JPH0824890A - Anaerobic treatment device - Google Patents

Abstract

PURPOSE:To treat even an organic waste water containing a suspended solid efficiently by mixing an organic industrial waste water with a magnetic powder which increases the density of a suspended solid to a high level, in a treatment vessel and at the same time, connecting a branched pipe for extracting the suspended solid running obliquely upward on the side face part of the vessel. CONSTITUTION:Industrial waste water flowing into a treatment vessel 1 from an inflow pipe 2 is treated and separatedly into a treated water and biogas by anaerobic microbes when passing through the vessel as the upward stream. The treated water is caused to flow out of a water flow pipe 3 as the overflow. In this case, a suspended solid SS in the waste water is turned to be at a high density level by a magnetic powder which is previously charged into the treatment vessel 1. If a liquid level containing this high-density SS reaches the elevation of an SS extraction means 7, air is ejected into a transport gas ejection pipe 10, so that the SS is raised. The magnetic powder J contained in the SS is attracted onto the internal wall surface of an SS extraction pipe 6 by the magnetic power of an electromagnet. 13. Thus, the SS which is free from the magnetic powder J is drawn from a liquid receiving vessel 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anaerobic treatment apparatus for biologically treating organic industrial wastewater with anaerobic microorganisms, and more particularly to organic industrial wastewater containing a high concentration of suspension. The present invention relates to an anaerobic treatment device for treating anaerobically.

[0002]

2. Description of the Related Art Conventionally, as a method for treating organic industrial wastewater containing soluble organic substances, there is a method using anaerobic microorganisms. This is for biologically decomposing soluble organic substances in organic industrial wastewater with anaerobic microorganisms such as methanogenic bacteria. For example, it is treated by an anaerobic treatment apparatus as shown in FIG. . In this anaerobic treatment apparatus, an inflow pipe b for introducing the organic industrial wastewater is provided at a lower end portion of a treatment container a in which granules (not shown) in which the anaerobic microorganisms are densely accumulated are stored. In addition to being connected, it is equipped with gas-liquid separation means c and the like inside, and while the organic industrial wastewater introduced from the inflow pipe b is allowed to flow in an upward flow, it is dissolved in the organic industrial wastewater by the anaerobic microorganisms. The organic substance is biologically decomposed, and biogas containing CO2 and methane as main components and treated water are discharged from the upper end thereof.

[0003]

By the way, the wastewater to be treated by this anaerobic treatment apparatus is almost limited to the wastewater mainly composed of soluble organic substances, and a suspension of sludge (SS: usually, the wastewater is filtered by a filter). It is the present condition that it is hardly used for the wastewater containing the residue obtained in this way, the unit of which is expressed in mg / l. That is, when this SS flows into the processing container a, it occupies a certain part of the processing container a, making it difficult for granules and biofilms to be formed by microorganisms, and the decomposition rate of organic matter is greatly reduced. This is because it will end up. Therefore, by applying a magnetic separation method or the like used in rainwater sewage treatment, etc., to mix magnetic powder such as magnetite into this SS to densify it, and only the densified SS flows into the processing container a. It is also possible to extract the waste water from the waste water b, but for that purpose, it is necessary to newly install a large amount of magnetic powder or a device for recovering the magnetic powder from the SS, thus increasing the installation space and increasing the cost. There was an inconvenience to invite.

The present invention has been devised in order to effectively solve the above problems, and its purpose is to increase the installation space and cost without increasing the organic wastewater containing SS. However, it is intended to provide a novel anaerobic treatment device capable of efficiently treating.

[0005]

In order to achieve the above object, the present invention is directed to the inside of a processing vessel in which an organic industrial wastewater containing soluble organic matter is introduced from the lower end portion, flowed in an upward flow, and overflowed from the upper end portion. In the anaerobic treatment apparatus containing anaerobic microorganisms for decomposing soluble organic matter in the organic industrial wastewater, the suspension in the organic industrial wastewater is densified in the treatment container. In addition to mixing the magnetic powder, an SS extraction pipe for extracting the densified SS is connected to the lower part of the SS branch by branching diagonally upward from this, and the SS is air-lifted below the SS extraction pipe to SS. In addition to providing an SS withdrawing means for removing the SS while removing the magnetic powder from above, a magnetic powder collecting means for adsorbing and collecting the magnetic powder in the extracted SS is provided above it. The magnetic powder recovery means includes an electromagnet surrounding the SS withdrawal pipe and a cleaning means for causing a part of the treated water overflowing from the treatment container to flow back into the SS withdrawal pipe. It is a thing.

