JP2008155112A - Recovery method of zirconium chemical forming treatment washing wastewater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recovery method of zirconium chemical forming treatment washing wastewater excellent from an aspect of economical efficiency or environment capable of recovering zirconium/fluorine complex ions and washing water from chemical forming treatment washing wastewater composed of a solution containing zirconium and fluorine, in a high yield to reutilize them. <P>SOLUTION: The closed circulating type recovery method of the zirconium chemical forming treatment washing wastewater for recovering zirconium/fluorine complex ions and washing water from the zirconium chemical forming treatment washing wastewater has the separation process of separating the zirconium chemical forming treatment washing wastewater into a concentrated solution and a permeated solution by reverse osmosis membrane treatment, the cation exchange process of treating the concentrated solution obtained in the separation process with a cation exchange resin, the concentrated solution sending process of sending the liquid treated with the cation exchange resin to a chemical forming treatment tank and a permeated liquid sending process of sending the permeated liquid obtained in the separation process to a final washing tank. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a method for recovering waste water from zirconium conversion treatment water.

Zirconium treatment is performed in a chemical conversion treatment method for a metal substrate. However, the reuse and recovery method of the washing water discharged in the washing step in this zirconium chemical conversion treatment has not been sufficiently studied so far.
Therefore, there has been a demand for a method for reusing and recovering water from waste water generated by zirconium chemical conversion, which is excellent in workability and economy.

In Patent Document 1, after adjusting the pH of the washing water with an acid, the first reverse osmosis membrane treatment is performed to separate the permeate and the concentrate, and the permeate is neutralized with an alkali. The second reverse osmosis treatment is performed to separate the second permeate and the concentrate, the first concentrate is sent to the phosphate coating conversion treatment tank, and the second permeate is sent to the water washing tank for reuse. In addition, a method for recovering the washing water of the phosphate coating conversion treatment is disclosed, in which the second concentrated liquid is discharged out of the system.

Patent Document 2 discloses a method for reusing a phosphate chemical treatment waste water which is supplied to a pressure dialysis apparatus at a dialysis pressure and separated into a permeate and a concentrated liquid. .

However, in the zirconium chemical conversion treatment, when the zirconium fluoride complex ion (ZrF ₆ ^2- ion) is to be recovered from the treated washing waste water, the treatment liquid contains a large amount of metal ions eluted from the surface of the treatment object. In addition, since zirconium is in a low concentration, zirconium cannot be efficiently recovered even if such a reprocessing method of the phosphate chemical treatment flush water is applied as it is.
JP 2001-164389 A JP 2002-59162 A

In view of the above-mentioned present situation, the present invention can recover and reuse zirconium fluoride complex ions and washing water in a high yield from a chemical conversion treatment washing wastewater comprising a solution containing zirconium and fluorine. An object of the present invention is to provide a method for recovering waste water from zirconium conversion treatment water that is excellent in water.

The present invention is a zirconium chemical treatment flush wastewater recovery method for recovering zirconium fluoride complex ions and flush water from zirconium chemical treatment flush wastewater, wherein the zirconium chemical treatment flush wastewater is converted into a concentrated liquid and a permeate by reverse osmosis membrane treatment. A separation step for separating, a cation exchange step for treating the concentrated liquid obtained in the separation step with a cation exchange resin, a concentrated liquid water feeding step for feeding the liquid treated with the cation exchange resin to a chemical conversion treatment tank, and A closed circulation type zirconium chemical conversion treated water drainage recovery method comprising a permeate water feeding step of feeding the permeate obtained in the separation step to a final water washing tank.

It is preferable that the zirconium chemical conversion treatment waste water recovery method further includes a step of setting the TOC value of the zirconium chemical conversion treatment water drainage to 5 or less with an activated carbon layer.
It is preferable that the zirconium chemical conversion treatment water drainage recovery method further includes a step of setting the FI value of the zirconium chemical conversion treatment water drainage to 4 or less by a membrane filter.
The reverse osmosis membrane used in the reverse osmosis membrane treatment preferably has a sodium inhibition rate of 50% or more.
The cation exchange resin is preferably a strong acid cation exchange resin, a weak acid cation exchange resin or a chelate resin.
The liquid treated with the cation exchange resin preferably has a zirconium fluoride complex ion concentration of 50 to 1000 ppm in terms of zirconium.
The liquid treated with the cation exchange resin preferably has a zinc concentration of 100 ppm or less, an aluminum concentration of 50 ppm or less, and an iron concentration of 100 ppm or less.

It is preferable that the said zirconium chemical conversion water washing waste_water | drain contains at least 1 sort (s) among a zirconium fluorine complex ion and a zinc ion, an iron ion, and an aluminum ion.
The zirconium chemical treatment flush waste water has a zirconium fluoride complex ion concentration of 5 to 100 ppm in terms of zirconium, a zinc concentration of 200 ppm or less, an aluminum concentration of 10 ppm or less, an iron concentration of 200 ppm or less, and a pH of It is preferable that it is 4.5 or less.
Hereinafter, the present invention will be described in detail with reference to FIG. 1 showing an apparatus used in the method of recovering waste water from zirconium conversion treatment of the present invention.

The zirconium chemical treatment flush wastewater recovery method of the present invention includes a separation step of separating the zirconium chemical treatment flush wastewater into a concentrate and a permeate by the reverse osmosis membrane 6, and a cation exchange resin 7 for the concentrate obtained in the separation step. The cation exchange process processed by the above, the concentrated liquid feed process for feeding the liquid treated with the cation exchange resin 7 to the chemical conversion treatment tank 1, and the permeate obtained in the separation process are fed to the final washing tank 3. Therefore, it is possible to recover the treatment water and the washing water containing zirconium fluorine complex ions in a high yield from the chemical conversion treatment washing waste water composed of a solution containing zirconium and fluorine. Accordingly, it is possible to reduce the amount of chemicals used and the amount of water used for the zirconium chemical conversion treatment. That is, it is suitable for the treatment of wastewater mixed with zinc ions, iron ions, aluminum ions, etc., which can be removed by cation exchange, specifically from iron, galvanized steel sheet, aluminum alloy. It is more suitable for wastewater treatment of chemical conversion treatment of metal material. Moreover, since it is cation exchange, a zirconium fluorine complex ion (ZrF ₆ ²⁻ ) can be recovered without being exchanged.

The concentrated solution obtained by separation with the reverse osmosis membrane is a solution in which zirconium fluoride complex ions are concentrated to a concentration that can be reused as a chemical conversion treatment solution. However, miscellaneous ions such as iron, zinc, and aluminum cannot be sufficiently removed only by the treatment with the reverse osmosis membrane. The miscellaneous ions are ions that cause chemical conversion inhibition when accumulated on a metal substrate when applied again as a chemical conversion solution. In the present invention, the concentrated liquid obtained by the reverse osmosis membrane treatment is further treated with a strong acidic cation exchange resin or the like, so that it contains zirconium fluoride complex ions at an effective concentration, and unnecessary components such as miscellaneous ions are It is possible to obtain a treatment liquid that can be reused for the chemical conversion treatment, such as a control value or less. In addition, it is preferable that the said management value is iron ion 100ppm or less, aluminum 50ppm or less, and zinc ion 100ppm or less.
The present invention also enables a closed system of a chemical conversion treatment line that can be reused without draining the waste water from the system in the water washing step in the zirconium chemical conversion treatment. Accordingly, it is possible to reduce the environmental load due to the amount of drainage and drainage.

The zirconium chemical conversion treatment water drainage recovery method of the present invention is a treatment method for water drainage generated in the water washing step after the chemical conversion treatment of the metal substrate. For example, in FIG. 1, the chemical conversion treatment is performed by immersing a metal substrate in a zirconium chemical conversion treatment liquid in the chemical conversion treatment tank 1. It does not specifically limit as a zirconium chemical conversion treatment liquid used in this invention, For example, the general zirconium chemical conversion liquid containing a zirconium fluorine complex ion can be mentioned.

The metal substrate subjected to the chemical conversion treatment is washed in a water washing step. The water washing step is usually performed to remove the chemical conversion treatment component so as not to adversely affect the adhesion, corrosion resistance, and the like after the subsequent various coatings. The washing with water here can be performed by a full dip method, a spray method or a combination thereof. In the final water washing step, mist spray or the like may be used in combination as necessary. In the above-described washing process comprising one or more stages of washing, a predetermined amount of fresh washing water is supplied to the final washing tank 3, overflow water is supplied to the previous washing tank, and finally water is supplied to the first washing tank 2. Is done. Here, the supply amount of fresh rinsing water is set so that the concentration of the chemical conversion liquid in the first water rinsing tank 2 is 10 times the normal chemical conversion liquid concentration.

The zirconium chemical conversion treatment waste water recovery method of this invention has the separation process which isolate | separates the zirconium chemical conversion treatment water drainage produced in the water washing process mentioned above into a concentrate and a permeate by reverse osmosis membrane treatment.
The chemical conversion treatment waste water is separated into a concentrated liquid containing zirconium fluoride complex ions, which are effective components of the chemical conversion liquid, and a permeate reusable as flush water by the above process.

The reverse osmosis membrane used in the reverse osmosis membrane treatment preferably has a sodium inhibition rate of 50% or more. If the sodium inhibition rate is less than 50%, it is difficult to concentrate by reverse osmosis membrane treatment, and a concentrated solution having a desired concentration may not be obtained.
In addition, the sodium inhibition rate described above was obtained by allowing a 0.15 mass% sodium chloride solution to permeate at a pressure of 15 kgf / cm ² and a temperature of 25 ° C. with an 8-inch element, and the sodium concentration in the obtained permeate was This is a value determined by a calculation formula of (sodium concentration in 0.15% by mass sodium chloride solution−sodium concentration in permeate) / sodium concentration in 0.15% by mass sodium chloride solution × 100.

Any known reverse osmosis membrane can be used as long as it satisfies the sodium inhibition rate. As a commercial item of the said reverse osmosis membrane, the membrane master RUW-5A (made by Nitto Denko Corporation) etc. which used LF10 membrane module can be mentioned, for example.

It is preferable that the zirconium chemical conversion treatment water drainage collection method of this invention is applied to the zirconium chemical conversion treatment water drainage containing a zirconium fluoride complex ion and at least 1 type of zinc ion, iron ion, and aluminum ion.

It is preferable that the zirconium chemical conversion treatment waste water has a zirconium fluoride complex ion concentration of 5 to 100 ppm in terms of zirconium.
When the zirconium concentration is within the above range, zirconium can be recovered more favorably from the above-mentioned washing waste water in the method of the present invention. More preferably, it is 30-60 ppm.

In addition, the zirconium chemical conversion treatment water drainage recovery method of the present invention is a zirconium chemical conversion in which the zinc concentration is 200 ppm or less, the aluminum concentration is 10 ppm or less, the iron concentration is 200 ppm or less, and the pH is 4.5 or less. Suitable for the treatment of treated waste water. When the concentration and pH of each ion are within the above ranges, the reverse osmosis membrane treatment can be suitably performed, and a concentrated solution containing a zirconium fluoride complex ion at a suitable concentration and a permeate can be obtained.
In the present invention, the zirconium concentration, iron concentration, zinc concentration, and aluminum concentration are values obtained by measurement using an ICP (inductively coupled plasma emission analysis) or atomic absorption spectrometer.

The concentrated liquid obtained by the reverse osmosis membrane treatment preferably has a zirconium fluoride complex ion concentration of 50 to 1000 ppm in terms of zirconium. When the concentration is in the above range, the obtained concentrated liquid can be reused as a chemical conversion treatment liquid. The concentration is more preferably 300 to 600 ppm.
Moreover, it is preferable that pH of the said concentrate is 4.5 or less normally.

The permeate obtained by the reverse osmosis membrane treatment is preferably nitrate ions 0 to 100 ppm, fluorine ions 0 to 100 ppm, and sodium ions 0 to 100 ppm. When the concentration is in the above range, the obtained permeate can be reused as washing water.

The zirconium chemical conversion treatment water drainage recovery method of the present invention includes a cation exchange step of treating the concentrated liquid obtained in the separation step with a cation exchange resin 7.
In the cation exchange step, zinc ions and iron ions, which are unnecessary components in the concentrated liquid, are adsorbed and removed, and the concentration of zinc and iron is reduced to a control value or less, whereby a reusable processing liquid is obtained as a chemical conversion liquid. Obtainable.

The cation exchange resin 7 is preferably a strong acid cation exchange resin, a weak acid cation exchange resin, or a chelate resin. Of these, strong acid cation exchange resins are preferred.
Examples of the strong acid cation exchange resin include a commercial product, ND mini clopack CR-40G tower manufactured by Nippon Electric Works.

