JP4465987B2 - Decolorization method and decolorization device for colored beverage drainage - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for decolorizing colored beverage wastewater, and more specifically, efficiently decolorizes colored beverage wastewater without generating waste such as sludge using a flocculant used in a conventional decolorization step. The present invention relates to a method and an apparatus.
[0002]
[Prior art]
Wastewater generated in the beverage manufacturing process (hereinafter referred to as “beverage wastewater”) is discharged into rivers and the like after various treatments in consideration of safety and the environment. In the case where the drinking water is colored, the waste water treatment is also targeted for the decoloring treatment.
[0003]
A conventional method for decoloring colored beverage wastewater is to aggregate and separate colored components in the wastewater by a flocculant. That is, as shown in FIG. 8, first, the colored beverage wastewater is introduced into the reaction tank a, and a predetermined amount of an inorganic flocculant such as ferric chloride is introduced into the reaction tank a to react with the colored components. And the surface charge of the particles is electrically neutralized to form aggregates. At the same time, a pH adjusting agent such as caustic soda is added to bring the pH of the aggregate to an appropriate range. Next, the wastewater that has been reacted is introduced into the agglomeration tank b, and a polymer flocculant is introduced into the wastewater to increase the strength and particle size of the colored component agglomerates, and the wastewater containing the agglomerates is precipitated. It introduce | transduces into the tank c, the aggregate d is settled in the precipitation tank c, and is isolate | separated. The supernatant water of the precipitation tank c from which the colored components have been separated is then discharged after being sterilized in the sterilization process. On the other hand, the agglomerates d containing the colored components that have precipitated are periodically taken out from the precipitation tank c, and are separately treated as sludge and discarded.
[0004]
[Problems to be solved by the invention]
Such a conventional decolorization method is a method in which colored components in drinking water are agglomerated and separated by an inorganic flocculant and a polymer flocculant, and sludge is discharged from the sedimentation tank. There is a problem of labor. In addition, from the viewpoint of protecting the natural environment, reduction of waste generation is strongly demanded.
[0005]
An object of the present invention is to solve the problems of the conventional decoloring method and to provide a method and an apparatus for efficiently decolorizing colored beverage wastewater without generating sludge.
[0006]
[Means for Solving the Problems]
The method for decolorizing colored beverage wastewater according to the present invention is a method for decolorizing colored beverage wastewater comprising a decolorizing step of bringing colored beverage wastewater into contact with a catalyst in the presence of an oxidizing agent. A mixing step of adding and mixing a colored beverage drainage mixed with an oxidizer with a catalyst, and the concentration of the oxidant is higher than that during normal operation when stopping the flow of the colored beverage drainage. Further, high water is brought into contact with the catalyst to decompose and remove oxidizable substances remaining on the catalyst.
[0007]
The decolorizing device for colored beverage drainage of the present invention comprises an adjustment tank provided with a means for mixing the liquid in the tank, a means for introducing the colored beverage drainage into the adjustment tank, the colored beverage drainage introduced into the adjustment tank and / or the An oxidizing agent adding means for adding an oxidizing agent to the adjustment tank, a catalyst tower filled with a metal oxide catalyst into which the outflow water from the adjustment tank is introduced, and a circulation for returning the outflow water of the catalyst tower to the adjustment tank and line, a bleaching system colored beverage wastewater and means for introducing city water or industrial water to the conditioning tank, sometimes stops water flow colored beverage wastewater instead of colored beverage wastewater in the conditioning tank City water or industrial water is introduced and an oxidizing agent is added, and water in the adjustment tank in which the oxidizing water is added to the city water or industrial water is passed through the catalyst tower, and effluent water from the catalyst tower is It is characterized by being returned to the adjustment tank and circulated.
[0008]
According to the present invention, an oxidant is added to and mixed with colored beverage effluent to oxidize and decolorize colored components in the colored beverage effluent, and then contact with a catalyst to promote decolorization, thereby providing a colored beverage. The waste water can be highly decolorized, and treated water with good water quality can be obtained stably and efficiently.
[0009]
According to the present invention, it is possible to perform decolorization at the same level or higher as before without generating sludge due to aggregation of colored components, and it is also excellent in terms of environmental protection. . Moreover, according to the present invention, it is possible to remove hardly decomposed components in the colored beverage wastewater, which is effective for improving the quality of the treated water.
