JP2005261994A - Photograph waste liquid treatment method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photograph waste liquid treatment method and apparatus which enable the productivity efficiency improvement of dehydration and solidification by the drying of high moisture content solid precipitations generated by the decomposition of chemical substances in photograph waste liquid, a reduction of transport costs by a weight reduction of solid-containing waste, and a reduction of operation costs for final treatment. <P>SOLUTION: A porous filter means 16 for collecting solid decomposed materials P is accommodated and held in a separation container 15. The separation container 15 is rotated to centrifuge the solid decomposed materials P by a centrifugal filter 14. After the centrifugal separation, hot air is supplied for drying the solid decomposed materials P collected by the porous filter means 16. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a processing method and processing apparatus for photographic waste liquid that collects solid decomposition products generated by decomposition of chemical substances contained in photographic waste liquid to obtain a solid substance having a low water content.

  Conventionally, a photographic waste liquid contains a solid decomposition product of a chemical substance generated during a decomposition process, and a separation process for removing the solid decomposition product from the photographic waste liquid has been performed. As an apparatus for separating a solid decomposition product, for example, as shown in Patent Document 1 below, it was separated and recovered by porous filter filtration.

  Moreover, as a method of solid-liquid separation, for example, as shown in Patent Documents 2, 3, 4, and 5 below, separation by a liquid cyclone, a centrifugal separator, and a centrifugal filter is performed.

Japanese Patent No. 3384166 Japanese Patent No. 2825695 Japanese Patent No. 3046554 JP-A-8-192200 Japanese Patent Laid-Open No. 5-68980

  However, in the separation treatment by filtration of the porous filter, the frequency of replacement of the porous filter was high due to adhesion of solid content on the porous filter surface and clogging of filter holes. In addition, the solid water content of the chemical substance generated during the decomposition process of the photographic waste liquid was about 90%, and it was difficult to recover and remove from the porous filter.

  Furthermore, a great deal of labor is required for handling the slurry-like solids removed for the recovery process and for cleaning the equipment used, and it has been necessary to perform cleaning using a large amount of cleaning water.

  The water content of the solid slurry separated by the liquid cyclone is 98% or more, and handling such as transfer for recovery is easy, but in order to reduce the water content, dehydration by centrifugal filtration or the like is performed. It was necessary to do.

  Patent Document 4 discloses a method of drying a dewatered sewage sludge cake using a centrifuge with a dryer. However, the moisture content of the dewatered sewage sludge cake is around 80%, and it is not easy to transfer and handle to a separately installed dryer, and the residual residue in the centrifuge or transfer pipe Treatment and recovery of the occurrence and its attached residue is also necessary, but no specific method and apparatus are described.

  In the processing of the photosensitive material processing waste liquid of Patent Document 5 described above, solid content is separated using a centrifugal filter. However, there is no description about a solid content recovery process and a drying method from the filter cloth.

  The present invention has been made in view of the above circumstances, and its purpose is to improve the productivity efficiency of dehydration and dry solidification of solid precipitates with a high water content generated by the decomposition of chemical substances in photographic processing waste liquid, solid content It is an object of the present invention to provide a photographic waste liquid processing method and a photographic processing waste liquid processing apparatus that reduce transportation costs and reduce final processing operation costs by reducing waste.

  The above object of the present invention is to process a photographic waste liquid that circulates the photographic waste liquid along a circulation path and clarifies and drains the photographic waste liquid by collecting solid decomposition products contained in the photographic waste liquid. A porous filter means for collecting the solid decomposition product, and a centrifugal filter for centrifuging the solid decomposition product by rotating and holding the porous filter means in the separation container and rotating the separation container, In order to dry the solid decomposition product collected by the porous filter means after centrifugation, a drying means for blowing hot air to the solid decomposition product is provided.

  The apparatus for processing photographic waste liquid according to the present invention is capable of collecting solid decomposition products contained in the photographic waste liquid with a centrifugal filter, and includes drying means for drying the solid decomposition products collected after centrifugation. ing. After the centrifugal separation, the collected solid decomposition product contains moisture, but by blowing warm air from the drying means to the solid decomposition product, the moisture contained in the solid decomposition product is evaporated and reduced. be able to. Therefore, since the moisture content of the collected solid decomposition product becomes extremely small, the operation of recovering and removing the solid decomposition product from the porous filter means and handling of the recovered solid decomposition product becomes easy. In addition, it is possible to prevent the solid decomposition product from adhering to the porous filter means and making it difficult to remove, and the porous filter means from which the solid decomposition product has been recovered and removed can be used repeatedly. Furthermore, by reducing the water content of the solid decomposition product, the volume can be reduced as compared with the collected solid decomposition product.

