JP3864447B2 - Wastewater treatment method and wastewater treatment equipment for alkaline waste liquid - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wastewater treatment method for an alkaline waste liquid containing a resin component such as an etching resist generated in the manufacturing process of a printed wiring board, and a wastewater treatment apparatus therefor.
[0002]
[Prior art]
In recent years, as efforts to protect the global environment have been strengthened, various ideas have been made in the treatment of waste liquid generated in various productions, and various regulations have been established.
[0003]
Various waste liquids are also generated in the manufacturing process of printed wiring boards. Among them, resin-based alkaline waste liquids produced when photosensitive films (commonly called dry films) and printing inks used as etching resists are removed with alkaline solutions. It was a big problem.
[0004]
Therefore, conventionally, an acidic chemical solution is added to an alkaline waste liquid containing a resin component, heated to cause a coagulation reaction, and the supernatant liquid is removed. Then, the residual waste liquid containing resin sludge is treated with resin sludge and treated water using a separator. And was to be separated.
[0005]
[Problems to be solved by the invention]
The resin sludge separated by the separation device is entrusted to a waste disposal contractor. However, there is a problem that the amount of industrial waste becomes very large due to the sludge shape with a high water content, resulting in high processing costs. It was.
[0006]
Of course, it is conceivable to further reduce the water content with a separator, but the resin sludge that has undergone agglomeration is in a state where moisture has been taken into the interior, so moisture can be easily separated even with a separator. As a result, as described above, the amount of industrial waste entrusted to an industrial processor is extremely large.
[0007]
Accordingly, an object of the present invention is to reduce the amount of industrial waste entrusted to an industrial processor by lowering the water content in the resin sludge.
[0008]
[Means for Solving the Problems]
In order to achieve this object, the present invention adds an acidic chemical solution to an alkaline waste solution containing a resin component, warms it to a first temperature, causes an agglomeration reaction, and then performs a second reaction at a temperature higher than the first temperature. The agglomeration reaction is carried out by heating to a temperature of 1, and then the resin sludge and treated water are separated by a separation device, thereby achieving the intended purpose.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, the aggregation reaction is performed at the first temperature and the second temperature higher than the first temperature, and the heating temperature is gradually changed from low to high. By doing so, the sludge that agglomerates becomes large at once, so that a large amount of moisture is not taken in, and as a result, it becomes very easy to separate the moisture in the subsequent separation apparatus, thereby allowing the industrial processor to The amount of industrial waste entrusted to the company is extremely small, and the processing cost can be reduced.
[0010]
In the invention according to claim 2 of the present invention, an acidic chemical solution is added to an alkaline waste solution, heated to 30 to 50 ° C., and the residual sludge containing resin sludge is removed after removing the supernatant solution after coagulation precipitation. The method according to claim 1, wherein the temperature is raised to 70 ° C, wherein the first temperature is set to 30 to 50 ° C to improve the transportability to the next, and the second temperature. Is set to 55 to 70 ° C. to improve the separability.
[0011]
The invention according to claim 3 of the present invention is characterized in that the temperature of the alkaline waste liquid according to claim 1 or 2 is temporarily lowered when the resin sludge containing waste liquid heated to the second temperature is transferred. This is a wastewater treatment method in which the agglomerated reaction product is cooled to a temperature suitable for transportability.
[0012]
Invention of Claim 4 of this invention is set as the wastewater treatment method of the alkaline waste liquid of Claim 3 characterized by temperature-falling to 20-40 degreeC, and temperature-falls to the temperature excellent in the conveyance property. It has the action.
[0013]
The invention described in claim 5 of the present invention is the wastewater treatment method for alkaline waste liquid according to claim 1, wherein the coagulation reaction is performed in an acidic region. There is a difference in fluidity, and the aggregated precipitate generated in the acidic region is suitable for wastewater treatment.
[0014]
The invention according to claim 6 of the present invention is the wastewater treatment method for alkaline waste liquid according to claim 5, characterized in that the pH value of the acidic region is 2 to 4, and among the acidic region, Aggregated precipitates generated in the range of PH2-4 are particularly excellent in wastewater treatment.
[0015]
The invention according to claim 7 of the present invention includes a reaction vessel provided with a stirrer and a first heater, a metering pump for dropping a chemical solution from the chemical solution tank to the reaction vessel, and raising the temperature of the waste liquid in the reaction vessel. A pump for transferring to the tank; a second heater provided in the temperature raising tank; and a pump for transferring waste liquid from the temperature raising tank to the separation device, wherein the heating temperature by the second heater is the first temperature. The effect of claim 1 is achieved by setting the temperature higher than the heating temperature by the heater.
[0016]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an apparatus showing a method for treating wastewater of alkaline waste liquid according to the present invention. In FIG. 1, 1 is an alkaline waste solution containing a resin component of an etching resist, 2, 2a is a resin sludge, 3 is a water storage tank, 4 is a reaction tank, 5 is a heater, 6 is a stirrer, and 7a to 7e are transfer pumps. , 8 is a metering pump, 9 is a temperature raising tank, 10 is a separation device, 11a to 11f are transfer pipes, 12 is a valve, 13 is a chemical solution tank, 14 is an acidic drug, 15 is a thermometer, 16 is a PH meter, 17a , 17b is treated wastewater.
[0017]
In the manufacturing process of the printed wiring board, the alkaline waste liquid 1 having a deteriorated developing and peeling ability is sent to the water storage tank 3 of the wastewater treatment facility via the transfer pipe 11a as shown in FIG. Relatively large resin sludge 2 and foreign matters in the alkaline waste liquid 1 accumulate on the bottom of the water storage tank 3. The alkaline waste liquid 1a in the supernatant of the water storage tank 3 is sent to the reaction tank 4 by the transfer pump 7a through the transfer pipe 11b, and the resin sludge 2 and foreign matter deposited on the bottom of the water storage tank 3 are periodically removed by opening the valve 12. After that, it is consigned to an industrial processor as industrial waste.
[0018]
While stirring the alkaline waste liquid 1a in the reaction tank 4 with the stirrer 6 and heating it with the warmer 5, 60 vol% sulfuric acid is dropped into the reaction tank 4 with the metering pump 8 as the acidic chemical 14 in the chemical liquid tank 13. The pH meter 16 provided in the reaction tank 4 stops dropping the acidic drug 14 when the PH value is 3 to 4, and the heating is finished when the measured value of the thermometer 15 is 30 to 50 ° C. After 10 to 20 minutes, the agitator 6 is stopped. Thereafter, the agglomerated reaction product generated in the reaction tank 4 is allowed to stand for about 10 to 12 hours, and is deposited on the bottom of the reaction tank 4 as a resin-based sludge 2a. About 70% of the supernatant processing waste water 17a in the reaction tank 4 is sent to the raw water tank (not shown) by the transfer pump 7B via the transfer pipe 11c, and is discharged as general waste water by adjusting the pH.
[0019]
The remaining alkaline waste liquid 1b containing the resin sludge 2a corresponding to the remaining 30% is sent to the heating tank 9 by the transfer pump 7c through the transfer pipe 11d. Since the alkaline waste liquid 1b is an agglomerated reaction product at 30 to 50 ° C., the water content is high and the separability is not good, but the fluidity is high and the pumpability is excellent. While stirring the alkaline waste liquid 1b in the temperature raising tank 9 with the stirrer 6, the temperature is raised to 55 to 70 ° C. with the heater 5 and the stirring is stopped. The resin sludge 2a at this time becomes an alkaline waste liquid 1c having a low water content. Thereafter, the alkaline waste liquid 1c heated to 55 to 70 ° C. is cooled to 20 to 40 ° C. by natural standing or the like in order to improve fluidity and transportability, and sent to the separation device 10 by the transfer pump 7d through the transfer pipe 11e. . A precipitate at 20 to 40 ° C. is clay-like and has excellent transportability.
[0020]
Next, the resin sludge 2b and the treated water (filtrate) are separated using the centrifugal separator of the separation device 10, and the treated wastewater 17b is sent to the raw water tank by the transfer pump 7e through the transfer pipe 11f. To discharge as general wastewater. The residual resin sludge 2b at this time has a very low moisture content, and can reduce the amount of industrial waste.
[0021]
【The invention's effect】
As described above, according to the present invention, the aggregation reaction is performed at the first temperature and the second temperature higher than the first temperature. By performing the heating temperature stepwise from a low temperature to a high temperature, Aggregating sludge does not take in a large amount of moisture when it becomes large at once as a conventional method, and as a result, it becomes very easy to separate moisture in the subsequent separation equipment, thereby industrial waste entrusted to industrial processors The amount of material is extremely reduced, and the processing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an alkaline waste liquid wastewater treatment apparatus according to the present invention.
DESCRIPTION OF SYMBOLS 1 Alkaline waste liquid 2,2a, 2b Resin system sludge 3 Water storage tank 4 Reaction tank 5 Heater 6 Stirrer 7a-7e Transfer pump 8 Metering pump 9 Temperature rising tank 10 Separation apparatus 11a-11f Transfer pipe 12 Valve 13 Chemical solution tank 14 Acidic medicine 15 Thermometer 16 PH meter 17a, 17b Treatment wastewater

