JPH07971A - Treatment of waste liquid and its device - Google Patents

Abstract

PURPOSE:To effectively treat emulsified waste liquid contg. a lot of colloidal particles by feeding a coagulant consisting of metal salt, an inorganic coagulant having the power to form flocs, and a coagulant consisting of a high molecular coagulant in order into waste liquid and mixing them by agitation. CONSTITUTION:When waste liquid is treated, first a solenoid valve 7a is opened to operate a filter with pump 1, causing the waste liquid to be sent to a treating tank 2. Next, when a level sensor 11 of the treating tank 2 detects the specific quantity, a solenoid valve 7b of a treating liquid tank chamber 3a is opened to introduce the 1st treating liquid into the treating tank 2. The 1st treating liquid and the waste liquid are agitated by an agitator 10 to join a coagulant of the treating liquid with colloidal particles in the waste liquid, causing the particles to be huge. Consecutively the 2nd and 3rd treating liquids are each introduced into the treating tank 2 from the treating liquid tanks 3b, 3c through solenoid valves 7c, 7d in order. Finally colloidal particles are turned into large and heavy flocs, which are deposited. Then the flocs are discharged into a centrifuge 4 and dehydrated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating post-washing waste liquid, livestock waste liquid such as swine urine, domestic wastewater, and other various waste liquids in the machinery industry, semiconductor industry, etc., and particularly to emulsified waste liquids. A suitable waste liquid treatment method.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
As shown in Fig. 2, the wastewater from the factory and sewage are treated by first leaving the wastewater in a sedimentation basin, and then concentrating the sludge that has precipitated, coagulating it by adding a coagulant such as vanadium sulfate, and dehydrating it before incineration. On the other hand, the supernatant is discharged after removing the precipitate by aeration by the activated sludge method or the like.

Such sewage treatment requires a large-scale sewage treatment facility, and it has been difficult for a small-to-medium-sized factory to prepare such a facility. By the way, due to recent freon regulations, an aqueous detergent solution such as a surfactant is used as an alternative to freon for washing machined products and semiconductor devices. The waste liquid after washing with such a detergent aqueous solution generally contains oil as an emulsion and is mixed with water, and therefore does not precipitate even when left standing and cannot be removed by the activated sludge method.
As a method of removing such colloidal particles, there is a method of aggregating with an aggregating agent such as vanadium sulfate to precipitate and collect, but such a method is effective for a relatively small amount of colloid, Emulsions such as machining effluent cannot completely remove colloidal particles. Therefore, the emulsified waste liquid is currently dumped in the mountains.

It is desirable that these aqueous detergent solutions can be recycled for use from the viewpoint of resource utilization, but at present, no effective method for separating colloidal particles and aqueous solution has been proposed.

[0005]

[PROBLEMS] The present invention has been made to solve such conventional problems, and provides a waste liquid treatment method and an apparatus therefor, which are effective in treating waste liquids, particularly emulsified waste liquids containing a large amount of colloid particles. The purpose is to do. Also,
An object of the present invention is to provide a waste liquid treatment method capable of reusing a detergent aqueous solution after removal of colloidal particles.

Another object of the present invention is to provide a waste liquid treatment apparatus having a relatively small scale.

[0007]

The method for treating waste liquid according to the present invention for achieving the above object comprises a first step of mixing and stirring a first flocculant consisting of a metal salt in the waste liquid, and Second, mixing and stirring inorganic flocculants with floc forming ability
And a third step of mixing and stirring a second flocculant composed of a polymer flocculant, wherein aluminum sulfate is used as the first flocculant, and zeolite is used as the inorganic flocculant. As the second aggregating agent, a nonionic polymer aggregating agent is suitable.

Further, in the waste liquid treatment apparatus of the present invention, after the first filtration machine into which the waste fluid is introduced, the first filtration machine is connected to the first filtration machine by an electromagnetic valve, and the first filtration machine filters the waste fluid. The treatment tank for treating the waste liquid of the above with a plurality of treatment liquids, a plurality of treatment liquid tanks each containing a plurality of treatment liquids and connected to the treatment tank by a solenoid valve, and the bottom of the treatment tank and a solenoid valve are connected. And a second filtering machine connected to the side of the processing tank by a solenoid valve, and a controller for controlling the opening and closing of each solenoid valve. The plurality of treatment liquid tanks include a first treatment liquid tank containing aluminum sulfate, a second treatment liquid tank containing zeolite, and a third treatment liquid tank containing a nonionic polymer flocculant. is there. Further, the control device is configured to control the opening / closing of the electromagnetic valves that connect the processing liquid tanks and the processing tanks in a time series.

