Method for treating electrolytic plating waste liquid and system for treating electrolytic plating waste liquid

Abstract

Disclosed is a treatment method for electrolytic-free plating waste liquid and a treatment system for electrolytic-free plating waste liquid. The electrolytic-free plating waste liquid contains at least metal ions, ammonia, a reducing agent, reducing agent waste, and a complexing agent. The treatment method for electrolytic-free plating waste liquid includes: an electrolysis treatment step of electrolyzing the electrolytic-free plating waste liquid to remove the metal ions; an ammonia volatilization step of volatilizing and removing the ammonia from the electrolytic-free plating waste liquid subjected to the electrolysis treatment step; an ultraviolet ray / ozone treatment step of oxidizing the electrolytic-free plating waste liquid subjected to the ammonia volatilization step to decompose the reducing agent, the reducing agent waste, and the complexing agent; and a phosphate removal step of adding a calcium compound to the electrolytic-free plating waste liquid subjected to the ultraviolet ray / ozone treatment step to precipitate and remove phosphates.

Description

TECHNICAL FIELD

[0001] The present application relates to a treatment method for electrolyticless plating waste liquid and a treatment system for electrolyticless plating waste liquid. BACKGROUND

[0002] Conventionally, in the field of electronic components, electrolyticless plating film is formed on Al or Cu patterns of flexible substrates, silicon wafer substrates.

[0003] Electrolyticless plating treatment is different from electroplating treatment, and is a method in which a metal coating film is formed on the surface of a plated object by immersing the plated object in a plating solution. This method is suitable for plating processing of complex shapes and precise components because a uniform thickness of the coating film can be obtained regardless of the shape and type of the raw material.

[0004] Here, electrolyticless plating solution refers to a plating solution in which metal ions (e.g., nickel ions) contained in the solution are reduced by a reducing agent such as hypophosphite to be deposited on the surface of a plated object as metal. However, as plating proceeds, the hypophosphite is oxidized to reducing agent waste, i.e., phosphorous acid, and accumulates. As a result, the deposition rate of plating and the physical properties of the electrolyticless plating film decrease, and the electrolyticless plating solution cannot be used as a plating solution. Therefore, it is necessary to discharge the electrolyticless plating solution as waste liquid.

[0005] In addition, since electrolyticless plating solution contains organic substances such as complexing agents in addition to metal ions and reducing agents, it is necessary to remove or decompose them to meet the drainage standards when waste treatment of electrolyticless plating waste liquid is performed.

[0006] As a treatment method for electrolyticless plating waste liquid, a method is proposed in which, for example, drainage liquid containing heavy metal ions such as iron, nickel, copper, zinc, and aluminum is introduced from a water storage tank to a pH adjustment tank, the pH value is adjusted, and the heavy metal ions are separated and precipitated by coagulation and sedimentation (for example, refer to Patent Document 1).

[0007] In addition, a method is proposed in which, in waste liquid containing phosphorous acid after removal of nickel, an oxidizing agent such as hydrogen peroxide or sodium hypochlorite is added to oxidize the phosphorous acid to orthophosphoric acid, and a calcium salt is added thereto to remove it as calcium phosphate precipitate (for example, refer to Patent Document 2).

[0008] Patent Document 1: Japanese Laid-Open Patent Publication No. Hei 11-221575

[0009] Patent Document 2: Japanese Laid-Open Patent Publication No. 2003-112190 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] However, in the coagulation sedimentation method described in the above Patent Document 1, since the chelate-containing drainage liquid is mixed in the drainage liquid containing heavy metals such as nickel, the heavy metals forming a complex remain in the coagulation-treated water, and thus there is a problem that the heavy metals cannot be removed to below the limit value of the drainage standard.

[0012] Further, in the oxidation sedimentation method described in the above Patent Document 2, although the phosphorous acid can be removed, there is a problem that it is difficult to decompose and remove organic matters such as the complexing agent.

[0013] Therefore, the present application has been achieved in view of the above problems, and aims to provide a plating waste liquid treatment method and a non-electrolytic plating waste liquid treatment system in which all of metal ions, ammonia, a reducing agent, reducing agent waste, and a complexing agent are removed or decomposed in a manner satisfying the drainage standard without using a complicated device, a special agent, or the like.