Claims (7)

An acidic chemical solution is added to an alkaline waste liquid containing a resin component, heated to a first temperature to cause an agglomeration reaction, and then heated to a second temperature higher than the first temperature to cause an agglomeration reaction. Waste water treatment method for alkaline waste liquid, which is then separated into resin sludge and treated water by a separation device. An acidic chemical solution is added to the alkaline waste liquid, heated to 30 to 50 ° C., the supernatant liquid after coagulation precipitation is removed, and the remaining resin sludge-containing waste liquid is heated to 55 to 70 ° C. The wastewater treatment method of the alkaline waste liquid according to claim 1. The wastewater treatment method for alkaline waste liquid according to claim 1 or 2, wherein the temperature is temporarily lowered when the resin sludge-containing waste liquid heated to the second temperature is transferred to the separation device. The method for treating wastewater of an alkaline waste liquid according to claim 3, wherein the temperature is lowered to 20 to 40 ° C. The wastewater treatment method for alkaline waste liquid according to claim 1, wherein the coagulation reaction is performed in an acidic region. 6. The method for treating wastewater of an alkaline waste liquid according to claim 5, wherein the pH value of the acidic region is 2 to 4. A reactor equipped with a stirrer, a first heater, a metering pump for dropping a chemical solution from the chemical solution tank into the reaction vessel, a pump for transferring the waste solution of the reaction vessel to the temperature raising tank, and the temperature raising tank An alkali having a second heater provided and a pump for transferring the waste liquid from the heating tank to the separation device, wherein the heating temperature by the second heater is higher than the heating temperature by the first heater; Wastewater treatment equipment for waste liquid.

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