JP2003190966A - Treating method for waste washing water when dismantling waste incineration facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treating method for waste washing water when dismantling a waste incineration facility, in which a wastewater treating apparatus is temporarily installed and is assembled at a low cost and does not need a large space for the installation. <P>SOLUTION: This method treats the waste washing water caused by washing of the apparatus or buildings during the dismantlement of the waste incineration facility. The waste washing water is collected and is temporarily stored in vessels (vessels for the waste washing water) selected from the waste incineration facility to be dismantled. The waste washing water stored in these vessels is sent to the wastewater treatment apparatus 20 mounted on a vehicle 21 and subjected to flocculation and sedimentation treatment, thus the solid content in the wastewater is precipitated, and then the supernatant of the waste washing water is filtered so as to remove dioxins from the waste washing water. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating cleaning wastewater for removing dioxins from the cleaning wastewater generated by cleaning equipment and buildings when dismantling a waste incineration facility in which municipal solid waste is incinerated.

[0002]

2. Description of the Related Art When dismantling a facility for incineration of waste such as municipal solid waste, it is necessary to remove dioxins adhering to the inner surface of the equipment or the building before dismantling the equipment. There is a washing method in which the building is washed with high pressure water. However, when this washing method is adopted, when the washing wastewater is discharged, it is necessary to carry out a treatment to reduce the concentration of dioxins taken into the washing wastewater to a regulated value or less. For this reason, when implementing the water washing method, a water tank for receiving and storing washing water and a wastewater treatment facility for treating this washing water are temporarily installed in the site of the waste incineration facility to be dismantled,
The cleaning wastewater is sent to this temporary wastewater treatment facility to remove dioxins.

[0003]

However, in the above-mentioned prior art, the waste water treatment equipment must be temporarily installed as a part of the construction for dismantling the waste incineration facility, and the equipment must be removed after the construction is completed. Further, it is difficult to divert the wastewater treatment equipment after removal to other uses, and most of the wastewater treatment equipment after removal is discarded. Therefore, the temporary cost of the wastewater treatment equipment is added to the dismantling work cost of the waste incineration facility, and the cost of the dismantling work becomes high.

In addition to the equipment for treating the cleaning water, it is necessary to install a cleaning water storage tank on the premises of the waste incineration facility, but the cleaning drainage flows out irregularly. The storage tank must have a large capacity. Therefore, a considerable space is required to install the wastewater treatment device.

The present invention solves the above problems and allows a wastewater treatment device provided on the premises of a waste incineration facility to be temporarily installed and removed at a small cost, requiring a large space for installation of the wastewater treatment device. Not intended to provide a method for treating cleaning wastewater when dismantling a waste incineration facility.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 is a method for treating cleaning wastewater generated by cleaning an apparatus or a building when dismantling a waste incineration facility. In this case, the cleaning drainage generated when cleaning the equipment and building is collected and temporarily stored in a tank selected from the waste incineration facility to be dismantled, and the cleaning drainage stored in this tank is stored in the vehicle. It is characterized in that the dioxin is removed from the cleaning wastewater by sending it to a wastewater treatment equipment installed in the equipment, performing a coagulating sedimentation treatment to precipitate a solid content, and then filtering the supernatant water.

According to the second aspect of the present invention, the cleaning wastewater treated by the treatment method according to the first aspect is introduced into a dioxin decomposing apparatus for treating with ozone and ultraviolet rays, and remains in the treated cleaning wastewater. The feature is that it decomposes existing dioxins.

In the above invention, the vehicle does not mean only an automobile, but may be a truck that can be towed.

In the present invention, most of the dioxins can be removed by coagulating and precipitating the washing wastewater containing dust (solid content) washed off from the apparatus or building to precipitate the solid content. . According to the knowledge of the present inventors, when water containing dioxins and solids is subjected to coagulation-sedimentation treatment, dioxins are removed from water in a state where they are attached to or adsorbed on solids. Next, the coagulation-precipitated supernatant water is filtered to perform a finishing treatment for removing dioxins.