[0010]
In the present invention, the decolorized water may be further treated with activated carbon. Therefore, the colored beverage waste water decoloring apparatus of the present invention may be provided with an activated carbon tower into which the outflow water of the catalyst tower is introduced. Thereby, for example, chlorine generated by decoloring treatment using a chlorine-based oxidizing agent can be removed by activated carbon, and the remaining hardly decomposed components can be adsorbed and removed by activated carbon. Further, prior to the decolorization treatment, the colored beverage wastewater may be filtered to remove foreign matters in the beverage wastewater.
[0011]
Furthermore, in the present invention, when a chlorine-based oxidizing agent is used as the oxidizing agent, the residual chlorine concentration of the decolorized water may be measured immediately after the decolorizing process. Therefore, in the decolorizing apparatus for colored beverage drainage of the present invention, a measuring means for measuring the residual chlorine concentration of the effluent of the catalyst tower may be provided. By doing so, the chromaticity of the decolorized water can be easily calculated from the measured residual chlorine concentration without requiring a complicated operation of measuring the chromaticity of the decolorized water by measuring absorbance or the like. Is possible. Furthermore, in the present invention, it is also possible to control the addition amount of the chlorine-based oxidant based on the measured residual chlorine concentration, thereby adding an appropriate amount of the chlorine-based oxidant to the colored beverage drainage. Thus, the chromaticity of the decolorized water can be efficiently brought close to a predetermined set value.
[0012]
In the present invention, the oxidizing agent is preferably sodium hypochlorite. The catalyst is preferably a nickel peroxide supported catalyst.
[0013]
In the present invention, the mixing step of the colored beverage drainage and the oxidizing agent is preferably performed for a time until the chromaticity of the mixed solution of the colored beverage drainage and the oxidizing agent reaches a predetermined chromaticity. The mixing time is appropriately set according to the chromaticity of the colored beverage drainage, the added amount of the oxidizing agent, the target chromaticity, etc., and when mixing is performed by stirring, the mixing time is, for example, 10 minutes or more. Can do.
[0014]
Moreover, it is preferable to perform also the contact process of this liquid mixture and a catalyst for the time until the chromaticity of the decoloring process water obtained reaches predetermined chromaticity. The contact time is also appropriately determined according to the water quality and treatment amount of the colored beverage wastewater, the addition amount of the oxidizing agent, the amount of the catalyst used, the target chromaticity, etc. In the case of water flow treatment to the catalyst tower, It is preferable that the residence time in the tower (time to pass through the catalyst tower) is, for example, 6 minutes or more.
[0015]
In the present invention, a part of the decolorized water may be returned to the decoloring step and circulated. That is, in the decolorizing apparatus for colored beverage drainage of the present invention, a circulation line for returning a part of the effluent of the catalyst tower to the adjustment tank may be provided. By performing the circulation process in this manner, it becomes possible to circulate the treated water having a chromaticity equal to or higher than the reference value and perform the process again, and a reliable decoloring process can be performed. Further, by circulating the water containing the residual oxidant in this way, part or all of the oxidizable substance adhering to the catalyst is removed, and the metal oxide and the oxidizable substance during the period when the water flow is stopped The durability of the catalyst can be improved by the effect of preventing the elution of the metal component due to the reaction with the catalyst.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0017]
FIG. 1 is a system diagram showing an embodiment of a decoloring device for colored beverage drainage (hereinafter simply referred to as “decoloring device”) 10 of the present invention. Such a decoloring apparatus is incorporated in, for example, the decoloring processing unit 4 of the colored beverage drainage processing system shown in FIG. The colored beverage wastewater treatment system 1 shown in FIG. 2 includes a biological treatment unit 2, a filtration treatment unit 3, a decolorization treatment unit 4, and a disinfection treatment unit 5, and the colored beverage wastewater is treated by these treatment units. It is discharged after being processed. The biological processing unit 2, the filtration processing unit 3 and the disinfection processing unit 5 can adopt the same structure and function as those in the conventional processing system, and detailed description thereof will be omitted.
[0018]
A decolorizing apparatus 10 shown in FIG. 1 is supplied with a colored beverage drainage to be treated by a conduit 20 from a filtration processing unit 3 including a raw water tank 3A and a filter 3B. From the oxidant storage tank 12 for storing the oxidant to be supplied, the catalyst tower 13 connected to the adjustment tank 11 via the conduit 21 on the downstream side (as viewed in the flow direction of the waste water) from the adjustment tank 11, and from the catalyst tower 13 An activated carbon tower 14 connected to the catalyst tower 13 via a conduit 22 with a valve 41 is provided on the downstream side (as viewed in the flow direction of the waste water). At least one supply pipe 24 is connected to the oxidant storage tank 12, and the oxidant stored in the oxidant storage tank 12 is supplied into the adjustment tank 11 through the supply pipe 24 by the pump 33. Yes. Therefore, in this embodiment, the oxidant storage tank 12, the pump 33, and the supply pipe 24 constitute an oxidant addition means. In this embodiment, liquid sodium hypochlorite is used as the oxidizing agent, but oxidizing agents using other chlorine-based compounds can also be used. The adjustment tank 11 is provided with at least one stirrer 31 (two in this embodiment) so that the colored beverage drainage and the oxidizing agent can be mixed by stirring.
[0019]
A pump 32 is connected to the conduit 21 connected to the adjustment tank 11 adjacent to the adjustment tank 11, and the beverage drainage is oxidatively decolorized to the catalyst tower 13 from the adjustment tank 11 through the conduit 21 to the catalyst tower 13 by the pump 32. It is designed to send a mixture of oxidant and oxidant. The catalyst tower 13 is filled with a desired amount of a metal oxide catalyst by a known method, and a mixed liquid of beverage wastewater and oxidant which has been oxidatively decolorized in the adjustment tank 11 in the catalyst tower 13 is oxidized into the metal. It can come into contact with the product catalyst. In this embodiment, a nickel peroxide-supported catalyst is used as an example of such a metal oxide catalyst. However, other catalysts that promote a metal oxidation-reduction reaction may be used. The activated carbon tower 14 is filled with known activated carbon, and comes into contact with the decolorized water sent from the catalyst tower 13 to remove chlorine and hardly decomposed components in the water. A conduit 23 provided with a valve 42 is connected to the outlet side of the activated carbon tower 14 so that the water treated in the activated carbon tower 14 is sent to the disinfection treatment unit 5. One end of a return conduit 25 provided with a valve 43 is connected to the conduit 23 between the activated carbon tower 14 and the valve 42, and the return conduit 25 returns the return flow into the regulating tank 11. One end of a branch pipe 26 provided with a valve 44 is connected to the conduit 22 connected to the outlet side of the catalyst tower 13, and the other end of the branch pipe 26 is connected to the return conduit 25. In addition, a chlorine concentration measuring device 47 is provided on the side of the catalyst tower 13 of the conduit 22.
[0020]
Reference numeral 27 denotes a conduit for backwashing the activated carbon tower 14 using decolorized water sent from the catalyst tower 13, and 45 is a valve provided in the conduit 27. 29 is a conduit for sending backwash waste water from the activated carbon tower 14 to the miscellaneous drainage tank 15, and 46 is a valve provided in the conduit 29. An air vent line 28 with a valve is connected to the catalyst tower 13 and the activated carbon tower 14.
[0021]
In the present embodiment, one catalyst tower 13 and one activated carbon tower 14 are provided, but a plurality of them may be provided in series and / or in parallel depending on the processing conditions of the colored beverage wastewater. Absent.
[0022]
Next, operation | movement of this decoloring apparatus 10 is demonstrated.
[0023]
The filtered colored beverage wastewater sent from the filtration processing unit 3 is introduced into the adjustment tank 11. For example, a sodium hypochlorite aqueous solution is supplied as a liquid oxidant from the oxidant storage tank 12 through the conduit 24 into the adjustment tank 11. In the adjustment tank 11, the beverage drainage and the oxidant are agitated by the stirrer 31, and the oxidant and the beverage drainage are mixed. The amount of liquid oxidant added varies depending on the type and color of the beverage drainage, and is, for example, 10 to 800 mg-Cl / L as sodium hypochlorite per liter of beverage wastewater. Sodium chlorite is stirred by the stirrer 31 for a desired time, for example, 10 minutes or longer, preferably 10-20 minutes. In the adjustment tank 11, the beverage wastewater is oxidized and the colored components are partially decolored, and then sent to the catalyst tower 13 via the conduit 21 by the pump 32. In the catalyst tower 13, the oxidized beverage wastewater comes into contact with the catalyst (in this embodiment, the nickel peroxide-supported catalyst), thereby facilitating the decolorization of the colored components. The required contact time between the inflow water from the adjustment tank 11 and the catalyst in the catalyst tower 13 varies depending on the type, amount, color, type and amount of the oxidizer and catalyst of the drinking water, The color components that could not be decolored by oxidation with an oxidant are within a range where the color components can be decolored to an acceptable value. In this embodiment, it is desirable to contact for 6 minutes or more, for example, 6 to 30 minutes.