[0014] Technical Solution for Solving the Technical Problem

[0015] In order to achieve the above object, the plating waste liquid treatment method according to the present application is a non-electrolytic plating waste liquid treatment method including at least metal ions, ammonia, a reducing agent, reducing agent waste, and a complexing agent, and is characterized by at least including: an electrolysis treatment step in which the non-electrolytic plating waste liquid is electrolyzed to remove the metal ions; an ammonia volatilization step in which the ammonia in the non-electrolytic plating waste liquid subjected to the electrolysis treatment step is volatilized to remove the ammonia; an ultraviolet ray · ozone treatment step in which the non-electrolytic plating waste liquid subjected to the ammonia volatilization step is oxidized to decompose the reducing agent, the reducing agent waste, and the complexing agent; and a phosphate removal step in which a calcium compound is added to the non-electrolytic plating waste liquid subjected to the ultraviolet ray · ozone treatment step to precipitate and remove the phosphate.

[0016] Further, the plating waste liquid treatment system according to the present application is a non-electrolytic plating waste liquid treatment system including at least metal ions, ammonia, a reducing agent, reducing agent waste, and a complexing agent, and is characterized by at least including: an electrolysis treatment device that electrolyzes the non-electrolytic plating waste liquid to remove the metal ions; an ammonia treatment device that volatilizes the ammonia in the non-electrolytic plating waste liquid subjected to the electrolysis treatment to remove the ammonia; an ultraviolet ray · ozone treatment device that oxidizes the non-electrolytic plating waste liquid subjected to the ammonia volatilization treatment to decompose the reducing agent, the reducing agent waste, and the complexing agent; and a phosphate treatment device that precipitates and removes the phosphate by adding a calcium compound to the non-electrolytic plating waste liquid subjected to the ultraviolet ray · ozone treatment.

[0017] -The effects of the invention-

[0018] According to the present invention, without the use of complex devices, special reagents, etc., it is possible to remove or decompose all substances such as metal ions, ammonia, reducing agents, reducing agent waste, and complexing agents in a manner that meets wastewater standards. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating a plating wastewater treatment system for explaining the plating wastewater treatment method using the present invention.

[0020] Figure 2 This is a schematic diagram illustrating the electrolytic treatment apparatus used in the method for treating plating waste liquid of the present invention;

[0021] Figure 3 This is a schematic diagram of an ammonia volatilization device used in the method for treating plating waste liquid of the present invention;

[0022] Figure 4 This is a schematic diagram of the ultraviolet and ozone treatment apparatus used in the method for treating plating waste liquid of the present invention.

[0023] Figure 5 This is a schematic diagram illustrating the phosphate removal apparatus used in the method for treating plating waste liquid according to the present invention. Detailed Implementation

[0024] The method for treating plating waste liquid of the present invention will now be described.

[0025] <The plating waste liquid being treated>

[0026] There are no particular limitations on the plating waste liquid used in the treatment method of the present invention. For example, waste liquids containing metal ions, reducing agents, complexing agents, and ammonia can be cited, such as electroless nickel plating solution and electroless copper plating solution.

[0027] In this electroless nickel plating waste liquid, metal ions such as nickel ions (Ni) are present. 2+ ), as a reducing agent component, for example containing hypophosphite ions (HPO2). 2- Waste containing phosphate ions (HPO3) can act as a reducing agent. 2- ).

[0028] Further, as the complexing agent component, for example, organic acids such as citric acid, malic acid, tartaric acid, malonic acid, lactic acid, succinic acid, adipic acid, and gluconic acid; amino acids such as glycine, glutamic acid, and aspartic acid; and amine compounds such as ethylenediamine and diethanolamine can be given. Note that ammonia for neutralization is sometimes contained.

[0029] Further, regarding the concentrations of the respective components in the electrolysis-free nickel plating waste liquid to be treated, for example, the concentration of the metal ion, i.e., nickel ion, is 0.5 to 15 g / L, the concentration of the reducing agent, i.e., hypophosphite, is 0.5 to 100 g / L, the concentration of the reducing agent waste, i.e., phosphite, is 0 to 200 g / L, the concentration of the complexing agent is 10 to 150 g / L, and the concentration of ammonia is 0 to 30 g / L.

[0030] Note that the hypophosphite that is coordinated in the electrolysis-free nickel plating is reduced to metal (nickel) to become phosphite. Further, since the insufficient hypophosphite is replenished with nickel in the plating treatment, the phosphite that is generated by the reaction sometimes finally accumulates to 100 g / L or more. Further, although the complexing agent is slightly increased or decreased from the initial concentration, it can be said that the variation amount thereof is smaller than that of the accumulated phosphite.