[0006]

According to the present invention, due to the above-mentioned constitution, SS in the waste water flowing into the processing container is densified by the magnetic powder to increase the specific gravity and exists in the processing container in a concentrated state. The volume becomes smaller. As a result, the proportion of SS in the treatment container does not increase as much as in the prior art, and the ability of anaerobic microorganisms to decompose and treat organic substances in wastewater does not decrease. In addition, an SS is provided by an air lift provided below the SS extraction means.
Then, the magnetic powder is removed from the SS, and then the electromagnet of the magnetic powder recovery means provided above the SS extraction means separates only the magnetic powder in the SS to be extracted, and this is washed again into the processing container by the cleaning means. Since the magnetic powder is collected, the surplus SS can be extracted without reducing the magnetic powder. Further, by providing the SS withdrawal tube away from the bottom of the processing container, it is possible to selectively withdraw SS without extracting the granules that tend to settle in the processing container.

[0007]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the anaerobic treatment apparatus according to the present invention. As shown in the figure, this anaerobic treatment apparatus has substantially the same structure as the conventional one, and an inflow pipe 2 for introducing an organic industrial wastewater containing SS to the lower end portion of a treatment container 1 having a substantially cylindrical shape. And an exhaust pipe 4 for exhausting the treated water and an exhaust pipe 4 for exhausting biogas are respectively connected to the upper end of the inflow pipe 2.
The wastewater that has flowed in from is flowed in an upward flow. Further, a granule (not shown) accumulating anaerobic microorganisms such as methane-oxidizing bacteria and a gas-liquid separating means 5 are housed inside the processing container 1, and the organic industry introduced through the inflow pipe 2 Waste water is biologically decomposed into treated water and biogas containing methane as a main component by the above microorganisms. In addition, magnetic powder such as fine magnetite having an average particle size of 10 μm or less is mixed in the processing container 1, and the SS that has flowed into the processing container 1 is adhered to increase the density. It is designed to be concentrated in the container 1.

Further, an SS extraction pipe 6 extending obliquely upward from the side wall of the processing container 1 is connected to the side wall. This SS withdrawing pipe 6 is for withdrawing SS accumulated in the processing container 1, and in the middle thereof, an SS withdrawing means 7 and a magnetic powder collecting means 8 are provided from the bottom to the top.
And an SS liquid receiving container 9 is provided. The SS extraction means 7 is composed of a carrier gas injection pipe 10 whose front end penetrates the SS extraction pipe 6 and faces the inside thereof, a check valve 11, and a pump 12, and is delivered from the pump 12. The SS in the SS extraction pipe 6 is extracted by an air lift while separating the magnetic powder by a carrier gas such as air. Further, the magnetic powder collecting means 8 is provided so as to surround the SS extraction pipe 6, and is composed of an electromagnet 13 which can be excited at will and a cleaning means 14 provided above the electromagnet 13, A magnetic field is formed in the extraction pipe 6, and only the rising magnetic powder J in SS is adsorbed and returned to the inside of the processing container 1. The cleaning means 14 is composed of a cleaning pipe 15 connecting the SS extraction pipe 6 above the electromagnet 13 and the outflow pipe 3, a check valve 16 and a pump 17, and a process for flowing in the outflow pipe 3. A part of the water is withdrawn, the water is withdrawn into the SS withdrawal pipe 6 and the magnetic powder J adsorbed by the electromagnet 13 is pressure-fed into the processing container 1. Further, the SS liquid receiving container 9 is provided so as to surround the tip end portion of the SS withdrawing pipe 6 opened upward, so that the SS overflowed from the SS withdrawing pipe 6 is collected and sent to an SS processing means (not shown). Has become. The upper end of the SS extraction pipe 6 is opened at a position slightly higher than the height of the outflow pipe 3 of the processing container 1 so that the waste water in the SS extraction pipe 6 does not naturally overflow.

Next, the operation of this embodiment will be described.