  The above photographic waste liquid treatment device is arranged on the upstream side of the centrifugal filter in the circulation path by centrifuging the photographic waste liquid to separate solid decomposition products as precipitates, and a liquid cyclone capable of supplying the precipitates to the centrifugal filter is disposed. It is preferable that

  This photographic waste liquid processing apparatus is configured to drive a centrifugal filter and then perform centrifugal separation after the solid decomposition product separated by the liquid cyclone is supplied to the centrifugal filter. A hydrocyclone has a lower running cost than a centrifugal filter. For this reason, the said processing apparatus can reduce a running cost compared with the structure which always drives only a centrifugal filter and performs centrifugation.

  It is preferable that the photographic waste liquid processing apparatus is provided with a stock tank capable of storing the photographic waste liquid and adding a flocculant to the photographic waste liquid stored after the centrifugation in the circulation path.

  In this processing apparatus, a stock tank is provided in the circulation path, and the flocculant is circulated through the circulation path together with the photographic waste liquid by adding the flocculant to the stock tank. And this flocculant is collected with the solid decomposition product already collected in the porous filter means. Then, the operation | work which collects and removes a solid decomposition product from a porous filter means becomes still easier.

  In addition, the above-described object of the present invention is to circulate the photographic waste liquid along the circulation path, and to clarify and drain the photographic waste liquid by clarifying and draining the photographic waste liquid by collecting solid decomposition products contained in the photographic waste liquid. A processing method, in which a porous filter means for collecting solid decomposition products is housed and held in a separation container, and the solid decomposition products are centrifuged by a centrifugal filter by rotating the separation container. This is achieved by a method for treating photographic waste liquid, characterized in that hot air is supplied to dry the solid decomposition product collected by the means.

  The photographic waste liquid treatment method described above is that after centrifugation, the water contained in the collected solid decomposition product is evaporated by blowing warm air from the drying means to the solid decomposition product, and as a result, collected. The water content of the solid decomposition product can be extremely reduced. For this reason, the operation | work which collects and removes a solid decomposition product from a porous filter means and handling of the collect | recovered solid decomposition product become easy. In addition, it is possible to prevent the solid decomposition product from adhering to the porous filter means and making it difficult to remove, and the porous filter means from which the solid decomposition product has been recovered and removed can be used repeatedly. Furthermore, by reducing the water content of the solid decomposition product, the volume can be reduced as compared with the collected solid decomposition product.

  The above-mentioned photographic waste liquid treatment method uses a liquid cyclone arranged upstream of the centrifugal filter in the circulation path to centrifuge the photographic waste liquid to separate the solid decomposition product as a precipitate, and the precipitate to the centrifugal filter. It is preferable to supply.

  If it carries out like this, after centrifuging with the liquid cyclone whose running cost is lower than a centrifugal filter, what is necessary is just to drive the centrifugal filter and to centrifuge the solid decomposition product supplied from the liquid cyclone. For this reason, the processing method of the said photographic waste liquid can reduce a running cost compared with the processing method which always drives only a centrifugal filter and performs centrifugation.

  In the photographic waste liquid treatment method described above, it is preferable to add a flocculant to the photographic waste liquid after centrifugation and circulate it to aggregate the solid decomposition product.

  By doing so, the operation of recovering and removing the solid decomposition product from the porous filter means is further facilitated.

  Further, the above object of the present invention is to recycle the photographic waste liquid along a circulation path, and to clarify and drain the photographic waste liquid by collecting the solid decomposition product contained in the photographic waste liquid. The solid decomposition product obtained by centrifuging the solid decomposition product by centrifugal separation means and then aggregating the coagulant into the photographic waste liquid to circulate is collected. This is achieved by a waste liquid treatment method.