[0031] <Plating waste liquid treatment method>

[0032] As described above, the electrolysis-free plating solution is a concentrated solution containing a large amount of organic matter and reducing agent waste, which are continuously accumulated during use. Since the amount of the electrolysis-free plating waste liquid to be treated is larger than that of the electrolytic plating waste liquid, there is a problem that it is difficult to treat the electrolysis-free plating waste liquid by the above-described conventional coagulation precipitation method, oxidation precipitation method, and the like.

[0033] Thus, the present inventors have studied the above-described problem, and as a result, have found a method in which all of the metal ion, ammonia, reducing agent, reducing agent waste, and complexing agent are removed or decomposed in a manner satisfying the discharge standards without using a complicated device, a special reagent, or the like.

[0034] Next, the plating waste liquid treatment method of the present application will be described in detail using the drawings. Figure 1 is a schematic view for explaining a plating waste liquid treatment system using the plating waste liquid treatment method of the present application.

[0035] As Figure 1As shown, the plating waste liquid treatment method of the present application includes: an electrolytic treatment step in which electrolytic treatment device 2 is used to electrolyze the plating waste liquid to remove metal ions; an ammonia volatilization step in which ammonia treatment device 6 is used to remove ammonia from the plating waste liquid; an ultraviolet ray · ozone treatment step in which ultraviolet ray · ozone treatment device 9 is used to oxidize the plating waste liquid, decomposing the reducing agent, reducing agent waste, and complexing agent; and a phosphate removal step in which phosphate treatment device 16 is used to precipitate and remove the phosphate produced by the ultraviolet ray · ozone treatment step.

[0036] (Electrolytic treatment step)

[0037] The plating liquid (plating waste liquid) 1 used in the electrolytic plating treatment is transported from the plating tank in which the plating treatment was performed to the electrolytic tank 3 in the electrolytic treatment device 2 by a pump (not shown).

[0038] As this electrolytic treatment device 2, a publicly known stirrable electrolytic treatment device can be used, for example, as shown in Figure 2 As shown, an electrolytic treatment device in which an anode 4 formed of platinum-titanium alloy or the like, a cathode 5 formed of SUS or the like, and a stirrer 20 are provided inside the electrolytic tank 3 can be used.

[0039] Then, the plating waste liquid 1 is subjected to electrolytic treatment for a prescribed time at a prescribed electrolytic current in the electrolytic tank 3, to remove the metal ions. More specifically, in the case where the plating waste liquid being treated is the waste liquid of the above-described electrolytic-free nickel plating liquid, by this electrolytic treatment step, the reducing agent component, i.e., the hypophosphite ion, in the plating waste liquid 1 is oxidized to phosphite ions at the anode 4, and the reducing agent waste, i.e., the phosphite ion, is oxidized to phosphate ions, and the nickel ions are reduced to nickel and subjected to deposition treatment at the cathode 5, so that the nickel ion concentration in the plating waste liquid can be reduced to the drainage standard, i.e., 2 mg / L or less.

[0040] Note that in the case where the plating waste liquid being treated is the waste liquid of the electrolytic-free nickel plating liquid, heavy metals, iron, zinc, and the like contained in the plating waste liquid can also be removed.

[0041] The treatment temperature at the time of electrolytic treatment is not particularly limited, and treatment can also be performed at ordinary temperature, but from the viewpoint of reducing the burden on the device and improving the efficiency of electrodeposition, it is preferable to be 40 to 60°C.

[0042] Furthermore, from the viewpoint of suppressing costs and power consumption and improving the efficiency of electrodeposition, the current density at the time of electrolytic treatment is preferably 2 A / dm 2 More preferably, it is 5 to 15 A / dm 2 .

[0043] Furthermore, from the viewpoint of suppressing cost and improving the efficiency of electrodeposition, the surface area of the electrode used is preferably 0.2 dm2or more, more preferably 0.5 to 1.5 dm2. 2 / L, more preferably 0.5 to 1.5 dm2. 2 / L.

[0044] Furthermore, the pH of the plating waste solution 1 subjected to electrolysis treatment is not particularly limited, but in the case where ammonia (NH3) is contained, it is preferably 7 or more, more preferably 8 to 10. By performing electrolysis treatment in this pH range, volatilization of ammonia also occurs simultaneously, and thus the treatment time in the next process (ammonia volatilization treatment process) can be shortened.