The liquid obtained by the treatment with the cation exchange resin 7 has a zirconium fluoride complex ion concentration of 50 to 1000 ppm in terms of zirconium, a zinc concentration of 100 ppm or less, an aluminum concentration of 50 ppm or less, and an iron concentration of 100 ppm or less. It is preferable that When the concentration is in the above range, it can be suitably reused as a chemical conversion treatment liquid.

The zirconium chemical conversion treatment water drainage recovery method of the present invention further includes a concentrated liquid water supply step for supplying the liquid processed by the cation exchange resin 7 to the chemical conversion treatment tank 1. The concentrated solution treated with the cation exchange resin 7 is sent to the chemical conversion treatment tank 1 through the concentrated liquid take-out tube 9 and used again as the chemical conversion treatment solution. For this reason, the amount of chemicals used can be reduced.

The zirconium chemical conversion treatment waste water recovery method of the present invention includes a permeate water feeding step of feeding the permeate obtained in the separation step to the final water washing tank 3.
The permeate obtained in the separation step is fed to the final washing tank 3 through the permeate take-out pipe 10 and can be applied again as washing water in the water washing step of the chemical conversion treatment. For this reason, reduction of the amount of drainage and the amount of water used can be aimed at.

The permeate obtained in the separation step may be further treated with a cation / anion resin 8. By the cation / anion exchange treatment, it is possible to more suitably obtain washing water in which nitrate ions, fluorine ions, and sodium are reduced to the desired concentration described above, and this can be reused.
As said cation / anion resin, what is necessary is just to use a well-known thing, for example, commercial items, such as ND mini clo pack CR-40M tower made by Nippon Electric Works, Ltd. can be mentioned.

The zirconium chemical treatment flush wastewater recovery method of the present invention has a TOC value of 5 by the activated carbon layer 4 before the step of separating the zirconium chemical treatment flush wastewater into a concentrate and a permeate by reverse osmosis membrane treatment. The following steps may be included. In particular, when a treatment liquid containing organic components (resin, phenol compound, etc.) is used in the waste water, it is preferable to perform such treatment. The durability of the reverse osmosis membrane can be improved by performing the above steps.

Although it does not specifically limit as the said activated carbon layer 4, Usually, the gravity type adsorption apparatus etc. which used granular activated carbon can be used. It does not specifically limit as said gravity type adsorption | suction apparatus, For example, CR-700C (made by Nippon Electric Works) etc. can be mentioned.

The TOC value of the chemical conversion treated waste water treated by the activated carbon layer 4 is preferably 5 or less. If it exceeds 5, the durability of the reverse osmosis membrane may be reduced.
The TOC value is the total amount of carbon, and can be obtained by measuring with TOC-5000 (manufactured by Shimadzu Corporation).

Moreover, the zirconium chemical conversion treatment waste water recovery method of this invention is the FI of the said chemical conversion treatment water drainage further by the membrane filter 5 before the process which isolate | separates a zirconium chemical conversion treatment water drainage into a concentrate and a permeate by reverse osmosis membrane treatment. A step of setting the value to 4 or less may be included. In particular, when a treatment liquid containing organic components (resin, phenol compound, etc.) is used in the waste water, it is preferable to perform such treatment. The durability of the reverse osmosis membrane can be improved by performing the above steps.

The membrane filter 5 is not particularly limited. For example, when the filter agent is clogged and the filtration capacity is reduced, an air back-washing system in which backwashing is performed only with air to recover the capacity. be able to. Although it does not specifically limit as said membrane filter of the air backwashing system, For example, what uses a hollow fiber is preferable, Specifically, commercially available FEX-400 (made by Mitsubishi Rayon Co., Ltd.) etc. can be mentioned. When the membrane filter is clogged and the filtration capacity is reduced, air is supplied and backwashing is performed. The backwash wastewater generated at this time is discarded.

The FI value of the chemical conversion treated waste water treated by the membrane filter is preferably 4 or less. If it exceeds 4, the durability of the reverse osmosis membrane may be reduced.
The FI value is turbidity, and this is an index of a component that adheres to the reverse osmosis membrane and deteriorates. Specifically, the value can be obtained by the following method. That is, the initial time (T1) required to filter and collect 500 ml of sample water at a filtration pressure of 30 psi (206 kPa) using a 47 mm diameter 0.45 micron filter and the time required after 15 minutes of continuous operation (T2) is measured and the FI value is expressed by the following formula:
FI value = PF / T
However, PF is a clogging coefficient (dirt%) = 100 × (1−T1 / T2),
T1 is the time (seconds) required to filter and collect 500 ml of the first time,
T2 is the time (seconds) required to filter and collect 500 ml after T minutes,
T represents the time from the T1 filtration / collection start time to the T2 filtration / final start time (usually 15 minutes).

The zirconium chemical conversion treatment waste water recovery method of the present invention can be used particularly suitably as a water recovery waste water recovery method in zirconium conversion treatment of at least part of an iron-based or zinc-based substrate. As used herein, the iron-based substrate means one made of iron and / or an alloy thereof. It does not specifically limit as said iron-type base material, For example, a cold-rolled steel plate, a hot-rolled steel plate, a high-tensile steel plate etc. can be mentioned.

The zinc-based substrate is not particularly limited. For example, galvanized steel sheet, zinc-nickel plated steel sheet, zinc-iron plated steel sheet, zinc-chromium plated steel sheet, zinc-aluminum plated steel sheet, zinc-titanium plated steel sheet, zinc- Examples thereof include zinc-based electroplating such as magnesium-plated steel sheet and zinc-manganese-plated steel sheet, zinc such as hot-dip plating and vapor-deposited steel sheet, or zinc-based alloy-plated steel sheet.

The metal substrate which is the object to be treated of the present invention may also be an aluminum substrate made of aluminum and / or an alloy thereof. It does not specifically limit as said aluminum-type base material, For example, 5000 series aluminum alloy, 6000 series aluminum alloy, etc. can be mentioned. Moreover, as said to-be-processed object, you may consist of a some metal base material among an iron-type base material, a zinc-type base material, and an aluminum-type base material.

The metal substrate is preferably subjected to a degreasing treatment and a water washing treatment after degreasing before the chemical conversion treatment with the chemical conversion treatment solution.
The degreasing treatment is performed to remove oil and dirt adhering to the surface of the base material, and usually with a degreasing agent such as phosphorus-free and nitrogen-free degreasing cleaning liquid at about 30 to 55 ° C. for about several minutes. Immersion treatment is performed. If desired, a preliminary degreasing process can be performed before the degreasing process.
The post-degreasing rinsing treatment is performed by performing spraying once or more with a large amount of rinsing water in order to remove the degreaser remaining on the substrate surface after the degreasing treatment.

Since the metal base material processed by the zirconium chemical conversion water washing wastewater collection method of the present invention has good corrosion resistance, adhesion after coating, and the like, it can be used in various fields. The field to be used is not particularly limited, and examples thereof include automobile bodies, automobile parts, building materials, OA equipment, home appliances, and general metal products.

The present invention relates to a method for recovering zirconium chemical treatment flushed wastewater, a separation step of separating the zirconium chemical treatment flushed wastewater into a concentrate and a permeate by reverse osmosis treatment, and a cation exchange resin for the concentrate obtained in the separation step. A cation exchange step for treating with water, a concentrated water feeding step for feeding the liquid treated with the cation exchange resin to the chemical conversion treatment tank, and a permeate for feeding the permeate obtained in the separation step to the final washing tank. It has a water supply process. For this reason, it is possible to suitably obtain a liquid containing zirconium fluoride complex ions, which are active ingredients, and flush water from the zirconium chemical treatment flush waste water, and these can be reused.

Since the recovery method of the zirconium chemical conversion treatment washing waste water of the present invention has the above-described configuration, a liquid containing a zirconium fluoride complex ion that can be reused as the chemical conversion treatment liquid and reusable flush water are suitably obtained. It is excellent in terms of economy and environment. Therefore, the zirconium chemical conversion water washing waste water collection method of the present invention can be suitably applied as a pre-painting process for metal molded products such as automobile bodies and automobile parts, or a pre-painting process for general industrial members.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Example)
1000 L of zirconium chemical conversion water washing waste water was collected. First, filtration was performed at a pressure of 0.5 kg / cm ² and a flow rate of 2.0 L / min using a commercially available Mitsubishi Rayon Co., Ltd., hollow fiber membrane module small capacity filter (FEX-400). Next, the obtained solution was treated at a treatment temperature of 25 to 30 ° C. and a pressure of 2.0 using a membrane master RUW-5A (Na inhibition rate 99.5%, manufactured by Nitto Denko Corporation) using a commercially available LF10 membrane module. It is subjected to reverse osmosis membrane treatment under processing conditions of ~ 2.5 MPa, concentrated liquid circulation flow rate of 5.9 to 6.1 L / min, and permeate flow rate of 1.0 to 3.0 L / min. Obtained. Table 1 shows the analysis results of the concentrate and permeate.
The concentrated solution obtained above was passed through a commercially available ND mini clopack CR-40G tower (manufactured by Nippon Electric Works) at a flow rate of SV5 (3 L / h) to obtain a solution after cation exchange treatment. Table 1 shows the analysis results of the obtained liquid after the cation exchange treatment.

In addition, about the ion concentration of a fluorine ion and nitrate ion, it measured using the ion chromatograph SERIES 4000 (made by DIONEX). The zirconium concentration was measured using a plasma emission spectroscopic analyzer CIROS 120 ICP (manufactured by Rigaku Corporation). About other ion, it measured using atomic absorption ATOMIC ABSOPTION SPECTROMETER 3300 (made by PERKIN ELMER).

From Table 1, in the examples, a treatment liquid containing zirconium fluorine complex ions that can be reused as a chemical conversion treatment liquid, that is, containing zirconium fluorine complex ions at an appropriate concentration, and unnecessary iron ions, aluminum ions, zinc ions. A liquid having a control value below the control value could be obtained. At the same time, a permeate (fluorine ion, nitrate ion, and sodium ion was 100 ppm or less each) that could be reused as washing water was obtained.

The zirconium chemical conversion washing water drainage collection method of the present invention can be suitably applied as a pre-painting process for metal molded products such as automobile bodies and automobile parts, or a pre-painting process for general industrial members.

An example of the schematic diagram of the apparatus used with the zirconium chemical conversion water washing waste_water | drain collection | recovery method of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chemical conversion treatment tank 2 First water washing tank 3 Final water washing tank 4 Activated carbon layer 5 Membrane filter 6 Reverse osmosis membrane 7 Cation exchange resin 8 Cation and anion exchange resin 9 Condensate extraction pipe 10 Permeate extraction pipe

Claims (9)

Zirconium conversion treatment water drainage recovery method for recovering zirconium fluoride complex ions and flush water from zirconium chemical treatment water drainage,
A separation step of separating the zirconium chemical conversion water washing wastewater into a concentrate and a permeate by a reverse osmosis membrane treatment;
A cation exchange step of treating the concentrated liquid obtained in the separation step with a cation exchange resin;
Concentrated liquid feeding step for feeding the liquid treated with the cation exchange resin to the chemical conversion treatment tank, and
A closed circulation type zirconium chemical conversion treatment water drainage recovery method comprising a permeate water feeding step of feeding the permeate obtained in the separation step to a final water washing tank. The method of claim 1, further comprising a step of setting the TOC value of the zirconium chemical treatment water drainage to 5 or less by the activated carbon layer. The method of claim 1 or 2, further comprising the step of setting the FI value of the zirconium chemical treatment effluent drainage to 4 or less with a membrane filter. The method of claim 1, 2, or 3, wherein the reverse osmosis membrane used in the reverse osmosis membrane treatment has a sodium inhibition rate of 50% or more. The method of claim 1, 2, 3, or 4, wherein the cation exchange resin is a strong acid cation exchange resin, a weak acid cation exchange resin, or a chelate resin. The method of claim 1, 2, 3, 4 or 5, wherein the concentration of zirconium fluoride complex ions in the liquid treated with the cation exchange resin is 50 to 1000 ppm in terms of zirconium. The method of claim 6, wherein the solution treated with the cation exchange resin has a zinc concentration of 100 ppm or less, an aluminum concentration of 50 ppm or less, and an iron concentration of 100 ppm or less. Zirconium conversion treated water drainage waste water according to claim 1, 2, 3, 4, 5, 6 or 7 containing zirconium fluoride complex ions and at least one of zinc ions, iron ions and aluminum ions. Collection method. Zirconium conversion treated washing wastewater has a zirconium fluoride complex ion concentration of 5 to 100 ppm in terms of zirconium, a zinc concentration of 200 ppm or less, an aluminum concentration of 10 ppm or less, an iron concentration of 200 ppm or less, and a pH of 4 The method of claim 1, 2, 3, 4, 5, 6, 7, or 8, for recovering the waste water from zirconium conversion treatment water.

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