  The processing method of the above photographic waste liquid is first a step of collecting a solid decomposition product by a centrifugal separator such as a centrifugal filter or a liquid cyclone, and then adding a flocculant to the photographic waste liquid. A step of circulating the photographic waste liquid is performed. Then, the flocculant is also collected together with the solid decomposition product. As a result, the flocculant is mixed into the collected solid decomposition product, so that the solid decomposition product can be easily recovered and removed.

  According to the present invention, the productivity efficiency of dewatering and drying solidification of high water content solid precipitates generated by the decomposition of chemical substances in photographic processing waste liquid is improved, the transportation cost is reduced by reducing the amount of solid containing waste, and the final It is possible to provide a photographic waste liquid processing method and a photographic processing waste liquid processing apparatus capable of reducing processing operation costs.

Embodiments of a photographic waste liquid processing apparatus and processing method according to the present invention will be described below in detail with reference to the drawings.
FIG. 1 shows a first embodiment of a photographic liquid processing apparatus according to the present invention. The photographic waste liquid processing apparatus 10 is configured to circulate the photographic waste liquid W along a circulation path and to clarify and drain the photographic waste liquid W by collecting solid decomposition products generated in the photographic waste liquid W. is there. The method for processing photographic waste liquid according to the present invention can be preferably carried out by using the photographic waste liquid processing apparatus 10 described above.

  The photographic waste liquid contains many kinds of waste liquids generated in the photographic industry such as fixing waste liquid or photolithography, in addition to waste liquids of photographic processing liquids used for processing color photosensitive materials and monochrome photosensitive materials.

  Constituent chemicals that were not included in the photographic processing solution formulation and were not consumed in the photographic waste solution, that is, a developing agent derived from a developer, an alkali compound, a buffer, a preservative such as a sulfite or a hydroxylamine derivative, an alkali halide, etc. Bleaching agents such as ammonium salts, sodium salts, potassium salts, and alkali halides of thiosulfuric acid and sulfite derived from fixing processing solutions, and iron (III) complex salts of polyaminopolycarboxylic acids derived from bleaching processing solutions, rehalogenating agents, and buffers In addition to salt and other functional compounds such as water softeners and surfactants discharged from each process tank, elution components such as gelatin and photosensitive dyes that are eluted from the photosensitive material during processing In addition, reaction products generated during the treatment are mixed, and a wide variety of chemical components are included.

  From the viewpoint of the water quality and environmental factors, the photographic waste liquid contains high concentrations of BOD, COD, nitrogen, and phosphorus, and contains a large amount of hardly decomposable components even by biological treatment or chemical treatment. Although it varies considerably depending on the type of treatment and the mixing ratio of waste liquid from each step of the treatment, it is approximately COD 30,000 to 50,000 mg / l, BOD 5,000 to 15,000 mg / l, TOC (Total Organic Carbon) 10,000 to 25,000 mg / l l, Kjeldahl nitrogen 10,000-15,000 mg / l, total phosphorus 100-500 mg / l. The ratio of COD: BOD: TOC is approximately 4: 1: 1.5, which is characterized by high COD, and the element ratio of C: N: P is approximately 100: 100: 1, which is characterized by high N content.

  As shown in FIG. 1, the photographic waste liquid processing apparatus 10 of this embodiment is provided in a stock tank 11 in which photographic waste liquid W is stored in order along the circulation direction of the circulation path, and on the downstream side of the stock tank 11. The valve V11, the liquid feed pump 12 for sending the photographic waste liquid W to the downstream side of the circulation path at a predetermined pressure, and the chemical substances contained in the photographic waste liquid W are decomposed by electrolytic oxidation or ultrasonic cavitation decomposition. A decomposition device 13 and a centrifugal filter 14 that centrifuges solid decomposition products generated in the photographic waste liquid W by the decomposition device 13 are provided.

  The centrifugal filter 14 includes a substantially bowl-shaped separation container 15 therein. A peripheral wall surface of the separation container 15 is formed in a substantially net shape, and a drive shaft 17 is coupled to the bottom surface. The drive shaft 17 is connected to the motor M. The separation container 15 is configured such that when the motor M is driven, a driving force is transmitted from the drive shaft 17 and rotates.

  A liquid leakage prevention seal member S is provided between the outer container of the centrifugal filter 14 and the drive shaft 17.

  The separation container 15 has a porous filter 16 formed in a bag shape therein. The porous filter 16 functions as a porous filter means for collecting the solid decomposition product P contained in the photographic waste liquid W by filtering the photographic waste liquid W circulating in the circulation path.

  As the porous filter 16, a UF membrane, an RO membrane, a porous polymer single membrane filter, a ceramic single membrane filter, and a pulp fiber filter can be used. Any one having a pore size of 0.05 μm to 50 μm, preferably 0.1 μm to 30 μm, more preferably 0.2 μm to 10 μm may be used. Specifically, single membrane filters of porous polymers such as vinyl chloride, polyethylene, polypropylene, polybutylene, polysulfone, acrylonitrile, porous glass, unglazed plates, igneous rock plates, ceramic single membrane filters such as foaming nitride, filter paper , 0.01 denier fiber (nylon, polypropylene, polyethylene) fiber filter, and the like. Commercially available products of these filters include various Yumicron membranes manufactured by Yuasa Co., Ltd., Millipore filters manufactured by Millipore (for example, Millipore AA, DA, HA, PH, GS, FG, UC, UM, US, GU, HP). And Kuraray Co., Ltd. microfiltration filters (SF-301, SF-101, SF-401), and Gore-Tex membranes manufactured by Gore-Tex.

  The centrifugal filter 14 rotates the separation container 15 to separate moisture from the solid decomposition product of the porous filter 16 accommodated and held in the separation container, and discharges the water to the outside of the separation container. The discharged water is supplied downstream of the circulation path by the filtrate pipe 14a provided at the bottom of the centrifugal filter.

  A filtrate stock tank 18 for storing the photographic waste liquid W discharged from the filtrate tube 14 a is provided downstream of the centrifugal filter 14.

  Further, the processing apparatus 10 according to the present embodiment is provided with a level detector 19 that detects the storage amount of the photographic waste liquid W according to the water surface position of the photographic waste liquid W stored in the filtrate stock tank 18.

  A liquid feed pump 22 that feeds the photographic waste liquid W to the stock tank 11 is provided downstream of the filtrate stock tank 18.

  Further, a three-way valve V13 capable of switching the flow of the photographic waste liquid W flowing from the liquid feed pump V22 side in two directions is provided downstream of the liquid feed pump V22. At the time of centrifugation, the three-way valve V13 is adjusted so that the photographic waste liquid W fed from the liquid feeding pump 22 is circulated to the stock tank 11. When draining the clarified photographic waste liquid W after centrifugation, the three-way valve V13 is switched, and the photographic waste liquid W fed from the liquid feed pump 22 is drained in the direction shown in FIG.

  In the upper part of the stock tank 11, an exhaust pipe 11a for discharging gas generated in the circulation path of the photographic waste liquid W is provided. In addition, an exhaust pipe 14b is provided at the upper part of the centrifugal filter 14 in order to discharge the gas in the same manner.

  The processing apparatus 10 for photographic waste liquid of the present embodiment includes a drying device 21 that functions as a drying means for drying the solid decomposition product collected by the porous filter 16 after centrifugation. The drying device 21 includes a blower pipe 21a connected to the upper part of the centrifugal filter 14, and the solid decomposition product P collected by the porous filter 16 inside the centrifugal separator 14 is dried through the blower pipe 21a. It is the structure which blows warm air.

  Further, the processing apparatus 10 is provided with a magnetic coupling type stirring unit 23 at the bottom of the stock tank 11. When the aggregating agent described later is added to the photographic waste liquid W stored in the stock tank 11, the agitating unit 23 rotates the photographic waste liquid W in the photographic waste liquid W by rotating the agitating blade 23a. It functions as a stirring means to be mixed.

  Next, a process of collecting a solid decomposition product from the photographic waste liquid and clarifying the photographic waste liquid by the processing apparatus of this embodiment will be described.

  First, the photographic waste liquid W is stored in the stock tank 11, the valves V11 and V12 are opened, and the three-way valve V13 is adjusted so as to allow the circulation of the photographic waste liquid W from the liquid feed pump 22 to the stock tank 11. Further, the liquid feed pump 12 is driven to feed the photographic waste liquid W stored in the stock tank 11 along the circulation path.

  The photographic waste liquid W is sent to the decomposition apparatus 13 by the liquid feed pump 12, and chemical substances contained in the photographic waste liquid W are decomposed by the electrolytic oxidation method or the ultrasonic cavitation decomposition method in the decomposition apparatus 13.