[0009]

The liquid waste after being filtered by the first filtering machine is sent to the processing tank by opening the electromagnetic valve, where the electromagnetic valve between the first processing solution tank and the first processing liquid tank is first opened. The treatment liquid of No. 1 is introduced into the treatment tank and mixed and stirred. This causes the first flocculant to bind around the colloidal particles in the waste liquid to form small flocs. Next, the electromagnetic valve with the first processing liquid tank is closed and the electromagnetic valve with the second processing liquid tank is opened, the second processing liquid is introduced into the processing tank, and mixed and stirred. The inorganic coagulant contained in the second treatment liquid further binds to the periphery of the first coagulant to increase flocs. Further, the electromagnetic valve with the second processing liquid tank is closed and the electromagnetic valve with the third processing liquid tank is opened, and the third processing liquid is introduced into the processing tank and mixed and stirred. The polymer flocculant in the third treatment liquid causes the flocs generated by the second treatment liquid to further aggregate and quickly precipitate.

The precipitated flocs are guided from the bottom of the processing tank to a dehydrator through a solenoid valve, where they are dehydrated and incinerated. On the other hand, the supernatant of the treatment tank is discharged through a second filter connected to the side of the treatment tank, or is replenished with necessary detergent and then recycled as a cleaning liquid.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a waste liquid processing method and a processing apparatus of the present invention will be described with reference to the embodiments shown in the drawings. FIG. 1 shows one embodiment of a treatment apparatus to which the method for treating waste liquid of the present invention is applied, and is mainly connected to a first filter-type filter machine 1, a treatment tank 2, and an upper portion of the treatment tank 2. And a processing liquid tank 3 composed of four processing liquid tank chambers 3a, 3b, 3c, 3d,
A centrifugal separator 4 which is a dehydrator connected to the bottom of the treatment tank 2, a second filter equipped with a pump 5 connected to the side of the treatment tank 2, and a controller 6 are provided. Between the filter-equipped filtration machine 1 and the treatment tank 2, the treatment liquid tank chambers 3a, 3b, 3
c and 3d and the treatment tank 2, between the treatment tank 2 and the centrifuge 4, and between the treatment tank 2 and the second filter 5 with a pump, opening and closing are controlled by the control device 6, respectively. Solenoid valve 7a
7g is provided.

Both the first and second filtration machines with pumps 1 and 5 pass through a sand tank and remove sludge in the waste liquid. The filtration rate may be slow filtration or rapid filtration, but is usually about 10 to 200 tons (t) / day. The pump is used to apply pressure to the filter side (pressurizing type) or to depressurize the suction part (vacuum filter). The first tank-equipped filter machine 1 is connected to the upper side of the processing tank 2 via the pipe 8 and the solenoid valve 7a, and the second tank-filtered machine 5 is connected to the lower side thereof. Further, the processing tank 2 has a conical shape with a gentle slope at the bottom, and the pipe 8 is
The centrifugal separator 4 is connected via the electromagnetic valve 7f, and the floc-like precipitate generated by the processing liquid is accumulated and discharged. On the other hand, the processing liquid tank 3 is installed on the support base 9 above, and the tank chambers 3a to 3d of the processing liquid tank 3 are connected via the pipe 8 and the electromagnetic valves 7b to 7e. Further, a stirrer 10 and a liquid level sensor 11 are attached to the treatment tank 2 so as to monitor the amounts of the waste liquid and the treatment liquids introduced and to efficiently mix and stir the treatment liquids.

