, reducing solutions used in plate-making operations, and development processing tank cleaning solutions. Examples include image stabilizing liquid.

In general, photographic processing waste liquids include those containing a large amount of silver ions eluted from silver halide photographic light-sensitive materials into the processing liquid for the purpose of recovering silver, which is a valuable metal, and those containing a large amount of silver ions (silver-containing type) and those containing other types (silver-containing type). It is classified as non-silver-containing type and recovered. The used processing waste liquid from the fixing process in black and white development, the bleaching process in color development, the fixing process and the bleach-fixing process is classified as silver-containing, and the used processing waste liquid from the development process in color development and black and white development is non-silver-containing. It is classified as a system. The used processing waste liquid from the water washing treatment and stabilization treatment in color development and black-and-white development is classified into silver-containing type or non-silver-containing type depending on the concentration of silver ions contained therein. In the present invention, silver-containing waste liquid subjected to silver recovery treatment is classified as silver recovery waste liquid, and non-silver-containing waste liquid is classified as developing system waste liquid.

[0025] Methods for recovering silver include a method in which silver is precipitated using electrolysis, and a method in which steel wool is introduced and silver in the solution is precipitated on the steel wool by utilizing the difference in ionization tendency between iron and silver. Any method can be used, such as a method in which silver is precipitated as silver sulfide by adding a sodium sulfide solution or a method in which silver is precipitated as silver sulfide.

The silver recovery waste liquid contains a large amount of ammonium thiosulfate and sodium sulfite, which are reducing inorganic sulfur compounds. The developing system waste liquid contains a large amount of a highly concentrated organic compound, for example, a developing agent such as hydroquinone.

The main components and concentration range of the silver recovery system waste liquid to be treated in the present invention are ammonium thiosulfate 20~
150g/l, sodium sulfite 1-10g/l, acetic acid 0-50g/l, EDTA iron ammonium 2-20g/l
One example is ammonium thiosulfate, about 9
0g/l, sodium sulfite approx. 5g/l, acetic acid approx. 15g
/l, EDTA iron ammonium about 7g/l.

[0028] The main components and their concentration ranges in the waste liquid of the developer system used are: 4 to 30 g/l of hydroquinone, 1 to 15 g/l of color developing agent, and 0 to 5 g/l of benzyl alcohol.
g/l, hydroxylamine 0-4 g/l, acetic acid 0-4
g/l, 5-sulfosalicylic acid 0 to 20 g/l,
For example, hydroquinone is about 11 g/l, color developing agent is about 3 g/l, and benzyl alcohol is about 2 g/l.
, hydroxylamine about 1 g/l, acetic acid about 1 g/l, 5
- about 7 g/l of sulfosalicylic acid.

The concentration values of these components are representative values, and the application of the present invention is not limited to waste liquids having these values.

The present invention can be applied to both silver recovery system waste liquid and developing system waste liquid, and is particularly effective in a waste liquid that is a mixture of these. is preferred.

Depending on the salt concentration of the mixed waste liquid, it is preferable to dilute it 3 to 10 times so that the inorganic salt concentration is 3% or less, but in the case of the present invention, the effect is maximized at a high concentration, so the COD value is Application to wastewater of 3000 to 10000 ppm is desirable.

The color developer usually contains an aromatic primary amine color developing agent as a main component. It is mainly p-phenylenediamine derivatives, typical examples being N,N
-diethyl-p-phenylenediamine, 2-amino-5
-diethylaminotoluene, 2-methyl-4-[N-ethyl-N-(β-hydroxyethyl)amino]aniline, N-ethyl-N-(β-methanesulfonamidoethyl)-3-methyl-4-aminoaniline It is. Further, these p-phenylenediamine derivatives are salts such as sulfate, hydrochloride, sulfite, and p-toluenesulfonate. The content of the aromatic primary amine developing agent ranges from about 0.5 g to about 10 g per liter of developer solution.

In addition, 1-phenyl-3 is contained in the black and white developer.
-pyrazolidone, 1-phenyl-4-hydroxymethyl-4-methyl-3-pyrazolidone, N-methyl-p-aminophenol and its sulfate, hydroquinone and its sulfonate, and the like.

Color and black and white developers contain preservatives such as
It usually contains sulfites such as sodium sulfite, potassium sulfite, sodium bisulfite, potassium bisulfite, sodium metasulfite, potassium metasulfite, and carbonyl sulfite adducts, and the content of these is 0g per liter of developer. ~5g.

Color and black and white developers contain various hydroxylamines as preservatives. Both substituted and unsubstituted hydroxylamines can be used. Substituted products include those in which the nitrogen atom of hydroxyalumines is substituted with a lower alkyl group, especially N substituted with two alkyl groups (for example, carbon number 1 to 3).
, N-dialkyl-substituted hydroxylamines. Also used are combinations of N,N-dialkyl substituted hydroxylamines and alkanolamines such as triethanolamine. The content of hydroxylamines is 0 to 5 g per liter of developer.

Color and black and white developers have a pH of 9-12. Various buffers are used to maintain the above pH. Buffers include carbonate, phosphate, borate, tetraborate, hydroxybenzoate, glycine salt, N
, N-dimethylglycine salt, leucine salt, norleucine salt, guanine salt, 3,4-dihydroxyphenylalanine salt, alanine salt, aminobutyrate, 2-amino-2-methyl-1,3-propanediol salt, valine salt, Proline salts, trishydrocyaminomethane salts, lysine salts, etc. can be used. In particular, carbonates, phosphates, tetraborates, and hydroxybenzoates have excellent solubility and buffering ability in the high pH range of pH 9.0 or higher, and even when added to the developer, they do not adversely affect photographic performance. These buffering agents are often used because they have the advantages of being free from fog (fogging, etc.) and being inexpensive. The amount of the buffer added to the developer is usually 0.1 mol to 1 mol per liter of the developer.

[0037] In addition, various chelating agents are added to the developer to prevent precipitation of calcium or magnesium, or to improve the stability of the developer. Typical examples include nitrilotriacetic acid, diethylenetriaminepentaacetic acid, nitrilo-N,N,N-trimerimethylenephosphonic acid, ethylenediamine-N,N,N',N'-tetramethylenephosphonic acid, and 1,3-diamino-2 -propanoltetraacetic acid, transcyclohexanediaminetetraacetic acid, 1,3-diaminopropanetetraacetic acid, 2-phosphonobutane-1,2,
4-tricarboxylic acid, 1-hydroxyethylidene-1,
Examples include 1-diphosphonic acid. Two or more of these chelating agents may be used in combination, if necessary.

The developer contains various development accelerators. As the development accelerator, thioether compounds, p-phenylenediamine compounds, quaternary ammonium salts, p-
These include amine phenols, amine compounds, polyalkylene oxides, 1-phenyl-3-pyrazolidones, hydrazines, meso ion type compounds, thione type compounds, imidazoles, and the like.

Many color developers for color paper are
It contains alkylene glycols and benzyl alcohols along with the above color developing agents, sulfites, hydroxylamine salts, carbonates, water softeners, and the like. On the other hand, color negative developers, color positive developers, and some color paper developers do not contain these alcohols.

[0040]Although the developer often contains bromide ions for the purpose of preventing fogging, it is also possible to use a developer that does not contain bromide ions for photosensitive materials containing silver chloride as the main ingredient. be. In addition, N is used as an inorganic antifoggant.
It may contain compounds that provide chloride ions, such as aCl and KCl. They also often contain various organic antifoggants. The organic antifoggant may contain, for example, adenines, benzimidazoles, benztriazoles, and tetrazoles. The content of these antifoggants is 0.010 g to 2 g per liter of developer. These antifoggants include those that are eluted from the photosensitive material during processing and accumulate in the developer. In particular, in the present invention, the total halogen ion concentration such as bromide ions and chloride ions as described above is
Even waste liquid with a concentration of 1 mmol or more per liter can be effectively treated. This is particularly effective when the bromide ion concentration is 1 mmol or more per liter of the mixed solution.

The developing solution also contains various surfactants such as alkylsulfonic acids, arylphosphonic acids, fatty acid carboxylic acids, and aromatic carboxylic acids.

In black-and-white photographic processing, a fixing process is performed after the developing process. In color photographic processing, a bleaching process is usually performed between the developing process and the fixing process, and the bleaching process is sometimes performed simultaneously with the fixing process by bleach-fixing (Brix). The bleaching solution contains iron (II) as an oxidizing agent.
I) or Co(III) EDTA, diethylenetriaminepentaacetic acid, nitrilotriacetic acid, 1,3-diamino-
Contains propanetetraacetate, phosphonocarboxylate, persulfate, quinones, etc. In addition, it may contain appropriate rehalogenating agents such as alkali bromide and ammonium bromide, borates, carbonates, and nitrates. Fixers and bleach-fix solutions usually contain thiosulfates (sodium salts, ammonium salts), acetates, borates, ammonium or potassium alum sulfites.

In the processing of silver halide photographic materials, it is common to perform a fixing process or a bleach-fixing process, followed by washing with water and/or a stabilizing process. In the water washing process, problems such as bacteria breeding in the processing tank and the resulting floating substances adhering to the photosensitive material may occur. As a solution to this problem, calcium ions, as described in Japanese Patent Application Laid-Open No. 131632/1982, are added to the washing water.
A method of reducing magnesium ions can be used. In addition, chlorine-based disinfectants such as isothiazolone compounds, cyabendazole, chlorinated sodium isocyanurate, and other benzotriazoles described in JP-A No. 57-8542, "Chemistry of Antibacterial and Antifungal Agents" by Hiroshi Horiguchi Disinfectants described in ``Sterilization, sterilization, and anti-mildew technology of microorganisms'' published by the Society of Hygienic Engineers, and ``Encyclopedia of antibacterial and anti-fungal agents'' published by the Japanese Society of Antibacterial and Mildew Prevention may also be used.

[0044] Following such washing treatment with washing water, or instead of washing treatment, stabilization treatment using a stabilizing bath may be performed. An example thereof is a stabilizing bath containing formalin and a surfactant, which is used as a final bath for color photographic materials. Various chelating agents and antifungal agents can also be added to this stabilizing bath.

[0045]

EXAMPLES The present invention will be explained in more detail below based on Examples, but the present invention is not limited thereto. [Description of waste liquid used] Silver recovery system waste liquid (color photographic processing CN-16 fixing liquid, CN-16Q bleaching liquid, fixing liquid mixture, CP-20 bleach-fixing liquid, CP-23 bleach-fixing liquid) liquid, and black and white photographic processing fixer, Fuji F, GR-F1 (
The above is a product obtained by mixing waste liquid (trade name, manufactured by Fuji Photo Film Co., Ltd.) and water in a ratio of 4, 1, 3, 2, 7, 3, 2, respectively, and then subjecting it to silver recovery treatment) and a developing system. Waste liquid (color photographic processing; CN-16, CN-16Q, CP-20, CP-
23 each developer and black and white photographic processing developer RD-3, G
4, 1, 3, 2, 7, 3, respectively, the waste liquid and water of RD1
2) were mixed at a volume ratio of 1:1. This solution was diluted 10 times, and phosphorus was added in the form of dipotassium phosphate hydrogen in an amount equivalent to about 3% of the COD value as a nutritional salt, and small amounts of calcium ions and magnesium ions were added. The pH of this waste liquid was 8.5. Moreover, the COD value was 4500 ppm.

Pour 90 ml of the above waste liquid into a 100 ml vial, inoculate it with 10 ml of photosynthetic bacteria acclimated with standard medium, and culture anaerobically for one week at room temperature under an electric light with a luminosity of 1.1 mw/cm2. went.

[0047] Also, the waste solution and bacterial cells were inoculated into a 200 ml Erlenmeyer flask in the same manner as above, and cultured with shaking at room temperature for one week.

After one week, the liquid was filtered through a 0.45μ filter and the chemical oxygen demand (COD) was measured. Also,
The above waste liquid is mixed with activated sludge that has not been cultured with photosynthetic bacteria.
■Activated sludge with dominant species of photosynthetic bacteria and sulfur-oxidizing bacteria;
■Activated sludge with sulfur-oxidizing bacteria as the dominant species; ■Activated sludge from a city sewage treatment plant under the same conditions;
D was measured.

[0049] Furthermore, the waste liquid mixed in the same manner and with the addition of nutrients was diluted 5 times, and then treated in the same manner using the bacteria ①, ②, ②, and ②. Table 1 shows the results of measuring COD in the same manner.
, shown in Table 2.

[0050]

[Table 1]

[0051]

[Table 2]

[0052] From this result, the following was clarified. Photosynthetic bacteria alone have a poor treatment rate, and anaerobic treatment generates odor, making it unsuitable for treatment. Furthermore, in the case of mixing the silver recovery system waste liquid and the developing system waste liquid and using a 10-fold diluted solution, treatment with activated sludge in which sulfur-oxidizing bacteria were the dominant species of photosynthetic bacteria was most efficient, and the condition of the sludge was also good. For the 5-fold diluted solution, only the above sludge treatment was effective.

[0053]

[Effects of the invention] (1) CO, which was difficult to treat biologically in the past
Photographic processing waste liquid with D of 3000 ppm or more can be treated stably and at a high processing rate. (2) Reducing inorganic sulfur compounds and organic compounds can be efficiently treated simultaneously. (3) The treatment rate is improved by the combination of activated sludge, in which sulfur-oxidizing bacteria are the dominant species, and photosynthetic bacteria, and the effect becomes apparent at higher concentrations.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a flow system of the treatment method of the present invention.

Claims (2)

[Claims] 1. A method for treating photographic processing waste liquid, which comprises aerobically decomposing the photographic processing waste liquid using activated sludge containing photosynthetic bacteria. 2. The method according to claim 1, wherein the activated sludge is a sludge in which sulfur-oxidizing bacteria are the predominant species.