[0045] In addition, by performing this process, the substances remaining in the plating waste solution that need to be treated are the reducing agent (substance not completely removed in this process), reducing agent waste (substance not completely removed in this process), complexing agent, and ammonia.

[0046] (Ammonia Volatilization Process)

[0047] Next, the plating waste solution 1 subjected to electrolysis treatment in the electrolysis treatment device 2 is transported from the electrolysis treatment device 2 subjected to electrolysis treatment to the heating treatment tank 7 in the ammonia treatment device 6 by a pump (not shown).

[0048] As this ammonia treatment device 6, a publicly known heating treatment device having a heat source can be used, for example, a device in which a heater 8 as a heat source and a stirrer 21 are provided inside the heating treatment tank 7, as shown in Fig. 1. Figure 3

[0049] Note that, when volatilizing ammonia, it is preferable to sufficiently stir the plating waste solution 1 by the stirrer 21 to sufficiently volatilize ammonia in the plating waste solution 1.

[0050] In addition, if ammonia remains in the plating waste solution 1, in the next process, the ultraviolet ray / ozone treatment process, ammonia becomes nitric acid and is difficult to remove, but in the present application, by performing heating treatment on the plating waste solution 1 at a prescribed temperature for a prescribed time in the heating treatment tank 7, ammonia in the plating waste solution 1 can be volatilized and removed (the concentration of ammonia in the plating waste solution is 100 mg / L or less, which is the drainage standard).

[0051] Note that the treatment temperature at the time of heating treatment is not particularly limited, but from the viewpoint of reducing the burden on the device and improving the efficiency of ammonia volatilization, it is preferably 40 to 60°C.

[0052] ​Furthermore, the pH value of the plating waste liquid 1 is not particularly limited, but from the viewpoint of promoting the volatilization of ammonia, it is preferably 7 or higher, and from the viewpoint of suppressing the generation of turbidity in the plating waste liquid 1 caused by a small amount of residual nickel ions becoming nickel hydroxide, it is more preferably 9 to 10.

[0053] In addition, for example, the volatilized ammonia can be deodorized by using a catalytic deodorization device (not shown) to render it harmless.

[0054] In addition, the plating waste liquid contains substances that need to be treated, including reducing agents, reducing agent waste, and complexing agents.

[0055] (Ultraviolet and ozone treatment process)

[0056] Next, the plating waste liquid 1, which has been heated in the ammonia treatment unit 6, is pumped (not shown) from the heated ammonia treatment unit 6 to the treatment tank 10 in the ultraviolet ozone treatment unit 9.

[0057] As the ultraviolet and ozone treatment device 9, for example, Figure 4 As shown, the following apparatus can be used, which includes a treatment tank 10 for collecting plating waste liquid 1, a pump 11 for circulating the plating waste liquid 1 collected in the treatment tank 10, an oxygen cylinder 12 for collecting oxygen to be converted into ozone, an ozone generating device 13 connected to the oxygen cylinder 12 for converting the oxygen supplied from the oxygen cylinder 12 into ozone, an injector 14 connected to the ozone generating device 13 for dispersing the ozone generated in the ozone generating device 13 into the circulating plating waste liquid 1, and an ultraviolet irradiation device 15 connected to the injector 14 and the treatment tank 10 for irradiating the circulating plating waste liquid 1 with ultraviolet light.

[0058] In addition, in the ultraviolet ozone treatment device 9, the oxygen supplied from the oxygen cylinder 12 is converted into ozone in the ozone generating device 13. The ozone generated in the ozone generating device 13 is dispersed in the circulating plating waste liquid 1 through the injector 14. As a result, the reducing agent component in the plating waste liquid 1, namely hypophosphoric acid, is oxidized into phosphorous acid, and the reducing agent waste, namely phosphorous acid, is oxidized into phosphoric acid. Moreover, the complexing agent component is decomposed into carbon dioxide and water.

[0059] Furthermore, by irradiating the circulating plating waste liquid 1 with ultraviolet light using the ultraviolet irradiation device 15, the efficiency of the oxidation reaction of the ozone treatment mentioned above is improved.

[0060] Note that the treatment temperature during the ultraviolet-ozone treatment is not particularly limited, but is preferably normal temperature to 50°C. This is because in the case where the treatment temperature is lower than normal temperature, the oxidation efficiency is sometimes lowered due to a decrease in the reaction rate, and in the case where the treatment temperature is higher than 50°C, the oxidation efficiency is sometimes lowered due to a decrease in the amount of dissolved ozone in the plating waste liquid 1.

[0061] Further, the pH of the plating waste liquid 1 is not particularly limited, but is preferably 7 or less from the viewpoint of suppressing crystallization (precipitation) of the generated phosphate in the ultraviolet-ozone treatment device 9.

[0062] In addition, by performing this process, the only substance that needs to be treated in the plating waste liquid is the phosphonium ion generated in this process.

[0063] (Phosphate removal process)

[0064] Next, the plating waste liquid 1 that has been subjected to the oxidation treatment in the ultraviolet-ozone treatment device 9 is transported from the ultraviolet-ozone treatment device 9 in which the oxidation treatment has been performed to the precipitation tank 17 in the phosphate removal device 16 by a pump (not shown).

[0065] As this phosphate removal device 16, for example, as shown in FIG. 2, a device in which a precipitation tank 17 that houses the plating waste liquid and to which a calcium compound is added, a stirrer 22 provided inside the precipitation tank 17, a pump 18 for transporting the plating waste liquid 1 housed in the precipitation tank 17, and a dewatering device 19 connected to the precipitation tank 17 by the pump 18 can be used. Figure 5

[0066] Thus, first, if a calcium compound (for example, calcium hydroxide, calcium chloride, calcium sulfate, or the like) is added to the plating waste liquid 1 housed in the precipitation tank 17, the phosphate ions in the plating waste liquid 1 form a phosphate (calcium phosphate) and precipitate. Next, the plating waste liquid 1 in which the phosphate has been formed is transported to the dewatering device 19 by the pump 18, and in the dewatering device 19, the filtrate and the precipitated component, that is, the phosphate, are separated by performing a dewatering treatment, and the phosphate is recovered. Note that since the compound that needs to be treated is not left in the filtrate, it can be subjected to a drainage treatment.

[0067] Further, as the dewatering device 19, for example, a filter press, a screw press, a centrifugal dewatering machine, a belt press, or the like can be used.

[0068] ​As described above, in the present application, by sequentially performing the electrolysis treatment step, the ammonia volatilization step, the ultraviolet ray · ozone treatment step, and the phosphate removal step, all of the metal ions, ammonia, reducing agents, reducing agent waste, and complexing agents can be removed or decomposed in a manner satisfying the drainage standards without using a complicated device, a special reagent, or the like.

[0069] Note that the above embodiment can also be modified as follows.

[0070] In the above embodiment, the ammonia in the electrolytic plating waste liquid subjected to the electrolysis treatment step is volatilized to remove it, but in the case where the treatment of plating waste liquid not containing ammonia is performed, the ammonia volatilization step can be omitted.

[0071] Further, in the case where the treatment of electrolytic copper plating waste liquid is performed, only the electrolysis treatment step and the ultraviolet ray · ozone treatment step can be performed, and the ammonia volatilization step and the phosphate removal step can be omitted.

[0072] [Example]

[0073] Hereinafter, the application involved in the present application will be described more specifically based on examples and comparative examples, but the present application is not limited by the following examples in any way.

[0074] (Example 1)

[0075] <Electrolytic plating waste liquid>

[0076] As the electrolytic nickel plating waste liquid, a substance having the following components equivalent to the use of six cycles (in each cycle, 30 g / L of nickel ions were supplemented, and the amount of sodium hypophosphite monohydrate and a pH adjuster, sodium hydroxide, corresponding to the consumption amount of the reducing agent, sodium hypophosphite monohydrate, was added) was prepared.

[0077] Nickel sulfate (as nickel ions) 5 g / L

[0078] Ammonia 6 g / L

[0079] Sodium hypophosphite monohydrate 20 g / L

[0080] Phosphorous acid 120 g / L

[0081] Malic acid, malonic acid, lactic acid total 50 g / L

[0082] <Electrolysis treatment>

[0083] Next, 10 L of a beaker provided with an anode formed of platinum-titanium alloy (5 dm 2 ) and a cathode formed of SUS (5 dm 2 ) was added with the above plating waste liquid, and the current density was set to 10 A / dm2 The electrolysis treatment was performed for 25 hours under conditions of a temperature of 25°C and a pH of 9.

