JP5602964B1 - Waste liquid treatment method - Google Patents

Abstract

Disclosed is a waste liquid treatment method for easily treating various waste liquids such as air conditioner cleaning waste liquid and fat waste liquid by an extremely easy procedure.
As a first step, an alkaline first waste liquid containing a dissolved synthetic resin component and a second waste liquid containing a pollutant are mixed at a predetermined ratio to obtain a mixed waste liquid. Next, as a second step, the aggregating agent is added dropwise to the mixed waste liquid while stirring the mixed waste liquid, and the synthetic resin component in the mixed waste liquid is aggregated including the pollutant. And as a 3rd process, the mixed waste liquid which passed through the 2nd process is filtered using the nonwoven fabric 117. FIG.
[Selection] Figure 1

Description

  The present invention relates to a waste liquid treatment method for purifying waste liquid to such an extent that it can be discharged into a river.

In many cases, a polymer wax is applied to the floor of a building as a flooring agent for the purpose of protection or aesthetics. This polymer wax is worn by dust or mechanical scratches or wear, and its function and aesthetics are deteriorated. Therefore, the polymer wax is usually repainted regularly. In order to repaint the polymer wax, it is necessary to peel off the already applied polymer wax from the floor as a pretreatment for repainting.
By performing the above-described periodic repainting, a large amount of polymer wax stripping waste liquid (hereinafter, the polymer wax stripping waste liquid is simply referred to as “stripping waste liquid”) is generated.

As will be described later, the stripping waste liquid is strongly alkaline and contains a large amount of an organic compound called a polymer wax. For this reason, it cannot be drained into sewers as well as rivers. This is because the pH balance of the sewage is destroyed by a large amount of alkaline liquid, which adversely affects the sludge decomposition treatment by bacteria.
However, the components of the stripping waste liquid are substantially constant. Therefore, it is much cheaper than sewage treatment facilities to remove organic compounds such as impurities and polymers from a large amount of exfoliated waste liquid by following routine procedures such as adding a predetermined chemical, stirring, and filtering. Thus, it can be purified to such a degree that it can be discharged into a river.
The inventors have sought a technology for treating the stripping waste liquid in a form that is friendly to the natural environment through the business of building maintenance, and have applied for a patent for the technical content. Patent document 1 is one of them.

JP 2010-194493 A

As a result of the ingenuity of the inventors over the years, a processing method and a waste liquid treatment apparatus for efficiently purifying the stripped waste liquid have been established.
On the other hand, waste liquids generated by cleaning air conditioners installed in building facilities, etc., which the inventors have not previously been subject to processing operations (hereinafter referred to as “air conditioner cleaning waste liquids”), and waste liquids generated by cleaning restaurant kitchens, etc. (Hereinafter referred to as “oil waste liquid”).
However, it was found that the air-conditioner cleaning waste liquid and the fat waste liquid are different from the separation waste liquid and cannot be treated in the same manner as the separation waste liquid.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a waste liquid treatment method for easily treating various waste liquids such as an air conditioner cleaning waste liquid and a fat waste liquid by an extremely easy procedure.

In order to solve the above problems, the waste liquid treatment method of the present invention executes the following steps.
First, as a first step, a mixed waste liquid is obtained by mixing a first waste liquid that is a polymer wax peeling waste liquid containing a dissolved synthetic resin component and a second waste liquid that is an air conditioner cleaning waste liquid in a ratio of 1: 3 or more. .
Next, as a second step, the mixed waste dropwise flocculant while stirring, coagulating synthetic resin component.
Next, as a third step, the mixed waste liquid that has passed through the second step is filtered.
And as a 4th process, a predetermined pH adjuster is mixed with the mixed waste liquid which passed through the 3rd process, and the pH value of a mixed waste liquid is adjusted.

According to the present invention, it is possible to provide a waste liquid treatment method that easily treats various waste liquids such as an air conditioner cleaning waste liquid and a fat waste liquid by an extremely easy procedure.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a perspective view of the peeling waste liquid processing apparatus in connection with embodiment of this invention. It is a block diagram which shows the structure of a peeling waste liquid processing apparatus.