The processing liquid tank 3 is divided into four processing liquid tank chambers 3a, 3b, 3c and 3d as described above, and each tank chamber stores the first to fourth processing liquids. There is. Liquid level sensors 11a to 11d for detecting the storage amount of the processing liquid are installed in each processing liquid tank chamber. The first treatment liquid comprises a dispersion liquid containing a first aggregating agent for aggregating the colloidal particles in the waste liquid. As such an aggregating agent, a metal salt complex that easily binds to the negatively charged detergent molecules (surfactant) in the outer layer of the colloidal particles is preferably used. Examples of such metal salt complexes include vanadium sulfate (aluminum sulfate), polyaluminum chloride, iron chloride (III), iron sulfate (II), sodium aluminate, and polyiron, but the water finally discharged. From the viewpoint of water quality, van sulphate soil is preferable.
Such a metal salt is preferably contained in the first treatment liquid in an amount of 6 to 8%.

In the first treatment liquid, an alkaline agent such as caustic soda, slaked lime or soda ash may be added as a coagulation aid in order to promote coagulation by these metal salts. Further, an auxiliary agent such as activated silicic acid which enhances the floc forming ability can be added. The amount of the first treatment liquid used varies depending on the type of waste liquid, but is about 25 l / t in the case of waste water having a relatively small amount of colloid particles, and 30 l / t in the case of emulsified waste liquid such as cleaning waste liquid. It is about t.

The second treatment liquid is for making flocs aggregated by the first flocculating agent into larger flocs and facilitating precipitation (increasing the apparent specific gravity of the flocs), and has a flocc forming ability. An inorganic flocculant is used. The inorganic flocculant may have a floc forming ability depending on the fine structure of the tissue or the crystalline structure, but a powdery one is preferably used.
As such an inorganic coagulant, zeolite (aluminosilicate), diatomaceous earth, (active) alumina, silica (gel), titanium oxide, activated carbon, activated clay, porous glass,
Fly ash and the like can be mentioned, but zeolite is preferable. The amount of the second treatment liquid used also varies depending on the type of waste liquid, but is usually about 5 kg / t. Since these inorganic coagulants are likely to precipitate, it is preferable that the agitator 12 is attached to the second treatment liquid tank chamber and is constantly agitated.

The third treatment liquid is for further aggregating the flocs generated by the second treatment liquid to increase the sedimentation speed, and a liquid containing a polymer flocculant is used. Such polymer flocculants include polyacrylamide, polyethylene oxide, nonionic polymer flocculants such as urea-formalin resin, sodium polyacrylate, polyacrylamide partial hydrolyzate, partially sulfomethylated polyacrylamide, poly ( 2-acrylamido) -2-methylpropane sulfate, sodium alginate, polyanion-based polymer flocculants such as CMC, polyaminoalkylmethacrylate, polyethyleneimine, halogen-based polydiallylammonium, aineone-based, polycations such as chitosan Examples of the high-molecular flocculant include nonionic polymer flocculants, which are preferable from the viewpoint of water quality.

The fourth treatment liquid is a preliminary treatment liquid for performing a treatment particularly required depending on the type of waste liquid, and is mainly an alkali agent such as sodium carbonate, sodium hydroxide, lime (calcium hydroxide) or the like. A neutralizing agent such as an acid such as dilute sulfuric acid or dilute hydrochloric acid or a pH adjusting agent is used. For example, when the waste liquid is an emulsion containing a protein discharged from a leather factory, a pH adjuster is added as a pretreatment before adding the first treatment liquid in order to remove the protein as a precipitate. Depending on its application, this fourth treatment liquid is used for any of the steps from the treatment with the first treatment liquid to the treatment with the third treatment liquid.

In the present embodiment, the first processing liquid tank chamber stores the first processing liquid and the second processing liquid tank chamber stores the second processing liquid. It goes without saying that these treatment liquids may be stored in any of the tank chambers as long as they are treated in the order of the first treatment liquid, the second treatment liquid and the third treatment liquid. The centrifuge 4 dehydrates the flocs that have settled at the bottom of the processing tank 2, and normally 8
A device having an ability of about 00 to 1200 rpm is used. A heater 4b is installed around the separation chamber 4a of the centrifuge 4 in order to efficiently perform dehydration.
180 ° C to 250 ° C, preferably 200 ° C to 230 ° C
Heat to a degree.

The control device 6 controls the operation of the pumps of the filtration machines 1 and 5, the opening and closing of the electromagnetic valves 7a to 7g, the operation of the agitators 10 and 12, and the operation of the processing device such as the liquid level sensor 11.
To control the replenishment of the processing liquid and the operation of the solenoid valves 7g and 7f. In addition, the control device 6 can also control the temperature, pressure, etc. of the processing tank 2 based on a sensor (not shown).

The operation of the waste liquid treatment apparatus having such a configuration will be described. First, the electromagnetic valve 7a is opened to operate the pump of the filter-equipped filter machine 1, and the sand layer is passed through the treatment tank 2 to feed the waste liquid after removing the suspended matter and the precipitate.
When the liquid level sensor 11 of the processing tank 2 detects that a predetermined amount has been introduced, the pump operation is stopped and the solenoid valve 7
Processing liquid tank chamber 3 in which a is closed and the first processing liquid is stored
The solenoid valve 7b of a is opened. When a predetermined amount of the first processing liquid is introduced, the electromagnetic valve 7b is closed and the stirrer 10 mixes and stirs the waste liquid and the processing liquid. As a result, the aggregating agent of the first treatment liquid binds to the colloidal particles in the waste liquid, and the particles become huge. Next, introduction of the second treatment liquid, mixing and stirring, introduction of the third treatment liquid, and mixing and stirring are sequentially performed by time-sequential driving of the solenoid valves 7c and 7d and driving of the stirrer 10, and finally colloid particles Becomes large heavy flocs and settles on the bottom of the processing tank 2.

The stirring time after the addition of each treatment liquid depends on the type of waste liquid, but in the case of a waste liquid such as household wastewater or a cleaning liquid which has a relatively small amount of dirt, it takes about 5 to 10 minutes. Then the floc and water are almost completely separated. When the treatment of the treatment liquid is completed, the electromagnetic valve 7g is opened after a lapse of a predetermined standing time if necessary, and the treatment tank 2
The supernatant is discharged to the filter-equipped filter machine 5. In the filter-equipped filter machine 5, the discharged supernatant is further filtered with a sand layer, and then the pump is operated to discharge or recycle. The pH of the wastewater is adjusted as necessary as a post-treatment.

After removing the supernatant, the sediment (flocs) accumulated at the bottom of the processing tank 2 is discharged to the centrifuge 4 by opening the electromagnetic valve 7f, and dehydrated while being heated by the heater 4b. , Incinerated or recycled as industrial materials. Also, the water discharged to the centrifuge 4 may be discharged as it is, but the filter equipped with the pump 5
It may be sent to a sandbox where the sand layer is used for filtration. Example 1 Using the treatment apparatus of FIG. 1, a 6-8% aqueous solution of vanadium sulfate as a first treatment liquid, a zeolite aqueous solution as a second treatment liquid, and a nonionic polymer flocculant as a third treatment liquid ( Sunpoly N500, a product of Sankyo Kasei Co., Ltd.)
Using the aqueous solution, 25 liters of emulsified cleaning waste liquid (solution concentration 0.2%) discharged from the machining plant was treated.

As a result, the water discharged from the filter-equipped filter 5 was found to be particles,
The presence of the mixture was not recognized, and it was confirmed that the mixture was a thin aqueous solution of detergent. This wastewater could be recycled as a cleaning liquid by adding the required amount of detergent. Example 2 Using the same treatment liquid as in Example 1, domestic wastewater 1 (liter) was treated.

As a result, the water discharged from the filter-equipped filter 5 was found to contain particles,
The presence of the mixture was not recognized.

[0025]

As is apparent from the above examples, according to the waste liquid treatment method of the present invention, treatment with a metal salt complex,
By sequentially performing the treatment with the inorganic flocculant and the polymer flocculant, the oil molecules mixed in the water as colloidal particles can be effectively removed as a precipitate, and the first and second flocculant treatments can be performed. By performing treatment with an inorganic coagulant such as zeolite in the meantime, flocs can be rapidly enlarged, have a high specific gravity, promote sedimentation, and can be treated promptly.

According to the method for treating waste liquid of the present invention, 1
Since treatments with different treatment liquids can be carried out sequentially in one treatment tank, the treatment device can be made relatively simple and small. Further, according to the waste liquid treatment method of the present invention, the coagulant is combined to purify water, so that the treated waste water can be obtained without polluting the environment even if discharged.

Further, according to the waste liquid treatment apparatus of the present invention, the waste liquid can be continuously treated by sequentially controlling the electromagnetic valves connecting the respective tanks.