[0084] Next, the concentration of each component in the plating waste liquid after the electrolysis treatment was measured. More specifically, the concentration of nickel ions was measured using an atomic absorption spectrometer (manufactured by Hitachi High-Tech Science Corporation, trade name: Hitachi Polarized Zeeman Atomic Absorption Spectrophotometer ZA-3300). In addition, the concentrations of ammonia, hypophosphite ions, phosphite ions, and phosphate ions were measured using a capillary electrophoresis device (manufactured by Agilent Technologies, trade name: Agilent 7100 CE). Furthermore, the concentration of nitrate ions was measured using the above capillary electrophoresis device. The results are shown in Table 1.

[0085] <Ammonia Volatilization Treatment>

[0086] Next, the plating waste liquid on which the above electrolysis treatment was performed was added to a 10-L beaker, and was left to stand for 30 hours under conditions of a temperature of 50°C and a pH of 9 while being stirred, and a ammonia volatilization treatment was performed.

[0087] Then, the concentration of each component in the plating waste liquid after the ammonia volatilization was measured by the above method. The results are shown in Table 1.

[0088] <UV / Ozone Treatment>

[0089] Next, the plating waste liquid (8 L) on which the above ammonia volatilization treatment was performed was subjected to a UV / ozone treatment for 60 hours using a UV / ozone treatment device (manufactured by Kyrin, trade name: UV-O3-1). More specifically, while the plating waste liquid (at ordinary temperature) was circulated at a rate of 20 L / minute using a pump, 1 L / minute of the plating waste liquid was blown with an ozone-containing gas at a supply rate of 8.6 g / hour using an atomizer, and an ozone treatment was performed. In addition, the circulated plating waste liquid was irradiated with ultraviolet rays under conditions of a wavelength of 254 nm using an ultraviolet irradiation device, and an ultraviolet treatment was performed.

[0090] Then, the concentration of each component in the plating waste liquid after the UV / ozone treatment was measured by the above method. The results are shown in Table 1.

[0091] <Phosphate Removal Treatment>

[0092] Next, calcium hydroxide was added to the plating waste liquid (8 L) subjected to the ultraviolet-ozone treatment, in such a manner that 300 g of calcium hydroxide was added per 1 L of the plating waste liquid, and a phosphate (calcium phosphate) was formed to be precipitated. Then, the plating waste liquid in which the calcium phosphate was formed was sent to a dewatering device by a pump, and in the dewatering device, a filtrate and a precipitated component, i.e., the calcium phosphate, were separated by performing a dewatering treatment.

[0093] Then, the concentrations of the components in the filtrate after the removal of the phosphate were measured by the above-described method. The results are shown in Table 1.

[0094] (Comparative Example 1)

[0095] The plating waste liquid treatment was performed in the same manner as in the above-described Example 1 except that the above-described ultraviolet-ozone treatment was not performed, and the concentrations of the components were measured. The results are shown in Table 2.

[0096] (Comparative Example 2)

[0097] The plating waste liquid treatment was performed in the same manner as in the above-described Example 1 except that the above-described ammonia volatilization treatment was not performed, and the concentrations of the components were measured.

[0098] The results are shown in Table 3.

[0099] (Comparative Example 3)

[0100] The plating waste liquid treatment was performed in the same manner as in the above-described Example 1 except that the above-described ultraviolet-ozone treatment was performed after the above-described electrolysis treatment, and then the above-described ammonia volatilization treatment was performed, and the concentrations of the components were measured. The results are shown in Table 4.

[0101] [Table 1]

[0102]

[0103] [Table 2]

[0104]

[0105] [Table 3]

[0106]

[0107] [Table 4]

[0108]

[0109] As shown in Table 1, in Example 1, it was found that the concentration of nickel ions in the plated waste liquid after electrolytic treatment reached the drainage standard, i.e., 2 mg / L (0.8 ppm) or less. In addition, it was found that, by electrolytic treatment, the reducing agent, i.e., sodium hypophosphite, was completely oxidized to phosphorous acid, and a part of the phosphorous acid was oxidized to phosphoric acid. Furthermore, since the pH value of the plated waste liquid 1 subjected to electrolytic treatment was 9, it was found that the concentration of ammonia was reduced from 6 g / L to 2 g / L by ammonia volatilization, and the treatment time in the next process (ammonia volatilization process) could be shortened.