As described above, since the solid content contained in the cleaning waste water serves as an auxiliary agent for removing dioxins, when the solid content in the cleaning waste water to be treated is small, a powder of the solid content is removed. If added, the removal rate of dioxins can be increased. As the powder of the solid content added to the cleaning waste water, a substance that is poorly soluble in water, such as activated carbon, zeolite, or diatomaceous earth, can be used.

In the present invention, since the wastewater treatment equipment mounted on the vehicle is used, the wastewater treatment equipment can be easily moved as required. Therefore, when temporarily installing or removing the wastewater treatment device, it is only necessary to move the onboard vehicle. In addition, the wastewater treatment equipment installed in the vehicle can be moved to a place near the washing place or a place near the tanks that temporarily store the wash drainage, so the wastewater treatment work corresponding to the situation of the water washing work is carried out. can do.

Further, according to the present invention, the cleaning waste water flowing out when cleaning the apparatus or the building is temporarily stored in the tanks such as the ash pit and the ash storage silo in the waste incineration facility to be dismantled. After that, the waste water is sent to the waste water treatment equipment, so it is not necessary to attach a water tank for storing the wash water to the waste water treatment equipment.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an example of a cleaning wastewater treatment method according to an embodiment of the present invention. In addition, FIG. 2 is a diagram showing the configuration of the wastewater treatment device mounted on the vehicle shown in FIG.

In FIG. 1, 10 is a location where cleaning wastewater is generated in a waste incineration facility to be dismantled, 13 is a cleaning drainage tank for receiving and temporarily storing cleaning wastewater that flows out when cleaning an apparatus or a building, and 20 is drainage. A treatment device 21 indicates a vehicle equipped with a wastewater treatment device. 12 and 14 are pumps. The cleaning drainage tank 13 is a tank for temporarily receiving and storing the cleaning drainage that irregularly flows out due to the cleaning of the apparatus and the building, and needs a considerably large capacity. For this reason,
The cleaning drainage tank 13 is selected from tanks capable of storing cleaning drainage, such as an ash pit and an ash storage silo in a waste incineration facility to be dismantled.
Further, the same tanks are not always used as the cleaning / drainage tank 13 during the entire period of the cleaning work, and when the cleaning location moves, another tank is used depending on the situation.
A temporary pipe such as a plastic pipe is provided between each of the above devices.

In FIG. 2, reference numeral 30 denotes a cleaning drainage supply tank,
32 is a flocculant supply tank, 34 is a flocculant mixer, 35 is a flocculation sedimentation tank, 36 is a sand filtration tower, 38 is a filter press, 3
9 is a cake receiving pan, and 40 is a filtrate receiving tank of a filter press. Reference numeral 42 is a dioxin decomposing apparatus provided for the case where it is necessary to further reduce the concentration of dioxins in the treated water filtered by the sand filtration tower. This dioxin decomposing device is based on the accelerated oxidation treatment method, and is a device for decomposing dioxins in wastewater by blowing ozone into the reaction tank into which wastewater flows in while irradiating ultraviolet rays. The power source for driving the above devices is supplied from the waste incineration facility to be dismantled.

The sand filter tower 36 is incorporated as a filter for filtering the supernatant water overflowing from the coagulating sedimentation tank 35 and capturing the solids and dioxins that could not be removed by the coagulating sedimentation tank 35. However, it is possible to replace the filter with another type. The other type of filter is required to have a function of capturing a small amount of solids and dioxins that could not be removed by the coagulating sedimentation tank 35, and for example, a microfiltration membrane or an ultrafiltration membrane was used. A membrane separator or the like is used.

The treatment of the cleaning wastewater by the treatment method shown in FIGS. 1 and 2 is performed as follows. The cleaning wastewater flowing out from the cleaning wastewater generation point 10 in the dismantling waste incineration facility is
The water is collected in a water collecting section 11 such as a place where a drain is partitioned, pumped up by a pump 12, and temporarily stored in a cleaning drainage tank 13. The cleaning wastewater stored in the cleaning drainage tank 13 is sequentially extracted by the pump 14 and sent to the wastewater treatment device 20 mounted on the vehicle, where it is subjected to a treatment for removing dioxins.

In the waste water treatment device 20, the wash waste water is received in the wash waste water supply tank 30, and the wash waste water extracted by the pump 31 and adjusted to a predetermined flow rate is sent to the coagulant mixer 34. In the coagulant mixer 34, the metering pump 3
The coagulant solution supplied from No. 3 and the cleaning drainage are mixed, and the mixed solution is sent to the coagulation sedimentation tank 35. In the coagulating sedimentation tank 35, the generated flocs settle, and the overflowed supernatant water is sent to the sand filtration tower 36, filtered, and then discharged. A part of the filtered water is used as water for washing the above equipment. If it is necessary to further reduce the concentration of dioxins in the filtered water discharged from the sand filtration tower 36, after the filtered water is introduced into the dioxin decomposing device 42, the dioxins are decomposed. , Release.

On the other hand, the sediment accumulated at the bottom of the coagulation sedimentation tank 35 is intermittently taken out by a pump 37, introduced into a filter press 38 and filtered. The filtered water is stored in the filtrate receiving tank 40, and is returned to the cleaning waste water supply tank 30 by the pump 41 for reprocessing. The filter cake is discharged to the cake receiving pan 39. This filter cake is sent to an incinerator of a waste incinerator or a facility equipped with a device for decomposing dioxins, and is subjected to high-temperature heat treatment to decompose dioxins.

[0020]

According to the present invention, the cleaning wastewater is treated by using the wastewater treatment equipment mounted on the vehicle, so that the wastewater treatment equipment can be appropriately moved as required.
Therefore, when temporarily installing / removing the wastewater treatment device, it is only necessary to move the mounted vehicle, and the cost required for the temporary installation / removal is extremely low.

Further, since the wastewater treatment equipment can be easily moved, it can be moved to a place near the washing place depending on the situation of the washing work of the waste incineration facility. Processing operations can be carried out.

Further, since the wastewater treatment equipment used in the present invention is mounted on a vehicle, it is not necessary to discard it even after the dismantling work of the waste incineration facility is completed, and the wastewater in the next dismantling work is kept as it is. It can be used for treatment and other similar wastewater treatment.

Further, in the present invention, the cleaning waste water is once received in the tanks such as the ash pit and the ash storage silo in the waste incineration facility to be dismantled and temporarily stored, and then sent to the waste water treatment device. Therefore, it is not necessary to attach a water tank for storing the wash water to the wastewater treatment device, and a large space is not required for installing the wastewater treatment device.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a cleaning wastewater treatment method according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a wastewater treatment device mounted on the vehicle shown in FIG.

[Explanation of symbols]

10 Cleaning wastewater generation points 11 Water catchment section 13 Cleaning drainage tank 20 Wastewater treatment equipment 21 Vehicles equipped with wastewater treatment equipment 30 Wash drainage tank 32 Flocculant supply tank 34 Flocculant Mixer 35 Coagulation sedimentation tank 36 sand filtration tower 38 Filter Press 39 Cake pan 40 Filtrate receiving tank 42 Dioxin decomposition device

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4D015 BA21 BA23 CA20 EA32 FA02                       FA11 FA15 FA24                 4D037 AA13 AB14 BA18 CA02 CA06                       CA09 CA12                 4D050 AA12 AB19 BB02 BC09 CA15                       CA16

Claims (2)

[Claims] 1. A method of treating cleaning wastewater generated by cleaning an apparatus or building when dismantling a waste incineration facility, collecting cleaning wastewater generated when cleaning the apparatus or building and dismantling it. Temporary storage in tanks selected from the waste incineration facility, and the cleaning wastewater stored in these tanks is sent to the on-vehicle wastewater treatment equipment, where it is subjected to coagulation sedimentation processing to precipitate solids. After that, the supernatant water is filtered to remove dioxins from the cleaning wastewater, which is a method for treating cleaning wastewater at the time of dismantling a waste incineration facility. 2. Cleaning effluent treated by the treatment method according to claim 1 is introduced into a dioxin decomposing device for treating with ozone and ultraviolet rays to decompose dioxins remaining in the treated cleaning effluent. A method for treating cleaning wastewater when dismantling a waste incineration facility, which is characterized by: