JPH07195091A - Treatment of waste water discharged from washing system - Google Patents

Abstract

PURPOSE:To adequately treat the waste water discharged from a washing system by an aq. detergent in place of a fluorocarbon compd. by successively subjecting the waste water from which an oily emulsion is separated to an oxidation decomposition treatment, active carbon treatment and ion exchange treatment. CONSTITUTION:The waste water is discharged from a washing system having a stage for washing various kinds of machines, etc., with the aq. detergent and a stage for finish washing the washed treating goods with water, respectively. In such a case, the waste water from which the oily emulsion is separated is subjected to an oxidation decomposition treatment then to an active carbon treatment and ion exchange treatment in order to treat the waste water. For example, the waste water is circulated by a circulating pump 12 from a storage tank 11 of a treating device 10. The oxidation decomposition by ozone incorporation, etc., are executed in a decomposition treating device 13. The granular active carbon is used in an active carbon treating device. Further, anion and cation exchange resins are used in an ion exchanger 15. As a result, the waste water by the aq. detergent in place of the fluorocarbon compd. is efficiently treated.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for treating wastewater,
In particular, it has both a cleaning process for cleaning various parts such as various machines and equipment, their constituent members with an aqueous cleaning agent, and a finish cleaning process for finishing and cleaning various parts cleaned in the cleaning process with water. The present invention relates to a method for treating wastewater discharged from a cleaning system.

[0002]

2. Description of the Related Art As a means for cleaning various parts such as various machines and devices and their constituent members, a cleaning method using a chlorofluorocarbon compound as a cleaning agent is very popular because it is the best method. However, in recent years, attention has been paid to the ozone layer depleting action of chlorofluorocarbon compounds, and the use of chlorofluorocarbon compounds is being prohibited worldwide. Therefore, a cleaning method in which the above-mentioned various parts are cleaned with an aqueous cleaning agent (surfactant) instead of the CFC compound is considered promising. As the cleaning method, a cleaning step of cleaning the above-mentioned various parts with an aqueous cleaning agent, and a finish cleaning step of finishing cleaning the various parts cleaned in the cleaning step with water (hereinafter also referred to as a rinse step) A cleaning system with When adopting a cleaning system for cleaning with such a water-based cleaning agent, treatment of wastewater discharged in each step becomes an important issue.

That is, a large amount of oily emulsion, various fine metal particles and an unused water-based cleaning agent are present in the wastewater discharged in the above-mentioned washing step, and the wastewater discharged in the finishing washing step. There is a small amount of oily emulsion and virgin water-based detergent present in it.
Therefore, it is preferable to remove a large amount of oily emulsion and recover unused detergent in the treatment of the wastewater discharged from the above-mentioned washing step, and to treat the wastewater discharged from the finishing washing step to a small amount of the oily emulsion. And it is preferable to remove unused detergent and discharge.

[0004]

By the way, in order to treat the wastewater discharged from the washing step, conventionally known specific gravity difference separation method, coalescer method and organic membrane method can be adopted. . In addition, a cross-flow filtration method using a ceramic filter can be adopted in order to improve the separation efficiency of the oily emulsion and the permeation capacity of the filtration membrane as compared with these methods. However, depending on the treatment method used, the wastewater treated by these methods contains a small amount of oily emulsion and unused cleaning agent, and the same applies to the wastewater from the finish cleaning step. Is slightly mixed in.

Therefore, it is preferable to remove even a small amount of contaminants in the wastewater treated water or the wastewater discharged from the finish cleaning step and discharge it as clean water. An object of the present invention is to provide a suitable method for treating the wastewater treated water or the wastewater from the finish cleaning step.

[0006]

The first invention of the present invention is as follows:
Cleaning that has both a cleaning process that cleans various parts such as various machines and equipment and their components with an aqueous cleaning agent, and a finish cleaning process that finishes and cleans various parts that have been cleaned in the same cleaning process with water. A method for treating wastewater discharged from the system, characterized in that the wastewater treated water discharged from the washing step and separated from the oily emulsion is subjected to oxidative decomposition treatment, followed by activated carbon treatment and ion exchange treatment. is there.

The second invention of the present invention is to provide various machines,
Emission from a cleaning system that has both a cleaning process for cleaning equipment and various components such as these components with a water-based cleaning agent, and a final cleaning process for finishing and cleaning various components cleaned in the cleaning process with water The method for treating wastewater is characterized in that the wastewater discharged from the finish cleaning step is subjected to oxidative decomposition treatment, followed by activated carbon treatment and ion exchange treatment.

[0008]

In the wastewater treatment method according to the present invention, the treated wastewater discharged from the washing step and separated from the oily emulsion or the wastewater discharged from the finish washing step is first subjected to ozone and oxidation. And / or it is decomposed by ultraviolet rays, and the high molecular weight substance in the mixture is lowered by such treatment, and the adsorption efficiency is remarkably improved in the subsequent treatment with activated carbon. Therefore, in the activated carbon treatment step, the high-molecular substances in the wastewater treatment water or the wastewater are efficiently removed, and the ionized substance is effectively adsorbed in the next treatment step, the ion-exchange treatment step, to a degree of cleanliness. The treated water is extremely high. That is, the treated water has a very low total organic matter concentration (TOC), BOD, COD, and n-hexane extract content, and there is no problem in releasing it to the outside.

[0009]

【Example】

(Wastewater treatment apparatus and treatment method of the present invention) FIG. 1 shows a treatment apparatus for carrying out the wastewater treatment method of the present invention. The processing apparatus 10 shown in FIG. 1 is subjected to a cleaning process in a cleaning process in which various parts such as various machines, devices, and their constituent members are cleaned with a water-based cleaning agent (sea surface active agent), and these various parts are finished and cleaned with water. This is a treatment device for waste water discharged from the finish washing step of performing a finish cleaning, which includes a storage tank 11, a circulation pump 12, a decomposition treatment device 13, an activated carbon treatment device 14, and an ion exchanger 15.
1, 12, 13, 14, and 15 are connected in series in this order to form a processing path.

In the decomposition processor 13, oxidative decomposition by addition of ozone or oxidative decomposition by ultraviolet rays is carried out individually or in combination. Further, in the activated carbon treatment device 14, granular activated carbon is used. Further, in the ion exchanger 15,
Anion and cation exchange resins are used. In the processing apparatus 10, waste water discharged from the rinse step 22 which constitutes the precision cleaning system shown in FIG. 2 is supplied.

The precision cleaning system 20 shown in FIG. 2 comprises three steps, namely, a cleaning step 21, a rinsing step 22 and a finish drying step 23. Cleaning process 21
Is composed of a first cleaning tank 21a and a second cleaning tank 21b. In the first cleaning tank 21a, various parts 24 transported in the tank are sprayed with cleaning water in which a cleaning agent is dissolved in a shower form to Machine oil and other contaminants that adhere to the surface of
Rinse off small metal particles. Washed parts 2
No. 4 is carried into the cleaning water in the second cleaning tank 21b, and ultrasonic cleaning is performed in the same cleaning tank. The cleaning water in the second cleaning tank 21b is the same as the cleaning water in the first cleaning tank 21a,
This completes the cleaning process. Both cleaning tanks 21a, 2
The wastewater discharged from 1b is supplied to the storage tank of another wastewater treatment process.

The rinsing step 22 is for finishing and cleaning various parts which have been subjected to the cleaning step 21 in the precision cleaning system. Is configured. The cleaning water from the third rinse tank 22c is supplied to the second rinse tank 22b, the cleaning water from the second rinse tank 22b is supplied to the first rinse tank 22a, and the first rinse tank 22a.
The wash water from is discharged to the storage tank 11 of the wastewater treatment device 10 in this embodiment.

(Experiment by the treatment method of the present invention) Using the treatment apparatus 10, a wastewater treatment experiment was conducted by the treatment method of the present invention. In the treatment experiment (Experiment A), the wastewater to be treated was the wastewater discharged from the rinse step. The components of the waste water and the components of the waste water treatment water are as shown in Table 1, and the conditions of the decomposition treatment step, the activated carbon treatment step and the ion exchange treatment step in the treatment experiment are as follows. In this experiment, as a comparative example, a treatment experiment (experiment B) in which the decomposition treatment step was omitted was performed.
The results are also shown in the table. However, the throughput in all the following steps is 5 l / min.

(1) Conditions of decomposition process: Oxidative decomposition condition by addition of ozone: Ozone added amount 20 ml, ultraviolet ray (U
V) Oxide decomposition conditions: UV power consumption 100W.

(2) Conditions of activated carbon treatment step: Activated carbon filling amount ... 20 l.

(3) Conditions for the ion exchange treatment step: amount of ion exchange resin: 20 l.

[0017]

[Table 1]

(Discussion) In this experiment, the treated water that has undergone the decomposition treatment step, the activated carbon treatment step and the ion exchange treatment step is TOC, BOD, COD, n compared with the water to be treated.
-The hexane extract was found to be significantly reduced and can be released to the outside without any problems. On the other hand, in the experiment (comparative example) in which the decomposition treatment step was omitted, a considerable amount of each of these components was still present in the treated water, and it was problematic to release the treated water to the outside in this state. There is.

In this embodiment, an example is shown in which wastewater discharged from the rinse step (finishing cleaning step) in the precision cleaning system is used as the water to be treated, but in the present invention, it is discharged from the cleaning step in the above system. It is possible to adopt the wastewater treated water obtained by subjecting the wastewater treated by the separation treatment of the oily emulsion, and such wastewater treated water also contains components substantially similar to the wastewater discharged from the above-mentioned rinsing step, and the same as in this example. It is effective.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a processing apparatus used in a processing method of the present invention.

FIG. 2 is a schematic configuration diagram of a cleaning system.

[Explanation of symbols]

11 ... Storage tank, 12 ... Circulation pump, 13 ... Decomposition processor, 14 ... Activated carbon processor, 15 ... Ion exchange processor, 2
0 ... precision cleaning system, 21 ... cleaning process, 22 ... rinse process (finish cleaning process), 23 ... finish drying process.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C02F 1/72 101 9/00 502 H J N R 503 A 504 B

Claims (2)

[Claims] 1. A washing process for washing various parts such as various machines and devices, and their constituent members with an aqueous cleaning agent, and a finish washing process for finishing washing various parts washed in the washing treatment step with water. Is a method for treating wastewater discharged from a cleaning system having both steps, wherein the wastewater treated water discharged from the cleaning step and separated from the oily emulsion is treated,
A method for treating wastewater discharged from a cleaning system, which comprises oxidative decomposition treatment, followed by activated carbon treatment and ion exchange treatment. 2. A cleaning process for cleaning various parts such as various machines and devices, and their components with an aqueous cleaning agent, and a finish cleaning process for finishing cleaning various parts cleaned in the cleaning process with water. A method for treating wastewater discharged from a cleaning system having both steps, wherein the wastewater discharged from the finishing cleaning step is subjected to oxidative decomposition treatment, and then activated carbon treatment and ion exchange treatment. Wastewater treatment method.