First, the air-conditioner cleaning waste liquid and the fat waste liquid, which are treatment targets in the waste liquid treatment method of the present embodiment, will be described.
The air-conditioner cleaning waste liquid is a slightly strong alkaline waste liquid having a pH of about 13.2 that is generated when cleaning the filter of the indoor unit or the outdoor unit. The air-conditioner cleaning waste liquid contains a lot of cotton dust, tobacco dust, mineral dust mainly composed of dirt, and the like.
The fat waste liquid is a slightly strong alkaline waste liquid having a pH of about 13.5 that is generated when the kitchen equipment is washed. In addition to dust in the air, fat and oil waste liquid contains a large amount of animal and vegetable oils and fats as the name suggests. Saponification of the fat and oil component contained in the fat and oil waste liquid has hardly progressed.

FIG. 1 is a block diagram showing a waste liquid treatment facility 101 according to this embodiment.
The stripping waste liquid tank 102 stores a stripping waste liquid 103 serving as a first waste liquid.
The second waste liquid tank 104 stores various waste liquids other than the stripping waste liquid 103, such as the air conditioner cleaning waste liquid and the fat waste liquid, which are the second waste liquid 105.
A flocculant 107 is stored in the chemical tank 106. The flocculant 107 is for solidifying the stripping waste liquid 103. In this embodiment, for example, dilute sulfuric acid is used. The flocculant 107 is not limited to dilute sulfuric acid, and exhibits an aggregating effect on the stripping waste liquid 103, and may be almost anything as long as it is an acid. Common acidic liquids such as dilute hydrochloric acid, citric acid, and acetic acid can be used.
The stripping waste liquid 103 is fed from the stripping waste liquid tank 102 to the aggregation tank 109 through the first pump 108. The second waste liquid 105 is supplied from the second waste liquid tank 104 to the aggregation tank 109 through the second pump 110. The aggregating agent 107 is supplied from the chemical solution tank 106 to the aggregating tank 109 through the third pump 111.

The agglomeration tank 109 is a cylindrical stainless steel or chemical-resistant container having an opening directly above, and a bottom 109a is formed in a tapered shape. Further, a transfer valve 112 is provided at the center of the bottom 109 a of the agglomeration tank 109 located at the tapered tip. The transfer valve 112 is controlled to open and close by a control device (not shown).
The coagulation tank 109 is provided with a waste liquid PH meter 113 for measuring the pH of the mixed waste liquid 118 filled therein.
A stirring bar 115 that is rotationally driven by a waste liquid stirring motor 114 is inserted in the center of the aggregation tank 109 near the bottom 109a.
A neutralization tank 116 is installed immediately below the aggregation tank 109. A nonwoven fabric 117 is interposed between the aggregation tank 109 and the neutralization tank 116.

The waste liquid treatment facility 101 shown in FIG. 1 is operated as follows.
First, as a first step, the first pump 108 and the second pump 110 are operated by a control unit (not shown), and the separation waste liquid 103 and the second waste liquid 105 are put into the aggregation tank 109. Then, the waste liquid stirring motor 114 is controlled to drive the stirring rod 115, whereby the separation waste liquid 103 and the second waste liquid 105 are mixed to obtain a mixed waste liquid 118. The ratio of the amount of waste liquid to be mixed is as follows.
In the case of the air-conditioner cleaning waste liquid, the air-conditioner cleaning waste liquid 4 is set to be equal to or less than the separation waste liquid 1. However, the air-conditioner cleaning waste liquid 1 or less is preferable with respect to the peeling waste liquid 4.
In the case of the fat waste liquid, the fat waste liquid 1 is set to 1 or less with respect to the peeling waste liquid 1.
It should be noted that the mixing of the mixed waste liquid 118 in the first step does not prevent manual operation.

Next, as the second step, the third pump 111 is operated while stirring the mixed waste liquid 118 with the stirring rod 115, and the coagulant 107 is dropped into the coagulation tank 109.
When the mixed waste liquid 118 is stirred with the stirring rod 115 while dripping the flocculant 107 little by little, a synthetic resin component (such as acrylic resin or urethane resin) that is a main component of the polymer wax contained in the mixed waste liquid 118 ( The polymer component) is solidified to form many polymer lumps having a diameter of about 0.5 mm or less. In this polymer mass, the contaminant contained in the second waste liquid 105 is trapped.
Then, while the control device (not shown) monitors the pH measurement value information of the mixed waste liquid 118 output from the waste liquid PH meter 113, the mixed waste liquid 118 is stirred until the pH of the mixed waste liquid 118 reaches a weak acidity of about 4 to 3. Then, dripping of the flocculant 107 is continued.
When the pH of the mixed waste liquid 118 reaches a desired weak acidity, the transfer valve 112 is opened as a third step. Then, the mixed waste liquid 118 is filtered by the nonwoven fabric 117. At this time, a polymer lump residue 119, which is an aggregate of polymer lump containing contaminants, remains on the nonwoven fabric 117, and the filtered waste liquid containing water-soluble impurities falls into the neutralization tank 116.

Thereafter, the filtration waste liquid is treated according to the method for treating the separation waste liquid 103, which the inventors have applied for patents so far. First, as a fourth step, the pH of the filtered waste liquid collected in the neutralization tank is adjusted with an alkaline agent such as sodium carbonate to obtain primary treated water. Next, an adsorbent is added to the primary treated water, and distillation by vacuum drying is performed to obtain secondary treated water. Further, the secondary treated water is put into a water tank containing aerobic bacteria to obtain tertiary treated water. In addition, instead of obtaining the secondary treated water, the moisture may be evaporated and released to the atmosphere by drying.
Further, the polymer lump residue 119 may be used as a solid fuel by drying separately after being squeezed, or can be treated as combustible waste.

  That is, as the first step, the separation waste liquid 103 as the first waste liquid is mixed with the second waste liquid 105 in an amount of a predetermined ratio or more, and then, as the second step, the mixed waste liquid 118 is agglomerated while stirring. Agent 107 is dropped. By carrying out like this, as a 3rd process, the process of the 2nd waste liquid 105 becomes possible by filtering with the nonwoven fabric 117 which is the completely same process as the processing method of the peeling waste liquid 103 which the inventors cultivated so far. That is, in this embodiment, the stripping waste liquid 103 is used as an organic polymer flocculant for aggregating the pollutant in the second waste liquid 105.

  In the second step, when the flocculant 107 is dropped, it is necessary to always stir the mixed waste liquid 118. Without agitation, the polymer mass particles become unnecessarily large, and not only the formation of the polymer mass residue 119 is inadequate in the third step, but also the contaminants cannot be taken into the polymer mass well. For stirring, for example, in a mixed waste liquid of about 20 L, a flow rate of 5 m / sec or more is required. Further, it is preferable that the flocculant 107 is dropped slowly as little as possible at a flow rate per unit time of about 1.7 mL / sec, for example, about 20 L of mixed waste liquid.

FIG. 2A is a table showing the results of the reaction process and the filtration process when the mixing ratio of the stripping waste liquid 103 and the air conditioner cleaning waste liquid is changed.
FIG. 2B is a table showing the results of the reaction process and the filtration process when the mixing ratio of the stripping waste liquid 103 and the fat waste liquid is changed.
The inventors conducted experiments shown in FIGS. 2A and 2B in order to complete the present invention, and specified the ratio of the first waste liquid and the second waste liquid 105.
In the table of FIG. 2A, the first record is the experimental result of the stripping waste liquid 0 cc and the air conditioner cleaning waste liquid 500 cc, that is, the waste liquid having a mixing ratio of 0: 1.
The second record is the experimental result in the stripping waste liquid 100 cc and the air conditioner cleaning waste liquid 400 cc, that is, the waste liquid having a mixing ratio of 1: 4.
The third record is the result of experiments on the stripping waste liquid 100 cc and the air conditioning cleaning waste liquid 300 cc, that is, the waste liquid having a mixing ratio of 1: 3.
In the same manner, eight types of waste liquids were prepared up to the eighth record.
The charging speed of dilute sulfuric acid as the flocculant 107 is 6.4 ml / min.

