CA2044107A1 - Closed loop photographic process wastewater treatment system and process therefor - Google Patents
Closed loop photographic process wastewater treatment system and process thereforInfo
- Publication number
- CA2044107A1 CA2044107A1 CA 2044107 CA2044107A CA2044107A1 CA 2044107 A1 CA2044107 A1 CA 2044107A1 CA 2044107 CA2044107 CA 2044107 CA 2044107 A CA2044107 A CA 2044107A CA 2044107 A1 CA2044107 A1 CA 2044107A1
- Authority
- CA
- Canada
- Prior art keywords
- zone
- wastewater
- filtration zone
- filtration
- filtrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 134
- 238000004065 wastewater treatment Methods 0.000 title 1
- 239000002351 wastewater Substances 0.000 claims abstract description 96
- 238000001914 filtration Methods 0.000 claims abstract description 90
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 55
- 239000000706 filtrate Substances 0.000 claims abstract description 45
- 150000001875 compounds Chemical class 0.000 claims abstract description 24
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 26
- 238000001728 nano-filtration Methods 0.000 claims description 22
- 238000004075 wastewater filtration Methods 0.000 claims description 22
- 238000005292 vacuum distillation Methods 0.000 claims description 21
- 239000012141 concentrate Substances 0.000 claims description 20
- 238000001223 reverse osmosis Methods 0.000 claims description 16
- 229910052709 silver Inorganic materials 0.000 claims description 12
- 239000004332 silver Substances 0.000 claims description 12
- 238000011045 prefiltration Methods 0.000 claims description 10
- 239000007787 solid Substances 0.000 claims description 9
- 238000005341 cation exchange Methods 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 7
- 150000002894 organic compounds Chemical class 0.000 claims description 4
- 230000005855 radiation Effects 0.000 claims description 3
- 238000004064 recycling Methods 0.000 abstract description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 12
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 9
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 9
- 239000002699 waste material Substances 0.000 description 8
- 239000000463 material Substances 0.000 description 7
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 6
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 description 6
- 229910021529 ammonia Inorganic materials 0.000 description 6
- 238000001704 evaporation Methods 0.000 description 6
- IOLCXVTUBQKXJR-UHFFFAOYSA-M potassium bromide Chemical compound [K+].[Br-] IOLCXVTUBQKXJR-UHFFFAOYSA-M 0.000 description 6
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 6
- 239000003344 environmental pollutant Substances 0.000 description 5
- 231100000719 pollutant Toxicity 0.000 description 5
- 239000002244 precipitate Substances 0.000 description 5
- XNCSCQSQSGDGES-UHFFFAOYSA-N 2-[2-[bis(carboxymethyl)amino]propyl-(carboxymethyl)amino]acetic acid Chemical compound OC(=O)CN(CC(O)=O)C(C)CN(CC(O)=O)CC(O)=O XNCSCQSQSGDGES-UHFFFAOYSA-N 0.000 description 4
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 4
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 4
- 239000011575 calcium Substances 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- 239000012528 membrane Substances 0.000 description 4
- -1 silver halide Chemical class 0.000 description 4
- WVDDGKGOMKODPV-UHFFFAOYSA-N Benzyl alcohol Chemical compound OCC1=CC=CC=C1 WVDDGKGOMKODPV-UHFFFAOYSA-N 0.000 description 3
- 241000195493 Cryptophyta Species 0.000 description 3
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 3
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 3
- 239000004743 Polypropylene Substances 0.000 description 3
- SWLVFNYSXGMGBS-UHFFFAOYSA-N ammonium bromide Chemical compound [NH4+].[Br-] SWLVFNYSXGMGBS-UHFFFAOYSA-N 0.000 description 3
- 235000019270 ammonium chloride Nutrition 0.000 description 3
- XYXNTHIYBIDHGM-UHFFFAOYSA-N ammonium thiosulfate Chemical compound [NH4+].[NH4+].[O-]S([O-])(=O)=S XYXNTHIYBIDHGM-UHFFFAOYSA-N 0.000 description 3
- 229910052791 calcium Inorganic materials 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 230000007812 deficiency Effects 0.000 description 3
- 238000004821 distillation Methods 0.000 description 3
- NXPHCVPFHOVZBC-UHFFFAOYSA-N hydroxylamine;sulfuric acid Chemical compound ON.OS(O)(=O)=O NXPHCVPFHOVZBC-UHFFFAOYSA-N 0.000 description 3
- 239000010808 liquid waste Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 150000003009 phosphonic acids Chemical class 0.000 description 3
- 229920001155 polypropylene Polymers 0.000 description 3
- 229940094035 potassium bromide Drugs 0.000 description 3
- 229910000027 potassium carbonate Inorganic materials 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- 229910052708 sodium Inorganic materials 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- ZSILVJLXKHGNPL-UHFFFAOYSA-L S(=S)(=O)([O-])[O-].[Ag+2] Chemical compound S(=S)(=O)([O-])[O-].[Ag+2] ZSILVJLXKHGNPL-UHFFFAOYSA-L 0.000 description 2
- 239000007844 bleaching agent Substances 0.000 description 2
- 239000002738 chelating agent Substances 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 230000002950 deficient Effects 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 238000005868 electrolysis reaction Methods 0.000 description 2
- LYCAIKOWRPUZTN-UHFFFAOYSA-N ethylene glycol Natural products OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 239000003456 ion exchange resin Substances 0.000 description 2
- 229920003303 ion-exchange polymer Polymers 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- 239000001103 potassium chloride Substances 0.000 description 2
- 235000011164 potassium chloride Nutrition 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000003643 water by type Substances 0.000 description 2
- 240000009108 Chlorella vulgaris Species 0.000 description 1
- 235000007089 Chlorella vulgaris Nutrition 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 description 1
- 101100128278 Mus musculus Lins1 gene Proteins 0.000 description 1
- 101000916532 Rattus norvegicus Zinc finger and BTB domain-containing protein 38 Proteins 0.000 description 1
- 235000019445 benzyl alcohol Nutrition 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- 239000003729 cation exchange resin Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910001425 magnesium ion Inorganic materials 0.000 description 1
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 1
- 235000019341 magnesium sulphate Nutrition 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 229920001467 poly(styrenesulfonates) Polymers 0.000 description 1
- 230000007420 reactivation Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000002910 solid waste Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/441—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/30—Treatment of water, waste water, or sewage by irradiation
- C02F1/32—Treatment of water, waste water, or sewage by irradiation with ultraviolet light
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Heat Treatment Of Water, Waste Water Or Sewage (AREA)
Abstract
ABSTRACT
A closed loop system for treating wastewater from a photographic process comprising chemical compounds used in the system is described. A processfor carrying out the system is also described. The system and process include an inlet zone for introducing wastewater from the photographic process, a filtration zone for the wastewater capable of producing a filtrate substantially free from the chemical compounds, and an outlet zone for introducing the filtrate as fresh wash water to the photographic process. The system is useful in recycling substantially all of the water used during the photographic process. Thus, the need for additional make-up water may be minimized.
A closed loop system for treating wastewater from a photographic process comprising chemical compounds used in the system is described. A processfor carrying out the system is also described. The system and process include an inlet zone for introducing wastewater from the photographic process, a filtration zone for the wastewater capable of producing a filtrate substantially free from the chemical compounds, and an outlet zone for introducing the filtrate as fresh wash water to the photographic process. The system is useful in recycling substantially all of the water used during the photographic process. Thus, the need for additional make-up water may be minimized.
Description
The present invention relates to a closed loop system for treating wastewater from a photographic process. The present invention also relates to a process for treating wastewater from a photographic process.
In the late 1980's to present, there has been an increasing awareness to develop technologies for use in various current industrial processes which will be less darnaging to the environment.
Of particular concern are those industrial processes which result in wastewater effluents. ~n many cases, such wastewater effluents are merely discharged to municipality sewer lines. Typically, the wastewater is tested prior to discharge to ensure that levels of all pollutants contained therein are within governmental guidelines. Notwithstanding this, the discharge of such wastewater is detrimental to the environment for at least two reasons. First, most municipal water treatment facilities can not accommodate the pollutants in many industrial process wastewaters.
Second, such discharge of wastewater requires replacement fresh water which places a tremendous strain on the municipal water treatment plants.
The photographic industry in particular utilizes large quantities of water in the various stages of film development and print processing. Accordingly, as used throughout this specification, the term "photographic process" is meant to encompass the processing of photographic materials such as film, paper and the like. The wastewater from the photographic process contains pollutants such as silver, organic compounds, chelating compounds, ammonia, sodium, potassium and the like. In the case of silver and some organic compounds, discharge into municipal sewer lines is particularly deleterious. In some cases the volume discharge wastewater from a single site conducting the photographic process can be 100,000 USGPD (United States gallons per day) or more.
Heretofore, there have been a number of known techniques for treating the wastewater effluent from the photographic process.
~ A 1 ~ ~? ~
In the late 1980's to present, there has been an increasing awareness to develop technologies for use in various current industrial processes which will be less darnaging to the environment.
Of particular concern are those industrial processes which result in wastewater effluents. ~n many cases, such wastewater effluents are merely discharged to municipality sewer lines. Typically, the wastewater is tested prior to discharge to ensure that levels of all pollutants contained therein are within governmental guidelines. Notwithstanding this, the discharge of such wastewater is detrimental to the environment for at least two reasons. First, most municipal water treatment facilities can not accommodate the pollutants in many industrial process wastewaters.
Second, such discharge of wastewater requires replacement fresh water which places a tremendous strain on the municipal water treatment plants.
The photographic industry in particular utilizes large quantities of water in the various stages of film development and print processing. Accordingly, as used throughout this specification, the term "photographic process" is meant to encompass the processing of photographic materials such as film, paper and the like. The wastewater from the photographic process contains pollutants such as silver, organic compounds, chelating compounds, ammonia, sodium, potassium and the like. In the case of silver and some organic compounds, discharge into municipal sewer lines is particularly deleterious. In some cases the volume discharge wastewater from a single site conducting the photographic process can be 100,000 USGPD (United States gallons per day) or more.
Heretofore, there have been a number of known techniques for treating the wastewater effluent from the photographic process.
~ A 1 ~ ~? ~
United States patent 4,959,122 discloses an apparatus for treating photographic process wastewater in which the wastewater stored in an evaporatingchamber is heated and concentrated by heat evaporation. The evaporating chamber includes the following components: (i) a precipitate separating means capable of5 separating precipitate generated in the concentrated solution, (ii) a circulation system to circulate the concentrates to the evaporating means through the precipitate separating means; and ~iii) a discharging means for discharging the precipitate separated at the precipitate separating means. Thus, the apparatus disclosed in this patent results in the requirement to use large amounts of energy to heat the 10 wastewater and thereafter condense the vaporized water.
United States patent 4,800,408 discloses an apparatus and process for economizing the wash water used in developing and processing photographic material.
The apparatus includes the following elements in succession: a developing tank, a 15 fixing tank, a pre-wash tank, a wash tank and a roller cleaning bath. Wash water flows from the roller cleaning bath to the wash tank and then to the pre-wash tank.
Thus, this patent proposes to overcome economic and environmental concerns of using large amounts of wash waters (and the resulting waste associated therewith) by reducing the amount of water used.
United States patent 4,791,444 discloses an apparatus for condensing or solidifying used processing solutions and an automatic photographic processor.
Specifically, the subject apparatus makes use of heated air from the drawing chamber of the automatic photographic processor to distil the waste solution. Distillation is 25 the primary technique used to treat the waste solution. The use of distillation techniques as the primary manner by which the wastewater is treated is inefflcient due to the large requirements of heat necessary to evaporate the liquid.
United States patent 4,767,498 discloses a method for the reduction of 30 water-based liquid waste generated during photographic processes and operations. In the method, the liquid waste is charged into a treatment vessel at a temperature of from about 120F to about 140F and is removed from the treatment vessel externally 3 4 ~ ' ' '' i and reintroduced to the top of the treatment vessel i~ such a manner that it is sprayed across a sand blasted perforated plate disposed above the level of the waste solution near the top of the vessel. During the method, air is introduced into the treatment vessel and is vented after it becomes supersaturated with water through the exhaust S duct. The remaining waste solution is in the form of a concentrated slurry and is removed from the bottom of the vessel. This method appears to be similar to the evaporation techniques discussed above with respect to the ' 122 and '444 patents and thus, the same deficiencies accrue with this method.
United States patent 4,~51,132 discloses an apparatus for processing silver halide colour photographic photosensitive material. The apparatus includes a developing tank, a blixing tank and a wash tank arranged such that the photographic materials may be sequentially processed through each tank. The apparatus also comprises a reverse osmosis apparatus having a wash water inlet connected with a15 wash tank and a condensed fluid outlet connected to the blixing tank and diluted water outlet connected to the wash tank. In such an arrangement, wash water overflows from the wash tank to the reverse osmosis apparatus where it is processed such that the condensed fluid is returned to the blixing tank while the diluted water is returned to the wash tank. This apparatus is deficient in that use of reverse osmosis as the 20 sole technique to treat photographic wastewater is inefflcient.
United States patent 4,302,317 relates to a silver recovery apparatus for use with waste photographic-fixer solutions. The apparatus apparently is concerned with using electrolysis for the removal and recovery of solely silver from 25 the fixer solution and recycling of the so-treated fixer solution to the fixer tank.
Unfortunately, the use of electrolysis as the sole technique for treating the wastewater is deficient since other species in the water such as various organics, chelating materials and the like, are relatively unaffected by such treatment. Further, there is no disclosure or suggestion of treating the wash water from the photographic process.
United States patent 4,025,426 discloses an apparatus and method using activated carbon to purify liquid wastes. More specifically, this patent discloses an apparatus which utilizes stacked carbon filters to remove silver from the photographic fixer and includes a method for in situ reactivation of the carbon. Unfortunately, the use of carbon filtration alone is inefficient in dealing with many of the pollutants in photographic wastewater.
s United States patent 3,733,994 discloses an apparatus for washing photographic material. The treatment of the photographic material includes evaporation of the effluent using a water processor or purifier such as a heat pump evaporator. The difflculties and deficiencies associated with using evaporation as the 10 sole technique for treating wastewater has been discussed above with respect to the '122, '444 and '498 patents.
Further, the use of certain known "filtration" means such as ion exchange resins, activated carbon and reverse osmosis as the sole technique to treat 15 wastewater from large scale photographic processes is not believed to be feasible due to fast loading rates which makes it necessary to have large scale devices.
In view of the above-mentioned deficiencies of the prior art, it would be desirable to have an improved system for treatment of wastewater from the 20 photographic process. Ideally, the system would be capable of dealing with substantially all of the pollutants in the wastewater in a relatively simple and efflcient manner. Further, it would be desirable if the system were closed loop such that substantially all of the water used in the photographic process could be recycled back to the process after treatment in the system. Still further, it would be desirable to 25 have a process for the system.
It is an object of the present invention to provide a novel closed loop system for treating wastewater from a photographic process.
30It is another object of the present invention to provide a closed loop system for the treatment of wastewater from a photographic process which 5 ~ 3~ ~
substantially minimizes the requirement for additional make-up water to be added to the treated water.
It is yet another object of the present invention to provide a novel S process for closed loop treatment of wastewater from a photographic process.
It is yet another object of the present invention to provide a closed loop process for the treatment of wastewater from a photographic process which substantially minimizes the requirement for additional make-up water to be added to the treated water.
Accordingly, in one of its aspects, the present invention provides a closed loop system for treating wastewater from a photographic process comprising chemical compounds used in the photographic process. The system comprises:
(a) an inlet zone for introducing wastewater from the photographic process;
(b) a filtration zone for the wastewater capable of producing a filtrate substantially free from the chemical compounds; and (c) an outlet zone for introducing the filtrate as fresh wash water to the photographic process.
In another of its aspects, the present invention provides a closed loop process for treating wastewater from a photographic process comprising chemical compounds used in the photographic process. The closed loop process comprises:
(a) feeding wastewater from the photographic process to an inlet zone;
(b) feeding the wastewater from the inlet zone to a filtration zone;
(c) treating the wastewater in the filtration zone to produce a filtrate substantially free from the chemical compounds; and (d) feeding the filtrate as fresh wash water to the photographic process.
Thus, the present invention is suitable for use in the closed loop treatment of wastewater ~rom the photographic process. In many photographic processes, a portion of the water used is lost during paper and film drying. For the most part this is unavoidable. Accordingly, as used in the present specification, the 5 term "closed loop" is meant to encompass treatment of wastewater effluent from the photographic process in a manner whereby the amount of water lost during treatment of this wastewater effluent (i.e. excluding the amount of water lost during paper and film drying in the photographic process), is less than about 8 percent, more preferably less than about 5 percent, based on the total volume of wastewater emanating from 10 the photographic process.
The wastewater introduced into the filtration zone comprises chemical compounds used in the photographic process. It will be appreciated that certain chemicals (e.g. minerals such as calcium and magnesium ions) are initially present 15 in the water and are not necessarily required and used in the photographic process.
As used in the present specification, the term "chemical compounds" is meant to encompass all chemicals used in the photographic process. These chemical compounds are found in the effluent from the wash stations used after fixing and non-fixing (e.g. developing and/or bleaching) operations in the photographic process. As 20 used in the present specification the term "fixer wastewater" is meant to encompass wastewater used as a wash water after a fixing operation. As used in the presentspecification the term "non-fixer wastewater" is meant to encompass wastewater used as a wash water after non-fixing operation.
Non-limiting examples of chemical compounds typically found in fixer wastewater include silver (present as silver thiosulphate complex), ammonium thiosulphate, ammonia, potassium chloride, potassium bromide and calcium (iron may also be present if used in the bleach/fixer operation). Non-limiting examples ofchemical compounds typically found in non-fixer wastewater comprise paraphenylediamine derivatives, hydroquinone, ammonium bromide, ammonium chloride, hydroxylamine sulphate, acetic acid, potassium carbonate and chelating ~ ~ ~ n agents such as phosphonic acid compounds, ethylenediaminetetraacetic acid (EDTA)and propylenediaminetetraacetic acid (PDTA~.
Preferably, the filtration zone comprises a first filtration zone into S which the wastewater is fed and a second filtration zone for receiving the effluent from the first filtration zone.
The inlet zone ideally comprises means for introducing the wastewater into the first filtration zone as fixer wastewater and non-fixer wastewater. In such 10 an embodiment, it is preferred to have a first filtration zone which comprises a fixer wastewater filtration zone capable of removing all relatively high molecular weight chemical compounds (e.g. silver and ammonium thiosulphate) from the fixer wastewater to produce a first filtrate and a non-fixer wastewater filtration zone capable of removing substantially all relatively high molecular weight chemical 15 compounds (e.g. paraphenylediamine derivatives, hydroquinone, hydroxylamine sulphate, acetic acid, potassium carbonate and chelating agents such as phosphonic acid compounds, EDTA and PDTA) from the non-fixer wastewater to produce a second filtrate.
The first filtrate and second filtrate may then be dispatched from the first filtration zone to the second filtration zone which serves to remove substantially all relatively low molecular weight chemical compounds (e.g. ammonia, potassium chloAde, potassium bromide, calcium, sodium, ammonium bromide and ammonium chloride) remaining in the wastewater after treatment in the first filtration zone.
Preferably, at least one, and more preferably both, of the fixer wastewater filtration zone and the non-fixer wastewater filtration zone comprisenanofiltration. Preferably, the second filtration zone comprises reverse osmosis.
The so treated wastewater from the second filtration zone (i.e. the filtrate from step (b)) may then be dispatched to the outlet zone for reuse in the photographic process. The requirement for additional make-up water to retain a constant volume of water in the photographic process is substantially minimized.
Preferably, the system further comprises a residue treatment zone into S which is fed the residue from at least one, and more preferably both, of the non-fixer wastewater filtration zone and the second filtration zone.
The residue treatment zone preferably comprises a vacuum distillation zone producing a distillate and a concentrate. The distillate from the vacuum 10 distillation zone may be dispatched to a third filtration zone to produce a third filtrate.
Preferably, the third filtration zone comprises at least one, and more preferably both, of an activated carbon filtration zone and a cation exchange zone which receive and treat the distillate. After treatment, the third filtrate may be combined with the first filtrate from the fixer wastewater filtration zone and the second filtrate from the non-lS fixer wastewater filtration zone and recycled for reuse in the photographic process viathe outlet zone.
It will be appreciated that, in certain instances, it is possible to combine the fixer wastewater and the non-fixer wastewater, and feed this combination as a 20 single effluent to the filtration zone. Preferably, the filtration zone comprises a first filtration zone and a second filtration zone. The first filtration zone preferably comprises nanofiltration and the second filtration zone preferably comprises reverse osmosis. In this embodiment, it is preferred to feed the residues from at least one, and more preferably both, of the first filtration zone and the second filtration zone to 25 a residue treatment zone. The residue treatment zone may be similar to the one described hereinabove.
In another preferred aspect of the present system, there is provided a pre-filtration zone into which the wastewater is introduced from the inlet zone. More 30 preferably, this pre-filtration zone comprises at least one, and more preferably both, of a solids filtration zone and an ultraviolet radiation treatment zone.
Embodiments of the present invention will be described with reference to the accompanying Figure which illustrates a schematic of the most preferred embodiment of the present system and process.
With reference to the Figure, there is illustrated a photographic process 10 which comprises the following stations in series: developer, bleach, wash 1, fixer, wash 2 and stabilizer. As will be appreciated by those skilled in the art, this is a conventional photographic process for the development of C-41 film. Spent wash water (i.e. the wastewater) from station wash 2 of photographic process 10 is pumped via a pump 14 through a line 12. Line 12 feeds a 660 gallon tank 16 which is connected to a solids filter zone 18.
The nature of solids filter zone 18 is not particularly restricted.
Preferably, the solids filter zone comprises a 20~m polypropylene cartridge filter in a stainless steel housing.
Wastewater in line 12 is then fed to an ultraviolet (UV) treatment zone 20 which serves to kill any algae present in the wastewater. The nature of ultraviolet treatment zone 20 is not particularly restricted. Preferably, the zone includes an apparatus consisting of a one pass flow-through ultraviolet lamp system installed in-line on line 12. An appropriate system to kill chlorella vulgaris (algae) is a 61 watt unit delivering an ultraviolet dosage of 30,000 ~uW seconds/cm2.
After ultraviolet treatment, the wastewater re-emerges in line 12 via a three-way valve 22 to a nanofiltration zone 26. Preferably, nanofiltration 26 comprises a pre-filtration stage (not shown) through which wastewater in line 12 is initially filtered. Typically, this pre-filtration stage comprises a 5~m bag filter followed by cooling (if required) in a heat exchanger. Thereafter, the pre-filtered wastewater is pumped through a series of nanofilters at elevated pressure. The filtrate (i.e. permeate) is then discharged from nanofiltration zone 26 to line 12.
r~
lf desired, it is possible to engage valve 22 to dire t wastewater in line 12 to a by-pass line 28 which is connected to station wash 2 in photographic process 10. By-pass line 28 may be used during shutdown of photographic process 10 (e.g.at night~ to assist in preventing the build-up of algae in line 12.
The choice of nanofiltration apparatus suitable for use in the present system is not particularly restricted. A suit ble nanofiltration device was supplied by Zenon as Model No. MF4740-NF. This device comprises a pre-filter, a high , . . . .
pressure process pump, twelve membrane modules, a clean-in-place system and a 10 solid state control system. The pre-filtration component comprises a 5~m polypropylene cartridge filter in a stainless steel housing. Each nanofiltrationmembrane in the membrane modules is capable of rejecting a minimum of 95 percentMgS04 (rejection under test conditions of 2,000 ppm MgSO4, 225 psi, 25C and pH
8).
Wastewater from station wash 1 of photographic process 10 is removed via a line 30 by a pump 32 to a 660 gallon tank 34. Tank 34 is connected to a solids filter zone 36 is similar to solids filter zone 18. Thereafter, wastewater in line 30 is fed to an ultraviolet (UV) treatment zone 40 which is similar to ultraviolet treatment 20 zone 20. Wastewater from treatment zone 40 is re-emerges in line 30 via a three-way valve 42 to a nanofiltration zone 46 which is similar to nanofiltration zone 26.
If desired, it is possible to engage valve 42 to direct wastewater in line 3û to a by-pass line 48 which is comlected to station wash 1 in photographic process 25 10. By-pass line 48 may be used in manner similar to that described hereinabove for by-pass line 28.
After nanofiltration of wastewaters from station wash 1 of photographic process 10 via line 30 and station wash 2 of photographic process 10 via line 12, lines 30 12 and 30 merge into a line 50 which is connected to a reverse osmosis zone 52 via a 2000 gallon tank 54.
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Reverse osmosis zone 52 typically comprises a membrane capable of providing finer filtratiGn of contaminants than the membranes used in nanofiltration zones 26 and 46. Reverse osmosis is the final step in wash water treatment.
Water in lins 50 emerges from reverse osmosis zone 52 into a 6,000 gallon tank 58. Thereafter, the treated water, which may now serve as fresh washwater for the photographic process, emerges from tank 58 to a supply line 62 via a pump 60. Supply line 62 is then split into a line 64 which supplies station wash 1 of photographic process 10 and a line 66 which supplies station wash 2 of photographic process 10.
The residue (i.e. concentrate) from nanofiltration 26 typically comprises relatively high molecular weight chemical compounds (e.g. silver thiosulphate complex and ammonium thiosulphate) and exits via a line 68 to a fixer make-up zone 70. The residue (i.e. concentrate) from nanofiltration zone 46 typically comprises relatively high molecular weight chemical compounds (e.g.
paraphenylediamine derivatives, hydroquinone, hydroxylamine sulphate, acetic acid, potassium carbonate and chelating agents such as phosphonic acid compounds, EDTAand PDTA) and exits nanofiltration zone 46 via a line 72. The residue (i.e.
concentrate) from reverse osmosis zone 52 typically comprises relatively low molecular weight chemical compounds (e.g. ammonia, potassium chloride, potassiumbromide, calcium, sodium, ammonium bromide and ammonium chloride) and exits reverse osmosis zone 52 via a line 74. Lines 72 and 74 merge into a line 76 which is directed to a 1,000 gallon tank 78. Waste concentrate from tank 78 enters a vacuum distillation zone 80 via a pump 82.
Vacuum distillation chamber 80 is preferably a Calfran STU-60-20 vacuum distillation unit. Typically, such a unit can be used to remove more thanabout 90 percent of the water from the concentrate. This water leaves vacuum distillation zone 80 via a line 84 to a 100 gallon tank 86 which feeds an activated carbon zone 92 via a pump 88. Treatment of the distillate in activated carbon zone 92 serves to remove substantially all by-products of developer solvents (e.g. ethylene -12- c~ ? r ~
glycol and benzyl alcohol) used in photographic process 10. The choice of activated carbon zone 92 is not particularly restricted. Preferably, this zone comprises a 290 gallon polypropylene vessel containing "Filtrasorb 400" granular activated carbon.
S Thereafter, the distillate enters a cation exchange zone 98. Cation exchange zone 98 serves to remove ammonia from the distillate. The choice of apparatus used in cation exchange zone 98 is not particularly restricted. Preferably, this zone comprises a vessel two feet in diameter and six feet high containing Dowex G-2S ion exchange resin. The cation exchange resin serves to remove ammonia fromthe distillate.
The treated water re-emerges into line 84 which feeds tank 58 containing treated water capable of being used as fresh wash water in the photographic process.
Concentrate from vacuum distillation zone 80 emerges via a line 102 to a 2000 gallon tank 104. This concentrate is then dispatched to a waste disposal site 106.
The pumps and valves utilized in the present system are not particularly restricted and are known to those of skill in the art.
It will be appreciated that the nature of the photographic process from which the wastewater is derived is not particularly restricted. For example, thepresent system may be utilized in conjunction with a dual paper/film photographic process. Non-limiting examples of suitable film processes include C-41, E-6 and black and white film. Non-limiting examples of suitable paper processes include colour paper (RA), type R paper, black and white paper and EP2. Using appropriate pump and valve techniques known to those skilled in the art, the wash waters from these various processes can be combined as a single effluent, preferably a fixer wash wastewater effluent and a non-fixer wash wastewater effluent, for treatment in the present system.
It has been found that the provision of the present system makes it possible to reduce substantially the amount of additional make-up water used to retain a constant amount of water in the photographic process. Accordingly, the presentsystem is substantially closed loop. As an added advantage, the silver and fixer5 chemistry recovered in the nanofiltration zone for the fixer wash water may beseparated and the fixer chemistry can be recycled into a suitable fixer make-up zone.
Accordingly, the present system is substantially closed loop for both water and fixer chemistry. The silver may be recovered separately and reused elsewhere.
In a test run of the present system and process, it was possible to provide a reduction of from 60,000 USGPD total water discharge (i.e. to sewer) to total water reuse and 200 USGPD of solid waste. In certain circumstances, it maybe necessary to add small amounts of additional make-up water to the overall system to compensate for water lost in the concentrate from vacuum distillation, paper and 15 film drying and other areas in the system and process. Typically, the amount of make-up water required compensate for water lost in the concentrate and other areas of the present system and process will be less than about 8 percent, more preferably less than about S percent, based on tlie total volume of wastewater emanating from the photographic process.
United States patent 4,800,408 discloses an apparatus and process for economizing the wash water used in developing and processing photographic material.
The apparatus includes the following elements in succession: a developing tank, a 15 fixing tank, a pre-wash tank, a wash tank and a roller cleaning bath. Wash water flows from the roller cleaning bath to the wash tank and then to the pre-wash tank.
Thus, this patent proposes to overcome economic and environmental concerns of using large amounts of wash waters (and the resulting waste associated therewith) by reducing the amount of water used.
United States patent 4,791,444 discloses an apparatus for condensing or solidifying used processing solutions and an automatic photographic processor.
Specifically, the subject apparatus makes use of heated air from the drawing chamber of the automatic photographic processor to distil the waste solution. Distillation is 25 the primary technique used to treat the waste solution. The use of distillation techniques as the primary manner by which the wastewater is treated is inefflcient due to the large requirements of heat necessary to evaporate the liquid.
United States patent 4,767,498 discloses a method for the reduction of 30 water-based liquid waste generated during photographic processes and operations. In the method, the liquid waste is charged into a treatment vessel at a temperature of from about 120F to about 140F and is removed from the treatment vessel externally 3 4 ~ ' ' '' i and reintroduced to the top of the treatment vessel i~ such a manner that it is sprayed across a sand blasted perforated plate disposed above the level of the waste solution near the top of the vessel. During the method, air is introduced into the treatment vessel and is vented after it becomes supersaturated with water through the exhaust S duct. The remaining waste solution is in the form of a concentrated slurry and is removed from the bottom of the vessel. This method appears to be similar to the evaporation techniques discussed above with respect to the ' 122 and '444 patents and thus, the same deficiencies accrue with this method.
United States patent 4,~51,132 discloses an apparatus for processing silver halide colour photographic photosensitive material. The apparatus includes a developing tank, a blixing tank and a wash tank arranged such that the photographic materials may be sequentially processed through each tank. The apparatus also comprises a reverse osmosis apparatus having a wash water inlet connected with a15 wash tank and a condensed fluid outlet connected to the blixing tank and diluted water outlet connected to the wash tank. In such an arrangement, wash water overflows from the wash tank to the reverse osmosis apparatus where it is processed such that the condensed fluid is returned to the blixing tank while the diluted water is returned to the wash tank. This apparatus is deficient in that use of reverse osmosis as the 20 sole technique to treat photographic wastewater is inefflcient.
United States patent 4,302,317 relates to a silver recovery apparatus for use with waste photographic-fixer solutions. The apparatus apparently is concerned with using electrolysis for the removal and recovery of solely silver from 25 the fixer solution and recycling of the so-treated fixer solution to the fixer tank.
Unfortunately, the use of electrolysis as the sole technique for treating the wastewater is deficient since other species in the water such as various organics, chelating materials and the like, are relatively unaffected by such treatment. Further, there is no disclosure or suggestion of treating the wash water from the photographic process.
United States patent 4,025,426 discloses an apparatus and method using activated carbon to purify liquid wastes. More specifically, this patent discloses an apparatus which utilizes stacked carbon filters to remove silver from the photographic fixer and includes a method for in situ reactivation of the carbon. Unfortunately, the use of carbon filtration alone is inefficient in dealing with many of the pollutants in photographic wastewater.
s United States patent 3,733,994 discloses an apparatus for washing photographic material. The treatment of the photographic material includes evaporation of the effluent using a water processor or purifier such as a heat pump evaporator. The difflculties and deficiencies associated with using evaporation as the 10 sole technique for treating wastewater has been discussed above with respect to the '122, '444 and '498 patents.
Further, the use of certain known "filtration" means such as ion exchange resins, activated carbon and reverse osmosis as the sole technique to treat 15 wastewater from large scale photographic processes is not believed to be feasible due to fast loading rates which makes it necessary to have large scale devices.
In view of the above-mentioned deficiencies of the prior art, it would be desirable to have an improved system for treatment of wastewater from the 20 photographic process. Ideally, the system would be capable of dealing with substantially all of the pollutants in the wastewater in a relatively simple and efflcient manner. Further, it would be desirable if the system were closed loop such that substantially all of the water used in the photographic process could be recycled back to the process after treatment in the system. Still further, it would be desirable to 25 have a process for the system.
It is an object of the present invention to provide a novel closed loop system for treating wastewater from a photographic process.
30It is another object of the present invention to provide a closed loop system for the treatment of wastewater from a photographic process which 5 ~ 3~ ~
substantially minimizes the requirement for additional make-up water to be added to the treated water.
It is yet another object of the present invention to provide a novel S process for closed loop treatment of wastewater from a photographic process.
It is yet another object of the present invention to provide a closed loop process for the treatment of wastewater from a photographic process which substantially minimizes the requirement for additional make-up water to be added to the treated water.
Accordingly, in one of its aspects, the present invention provides a closed loop system for treating wastewater from a photographic process comprising chemical compounds used in the photographic process. The system comprises:
(a) an inlet zone for introducing wastewater from the photographic process;
(b) a filtration zone for the wastewater capable of producing a filtrate substantially free from the chemical compounds; and (c) an outlet zone for introducing the filtrate as fresh wash water to the photographic process.
In another of its aspects, the present invention provides a closed loop process for treating wastewater from a photographic process comprising chemical compounds used in the photographic process. The closed loop process comprises:
(a) feeding wastewater from the photographic process to an inlet zone;
(b) feeding the wastewater from the inlet zone to a filtration zone;
(c) treating the wastewater in the filtration zone to produce a filtrate substantially free from the chemical compounds; and (d) feeding the filtrate as fresh wash water to the photographic process.
Thus, the present invention is suitable for use in the closed loop treatment of wastewater ~rom the photographic process. In many photographic processes, a portion of the water used is lost during paper and film drying. For the most part this is unavoidable. Accordingly, as used in the present specification, the 5 term "closed loop" is meant to encompass treatment of wastewater effluent from the photographic process in a manner whereby the amount of water lost during treatment of this wastewater effluent (i.e. excluding the amount of water lost during paper and film drying in the photographic process), is less than about 8 percent, more preferably less than about 5 percent, based on the total volume of wastewater emanating from 10 the photographic process.
The wastewater introduced into the filtration zone comprises chemical compounds used in the photographic process. It will be appreciated that certain chemicals (e.g. minerals such as calcium and magnesium ions) are initially present 15 in the water and are not necessarily required and used in the photographic process.
As used in the present specification, the term "chemical compounds" is meant to encompass all chemicals used in the photographic process. These chemical compounds are found in the effluent from the wash stations used after fixing and non-fixing (e.g. developing and/or bleaching) operations in the photographic process. As 20 used in the present specification the term "fixer wastewater" is meant to encompass wastewater used as a wash water after a fixing operation. As used in the presentspecification the term "non-fixer wastewater" is meant to encompass wastewater used as a wash water after non-fixing operation.
Non-limiting examples of chemical compounds typically found in fixer wastewater include silver (present as silver thiosulphate complex), ammonium thiosulphate, ammonia, potassium chloride, potassium bromide and calcium (iron may also be present if used in the bleach/fixer operation). Non-limiting examples ofchemical compounds typically found in non-fixer wastewater comprise paraphenylediamine derivatives, hydroquinone, ammonium bromide, ammonium chloride, hydroxylamine sulphate, acetic acid, potassium carbonate and chelating ~ ~ ~ n agents such as phosphonic acid compounds, ethylenediaminetetraacetic acid (EDTA)and propylenediaminetetraacetic acid (PDTA~.
Preferably, the filtration zone comprises a first filtration zone into S which the wastewater is fed and a second filtration zone for receiving the effluent from the first filtration zone.
The inlet zone ideally comprises means for introducing the wastewater into the first filtration zone as fixer wastewater and non-fixer wastewater. In such 10 an embodiment, it is preferred to have a first filtration zone which comprises a fixer wastewater filtration zone capable of removing all relatively high molecular weight chemical compounds (e.g. silver and ammonium thiosulphate) from the fixer wastewater to produce a first filtrate and a non-fixer wastewater filtration zone capable of removing substantially all relatively high molecular weight chemical 15 compounds (e.g. paraphenylediamine derivatives, hydroquinone, hydroxylamine sulphate, acetic acid, potassium carbonate and chelating agents such as phosphonic acid compounds, EDTA and PDTA) from the non-fixer wastewater to produce a second filtrate.
The first filtrate and second filtrate may then be dispatched from the first filtration zone to the second filtration zone which serves to remove substantially all relatively low molecular weight chemical compounds (e.g. ammonia, potassium chloAde, potassium bromide, calcium, sodium, ammonium bromide and ammonium chloride) remaining in the wastewater after treatment in the first filtration zone.
Preferably, at least one, and more preferably both, of the fixer wastewater filtration zone and the non-fixer wastewater filtration zone comprisenanofiltration. Preferably, the second filtration zone comprises reverse osmosis.
The so treated wastewater from the second filtration zone (i.e. the filtrate from step (b)) may then be dispatched to the outlet zone for reuse in the photographic process. The requirement for additional make-up water to retain a constant volume of water in the photographic process is substantially minimized.
Preferably, the system further comprises a residue treatment zone into S which is fed the residue from at least one, and more preferably both, of the non-fixer wastewater filtration zone and the second filtration zone.
The residue treatment zone preferably comprises a vacuum distillation zone producing a distillate and a concentrate. The distillate from the vacuum 10 distillation zone may be dispatched to a third filtration zone to produce a third filtrate.
Preferably, the third filtration zone comprises at least one, and more preferably both, of an activated carbon filtration zone and a cation exchange zone which receive and treat the distillate. After treatment, the third filtrate may be combined with the first filtrate from the fixer wastewater filtration zone and the second filtrate from the non-lS fixer wastewater filtration zone and recycled for reuse in the photographic process viathe outlet zone.
It will be appreciated that, in certain instances, it is possible to combine the fixer wastewater and the non-fixer wastewater, and feed this combination as a 20 single effluent to the filtration zone. Preferably, the filtration zone comprises a first filtration zone and a second filtration zone. The first filtration zone preferably comprises nanofiltration and the second filtration zone preferably comprises reverse osmosis. In this embodiment, it is preferred to feed the residues from at least one, and more preferably both, of the first filtration zone and the second filtration zone to 25 a residue treatment zone. The residue treatment zone may be similar to the one described hereinabove.
In another preferred aspect of the present system, there is provided a pre-filtration zone into which the wastewater is introduced from the inlet zone. More 30 preferably, this pre-filtration zone comprises at least one, and more preferably both, of a solids filtration zone and an ultraviolet radiation treatment zone.
Embodiments of the present invention will be described with reference to the accompanying Figure which illustrates a schematic of the most preferred embodiment of the present system and process.
With reference to the Figure, there is illustrated a photographic process 10 which comprises the following stations in series: developer, bleach, wash 1, fixer, wash 2 and stabilizer. As will be appreciated by those skilled in the art, this is a conventional photographic process for the development of C-41 film. Spent wash water (i.e. the wastewater) from station wash 2 of photographic process 10 is pumped via a pump 14 through a line 12. Line 12 feeds a 660 gallon tank 16 which is connected to a solids filter zone 18.
The nature of solids filter zone 18 is not particularly restricted.
Preferably, the solids filter zone comprises a 20~m polypropylene cartridge filter in a stainless steel housing.
Wastewater in line 12 is then fed to an ultraviolet (UV) treatment zone 20 which serves to kill any algae present in the wastewater. The nature of ultraviolet treatment zone 20 is not particularly restricted. Preferably, the zone includes an apparatus consisting of a one pass flow-through ultraviolet lamp system installed in-line on line 12. An appropriate system to kill chlorella vulgaris (algae) is a 61 watt unit delivering an ultraviolet dosage of 30,000 ~uW seconds/cm2.
After ultraviolet treatment, the wastewater re-emerges in line 12 via a three-way valve 22 to a nanofiltration zone 26. Preferably, nanofiltration 26 comprises a pre-filtration stage (not shown) through which wastewater in line 12 is initially filtered. Typically, this pre-filtration stage comprises a 5~m bag filter followed by cooling (if required) in a heat exchanger. Thereafter, the pre-filtered wastewater is pumped through a series of nanofilters at elevated pressure. The filtrate (i.e. permeate) is then discharged from nanofiltration zone 26 to line 12.
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lf desired, it is possible to engage valve 22 to dire t wastewater in line 12 to a by-pass line 28 which is connected to station wash 2 in photographic process 10. By-pass line 28 may be used during shutdown of photographic process 10 (e.g.at night~ to assist in preventing the build-up of algae in line 12.
The choice of nanofiltration apparatus suitable for use in the present system is not particularly restricted. A suit ble nanofiltration device was supplied by Zenon as Model No. MF4740-NF. This device comprises a pre-filter, a high , . . . .
pressure process pump, twelve membrane modules, a clean-in-place system and a 10 solid state control system. The pre-filtration component comprises a 5~m polypropylene cartridge filter in a stainless steel housing. Each nanofiltrationmembrane in the membrane modules is capable of rejecting a minimum of 95 percentMgS04 (rejection under test conditions of 2,000 ppm MgSO4, 225 psi, 25C and pH
8).
Wastewater from station wash 1 of photographic process 10 is removed via a line 30 by a pump 32 to a 660 gallon tank 34. Tank 34 is connected to a solids filter zone 36 is similar to solids filter zone 18. Thereafter, wastewater in line 30 is fed to an ultraviolet (UV) treatment zone 40 which is similar to ultraviolet treatment 20 zone 20. Wastewater from treatment zone 40 is re-emerges in line 30 via a three-way valve 42 to a nanofiltration zone 46 which is similar to nanofiltration zone 26.
If desired, it is possible to engage valve 42 to direct wastewater in line 3û to a by-pass line 48 which is comlected to station wash 1 in photographic process 25 10. By-pass line 48 may be used in manner similar to that described hereinabove for by-pass line 28.
After nanofiltration of wastewaters from station wash 1 of photographic process 10 via line 30 and station wash 2 of photographic process 10 via line 12, lines 30 12 and 30 merge into a line 50 which is connected to a reverse osmosis zone 52 via a 2000 gallon tank 54.
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Reverse osmosis zone 52 typically comprises a membrane capable of providing finer filtratiGn of contaminants than the membranes used in nanofiltration zones 26 and 46. Reverse osmosis is the final step in wash water treatment.
Water in lins 50 emerges from reverse osmosis zone 52 into a 6,000 gallon tank 58. Thereafter, the treated water, which may now serve as fresh washwater for the photographic process, emerges from tank 58 to a supply line 62 via a pump 60. Supply line 62 is then split into a line 64 which supplies station wash 1 of photographic process 10 and a line 66 which supplies station wash 2 of photographic process 10.
The residue (i.e. concentrate) from nanofiltration 26 typically comprises relatively high molecular weight chemical compounds (e.g. silver thiosulphate complex and ammonium thiosulphate) and exits via a line 68 to a fixer make-up zone 70. The residue (i.e. concentrate) from nanofiltration zone 46 typically comprises relatively high molecular weight chemical compounds (e.g.
paraphenylediamine derivatives, hydroquinone, hydroxylamine sulphate, acetic acid, potassium carbonate and chelating agents such as phosphonic acid compounds, EDTAand PDTA) and exits nanofiltration zone 46 via a line 72. The residue (i.e.
concentrate) from reverse osmosis zone 52 typically comprises relatively low molecular weight chemical compounds (e.g. ammonia, potassium chloride, potassiumbromide, calcium, sodium, ammonium bromide and ammonium chloride) and exits reverse osmosis zone 52 via a line 74. Lines 72 and 74 merge into a line 76 which is directed to a 1,000 gallon tank 78. Waste concentrate from tank 78 enters a vacuum distillation zone 80 via a pump 82.
Vacuum distillation chamber 80 is preferably a Calfran STU-60-20 vacuum distillation unit. Typically, such a unit can be used to remove more thanabout 90 percent of the water from the concentrate. This water leaves vacuum distillation zone 80 via a line 84 to a 100 gallon tank 86 which feeds an activated carbon zone 92 via a pump 88. Treatment of the distillate in activated carbon zone 92 serves to remove substantially all by-products of developer solvents (e.g. ethylene -12- c~ ? r ~
glycol and benzyl alcohol) used in photographic process 10. The choice of activated carbon zone 92 is not particularly restricted. Preferably, this zone comprises a 290 gallon polypropylene vessel containing "Filtrasorb 400" granular activated carbon.
S Thereafter, the distillate enters a cation exchange zone 98. Cation exchange zone 98 serves to remove ammonia from the distillate. The choice of apparatus used in cation exchange zone 98 is not particularly restricted. Preferably, this zone comprises a vessel two feet in diameter and six feet high containing Dowex G-2S ion exchange resin. The cation exchange resin serves to remove ammonia fromthe distillate.
The treated water re-emerges into line 84 which feeds tank 58 containing treated water capable of being used as fresh wash water in the photographic process.
Concentrate from vacuum distillation zone 80 emerges via a line 102 to a 2000 gallon tank 104. This concentrate is then dispatched to a waste disposal site 106.
The pumps and valves utilized in the present system are not particularly restricted and are known to those of skill in the art.
It will be appreciated that the nature of the photographic process from which the wastewater is derived is not particularly restricted. For example, thepresent system may be utilized in conjunction with a dual paper/film photographic process. Non-limiting examples of suitable film processes include C-41, E-6 and black and white film. Non-limiting examples of suitable paper processes include colour paper (RA), type R paper, black and white paper and EP2. Using appropriate pump and valve techniques known to those skilled in the art, the wash waters from these various processes can be combined as a single effluent, preferably a fixer wash wastewater effluent and a non-fixer wash wastewater effluent, for treatment in the present system.
It has been found that the provision of the present system makes it possible to reduce substantially the amount of additional make-up water used to retain a constant amount of water in the photographic process. Accordingly, the presentsystem is substantially closed loop. As an added advantage, the silver and fixer5 chemistry recovered in the nanofiltration zone for the fixer wash water may beseparated and the fixer chemistry can be recycled into a suitable fixer make-up zone.
Accordingly, the present system is substantially closed loop for both water and fixer chemistry. The silver may be recovered separately and reused elsewhere.
In a test run of the present system and process, it was possible to provide a reduction of from 60,000 USGPD total water discharge (i.e. to sewer) to total water reuse and 200 USGPD of solid waste. In certain circumstances, it maybe necessary to add small amounts of additional make-up water to the overall system to compensate for water lost in the concentrate from vacuum distillation, paper and 15 film drying and other areas in the system and process. Typically, the amount of make-up water required compensate for water lost in the concentrate and other areas of the present system and process will be less than about 8 percent, more preferably less than about S percent, based on tlie total volume of wastewater emanating from the photographic process.
Claims (64)
1. A closed loop system for treating wastewater from a photographic process comprising chemical compounds used in the photographic process, said system comprising:
(a) an inlet zone for introducing wastewater from said photographic process;
(b) a filtration zone for said wastewater capable of producing a filtrate substantially free from said chemical compounds; and (c) an outlet zone for introducing said filtrate as fresh wash water to said photographic process.
(a) an inlet zone for introducing wastewater from said photographic process;
(b) a filtration zone for said wastewater capable of producing a filtrate substantially free from said chemical compounds; and (c) an outlet zone for introducing said filtrate as fresh wash water to said photographic process.
2. The system defined in claim 1, wherein said filtration zone comprises a first filtration zone and a second filtration zone, said first filtration zone receiving said wastewater.
3. The system defined in claim 2, wherein said inlet zone comprises means for introducing said wastewater into said first filtration zone separately as fixer wastewater and non-fixer wastewater.
4. The system defined in claim 3, wherein said first filtration zone comprises a fixer wastewater filtration zone capable of removing substantially all silver and organic compounds from said fixer wastewater to produce a first filtrate and a non-fixer wastewater filtration zone capable of removing substantially allorganic compounds from said non-fixer wastewater to produce a second filtrate.
5. The system defined in claim 4, wherein said fixer wastewater filtrationzone comprises nanofiltration.
6. The system defined in claim 4, wherein said non-fixer wastewater filtration zone comprises nanofiltration.
7. The system defined in claim 4, wherein both of said fixer wastewater filtration zone and said non-fixer wastewater filtration zone comprise nanofiltration.
8. The system defined in claim 4, wherein said second filtration zone receives at least one of said first filtrate and said second filtrate from said first filtration zone.
9. The system defined in claim 4, wherein said second filtration zone receives both of said first filtrate and said second filtrate from said first filtration zone.
10. The system defined in any one of claims 2, 3, 4, 5, 6, 7, 8, or 9, wherein said second filtration zone comprises reverse osmosis.
11. The system defined in any one of claims 8 or 9, wherein said outlet zone receives the filtrate from said second filtration zone.
12. The system defined in claim 4, further comprising a residue treatment zone into which is fed the residue from at least one of said non-fixer wastewater filtration zone and said second filtration zone.
13. The system defined in claim 4, further comprising a residue treatment zone into which is fed the residue from both of said non-fixer wastewater filtration zone and said second filtration zone.
14. The system defined in any one of claims 12 or 13, wherein said residuetreatment zone comprises a vacuum distillation zone producing a distillate and aconcentrate.
15. The system defined in claim 14, wherein said vacuum distillation zone further comprises a third filtration zone for said distillate producing a third filtrate.
16. The system defined in claim 15, wherein said third filtration zone comprises an activated carbon filtration zone and a cation exchange zone.
17. The system defined in claim 15 or 16, wherein said outlet zone receives said third filtrate.
18. The system defined in claim 14, wherein said vacuum distillation zone further comprises drying zone for said concentrate.
19. The system defined in claim 2, wherein said first filtration zone comprises nanofiltration.
20. The system defined in claim 19, wherein said second filtration zone comprises reverse osmosis.
21. The system defined in claim 20, wherein said outlet zone receives the filtrate from said second filtration zone.
22. The system defined in any one of claims 2, 19, 20 or 21, further comprising a residue treatment zone into which is fed the residue from at least one of said first filtration zone and said second filtration zone.
23. The system defined in any one of claims 2, 19, 20 or 21, further comprising a residue treatment zone into which is fed the residue from both of said first filtration zone and said second filtration zone.
24. The system defined in claim 22, wherein said residue treatment zone comprises a vacuum distillation zone producing a distillate and a concentrate.