[Brief description of drawings]

FIG. 1 is an overall view showing an embodiment of a waste liquid treatment apparatus of the present invention.

FIG. 2 is a diagram showing a flow of conventional waste liquid treatment.

[Explanation of symbols]

 1, 5 ・ ・ ・ ・ ・ ・ Filtration machine 2 ・ ・ ・ ・ ・ Treatment tank 3 ・ ・ ・ ・ ・ ・ Treatment liquid tank 4 ・ ・ ・ ・ ・ ・ Centrifuge (dehydration device) 6 ・ ・ ・..Control devices 7a to 7g ... Solenoid valve

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[Procedure amendment]

[Submission date] August 5, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste liquid after washing in a machinery industry, a semiconductor industry, etc., a waste liquid for livestock industry such as swine urine, domestic waste water, waste water when disassembling fish, birds, beasts, waste water of leather industry, and others. The present invention relates to a method and apparatus for treating various waste liquids, and more particularly to a waste liquid treatment method suitable for emulsified waste liquids.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

The fourth treatment liquid is a preliminary treatment liquid for performing a treatment particularly required depending on the type of waste liquid, and is mainly an alkali agent such as sodium carbonate, sodium hydroxide, lime (calcium hydroxide) or the like. A neutralizing agent such as an acid such as dilute sulfuric acid or dilute hydrochloric acid or a pH adjusting agent is used. For example, when the waste liquid is an emulsion containing a protein discharged from a leather factory, or in the case of drainage when disassembling a fish, a bird, or a beast, etc., a pH adjuster is used as a first treatment to remove the protein as a precipitate. It is added as a pretreatment before adding the liquid. Depending on the application, the fourth treatment liquid is used in any of the steps from the treatment with the first treatment liquid to the treatment with the third treatment liquid.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

As a result, the water discharged from the filter-equipped filter 5 was found to contain particles,
The presence of the mixture was not recognized. In addition, although the case where the first coagulant and the inorganic coagulant are added as the treatment liquid by adjusting the addition amount with the solenoid valve has been described in the present embodiment, the treatment method of the present invention is such an addition method. However, it is needless to say that the coagulant may be added in the form of powder or granules as it is, and in that case, a solenoid valve or the like is not necessary.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Asada 1-6-37 Sachimachi, Shiki-shi, Saitama Hi-Mart Shiki 202 (72) Inventor Kazuo Yoshikawa 2-16-18 Narita Nishi, Suginami-ku, Tokyo Yoshikawa PVC Inside the industrial plant

Claims (7)

[Claims] 1. A first step of mixing and stirring a first coagulant composed of a metal salt in a waste liquid, a second step of mixing and stirring an inorganic coagulant having a floc forming ability with the first coagulant, and further polymer coagulation. And a third step of mixing and stirring a second flocculant composed of an agent, and treating the waste liquid. 2. The method for treating waste liquid according to claim 1, wherein the first coagulant contains aluminum sulfate. 3. The method for treating waste liquid according to claim 1, wherein the inorganic coagulant is zeolite. 4. The method for treating waste liquid according to claim 1, wherein the second flocculant is a nonionic polymer flocculant. 5. A first step of mixing and stirring a first processing solution containing aluminum sulfate with a waste solution, a second step of mixing and stirring a second processing solution containing zeolite with the first processing solution, and further a nonionic system. And a third step of mixing and stirring a third treatment liquid containing a polymer flocculant. 6. A first filtration machine into which waste liquid is introduced, and a plurality of treatments of the waste fluid after being filtered by the first filtration machine, which is connected to the first filtration machine by a solenoid valve. A treatment tank for treating with a liquid, a plurality of treatment liquid tanks each containing the plurality of treatment liquids and connected to the treatment tank by a solenoid valve, and a dehydrator connected to the bottom of the treatment tank by a solenoid valve An apparatus for treating waste liquid, comprising: a second filtration machine connected to a side portion of the treatment tank by a solenoid valve; and a control device that controls opening and closing of each solenoid valve. 7. The plurality of treatment liquid tanks include a first treatment liquid tank containing aluminum sulfate, a second treatment liquid tank containing zeolite, and a third treatment liquid tank containing a polymer coagulant. The waste liquid processing apparatus according to claim 6, which comprises: