JP6708863B2 - Contaminated water purification equipment - Google Patents

Description

The present invention relates to a VOC-contaminated water purification treatment apparatus using microbubbles.

In general, VOC (volatile organic compound) countermeasures against groundwater pollution include methods for cleaning contaminated soil and groundwater in-situ, methods for extracting contaminated soil gas, methods for pumping contaminated groundwater, methods for excavating and removing contaminated soil, etc. Is mentioned.

Among these methods, the method of pumping contaminated groundwater is to guide the contaminated water to a water tank and bubble the contaminated water with an air diffuser or an ejector pump installed in the water (1 mm or more in bubble size) to purify gas and liquid (aeration treatment). ) Has been done.

FIG. 15 shows an example thereof. In the figure, 1 is a raw water tank for storing contaminated water, 2 is an aeration tank, and a raw water pump 3 is placed in the raw water tank 1, whereby the aeration tank 2 is contaminated with water. Is sent.

The aeration tank 2 is provided with an underwater ejector 4 equipped with an intake pipe 5, by which contaminated water is bubbled to volatilize and desorb VOCs from the contaminated water, and the air containing the volatilized and desorbed VOCs is gas-liquid separated. The air is sent to the tank 6, the activated carbon is adsorbed on the activated carbon by the activated carbon adsorption tower 7, and the removed air is sent to the VOC management facility by the blower 8.

In addition, a drainage pit 9 having a drainage pump 10 installed therein is formed in the aeration tank 2, and the water obtained by volatilizing and desorbing VOCs from the contaminated water is sent to the muddy water treatment facility 11 by the drainage pump 10.

However, if this method is used to deal with a large amount of contaminated water, the tank will become large.

The purification efficiency of contaminated water largely depends on the uniformity of the aeration treatment of contaminated water in the treated water tank, but it is difficult to evenly agitate the entire aeration tank, so it is not possible to ensure uniformity with a single bubbling system. Difficult, especially in larger tanks.

In the following patent documents, as shown in FIG. 16, a large-sized water tank is divided into small pieces to a size that can ensure the uniformity of aeration treatment of contaminated water, and a bubbling system is provided in each of the water tanks. ..
JP, 2014-124543, A

The raw water inflow pipe connected to the underground pumping well communicates with the FRP aeration water tank body 12. This aeration water tank body 12 is provided with the FRP gas-liquid mixed resin layer member inside and the aeration blower 13 outside. A required number of units each comprising an activated carbon adsorption tank body 14 connected to the aeration water tank body 12 are connected in series or in parallel.

However, the above-mentioned Patent Document 1 has a drawback that the facility system becomes complicated and a wider installation place is required as compared with the case where a single large water tank is used.

The object of the present invention is to eliminate the disadvantages of the conventional example and to efficiently treat a large amount of VOC-contaminated water (concentration to be treated: 5,000 to 0.001 mg/L). Another object of the present invention is to provide a contaminated water purification treatment device which can be installed in a small space without requiring a multi-stage introduction.

In order to achieve the above-mentioned object, the present invention according to claim 1 has a double tube structure of an inner tube and an outer tube in which the inner tube is formed of a perforated tube. A plurality of microbubble generating modules that generate microbubbles are arranged to form a VOC extraction unit, contaminated water containing VOC (volatile organic compound) is passed through the inner tube of the microbubble generating module, and compressed air is passed through the outer tube. A chamber containing an impact plate is provided on the outlet side of the microbubble generation module, and an impact plate is provided in the chamber for colliding a mixture of VOC-containing bubbles discharged in a shower and purified water. Is the gist.

According to the first aspect of the present invention, in the micro-bubble generating module, the contaminated water is passed through the inner pipe, and the compressed air is introduced into the outer pipe, so that the action of the partition wall causes the VOC contaminated water side to reach from 20 μm. Microbubbles, which are a group of bubbles with a size distribution centered on less than 1 mm, are introduced.

When microbubbles come into contact with VOC-contaminated water at the boundary of the partition formed by the inner tube, VOCs migrate into the bubbles very efficiently as compared with the case where they come into contact with bubbles of a comparatively large size (1 mm or more). Due to this effect, the microbubbles that have extracted VOCs instantly combine with each other in the contaminated water when they leave the partition wall. As a result, on the treated water outlet side of the module, the size-increased VOC-containing bubbles and the contaminated water (purified water) after the VOC treatment exist in a mixed state.

In this way, by arranging a plurality of microbubble generating modules in the vertical direction to form a unit, the equipment can be downsized.

Furthermore, a mixture of VOC-containing bubbles and purified water is discharged like a shower in a chamber connected to the module outlet side and collided with an impact plate, whereby the purified water and VOC bubbles are separated by the impact of collision, The VOCs can be extracted into the chamber and appropriately exhausted from the chamber before being sent to the subsequent treatment such as decomposition or adsorption.

In addition, it does not require a water tank for bubbling required in the conventional VOC bubbling process, the equipment can be downsized, and the low treatment efficiency due to the uneven bubbling, which was a problem in the water tank treatment, is improved. To be done.

Here, it is important to immediately collide with the shower discharge on the module exit side. This is because if the time is given in the state of the mixture of the VOC-containing bubbles and the purified water, the VOCs are redissolved in the liquid phase.

The present invention according to claim 2 is characterized in that the microbubble generating module unit in which a plurality of microbubbles are arranged is installed in a treated raw water injection water tank.

According to the present invention as set forth in claim 2, by using the microbubble generating module as a unit, the equipment can be downsized, and a plurality of units can be installed in the treated raw water injection water tank (baking tank), and the water tank can be large. The processing capacity can be increased without conversion.

As described above, the apparatus for purifying contaminated water according to the present invention can efficiently treat a large amount of VOC contaminated water, and does not require the size and division of the treated water tank and the introduction of a multi-stage system as in the prior art. Therefore, it can be installed in a small space.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing a first embodiment of a contaminated water purification treatment device of the present invention, in which 20 is a VOC extraction unit.

In this VOC extraction unit 20, as shown in FIGS. 3 to 7, a plurality of microbubble generating tube modules 21 are arranged in the vertical direction and fixed to a frame 22.

8 and 9 show a microbubble generating tube module 21, which has a double tube structure of an inner tube and an outer tube of an outer tube 23 and an inner tube 24 formed of a porous membrane tube, and has a size distribution centered on 20 μm to less than 1 mm. This is to generate micro bubbles of a group of bubbles.

In the figure, 25 is a discharge port formed at the tip of the micro bubble generating tube module 21, 26 is a water supply port communicating with the inner pipe 24, 27 is an air supply port communicating with the outer pipe 23, and the inside is provided through the water supply port 26. Contaminated water is passed through the pipe 24, and compressed air is introduced into the outer pipe 23 through the air supply port 27.

The micro-bubble generation tube module 21 can increase the required number of modules according to the processing capacity in module or unit units, and does not necessarily require a water tank.

As shown in FIG. 1, a chamber 29 is provided on the module outlet side of the micro-bubble generation tube module 21 of the VOC extraction unit 20 in which a plurality of micro-bubble generation tube modules 21 are arranged in the vertical direction, and an impact plate 30 is provided in the chamber 29. Is provided so that the mixture of the VOC-containing bubbles discharged from the micro bubble generation tube module 21 into the chamber 29 and the purified water collides with the impact plate 30.

Although the impact plate 30 is of a zigzag and zigzag roof type in the drawing, various other types such as those in which inclined plates are arranged in parallel or a dome type can be adopted.

The micro-bubble generation tube module 21 has its discharge ports 25 opened side by side with the chamber 29, so that the mixture of VOC-containing bubbles and purified water can be discharged into the chamber 29 in a shower shape.

The VOC extraction unit 20 is connected to a compressed air source 36 and a VOC contaminated water inlet 35, and the microbubble generating pipe module 21 is connected as a branch pipe to a water supply port 26 thereof which is connected to a water supply manifold 37.

Further, the chamber 29 is provided with a cleaning water outlet 31 and a VOC gas outlet 32, and the VOC gas outlet 32 becomes a clean gas outlet 34 through an activated carbon treatment (equipment) 33.

As described above, the micro-bubble generating tube module 21 has a double tube structure, and the contaminated water is passed through the inner tube 24, and the compressed air is introduced into the outer tube 23. On the VOC-contaminated water side, microbubbles of a group of bubbles having a size distribution centered on 20 μm to less than 1 mm are introduced.

In this way, when the micro bubbles come into contact with the VOC-contaminated water at the boundary of the partition wall of the inner tube 24, the VOCs move into the bubbles very efficiently as compared with the case where the micro bubbles come into contact with the bubbles having a relatively large size. To do.

The microbubbles from which VOCs have been extracted almost instantly quickly combine in the contaminated water when leaving the inner tube 24.

As a result, on the treated water outlet side of the micro-bubble generating tube module 21, the VOC-containing bubbles that have been increased in size and the contaminated water (purified water) after the VOC treatment exist in a mixed state.

Further, when a mixture of VOC-containing bubbles and purified water is discharged like a shower in the chamber 29 connected to the module outlet side and collides with the impact plate 30, the impact of the collision separates the purified water and the VOC bubbles. , VOCs can be extracted into the chamber, appropriately exhausted from the chamber, and then sent to a subsequent process such as decomposition or adsorption.

Here, it is important to immediately collide with the shower discharge on the module exit side. This is because if the time is given in the state of the mixture of the VOC-containing bubbles and the purified water, the VOCs are redissolved in the liquid phase.

FIG. 2 shows a second embodiment of the present invention, in which a VOC extraction unit 20 in which a plurality of microbubble generating tube modules 21 are arranged in the vertical direction is installed in a treated raw water injection water tank 40 which is an aeration tank. In the present embodiment, as shown in FIG. 11, three units 20 are installed in the treated raw water injection water tank 40, but the number is not particularly limited to this.

The treated raw water injection water tank 40, which is the aeration tank, may be of a conventional type, and the unit 20 includes an air control unit 41 as shown in FIGS. 13 and 14, and a water control unit as shown in FIGS. The unit 42 is connected.

The treatment of the VOC contaminated water by the micro bubble generation tube module 21 in the treated raw water injection water tank 40 is the same as that of the first embodiment, and in the micro bubble generation tube module 21, the contaminated water is passed through the inside pipe and the outside By introducing compressed air into the pipe, microbubbles of a group of bubbles with a size distribution centering from 20 μm to less than 1 mm are introduced to the VOC-contaminated water side by the microbubble/nanoporous action of the partition wall, and gas-liquid separation (aeration). Is performed.

The removed VOC gas is treated with activated carbon to become a clean gas, and water is circulated to the water control unit 42 by the pump 44.

FIG. 1 is an explanatory view showing a first embodiment of a contaminated water purification treatment device of the present invention. It is explanatory drawing which shows 2nd Embodiment of the purification processing apparatus of the contaminated water of this invention. It is a front view of a VOC extraction unit. It is a side view of a VOC extraction unit. It is a rear view of a VOC extraction unit. It is a top view of a VOC extraction unit. It is a perspective view of a VOC extraction unit. It is a vertical side view of a micro-bubble generation module. It is a front view of a micro-bubble generation module. It is a front view which shows 2nd Embodiment of the purification processing apparatus of the contaminated water of this invention. It is a top view which shows 2nd Embodiment of the purification processing apparatus of the contaminated water of this invention. It is a top view of a water control unit. It is a top view of an air control unit. It is a front view of an air control unit. It is explanatory drawing which shows a prior art example. It is explanatory drawing which shows another prior art example.

1... Raw water tank 2... Aeration tank 3... Raw water pump 4... Underwater ejector 5... Intake pipe 6... Gas-liquid separation tank 7... Activated carbon adsorption tower 8... Blower 9... Drainage pit 10... Drainage pump 11... Turbid water treatment facility 12... Aeration water tank body 13... Aeration blower 14... Activated carbon adsorption tank body 20... Unit 21... Micro bubble generation tube module 22... Frame 23... Outer tube 24... Inner tube 25... Outlet port 26... Water supply port 27... Air supply port 29 ... Chamber 30 ... Impact plate 31 ... Wash water outlet 32 ... VOC gas outlet 33 ... Activated carbon treatment (equipment) 34 ... Clean gas outlet 35 ... VOC contaminated water inlet 36 ... Compressed air source 37 ... Water absorption manifold 40 ... Treatment raw water injection water tank 41 … Air control unit 42… Water control unit 44… Pump

Claims (2)

The VOC has a double-tube structure consisting of an inner tube and an outer tube, each of which is made of a perforated inner tube, and has multiple microbubble generation modules that generate microbubbles of a group of bubbles having a size distribution centered on 20 μm to less than 1 mm. As an extraction unit, contaminated water containing VOC (volatile organic compound) is passed through the inside tube of the microbubble generation module, compressed air is introduced into the outside tube, and impact is applied to the outlet side of the microbubble generation module. An apparatus for purifying contaminated water, comprising a chamber containing a plate, and an impact plate for colliding a mixture of VOC-containing bubbles discharged in a shower shape and purified water in the chamber . The apparatus for purifying contaminated water according to claim 1, wherein the microbubble generating module unit in which a plurality of microbubbles are arranged is installed in a treated raw water injection water tank.

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