The eighth record in the table of FIG. 2A is the experimental result where the mixing ratio of the stripping waste liquid 103 and the air conditioner cleaning waste liquid is 4: 1. While the flocculant 107 is dropped into the mixed waste liquid 118, stirring is performed until a polymer lump is generated and the waste liquid is not turbid. The stirring time was about 3 minutes. When this mixed waste liquid 118 was passed through the nonwoven fabric 117, it passed almost instantly. Although it is described as 5 seconds in the table, this is a convenient measurement time, which is actually a shorter time and indicates that the time measurement itself has no meaning.
The seventh record in the table of FIG. 2A is an experimental result in which the mixing ratio of the stripping waste liquid 103 and the air conditioner cleaning waste liquid is 3: 1. While the flocculant 107 is dropped into the mixed waste liquid 118, stirring is performed until a polymer lump is generated and the waste liquid is not turbid. The stirring time was about 3 minutes. When this mixed waste liquid 118 was passed through the nonwoven fabric 117, it took 5 minutes for all the mixed waste liquid 118 to pass through the nonwoven fabric 117. In other words, when the mixing ratio of the stripping waste liquid 103 to the air conditioner cleaning waste liquid is reduced from 4: 1 to 3: 1, the separation time increases dramatically. Similarly, the mixing ratio of the separation waste liquid 103 to the air conditioner cleaning waste liquid described in the second record up to 1: 4 is the mixing ratio at which the filtration by the nonwoven fabric 117 functions effectively.

The first record in the table of FIG. 2A is the experimental result when the mixing ratio of the stripping waste liquid 103 and the air conditioner cleaning waste liquid is 0: 1. In this case, the mixed waste liquid 118 is only the air-conditioner washing waste liquid, and is substantially not the mixed waste liquid. However, the flocculant 107 is dropped into the mixed waste liquid 118 and stirring is performed until a lump is generated and the waste liquid is no longer turbid. . The stirring time was about 4 minutes. However, the resin component that is the main component of the polymer wax is hardly present in the pure air-conditioner waste liquid. When this mixed waste liquid 118 was passed through the nonwoven fabric 117, an aggregate was formed, but even the aggregate passed through the nonwoven fabric 117 and could not be filtered.
From the above experimental results, it was found that the mixing ratio of the stripping waste liquid 103 to the air conditioning cleaning waste liquid, which is effective as the mixed waste liquid 118, is up to 1: 4. However, the practical mixing ratio for industrial processing is 4: 1 or less.

  Although not shown in FIG. 2A, it has been found that the agglomerate particles can be enlarged by adding ferric sulfate to dilute sulfuric acid as the flocculant 107 of the air-conditioner cleaning waste liquid. However, the air-conditioner cleaning waste liquid to which ferric sulfate was added and stirred could not pass through the nonwoven fabric 117 at all. This is because the aggregate particles cause clogging of the nonwoven fabric 117.

In the table of FIG. 2B, the first record is the experimental result in the stripping waste liquid 0 cc and the fat waste liquid 500 cc, that is, the waste liquid having a mixing ratio of 0: 1.
The second record is the experimental result in the stripping waste liquid 200 cc and the fat waste liquid 400 cc, that is, the waste liquid having a mixing ratio of 1: 2.
The third record is the experimental result in the stripping waste liquid 250 cc, the fat waste liquid 250 cc, that is, the waste liquid having a mixing ratio of 1: 1.
As described above, waste liquids having three kinds of mixing ratios were prepared.
The charging speed of dilute sulfuric acid as the flocculant 107 is 6.4 ml / min.

The fourth record in the table of FIG. 2B is an experimental result in which the mixing ratio of the stripping waste liquid 103 and the air conditioner cleaning waste liquid is 2: 1. While the flocculant 107 is dropped into the mixed waste liquid 118, stirring is performed until a polymer lump is generated and the waste liquid is not turbid. The stirring time was about 5 minutes. When this mixed waste liquid 118 was passed through the nonwoven fabric 117, it passed almost instantly. Although it is described as 5 seconds in the table, this is a convenient measurement time, and is actually a shorter time.
The 3rd record of the table | surface of FIG. 2B is an experimental result with the mixing ratio of peeling waste liquid 103 and an air-conditioner washing | cleaning waste liquid being 1: 1. While the flocculant 107 is dropped into the mixed waste liquid 118, stirring is performed until a polymer lump is generated and the waste liquid is not turbid. The stirring time was about 5 minutes. When this mixed waste liquid 118 was passed through the nonwoven fabric 117, although some residual water remained in the nonwoven fabric 117, it passed almost instantly as in the fourth record.

The second record in the table of FIG. 2B is the experimental result where the mixing ratio of the stripping waste liquid 103 and the air conditioner cleaning waste liquid is 1: 2. While the flocculant 107 is dropped into the mixed waste liquid 118, stirring is performed until a polymer lump is generated and the waste liquid is not turbid. The stirring time was about 8 minutes. When this mixed waste liquid 118 was passed through the nonwoven fabric 117, it passed almost instantly as in the fourth record and the third record. However, the separated water that passed through the nonwoven fabric 117 was turbid due to the components of the fat waste liquid. That is, it shows that the coagulation action of the pollutant by the polymer mass was not sufficient.
From the above experimental results, it was found that the mixing ratio of the stripping waste liquid 103 to the fat waste liquid that is effective as the mixed waste liquid 118 is up to 1: 1.

This embodiment can be applied as follows.
(1) In order to increase the processing efficiency of the oil / fat waste liquid, it is conceivable that caustic soda is added in advance to saponify the oil / fat component as a pre-stage of the processing according to this embodiment. Moreover, in order to perform this saponification more efficiently, it is also possible to take out the supernatant part of the fat waste liquid, add caustic soda, and then heat-treat.

  (2) In the present embodiment, the stripping waste liquid 103 is used as the first waste liquid. However, the first waste liquid used as the organic polymer flocculant is not limited to the peeling waste liquid 103. For example, a cleaning waste liquid of a 3D printer that has begun to spread rapidly in recent years is an alkaline waste liquid containing a resin component that is close to the peeling waste liquid 103. Such an alkaline waste liquid containing a dissolved synthetic resin component can be used as a first waste liquid used as an organic polymer flocculant for aggregating a desired second waste liquid 105.

In the present embodiment, the waste liquid treatment facility 101 is disclosed as an example of a novel waste liquid treatment method.
First, as a first step, an alkaline first waste liquid containing a dissolved synthetic resin component and a second waste liquid containing a pollutant are mixed at a predetermined ratio to obtain a mixed waste liquid.
Next, as a second step, the aggregating agent is added dropwise to the mixed waste liquid while stirring the mixed waste liquid, and the synthetic resin component in the mixed waste liquid is aggregated including the pollutant.
And as a 3rd process, the mixed waste liquid which passed through the 2nd process is filtered using the nonwoven fabric 117. FIG.
Thus, by using the stripping waste liquid 103 as an organic polymer flocculant for aggregating the pollutant in the second waste liquid 105, it is possible to remove the pollutant from the air-conditioner cleaning waste liquid and fat waste liquid, which has been difficult to process. The polymer lump residue 119 can be agglomerated, and as a result, it can be easily purified in a short time.

  The embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and other modifications, Includes application examples.

  DESCRIPTION OF SYMBOLS 101 ... Waste liquid processing equipment, 102 ... Stripping waste liquid tank, 103 ... Stripping waste liquid, 104 ... Second waste liquid tank, 105 ... Second waste liquid, 106 ... Chemical liquid tank, 107 ... Coagulant, 108 ... First pump, 109 ... Coagulation tank 110 ... second pump, 111 ... third pump, 112 ... transfer valve, 113 ... waste liquid PH meter, 114 ... waste liquid stirring motor, 115 ... stirring bar, 116 ... neutralization tank, 117 ... nonwoven fabric, 118 ... mixed waste liquid, 119 ... polymer lump residue

Claims (2)

A first step of obtaining a mixed waste liquid by mixing an alkaline first waste liquid containing a dissolved synthetic resin component and a second waste liquid that is an air conditioner washing waste liquid in a ratio of 1: 3 or more ;
A second step of aggregating the synthetic resin component by dropping a flocculant while stirring the mixed waste liquid;
A third step of filtering the mixed waste liquid having undergone the second step ;
A waste liquid treatment method comprising: a fourth step of adjusting a pH value of the mixed waste liquid by mixing a predetermined pH adjusting agent with the mixed waste liquid that has undergone the third step . A first step of obtaining a mixed waste liquid by mixing an alkaline first waste liquid containing a dissolved synthetic resin component and a second waste liquid, which is an oil waste liquid generated when washing kitchen equipment, at a ratio of 1: 1 or more. ,
A second step of aggregating the synthetic resin component by dropping a flocculant while stirring the mixed waste liquid;
A third step of filtering the mixed waste liquid having undergone the second step ;
A waste liquid treatment method comprising: a fourth step of adjusting a pH value of the mixed waste liquid by mixing a predetermined pH adjusting agent with the mixed waste liquid that has undergone the third step .

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