JP4489490B2 - Sewage sterilization using pulse power generated shock wave - Google Patents

Description

  In this invention, treated water in sewage treatment including sewage precipitates activated sludge in a spongy form in the final sedimentation basin, and sterilizes pathogenic microorganisms such as Escherichia coli contained in clean supernatant water as it is in the river Because it is discharged into the ocean and the ocean, depending on the treatment results, the discharged water will directly have a serious impact on the environment of the discharge destination water area, so the sewage sterilization method using pulse power generation shock waves that do not generate harmful disinfection by-products It is about.

The methods of sterilizing treated water in sewage treatment including sewage currently being implemented are roughly divided into chemical sterilization methods such as chlorine and ozone, and ultraviolet sterilization methods.
Methods for disinfection of chemicals such as chlorine and ozone are as follows: (1) When chemicals such as chlorine and ozone are added to sewage treated water, the chemicals themselves are toxic, so it is necessary to completely remove these additives after sterilization. Does not decompose completely by reacting with other organic matter, leaving harmful intermediate by-products, and the discharged water has a serious impact on the environment of the discharged water.
(2) Related equipment required for sterilization becomes large, and appropriate management of chemical injection amount and safety management of exhaust gas and the like are necessary in sterilization work.
(3) Cryptosporidium protozoa that cause disease due to parasitic on humans has recently been found to be highly resistant to chlorine and ineffective with conventional chlorine disinfection.
UV disinfection methods (1) Since the disinfection device has a large area in contact with the sewage treated water, sewage components in the water are likely to adhere to the immersion part and cause failure. The safety of the monitor remains uncertain due to the reduced accuracy of the monitor.
(2) Since the light receiving component directly receives ultraviolet rays, it is deteriorated and has a short life, and the ultraviolet lamp also needs to be replaced in a short period of time due to changes in illuminance with time, resulting in an increase in maintenance costs.
(3) The power consumption used for the irradiation of the ultraviolet lamp during the sterilization operation is large, and the running cost increases.

  In view of the above-described problems, the present invention has been devised to solve the problems. The object of the present invention is to create an underwater spark using a pulse power having a very short pulse width and a large power. By efficiently generating shock waves by discharge and killing pathogenic microorganisms contained in sewage treated water, not only can pathogenic microorganisms be sterilized efficiently in a short time, but also harmful disinfection by-products are generated. In addition, it is an object of the present invention to provide a sewage sterilization method using a pulse power generation shock wave that can be realized at a much lower cost than conventional methods.

In order to achieve the above object, the invention according to claim 1 is directed to a pulse power generator that generates a high-power pulse power with a very short pulse width, and a cylindrical sewage treatment for the pulses generated by the pulse power generator. Spark discharge occurs between high-voltage electrodes in fresh water separated from the sewage treated water inside the sewage treatment discharge pipe through a shock wave permeable membrane attached to the hole at the center upper part of the circumferential side of the discharge pipe. A shock wave generating part attached to the upper side of the hole for generating a shock wave and killing pathogenic microorganisms contained in the sewage treated water by the shock wave generated in fresh water and transmitted through the shock wave permeable membrane, with sterilized der those fresh water by the shock wave generator to the formed water inlet and water outlet so as to appropriately replace the fresh water of the shock wave generator shock wave generating portion is made of means to prevent the contaminated with impurities .

As is apparent from the above description, according to the sewage sterilization method using the pulse power generation shock wave according to the invention of claim 1 , the following effects can be obtained.
(1) Pathogenic microorganisms such as Escherichia coli contained in sewage treated water in sewage treatment can be subjected to spark discharge with pulse power to generate a shock wave to kill and sterilize.
(2) Although the pulse power generates a large amount of power, the pulse width is very short, so that the power consumption is small for generating the large amount of power.
(3) The basic device configuration is composed of a pulse power generation unit and a shock wave generation unit, and the installation of the present apparatus in a sewage treatment facility is not problematic in terms of space and economy.
(4) Since advanced sewage treated water can be obtained, clear and eco-friendly effluent water can be obtained, and it can be applied to water quality conservation in closed water areas and water recharge zones, and also to treatment plants that use treated water. .

Moreover, according to the sewage sterilization treatment method using the pulse power generation shock wave according to the first aspect of the invention, the following effects can be obtained.
(1) The environment in which shock waves are generated by spark discharge can always be kept appropriate regardless of the conductivity of sewage treated water into which shock waves are to be introduced.
(2) The sewage treated water to which shock waves are to be introduced is not contaminated with the molten material of the electrode.
(3) Deposition of substances in sewage treated water to which shock waves are to be introduced and pathogenic microorganisms such as Escherichia coli on the electrode does not occur.

Hereinafter, the present invention will be described more specifically based on the best mode for carrying out the invention described in the drawings.
Here, FIG. 1 is a schematic configuration diagram of a sewage sterilization apparatus used in a sewage sterilization treatment method using a pulse power generation shock wave, FIG. 2 is a spark discharge current and voltage waveform, and FIG. 3 is an efficient shock wave in sewage treated water. 4 is a schematic configuration diagram to be introduced, FIG. 4 is a schematic diagram of an experiment in which the present apparatus is attached to a sewage treatment discharge pipe, FIG. 5 is a cross-sectional view taken along the line AA in FIG.

  In FIG. 1, a pulse power as shown in the figure is applied to a high-voltage electrode (3) having an interval of several mm between shock wave generating parts (13) arranged in sewage treated water (2) in a sewage treated water filling container (1). When a pulse high voltage is applied using the capacitor discharge circuit of the generator (4), a spark discharge (5) is formed between the high voltage electrodes (3) of the shock wave generator (13) after a while. Accordingly, a shock wave (6) is generated from the shock wave generator (13). The intensity of the shock wave (6) increases with the magnitude of the pulse current immediately after turning to the spark discharge (5). A conduction current flows through the sewage treated water (2) from when a high pulse voltage is applied between the electrodes until the spark discharge (5) is formed, but the contribution of the current to the generation of the shock wave is small. However, the energy stored in the capacitor (7) is gradually consumed by this conduction current. The greater the energy consumed before the formation of the spark discharge (5), the smaller the current value immediately after switching to the spark discharge (5), resulting in a smaller intensity of the shock wave (6). This consumable energy increases as the conductivity of water increases. For this reason, when the conductivity of sewage treated water is large, it is not possible to generate a shock wave (6) by spark discharge (5) directly in sewage treated water having a high conductivity. Compared to the case of fresh water (12) having a low conductivity, the energy efficiency is extremely poor. In addition, generating the shock wave (6) by spark discharge (5) directly in the sewage treated water contaminates the sewage treated water (2) with the molten material of the high voltage electrode (3) of the shock wave generating part (13). Or deposition of substances in the sewage treated water or pathogenic microorganisms such as E. coli on the high voltage electrode (3). In FIG. 1, (8) is a DC power supply, (9) is a switch, (10) is a current, and (11) is a voltage.

  Therefore, as shown in FIG. 3, a shock wave generator (13) that generates a shock wave (6) using a spark discharge (5) in fresh water (12), and sewage treated water to which the shock wave (6) is to be introduced ( 14) is separated using, for example, a shock wave permeable membrane (15) such as silicon, so that the shock wave (6) can be efficiently introduced into the sewage treated water (14). That is, the shock wave (6) generated by the shock wave generator (13) disposed in the fresh water (12) is transmitted efficiently through the shock wave permeable membrane (15) into the sewage treated water (14). Pathogenic microorganisms such as E. coli contained in the treated water (14) are killed and sterilized. Further, by separating the shock wave generating part (13) and the sewage treated water (14) by using the shock wave permeable membrane (15), the molten material of the high voltage electrode (3) of the shock wave generating part (13) can be used. It is possible to prevent the sewage treated water (2) from being contaminated, and to prevent the deposition of substances in the sewage treated water and pathogenic microorganisms such as Escherichia coli on the high voltage electrode (3).

  A shock wave generator was installed in the sewage treatment discharge pipe, and an experiment was conducted to kill E. coli contained in the sewage treatment water. The experimental apparatus at this time is shown in FIGS. 4, 5, and 6, and the experimental results are shown in FIG. The target organism was placed in a container made of silicon rubber and placed 6 cm away from the discharge. E. coli was killed by one treatment (see FIG. 7B).

  Next, the structure of the experimental apparatus shown in FIGS. 4, 5, and 6 in which the present apparatus is installed in the sewage treatment discharge pipe and an experiment for killing Escherichia coli contained in the sewage treatment water will be described.

  For example, the sewage treatment discharge pipe (16) made of an iron pipe has a cylindrical shape, and an acrylic plate (17) prevents the sewage treatment water (14) inside the sewage treatment discharge pipe (16) from leaking to both ends thereof. ). A hole is formed in the central upper part of the sewage treatment discharge pipe (16), and a shock wave generating part (13) is attached to the upper side of the hole.