[0110] In addition, it was found that the concentration of ammonia in the plated waste liquid after the ammonia volatilization process reached the drainage standard, i.e., 0.1 g / L or less.

[0111] In addition, it was found that, after the ultraviolet ray / ozone treatment, the phosphorous acid in the plated waste liquid was completely oxidized to phosphoric acid, and the complexing agent component was decomposed (into carbon dioxide and water).

[0112] In addition, in the filtrate after the phosphate removal process, the phosphoric acid in the plated waste liquid was removed (i.e., as calcium phosphate), and the phosphorus concentration in the filtrate was measured using an inductively coupled plasma emission spectrometer (manufactured by Horiba, Ltd., trade name: Ultima Expert), and as a result, the phosphorus concentration reached the drainage standard, i.e., 16 ppm or less (1.8 ppm), and it was found that there was no remaining substance that needed to be treated, and thus drainage treatment could be performed.

[0113] On the other hand, in Comparative Example 1, since the ultraviolet ray / ozone treatment was not performed, as shown in Table 2, it was found that the decomposition treatment of the complexing agent component and the oxidation treatment of the phosphorous acid were not performed, and the complexing agent and the phosphorous acid were largely remaining in the filtrate.

[0114] In addition, in Comparative Example 2, since the ammonia volatilization treatment was not performed, as shown in Table 3, it was found that ammonia remained in the plated waste liquid, a part of which became nitric acid in the next process, i.e., the ultraviolet ray / ozone treatment process, and remained in the filtrate, and thus was difficult to remove.

[0115] In addition, in Comparative Example 3, since the ammonia volatilization treatment was not performed before the ultraviolet ray / ozone treatment, in the ultraviolet ray / ozone treatment, a part of the ammonia remaining in the plated waste liquid became nitric acid and remained, and in the ammonia volatilization treatment, if the pH value was increased (set to pH = 9), the solubility of sodium phosphate and sodium triphosphate would be lowered, and thus the phosphate would be crystallized and precipitated, and it would be difficult to deliver the liquid to the next process, and thus the next process, i.e., the phosphate removal treatment, could not be performed.

[0116] - Industrial applicability -

[0117] The plating waste liquid treatment method of the present application is particularly suitable for treatment of an electroless plating waste liquid containing metal ions, ammonia, a reducing agent, reducing agent waste, and a complexing agent.

Claims

1. A method for treating electroless plating waste liquid, wherein the electroless plating waste liquid contains at least metal ions, ammonia, reducing agent, reducing agent waste, and complexing agent, characterized in that: At least including: An electrolytic treatment process, wherein the electroless plating waste liquid is electrolyzed to remove the metal ions; The ammonia volatilization process involves removing the ammonia from the electroless plating waste liquid that has undergone the electrolytic treatment process by volatilizing it. In the ultraviolet-ozone treatment process, the electroless plating waste liquid that has undergone the ammonia volatilization process is oxidized, and the reducing agent, the reducing agent waste, and the complexing agent are decomposed; and In the phosphate removal process, calcium compounds are added to the electroless plating wastewater that has undergone the ultraviolet and ozone treatment process to precipitate and remove the phosphate.

2. The method for treating electroless plating waste liquid according to claim 1, characterized in that: The metal ion is nickel ion, and the reducing agent is hypophosphite.

3. The method for treating electroless plating waste liquid according to claim 1 or 2, characterized in that: In the ammonia volatilization process, the ammonia is volatilized while the electroless plating waste liquid that has undergone the electrolytic treatment process is stirred.

4. A treatment system for electroless plating waste liquid, wherein the electroless plating waste liquid contains at least metal ions, ammonia, reducing agent, reducing agent waste, and complexing agent, characterized in that: At least including: An electrolytic treatment device, wherein the electrolytic treatment device electrolyzes the electroless plating waste liquid to remove the metal ions; An ammonia treatment device that removes ammonia from the electroless plating waste liquid that has undergone electrolytic treatment by volatilizing the ammonia. An ultraviolet-ozone treatment device oxidizes the electroless plating waste liquid that has undergone ammonia volatilization treatment, and decomposes the reducing agent, the reducing agent waste, and the complexing agent; and A phosphate treatment device that removes phosphate by adding a calcium compound to the electroless plating waste liquid that has been treated with ultraviolet light and ozone, thereby causing the phosphate to precipitate.

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