  After the decomposition process, the photographic waste liquid W is fed by the liquid feed pump 12 into the driven centrifugal filter 14. The photographic waste liquid W injected into the centrifugal filter 14 is filtered by the porous filter 16 held in the separation container 15 that rotates at high speed. The separated filtrate is stored in the filtrate stock tank 18 via the filtrate tube 14a.

  The photographic waste liquid W stored in the filtrate stock tank 18 is detected by the level detector 19, and when the storage amount reaches a predetermined level, the liquid feed pump 22 is driven to send the stored photographic waste liquid W to the stock tank 11.

  In the present embodiment, the centrifugal acceleration of the separation container 15 of the centrifugal filter 14 is set to 800G to 3000G, and preferably 1000G to 2000G from the viewpoint of equipment and running cost. The pore size of the porous filter 16 is 1 μm to 50 μm, preferably 3 μm to 10 μm.

  After the separation of the photographic waste liquid W is completed, the liquid feeding pumps 12 and 22 are stopped, the flocculant is added to the stock tank 11 and stirred by the stirring means (stirring unit 23), and the photographic waste liquid W and the flocculant are mixed. To do. At this time, the amount of the flocculant to be added is 0.01 g to 0.5 g, preferably 0.05 g to 0.1 g, per liter of the photographic waste liquid W.

  After the flocculant is mixed with the photographic waste liquid W, the liquid feeding pumps 12 and 22 are driven, and the photographic waste liquid W is filtered by the porous filter 16 held in the separation container 15 rotating at high speed inside the centrifugal filter 14. . Then, ultrafine particles in the circulation path are aggregated, and these aggregated particles are collected by the porous filter 16 and the solid decomposition product (solid slurry) deposited on the porous filter 16 is peeled off. It becomes easy to do.

  Examples of the flocculant include inorganic flocculants such as aluminum sulfate, magnesium sulfate, polyaluminum chloride, calcium chloride, magnesium chloride, polyaluminum chloride, or organic flocculants such as polyacrylamide polymers and polyacrylic acid (salt). desirable.

  After adding the flocculant, the photographic waste liquid W is circulated through the circulation path about 2 to 3 times, the three-way valve V13 is switched to the drain side, and the photographic waste liquid W stored in the filtrate stock tank 18 is drained.

  After drainage of the filtrate, the rotational speed of the centrifugal filter 14 is set to a low speed of 50 rpm to 300 rpm, and hot air (50 ° C. to 100 ° C.) dried from the drying device 21 through the blower tube 21a is blown into the centrifugal filter 14 to obtain porous. The solid decomposition product P collected by the filter 16 is dried. Since the dried decomposed solid matter P can be easily peeled off from the porous filter 16 when the surface of the porous filter 16 is lightly vibrated, it is not necessary to wash the porous filter 16, and the porous filter 16 is removed again. Will be able to use. In addition, the decomposed solid material solidified by drying becomes a solid material that is not redissolved because it contains a small amount of water, and becomes a material that can be easily handled in the subsequent transport process and the like.

  FIG. 2 shows a second embodiment of the photographic liquid processing apparatus according to the present invention. In the embodiments described below, members having the same configuration / action as those already described are denoted by the same or corresponding reference numerals in the drawings, and description thereof is simplified or omitted.

  As shown in FIG. 2, the photographic waste liquid processing apparatus 20 of this embodiment includes a stock tank 11, a valve V21 provided on the downstream side of the stock tank 11, and a liquid feed in order along the circulation direction of the circulation path. A pump 12, a valve V22, and a decomposition device 13 are provided.

  The processing apparatus 20 of this embodiment includes a hydrocyclone 25 downstream of the decomposition apparatus 13. The liquid cyclone 25 injects the photographic waste liquid W sent from the decomposition apparatus 13 into the inside, and centrifuges the solid decomposition product contained in the photographic waste liquid W by turning the injected photographic waste liquid W into a rotating flow. It precipitates downward as a precipitate by its own weight. The liquid cyclone 25 is configured to collect these precipitates through a orifice 25a by a collection container 26 installed below the liquid cyclone 25 and to send the separated photographic waste liquid W to the downstream side of the circulation path. is there.

  The photographic waste liquid W separated by the hydrocyclone 25 is sent to the stock tank 11 via the valve V23.