25. The system defined in claim 23, wherein said residue treatment zone comprises a vacuum distillation zone producing a distillate and a concentrate.
26. The system defined in any one of claims 23, 24 or 25, wherein said vacuum distillation zone further comprises a third filtration zone for said distillate producing a third filtrate.
27. The system defined in claim 26, wherein said third filtration zone comprises an activated carbon filtration zone and a cation exchange zone.
28. The system defined in claim 26, wherein said outlet zone receives said third filtrate.
29. The system defined in claim 27, wherein said outlet zone receives said third filtrate.
30. The system defined in claim 24, wherein said vacuum distillation zone further comprises drying zone for said concentrate.
31. The system defined in any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 12,13, 15, 16, 18, 19, 20, 21, 24, 25, 27, 28, 29, 30, further comprising a pre-filtration zone into which said wastewater is introduced from said inlet zone.
32. The system defined in claim 31, wherein said pre-filtration zone comprises a solids filtration zone and an ultraviolet radiation treatment zone.
33. A closed loop process for treating wastewater from a photographic process comprising chemical compounds used in the photographic process, said closed loop process comprising the steps of:
(a) feeding wastewater from said photographic process to an inlet zone;
(b) feeding said wastewater from the inlet zone to a filtration zone;
(c) treating said wastewater in said filtration zone to produce a filtrate substantially free from said chemical compounds; and (d) feeding said filtrate as fresh wash water to said photographic process.
(a) feeding wastewater from said photographic process to an inlet zone;
(b) feeding said wastewater from the inlet zone to a filtration zone;
(c) treating said wastewater in said filtration zone to produce a filtrate substantially free from said chemical compounds; and (d) feeding said filtrate as fresh wash water to said photographic process.
34. The process defined in claim 33, wherein said filtration zone comprises a first filtration zone and a second filtration zone, said first filtration zone receiving said wastewater.
35. The process defined in claim 34, wherein said inlet zone comprises means for introducing said wastewater into said first filtration zone separately as fixer wastewater and non-fixer wastewater.
36. The process defined in claim 35, wherein said first filtration zone comprises a fixer wastewater filtration zone capable of removing substantially all silver and organic compounds from said fixer wastewater to produce a first filtrate and a non-fixer wastewater filtration zone capable of removing substantially allorganic compounds from said non-fixer wastewater to produce a second filtrate.
37. The process defined in claim 36, wherein said fixer wastewater filtration zone comprises nanofiltration.
38. The process defined in claim 36, wherein said non-fixer wastewater filtration zone comprises nanofiltration.
39. The process defined in claim 36, wherein both of said fixer wastewaterfiltration zone and said non-fixer wastewater filtration zone comprise nanofiltration.
40. The process defined in claim 36, wherein said second filtration zone receives at least one of said first filtrate and said second filtrate from said first filtration zone.
41. The process defined in claim 36, wherein said second filtration zone receives both of said first filtrate and said second filtrate from said first filtration zone.
42. The process defined in any one of claims 34, 35, 36, 37, 38, 39, 40 or 41, wherein said second filtration zone comprises reverse osmosis.
43. The process defined in any one of claims 40 or 41, wherein said outletzone receives the filtrate from said second filtration zone.
44. The process defined in claim 36, further comprising a residue treatment zone into which is fed the residue from at least one of said non-fixer wastewater filtration zone and said second filtration zone.
45. The process defined in claim 36, further comprising a residue treatment zone into which is fed the residue from both of said non-fixer wastewater filtration zone and said second filtration zone.
46. The process defined in any one of claims 44 or 45, wherein said residue treatment zone comprises a vacuum distillation zone producing a distillate and a concentrate.
47. The process defined in claim 46, wherein said vacuum distillation zonefurther comprises a third filtration zone for said distillate producing a third filtrate.
48. The process defined in claim 47, wherein said third filtration zone comprises an activated carbon filtration zone and a cation exchange zone.
49. The process defined in claim 47 or 48, wherein said outlet zone receives said third filtrate.
50. The process defined in claim 46, wherein said vacuum distillation zonefurther comprises drying zone for said concentrate.
51. The process defined in claim 34, wherein said first filtration zone comprises nanofiltration.
52. The process defined in claim 51, wherein said second filtration zone comprises reverse osmosis.
53. The process defined in claim 52, wherein said outlet zone receives thefiltrate from said second filtration zone.
54. The process defined in any one of claims 34, 51, 52 or 53, further comprising a residue treatment zone into which is fed the residue from at least one of said first filtration zone and said second filtration zone.
55. The process defined in any one of claims 34, 51, 52 or 53, further comprising a residue treatment zone into which is fed the residue from both of said first filtration zone and said second filtration zone.
56. The process defined in claim 54, wherein said residue treatment zone comprises a vacuum distillation zone producing a distillate and a concentrate.
57. The process defined in claim 55, wherein said residue treatment zone comprises a vacuum distillation zone producing a distillate and a concentrate.
58. The process defined in any one of claims 55, 56 or 57, wherein said vacuum distillation zone further comprises a third filtration zone for said distillate producing a third filtrate.
59. The process defined in claim 58, wherein said third filtration zone comprises an activated carbon filtration zone and a cation exchange zone.
60. The process defined in claim 58, wherein said outlet zone receives said third filtrate.
61. The process defined in claim 59, wherein said outlet zone receives said third filtrate.
62. The process defined in claim 56, wherein said vacuum distillation zone further comprises drying zone for said concentrate.
63. The process defined in any one of claims 33, 34, 35, 36, 37, 38, 39, 40, 41, 44, 45, 47, 48, 50, 51, 52, 53, 56, 57, 59, 60, 61, 62, further comprising a pre-filtration zone into which said wastewater is introduced from said inlet zone.
64. The process defined in claim 63, wherein said pre-filtration zone comprises a solids filtration zone and an ultraviolet radiation treatment zone.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2044107 CA2044107A1 (en) | 1991-06-07 | 1991-06-07 | Closed loop photographic process wastewater treatment system and process therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2044107 CA2044107A1 (en) | 1991-06-07 | 1991-06-07 | Closed loop photographic process wastewater treatment system and process therefor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2044107A1 true CA2044107A1 (en) | 1992-12-08 |
Family
ID=4147762
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2044107 Abandoned CA2044107A1 (en) | 1991-06-07 | 1991-06-07 | Closed loop photographic process wastewater treatment system and process therefor |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2044107A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2748130A1 (en) * | 1996-04-29 | 1997-10-31 | Kodak Pathe | METHOD AND DEVICE FOR SELECTIVE EXTRACTION OF HALOGENIC IONS FROM PHOTOGRAPHIC BATHS |
| EP0621237B1 (en) * | 1993-04-19 | 2000-10-11 | SCAN GRAPH ApS | Method and apparatus for purification of rinsing fluids from the graphic industries |
-
1991
- 1991-06-07 CA CA 2044107 patent/CA2044107A1/en not_active Abandoned
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0621237B1 (en) * | 1993-04-19 | 2000-10-11 | SCAN GRAPH ApS | Method and apparatus for purification of rinsing fluids from the graphic industries |
| FR2748130A1 (en) * | 1996-04-29 | 1997-10-31 | Kodak Pathe | METHOD AND DEVICE FOR SELECTIVE EXTRACTION OF HALOGENIC IONS FROM PHOTOGRAPHIC BATHS |
| US5958245A (en) * | 1996-04-29 | 1999-09-28 | Eastman Kodak Company | Method for regenerating seasoned aqueous fixing or bleach/fixing solutions |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20010607 |