  In addition, a shock wave permeable membrane (15) made of, for example, silicon is attached to the hole at the upper center of the sewage treatment discharge pipe (16), and the sewage treatment discharge pipe (16) is formed by the shock wave permeable film (15). For example, the central upper part of the sewage treatment water (14) and the sewage treatment discharge pipe (16) inside are separated. A space filled with fresh water (12) is formed at the upper center of the sewage treatment discharge pipe (16) separated by the shock wave permeable membrane (15). Fresh water (12) and, for example, sewage treated water (14) are separated vertically by this shock wave permeable membrane (15).

  The fresh water (12) is in contact with the shock wave generating section (13), and the shock wave generating section (13) does not directly contact the sewage treated water (14), for example. The shock wave generating part (13) has its electrode tip fitting (20) in fresh water (12). The electrode tip fitting (20) is attached to a metal mounting board constituting the upper side of the fresh water (12) at the center upper part of the sewage treatment discharge pipe (16) through the insulator (19). The electrode tip metal fitting (20) of the shock wave generating section (13) is connected to the pulse power generating section (4) through an insulated cable (18).

  Moreover, the water supply port (21) and the drainage port (22) are formed in the mounting board which comprises the upper side of the fresh water (12) of the center upper part of a sewage treatment discharge pipe (16), and fresh water (12) The electrode tip metal fitting (20) accompanying the generation of the shock wave (6) is prevented from being partly dissolved and eluted in the fresh water (12) and contaminated with the impurities. Yes.

  Note that the present invention is not limited to the best mode for carrying out the invention, and various modifications can be made without departing from the spirit of the invention.

It is a schematic block diagram of the sewage sterilization processing apparatus used with the sewage sterilization processing method by the pulse power generation | occurrence | production shock wave which shows the best form for implementing this invention. It is the electric current and voltage waveform figure of the spark discharge of the sewage sterilization processing method by the pulse power generation | occurrence | production shock wave which shows the best form for implementing this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which introduces a shock wave efficiently during the process in the sewage sterilization processing method by the pulse power generation | occurrence | production shock wave which shows the best form for implementing this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is an experiment schematic diagram which attached the sewage sterilization processing apparatus used with the sewage sterilization processing method by the pulse power generation | occurrence | production shock wave which shows the best form for implementing this invention to the sewage treatment discharge pipe. It is AA sectional drawing in the experiment outline figure which attached the sewage sterilization processing apparatus used with the sewage sterilization processing method by the pulse power generation | occurrence | production shock wave which shows the best form for implementing this invention to the sewage treatment discharge pipe. It is a schematic block diagram of the shock wave generation | occurrence | production part in the experiment schematic diagram which attached the sewage sterilization processing apparatus used with the sewage sterilization processing method by the pulse power generation | occurrence | production shock wave which shows the best form for implementing this invention to the sewage treatment discharge pipe. E. coli used for E. coli killing test in sewage sterilization by pulse power generation shock wave showing the best mode for carrying out the present invention is cultured, (A) before treatment, (B) after shock wave exposure. (Once).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sewage treatment water filling container 2 Sewage treatment water 3 High voltage electrode 4 Pulse power generation part 5 Spark discharge 6 Shock wave 7 Capacitor 8 DC power supply 9 Switch 10 Current 11 Voltage 12 Fresh water 13 Shock wave generation part 14 Sewage treatment water 15 into which shock wave is to be introduced 15 Shock wave permeable membrane 16 Wastewater treatment discharge pipe (iron pipe)
17 Acrylic plate 18 Insulated cable 19 Insulator 20 Electrode tip fitting 21 Water supply port 22 Drainage port

Claims (1)

A pulse power generator that generates high-power pulse power with a very short pulse width, and a pulse generated by the pulse power generator is attached to a hole in the upper center of the circumferential side of a cylindrical sewage treatment discharge pipe Shock wave generation attached to the upper side of the hole that generates a shock wave by spark discharge between high-voltage electrodes in fresh water separated from the sewage treatment water inside the sewage treatment discharge pipe through the shock wave permeable membrane And kills pathogenic microorganisms contained in sewage treated water by shock waves generated in fresh water and transmitted through a shock wave permeable membrane, sterilized , and water inlet and drain port formed in the shock wave generating part A method for sterilizing sewage with a pulse power generation shock wave, wherein the fresh water in the shock wave generation part is appropriately exchanged to prevent contamination of the fresh water in the shock wave generation part with impurities .

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