  A photographic waste liquid supply path is formed below the hydrocyclone 25 and the recovery container 26 so as to reach the centrifuge 14 via the valve V24. The configuration of the centrifuge 14 of the present embodiment is basically the same as that in the processing apparatus 10 of the first embodiment.

  Next, a process of collecting a solid separation from the photographic waste liquid and clarifying the photographic waste liquid by the processing apparatus of this embodiment will be described.

  First, the photographic waste liquid W is stored in the stock tank 11, the valves V21, V22 and V23 are opened, the liquid feed pump 12 is driven, and the photographic waste liquid W is fed along the circulation path.

  The photographic waste liquid W is decomposed in the decomposition device 13 and then injected into the liquid cyclone 25 by the liquid feed pump 12 and centrifuged, and the solid decomposition product P contained in the photographic waste liquid W is collected as a precipitate. 26 is deposited.

  After the predetermined solid decomposition product P is deposited in the recovery container 26, the liquid feeding pump 12 is stopped, the flocculant is added to the stock tank 11, and the mixture is stirred by the stirring means (stirring unit 23) to coagulate with the photographic waste liquid W. Mix the agent. At this time, the amount of the flocculant to be added is the same as that in the first embodiment.

  After the flocculant is mixed with the photographic waste liquid W, the liquid feed pump 12 is driven to circulate the circulation path through the liquid cyclone 25. After the photographic waste liquid W has circulated through the circulation path for about 2 to 3, the valve V24 located downstream of the hydrocyclone 25 is opened and the valve V23 is closed to centrifuge the solid decomposition product P deposited in the recovery container 26. Slowly send to 14. In the centrifugal separator 14, the solid decomposition product P is filtered by the porous filter 16 accommodated and held in the separation container 15 that rotates at high speed. In the processing apparatus 20, the filtrate produced by filtration is drained from the filtrate pipe 14a.

  In this embodiment, the conditions for centrifugal filtration in the centrifuge 14 are the same as those in the first embodiment.

  Further, after draining the filtrate, the solid decomposition product P collected by the porous filter 16 of the centrifugal filter 14 is dried by the drying device 21. At this time, the drying conditions of the solid decomposition product P are the same as those in the first embodiment.

  As described in the first embodiment and the second embodiment, the photographic waste liquid processing apparatus 10, 20 according to the present invention captures the solid decomposition product P contained in the photographic waste liquid W by the centrifugal filter 14. A drying means (drying device 21) for drying the solid decomposition product P collected after centrifugation can be provided. After the centrifugal separation, the collected solid decomposition product P contains moisture, but it is reduced by evaporating the water contained in the solid decomposition product P by blowing hot air from the drying means to the solid decomposition product P. Can be made. Therefore, since the moisture content of the collected solid decomposition product P is extremely small, the solid decomposition product P is recovered and removed from the porous filter means (porous filter 16) and the recovered solid decomposition product P is handled. Becomes easier. Further, by drying with a drying means, it is possible to prevent the solid decomposition product P from adhering to the porous filter means and making it difficult to remove, and it is possible to repeatedly use the porous filter means from which the solid decomposition product P has been recovered and removed. become able to. Furthermore, by reducing the water content of the solid decomposition product P, the volume can be reduced as compared with the collected solid decomposition product.

  If the liquid cyclone 25 is arranged upstream of the centrifugal filter 14 as in the second embodiment, the liquid cyclone 25 has a lower running cost than the centrifugal filter 14, so The processing device 20 can reduce the running cost compared to a configuration in which only the centrifugal filter 14 is always driven to perform centrifugation.

  Further, as in the first embodiment and the second embodiment, the stock tank 11 is provided in the circulation path, and the flocculant is added to the stock tank 11 together with the photographic waste liquid W by the circulation path. , The flocculant is collected together with the solid decomposition product P already collected in the porous filter means, and the solid slurry deposited on the porous filter means becomes easy to peel off. The operation of collecting and removing the solid decomposition product P from the filter means becomes even easier.

  The processing method of the photographic waste liquid using the processing apparatus 10 (or 20) of the said 1st Embodiment or 2nd Embodiment is a means for drying the moisture contained in the collected solid decomposition product after centrifugation. The solid decomposition product P is evaporated by blowing hot air on it, and as a result, the moisture content of the collected solid decomposition product P can be extremely reduced. For this reason, the operation | work which collects and removes the solid decomposition product P from a porous filter means and handling of the collect | recovered solid decomposition product P becomes easy. Moreover, it can prevent that the solid decomposition product P adheres to a porous filter means, and it becomes difficult to remove, and the porous filter means from which the solid decomposition product P was collect | recovered and removed can be used repeatedly. Furthermore, by reducing the water content of the solid decomposition product, the volume can be reduced as compared with the collected solid decomposition product.

  If the liquid cyclone 25 arranged on the upstream side of the centrifugal filter 14 in the circulation path centrifuges the photographic waste liquid W to separate the solid decomposition product P as a precipitate, and supplies the precipitate to the centrifugal filter 14, The running cost spent for centrifugation can be reduced.

  Furthermore, if the coagulant is added and circulated in the photographic waste liquid W after centrifugation to aggregate the solid decomposition product P, the operation of recovering and removing the solid decomposition product P from the porous filter means becomes even easier.

  Further, first, a step of collecting the solid decomposition product P by a centrifugal separation means such as a centrifugal filter 14 or a liquid cyclone 25 is performed, and after adding a flocculant to the photographic waste liquid W, the photographic waste liquid W is circulated. When the process is performed, the flocculant is also collected together with the solid decomposed product P. As a result, the flocculant is mixed into the collected solid decomposed product P, thereby recovering the solid decomposed product P. Easy to remove.

(Example)
Examples of the method for treating photographic liquid according to the present invention will be described below. In this example, Comparative Example 1 and Comparative Example 2 as described below will be described in order to prove the effect of the method for treating photographic liquid according to the present invention. In the photographic waste liquid treatment method of this example, the photographic waste liquid treatment apparatus shown in FIG. 1 was used.

  In this embodiment, as a photographic waste solution, a print color printing is performed on a commercially available color paper (Fuji color paper super) using a Fuji Photo Film printer F350, and processing is performed using a processing material CP-48S for Fuji color paper. A mixture of the developing waste solution obtained as an overflow solution from each of the development, bleach-fixing, and washing baths, the bleach-fixing waste solution, and the washing waste solution obtained as a processing waste solution (photographic waste solution) was used.

Samples of this treatment waste liquid were TOC 12016 mg / liter, EDTA 1484 mg / liter (iron conversion standard), ammonium salt 8480 mg / liter (NH ₃ conversion standard), thiosulfate ion 25200 mg / liter, silver thiosulfate complex amount 2880 mg / liter ( Silver conversion standard). This treatment waste liquid decomposed chemical substances by electrolytic oxidation to produce a solid precipitate.

As Comparative Example 1, the sample liquid 5 liter the waste solution, with decomposition chemicals through an electrical oxidizer (cracker) in the circulating liquid passing amount 1.4 liters per minute, the nominal 5μm pore size, filtration effective area 800 cm ² The produced precipitate was filtered and refluxed with a porous polymer cylindrical single membrane filter. However, in Comparative Example 1, the filter was clogged before the sample liquid of the processing waste liquid was completely decomposed, the filter filtration pressure became 0.4 MPa, the filter was changed twice, and the filter from the filter with the deposited deposit was removed. It was difficult to separate and collect the solid material slurry, and the recovered slurry had a water content of 93% and was about 140 g, and the recovery rate was about 55%.

As Comparative Example 2, 5 liters of sample liquid of the above-mentioned treatment waste liquid was decomposed through a chemical oxidation device (decomposition device) with a circulating flow rate of 1.4 liters per minute while decomposing chemical substances with a nominal 5 μm pore size and an effective filtration area of 140 cm ^2. The decomposition treatment was performed while filtering at a centrifugal acceleration of 1400 G with a centrifugal filter having a porous single membrane filter. After the decomposition of the waste liquid, the water content of the solid slurry material obtained at this time was about 84%. The amount of the water-containing solid slurry material corresponds to an amount of 2.3% of the amount of the raw liquid waste by weight ratio. In this state, the recovery rate of the solid slurry material that was recovered by taking out the filter was about 74% due to adhesion of the filter to the filter.

In Example 1, 5 liters of sample liquid of the above treatment waste liquid was passed through an electric oxidation device (decomposition device) at a circulating flow rate of 1.4 liters per minute while decomposing chemical substances. ^The decomposition treatment was carried out while filtering at a centrifugal acceleration of 1400 G with a centrifugal filter having ² porous single membrane filters. After the decomposition of the treatment waste liquid, 0.1 g of a polyacrylamide polymer flocculant (Super Growth A-121, manufactured by Ebara Manufacturing Co., Ltd.) is added to the stock tank of the photographic waste liquid, stirred and mixed, and then the treatment waste liquid is circulated. After circulating in the path for 10 minutes, the three-way valve was switched to discharge the filtrate. After discharging the filtrate, the centrifugal speed is set to 100 rpm, the air volume is 7 liters / minute, hot air is blown at a temperature of 90 ° C. for 5 minutes, and then the heater power is turned off for 15 minutes. Again, warm air was blown at a temperature of 90 ° C. for 5 minutes, the heater was turned off, and air was blown for 20 minutes to dry. The dried solid decomposition product was easily peeled off from the filter, and the water content of the solid decomposition product was less than 1%, and the recovery rate was about 99%. The amount of the solid substance was 0.3% of the amount of the raw waste liquid in a ratio as a weight.

  In other words, it is possible to recover the decomposition product precipitates of chemical substances in the photographic processing waste liquid in a short time with an easy operation efficiently and at a high recovery rate, and the recovery processing transport amount is 1% of the raw waste liquid amount. Could be done in less than.

It is a figure which shows 1st Embodiment of the processing apparatus of the photographic waste liquid which concerns on this invention. It is a figure which shows 2nd Embodiment of the processing apparatus of the photographic waste liquid which concerns on this invention.

Explanation of symbols

10, 20 Photo waste liquid processing equipment 11 Stock tank 14 Centrifugal filter 15 Separation vessel 16 Porous filter (porous filter means)
21 Drying device 25 Hydrocyclone P Solid decomposition product W Photo waste liquid

Claims (7)

A photographic waste liquid treatment device that circulates a photographic waste liquid along a circulation path and clarifies and drains the photographic waste liquid by collecting solid decomposition products contained in the photographic waste liquid,
A porous filter means for collecting the solid decomposition product, and a centrifugal filter for centrifuging the solid decomposition product by rotating and holding the porous filter means in a separation container. An apparatus for processing a photographic waste liquid, comprising: drying means for supplying hot air to the solid decomposition product to dry the solid decomposition product collected by the porous filter means after centrifugation.   A liquid cyclone capable of centrifuging the photographic waste liquid to separate the solid decomposition product as a precipitate and supplying the precipitate to the centrifugal filter is disposed upstream of the centrifugal filter in the circulation path. The apparatus for processing a photographic liquid according to claim 1.   The processing of the photographic waste liquid according to claim 1 or 2, wherein a stock tank capable of storing the photographic waste liquid and adding a flocculant to the photographic waste liquid stored after centrifugation is provided in the circulation path. apparatus. A method for treating a photographic waste liquid that circulates a photographic waste liquid along a circulation path and clarifies and drains the photographic waste liquid by collecting solid decomposition products contained in the photographic waste liquid,
A porous filter means for collecting the solid decomposition product is housed and held in a separation container, the solid decomposition product is centrifuged by a centrifugal filter by rotating the separation container, and after the centrifugal separation, the porous filter means is applied to the porous filter means. A method for treating a photographic waste liquid, wherein hot air is supplied to dry the collected solid decomposition product.   The photographic waste liquid is centrifuged by the liquid cyclone arranged on the upstream side of the centrifugal filter in the circulation path to separate the solid decomposition product as a precipitate, and the precipitate is supplied to the centrifugal filter. The processing method of the photographic waste liquid of Claim 4 characterized by these.   6. The method for processing a photographic waste liquid according to claim 4, wherein a coagulant is added to the photographic waste liquid after centrifugation and circulated to aggregate the solid decomposition product. A method for treating a photographic waste liquid that circulates a photographic waste liquid along a circulation path and clarifies and drains the photographic waste liquid by collecting a solid decomposition product contained in the photographic waste liquid,
A method for processing a photographic waste solution, comprising: centrifuging the solid decomposition product by a centrifugal separator; and then aggregating the solid decomposition product collected by mixing and circulating a flocculant in the photographic waste solution.

Images