[0024]
The water decolorized to an acceptable range by contact with the catalyst in the catalyst tower 13 is sent to the activated carbon tower 14 where it is contacted with the activated carbon filled therein, and residual oxidant components such as residual chlorine. And hardly decomposed components are removed. The effluent water from the activated carbon tower 14 is sent to the disinfection treatment unit 5.
[0025]
When returning a part of the effluent water of the activated carbon tower 14 to the adjustment tank 11, the valve 43 is opened and returned via the return conduit 25.
[0026]
A chlorine concentration measuring device 47 is installed at the outlet of the catalyst tower 13 and measures the residual chlorine concentration of the decolorized water treated by the catalyst tower 13. If the concentration is lower than the predetermined concentration, the valve 44 is opened to open the catalyst tower. 13 is returned to the adjustment tank 11 through the return conduit 25, or the valve 42 is closed and the valve 43 is opened to prevent foreign matter from entering the adjustment tank 11, and the effluent of the activated carbon tower 14 is returned to the return conduit. It is configured to return to the adjustment tank 11 through 25 and to perform oxidative decolorization again. Moreover, based on the measured value of the residual chlorine concentration, the oxidant addition amount can be adjusted by controlling the pump 33 of the oxidant storage tank 12.
[0027]
In FIG. 1, reference numerals 48 and 49 denote valves used for cleaning the catalyst in the catalyst tower 13. In the cleaning of the catalyst, the valve 44 and the valve 49 are opened, the valve 48 is closed, the cleaning water is passed through the catalyst tower 13, the catalyst is cleaned, and the cleaned cleaning water is discharged to the raw water tank.
[0028]
By the way, in the decoloring apparatus as shown in FIG. 1, when the drinking water drained with the oxidizing agent is passed through the catalyst tower filled with the metal oxide catalyst, the amount of water changes, holidays, equipment maintenance check, etc. For this reason, the operation of the apparatus may be stopped. In this case, after stopping the operation for a predetermined time, when the drinking water drainage to the catalyst tower is resumed, the metal component of the metal oxide catalyst is eluted in the decolorized water thus obtained, whereby the treatment at the time of restarting the operation is performed. In addition to the deterioration of water quality, the metal oxide catalyst in the catalyst tower may deteriorate due to the elution of the metal component, and the catalyst performance may decrease.
[0029]
This is because when the drinking water flow to the catalyst tower is stopped, the oxidant is decomposed and removed in the catalyst tower, the oxygen of the metal oxide on the catalyst surface, and the beverage remaining adsorbed on the catalyst. This is because the metal oxide of the catalyst is reduced and the metal component is eluted by a reaction with an oxidizable substance such as a colored component in the waste water.
[0030]
Therefore, in the present invention, in order to prevent the elution of the metal component from the metal oxide catalyst, the oxidizer in the water that is passed through the catalyst tower prior to the stoppage of the water flow when the apparatus is shut down. to increase the concentration. In this way, part or all of the oxidizable substance adhering to the catalyst is removed, and elution of the metal component due to the reaction between the metal oxide and the oxidizable substance during the period when water flow is stopped is prevented can do.
[0031]
In order to increase the oxidant concentration in the water passed through the catalyst tower, it is only necessary to increase the amount of oxidant added to the colored beverage effluent, but the oxidant concentration by reaction with the colored component in the colored beverage effluent. It is difficult to control the concentration of the oxidant because of the reduction of oxidant. Therefore, instead of colored beverage wastewater, water having a low concentration of oxidizable substances such as city water and industrial water may be used, and an oxidant may be added to the city water and industrial water and passed through the catalyst tower. Further, the oxidant concentration in the water introduced into the catalyst tower may be increased, and the effluent water from the catalyst tower may be circulated so as to pass through the catalyst tower again.
[0032]
Specifically, in the decoloring apparatus of FIG. 1, when water flow is stopped, city water or industrial water is introduced into the adjustment tank 11 instead of colored beverage wastewater, and the concentration of the oxidizing agent is higher than that during normal operation. Try to be high. Then, the valve 43 is closed, the valves 44 and 48 are opened, the water in the adjustment tank 11 is passed through the catalyst tower 13, and the total amount of the outflow water from the catalyst tower 13 is returned to the adjustment tank 11 for circulation. . As a result, water having a high oxidant concentration is circulated through the catalyst tower 13, and oxidizable substances such as colored components remaining on the catalyst in the catalyst tower 13 are decomposed and removed. . In this case, since water with a high oxidant concentration does not flow out of the system during the circulation, the processing cost for that purpose is suppressed, and the oxidant flowing out from the catalyst tower 13 is reused. Can be reduced.
[0033]
When water with a high oxidant concentration is circulated, the oxidant-containing water may continue to circulate even after the oxidizable substances such as colored components attached to the catalyst have been completely decomposed. Circulation may continue throughout the entire period. In this way, the oxidant gradually self-decomposes during the circulation due to catalytic action and the like, and the oxidant concentration in the water in the catalyst tower decreases. As a result, the oxidant concentration in the water flowing out from the catalyst tower at the time of restarting operation becomes low, and it becomes unnecessary to perform the oxidant removal treatment on the initial effluent water from the catalyst tower, or the treatment can be simple. It becomes like this.
[0034]
When increasing the oxidant concentration in the water when the water flow is stopped, the oxidant concentration in the catalyst tower inflow water is 1.0 to 40 times, particularly 2.0 to 10 times the oxidant concentration in the catalyst tower inflow water during normal operation. It is preferable to do so. Further, it is desirable that water with a high oxidant concentration is passed through the catalyst tower in an amount of 30 times or more, particularly 50 times or more of the catalyst tower volume, to sufficiently decompose oxidizable substances such as attached colored components. .
[0035]
When the operation is resumed after the operation stop period is over, the colored beverage drainage is resumed. At the beginning of the operation, the effluent from the catalyst tower contains a large amount of oxidant. There is. In the apparatus of FIG. 1, the remaining oxidant is removed by the activated carbon tower 14, but the catalyst tower effluent at the initial stage of resuming water flow is returned to the adjustment tank 11 for dilution, or transferred to another treatment system for treatment. You may do it.
[0036]
In the present invention, the oxidant added to the colored beverage wastewater is preferably a chlorine-based oxidant. There is no particular limitation on the chlorinated oxidant, as described above, in addition to sodium hypochlorite, for example, hypochlorite such as chlorine, potassium hypochlorite, calcium hypochlorite, sodium chlorite, Examples thereof include chlorites such as potassium chlorite, chlorates such as sodium chlorate, potassium chlorate and calcium chlorate, and perchlorates such as sodium perchlorate and calcium perchlorate. Among these, hypochlorites such as sodium hypochlorite have moderate oxidation properties and can be used preferably.
[0037]
If the amount of the oxidizing agent added to the colored beverage wastewater is too small, the decolorization treatment becomes insufficient, and if it is too large, there is a possibility that a large amount of the oxidizing agent remains in the treated water. When the oxidizing agent is a chlorine-based oxidizing agent, it is preferable to add the chlorine-based oxidizing agent so that the residual chlorine concentration in the colored beverage wastewater is 10 to 400 mg-Cl / L. “Mg-Cl / L” is the residual chlorine concentration in water indicated by converting the chlorine-based oxidant remaining in the treated water into chlorine.
[0038]
In the present invention, the catalyst is preferably a metal oxide catalyst, and the metal oxide catalyst is preferably a catalyst in which a metal oxide as a catalyst component is supported on a carrier. As this carrier, one type or two or more types of various types of zeolite and alumina can be used.
[0039]
Examples of the metal of the catalyst component include nickel, cobalt, copper, silver and the like, preferably nickel and cobalt, and nickel is particularly preferable. These catalyst metals may be used alone or in a combination of two or more.
[0040]
The metal oxide catalyst used in the present invention is preferably a catalyst in which these catalyst metals are supported on a carrier as a metal oxide, preferably a metal peroxide. The amount of the metal oxide supported on the carrier is nickel, cobalt. It is preferable that it is 0.1-100g-metal / 1000g-dry support | carrier by the load of catalyst metal conversion, such as. If the amount is less than this, the catalytic action of the metal oxide cannot be sufficiently obtained, and it is difficult to prepare a larger amount than this in terms of preparation of the catalyst.
[0041]
A metal peroxide-supported catalyst suitable for the present invention can be prepared by, for example, carrying a catalyst metal such as nickel on a support and reacting with an oxidizing agent as follows.
[0042]
First, an aqueous solution of sulfate, nitrate, chloride or the like of a catalyst metal such as nickel or a mixture thereof is prepared, and the carrier is immersed in the aqueous catalyst metal solution. Alternatively, a catalytic metal aqueous solution is passed through a column packed with a carrier in a transient or circulating manner to make contact. The concentration of the catalytic metal aqueous solution and the contact time are appropriately set according to the amount of metal supported on the metal peroxide-supported catalyst to be prepared. Thus, after the carrier carrying the catalyst metal such as nickel by ion exchange is washed with water, it is brought into contact with an alkaline aqueous solution containing an oxidizing agent. This contact method can be carried out by dipping or passing water through the column, as in the above-described supporting method. As the oxidizing agent for supporting the catalyst, hypochlorites such as sodium hypochlorite, chlorine gas, and the like can be used. As the aqueous alkali solution for supporting the catalyst, an aqueous solution of sodium hydroxide, potassium hydroxide or the like can be used. Although there is no restriction | limiting in particular about the oxidizing agent density | concentration of an aqueous alkali solution containing this oxidizing agent, or an alkali density | concentration, Usually, an oxidizing agent density | concentration of 0.5 to 10 weight%, especially 1 to 5 weight%, alkali concentration 0.1-10 The aqueous solution is preferably 0.5% by weight, particularly 0.5 to 2.5% by weight.
[0043]
Thus, the support | carrier which carry | supported catalyst metals, such as nickel, is contacted with the alkaline aqueous solution containing an oxidizing agent, Then, the metal peroxide carrying | support catalyst suitable for this invention can be obtained by washing with water.
[0044]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples.
[0045]
The colored beverage wastewater was biologically treated in the biological treatment unit 2 in the same manner as before, and then filtered in the filtration processing unit 3. The chromaticity of the beverage drainage after the filtration treatment was 1200. When this drinking water was processed by the conventional decoloring method using a flocculant shown in FIG. 8, the chromaticity of the treated water was 100 to 200.
[0046]
A decolorization test of beverage wastewater having such chromaticity was performed using a test apparatus 50 shown in FIG.
[0047]
The beverage draining in the raw water tank 51 is introduced at a flow rate of 180 t / h in the adjusting tank 53 by a pump P _1, adjusted at a predetermined rate by a pump P ₂ sodium hypochlorite solution in the oxidizer storage tank 52 It added in the tank 53. And in the adjustment tank 53, the drinking water and sodium hypochlorite were stirred and mixed with the stirrer 53A for a predetermined time, and decolorized. The mixture in the catalyst tower 54 by a pump P _3, after the mixture and the catalyst has catalytic decolorization treatment through at a flow rate such that continuous contact with a predetermined time was passed through the activated carbon tower 55. As the catalyst, a nickel peroxide supported catalyst was used.
[0048]
In this test, the state of decolorization caused by the reaction between the drinking water in the adjustment tank 53 and sodium hypochlorite, the amount of sodium hypochlorite added, the ratio of 100, 200, 400 or 800 mg-Cl / L. In addition, when the stirring time in the adjustment tank 53 is variously changed between 10 minutes and 1080 minutes, the stirring time and the chromaticity of the oxidative decoloring water (outflow water of the adjustment tank 53) When the relationship was obtained, the result shown in FIG. 4 was obtained. Further, the relationship between the residual chlorine concentration in the oxidized decolorized water and the stirring time was as shown in FIG.
[0049]
As is apparent from FIG. 4, even when the amount of sodium hypochlorite added is variously changed, the chromaticity of the beverage drainage, which is the water to be treated, rapidly decreases to 200 to 400 by stirring for about 10 minutes. It can be seen that after stirring for a certain time, the chromaticity hardly changes even if stirring is continued. Moreover, in order to decolorize the chromaticity of the drinking water which is the same level as the processing capacity of the conventional decoloring method up to 100, the stirring time had to be 1080 minutes. On the other hand, the residual chlorine concentration in the oxidative decolorized water also decreases until stirring for several minutes as is apparent from FIG. It can also be seen that the residual chlorine concentration increases as the amount of sodium hypochlorite added increases.
[0050]
From these results, the degree of decolorization by the oxidant can be determined by setting a predetermined stirring time for each oxidant concentration to be added, and this control can be performed by measuring the residual chlorine concentration. I understand.
[0051]
The same test was conducted by changing the amount of sodium hypochlorite added at a rate of 150, 300, 470 mg-Cl / L, and drinking effluent having a chromaticity of 1193 (test 1) and drinking effluent having a chromaticity of 780 (test 2) The chromaticity and hypochlorous acid of the oxidative decolorized water when the agitation time is 20 minutes for the drinking effluent (test 3) with a chromaticity of 1183 and the drinking effluent (test 4) with a chromaticity of 1272, respectively. When the relationship with the amount of sodium acid added was examined, it was as shown in FIG. From this result, when the amount of sodium hypochlorite added exceeds a predetermined amount (about 150 mg-Cl / L), there is almost no change in the chromaticity after decolorization even if the amount added is increased. It can be seen that the concentration of the oxidizing agent to be determined can be determined according to the target chromaticity.
[0052]
Furthermore, 470 mg-Cl / L of sodium hypochlorite was added, and the contact time between the water after oxidative decoloration by stirring and mixing for 20 minutes and the catalyst in the catalyst tower 54 and the decolorized water after the contact (catalyst) When the relationship with the chromaticity of water at the tower outlet was examined, it was as shown in FIG. It can be seen from FIG. 7 that the waste water near chromaticity 80 can be reduced to about 50 chromaticity by setting the contact time between the catalyst and the oxidative decolorized water to 6 minutes or longer. If the contact time is longer than that, the chromaticity can be lowered. However, if the contact time is longer than 6 minutes, no remarkable reduction effect is observed.
[0053]
In this example, the amount of sodium hypochlorite added was 180 mg-Cl / L, the stirring time in the adjustment tank 53 was 10 minutes, and after oxidative decolorization, the oxidative decolorization treated water and the catalyst in the catalyst tower 54 By setting the contact time to 6 minutes, decolorized water having a chromaticity of 100 or less and an average of 70 could be obtained.
[0054]
【The invention's effect】
As described above in detail, according to the method and apparatus for decoloring colored beverage drainage of the present invention, the following effects can be obtained.
(Ii) Decolorization of colored beverage wastewater is promoted by catalytic treatment after oxidation and decolorization. Sludge is not generated as in the conventional method. An effect can be obtained.
(B) By carrying out a catalyst treatment to promote decolorization, highly efficient decolorization can be performed very efficiently, and high-quality treated water can be stably obtained. In addition, it is possible to remove hardly decomposed components.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an embodiment of a decoloring apparatus for colored beverage drainage according to the present invention.
FIG. 2 is a system diagram of a colored beverage wastewater treatment system.
FIG. 3 is a system diagram showing a test apparatus used in Examples.
FIG. 4 is a graph showing the relationship between stirring time and chromaticity.
FIG. 5 is a graph showing the relationship between stirring time and residual chlorine concentration.
FIG. 6 is a graph showing the relationship between the amount of sodium hypochlorite added and chromaticity.
FIG. 7 is a graph showing the relationship between contact time with a catalyst and chromaticity.
FIG. 8 is a schematic diagram for explaining a conventional method for decolorizing colored beverage wastewater.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 3 Filtration processing part 5 Disinfection processing part 10 Decoloring apparatus 11 Adjustment tank 12 Oxidant storage tank 13 Catalyst tower 14 Activated carbon tower

Claims (17)

A method for decolorizing colored beverage wastewater comprising a decolorizing step of contacting the colored beverage wastewater with a catalyst in the presence of an oxidizing agent,
The decoloring step includes a mixing step of adding and mixing an oxidizing agent to the colored beverage wastewater, and a contacting step of bringing the colored beverage wastewater mixed with the oxidizing agent into contact with the catalyst.
Sometimes stops water flow colored beverage wastewater, characterized in that the concentration of the oxidizing agent is a high water than during normal operation in contact with the catalyst to decompose and remove oxidizable substances adhering remaining on the catalyst Decolorizing method of colored beverage drainage. The method for decoloring colored beverage wastewater according to claim 1, wherein the mixing step is a step of introducing the colored beverage wastewater into an adjustment tank equipped with a means for mixing the liquid in the tank, and adding and mixing an oxidant, The contact step is a step of passing the effluent water of the adjustment tank through a catalyst tower packed with a metal oxide catalyst,
Sometimes stops water flow colored beverage wastewater, adding an oxidizing agent is introduced the city water or industrial water instead of colored beverage wastewater in the conditioning tank, the effluent of the equalizing tank and passed through to the catalyst column A method for decolorizing colored beverage wastewater, characterized in that water having a high oxidant concentration is brought into contact with the catalyst by returning and circulating the effluent from the catalyst tower to the adjustment tank.   3. The method for decolorizing beverage drainage according to claim 1 or 2, further comprising an activated carbon treatment step of treating the treated water of the decolorization step with activated carbon.   4. The method for decoloring colored beverage wastewater according to claim 1, further comprising a filtration step of filtering the colored beverage wastewater supplied to the decolorization step.   5. The colored beverage drainage decolorization method according to claim 1, wherein the oxidizing agent is a chlorine-based oxidizing agent, and the residual chlorine concentration of the treated water in the decoloring step is measured. Decolorization method of drainage.   6. The method for decoloring colored beverage wastewater according to claim 5, wherein the amount of the chlorine-based oxidant added in the mixing step is controlled according to the measured residual chlorine concentration.   7. The method for decolorizing colored beverage wastewater according to claim 5 or 6, wherein when the measured residual chlorine concentration is lower than a predetermined concentration, the treated water in the decoloring step is returned to the mixing step. Decolorization method for drinking water.   The method for decolorizing beverage wastewater according to claim 5 or 6, further comprising an activated carbon treatment step of treating the treated water of the decolorization step with activated carbon, and when the measured residual chlorine concentration is lower than a predetermined concentration, the activated carbon A method for decolorizing colored beverage wastewater, wherein the treated water in the treatment step is returned to the mixing step.   The method for decolorizing colored beverage wastewater according to any one of claims 1 to 8, wherein the oxidizing agent is sodium hypochlorite.   10. The method for decoloring colored beverage wastewater according to claim 1, wherein the mixing step is performed for a time until the mixed solution of the colored beverage wastewater and the oxidizing agent reaches a predetermined chromaticity. Decolorization method for colored beverage drainage.   The method for decoloring colored beverage wastewater according to any one of claims 1 to 10, wherein the catalyst is a nickel peroxide-supported catalyst.   12. The method for decolorizing colored beverage wastewater according to claim 1, wherein the contacting step is performed until the chromaticity of the treated water reaches a predetermined chromaticity. Method. An adjustment tank provided with a means for mixing the liquid in the tank;
Means for introducing colored beverage wastewater into the adjustment tank;
Colored beverage drainage introduced into the adjustment tank and / or an oxidant addition means for adding an oxidant to the adjustment tank;
A catalyst tower filled with a metal oxide catalyst into which effluent water from the adjustment tank is introduced;
A circulation line for returning the effluent of the catalyst tower to the adjustment tank;
A decolorizing device for colored beverage drainage, comprising means for introducing city water or industrial water into the adjustment tank,
An adjustment tank in which city water or industrial water is introduced into the adjustment tank instead of colored drink drainage and an oxidizing agent is added to the adjustment tank, and an oxidizing agent is added to the city water or industrial water when stopping the flow of colored beverage wastewater. An apparatus for decolorizing colored beverage wastewater, wherein water in the inside is passed through the catalyst tower, and the outflow water from the catalyst tower is returned to the adjustment tank and circulated.   The decolorization apparatus for colored beverage wastewater according to claim 13, further comprising an activated carbon tower into which the outflow water of the catalyst tower is introduced.   15. The decoloring apparatus for colored beverage wastewater according to claim 13 or 14, wherein the oxidant is a chlorinated oxidant, and comprises a measuring means for measuring the residual chlorine concentration of the effluent of the catalyst tower. Beverage drainage decolorization equipment.   The decolorization apparatus for colored beverage wastewater according to claim 15, wherein when the residual chlorine concentration measured by the measuring means is lower than a predetermined concentration, the effluent of the catalyst tower is returned to the adjustment tank by the circulation line. A device for decolorizing colored beverage wastewater.   The decolorization apparatus for colored beverage wastewater according to claim 15, comprising: an activated carbon tower into which the effluent water of the catalyst tower is introduced; and a circulation line for returning the effluent water of the activated carbon tower to the adjustment tank; When the measured residual chlorine concentration is lower than a predetermined concentration, the effluent from the activated carbon tower is returned to the adjustment tank by this circulation line, and the decolorization device for colored beverage wastewater.

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