First, when the wastewater flowing into the processing container 1 from the inflow pipe 2 passes through the processing container 1 in an upward flow, it is decomposed by the anaerobic microorganisms in the processing container 1 into processed water and biogas. The treated water overflows and flows out from the outflow pipe 3, and the biogas is separated from the treated water by the gas-liquid separation means 5 and exhausted from the exhaust pipe 4. At this time, the SS in the waste water is aggregated and densified around the surroundings as shown in FIG. 2 by the magnetic powder previously charged into the processing container 1, and as shown in FIG. Is concentrated to.

The proportion of the high-density SS gradually increases with the introduction of the wastewater, but if the liquid level reaches the height of the SS withdrawing means 7 of the SS withdrawing pipe 6, for example. For example, the pump 12 of the SS extraction means 7 is actuated, carrier gas such as air is ejected into the carrier gas ejection pipe 10, and SS in the SS ejection pipe 6 is raised by an air lift. At the same time, when the electromagnet 13 of the magnetic powder collecting means 8 is energized to be excited, the magnetic powder J in SS rising in the SS extraction tube 6 is strongly mixed by aeration and separated from SS, and at the same time, It is separated from the SS by magnetic force and adsorbed on the inner wall surface of the SS extraction pipe 6. The SS from which the magnetic powder J has been separated is further SS
It rises in the extraction pipe 6, overflows from the upper end thereof, and is extracted from the SS liquid receiving container 9. As a result, the proportion of SS in the processing container 1 does not increase any more, and it is possible to prevent the degradation of the decomposition processing capacity by anaerobic microorganisms.

Next, in such a state, the S in the processing container 1 is
By extracting S, the magnetic powder J in the processing container 1 decreases, and when the decreased magnetic powder J gradually accumulates on the inner wall of the SS extraction pipe 6 near the electromagnet 13 as shown in FIG. , SS extraction by the SS extraction means 7 is stopped, and energization to the electromagnet 13 is stopped to bring it into a non-excited state. After that, when the pump 17 provided in the cleaning pipe 15 of the magnetic powder collecting means 8 is driven to guide a part of the treated water flowing through the outflow pipe 3 by the cleaning pipe 15 and make it flow backward into the SS extraction pipe 6, SS Magnetic powder J deposited on the inner wall of the extraction pipe 6
Flows back in the SS extraction pipe 6 and is returned to the processing container 1,
Again, it acts as an aggregating agent for densifying the SS in the processing container 1. Then, after the elapse of a certain time, the SS withdrawing work and the magnetic powder collecting work as described above are repeated again, whereby only the SS flowing into the processing container 1 one after another can be efficiently withdrawn.

As described above, according to the present invention, since the magnetic powder is mixed to increase the density of SS in the waste water to reduce the volume occupied in the processing container, almost no processing can be performed by the conventional anaerobic processing apparatus. It is possible to treat SS-containing organic wastewater, and the magnetic powder in this high-concentration SS is collected and reused at the same time as SS is extracted by using magnetic force, so new magnetic powder is added. It is not necessary to do so, and the increase in cost can be suppressed. In the present embodiment, an electromagnet was used to separate the magnetic powder, but instead of this, a general permanent magnet may be used mechanically close to or away from the SS extraction tube to obtain the same effect. Alternatively, instead of the air lift, a stirrer may be provided in the SS withdrawal pipe to physically separate the magnetic powder in SS by centrifugal force. Further, as shown in FIG. 3, the SS liquid receiving container 9 provided at the upper end portion of the SS withdrawing pipe 6 has a closed structure, and the SS liquid receiving container 9 is withdrawn from the SS liquid receiving container 9.
It is also possible to improve the magnetic powder recovery effect by the cleaning means 14 as shown in the figure by providing a solenoid valve 18 or the like in the line and closing the magnetic valve during the magnetic powder recovery operation to operate the pump 17.

[0015]

In summary, according to the present invention, SS which can hardly be treated by the conventional anaerobic treatment apparatus.
Since it is possible to treat the mixed organic wastewater, it is possible to improve the treatment capacity of the wastewater and to suppress an increase in installation space and manufacturing cost associated with the increase in size of the apparatus and the installation of the attached equipment. In addition, since the magnetic powder in this high-concentration SS is separated by an air lift, and then the magnetic force is used to collect and reuse SS at the same time as it is taken out, there is no need to add new magnetic powder, and SS is taken out. It is possible to exert an excellent effect such that it is possible to suppress the loss of the magnetic powder and the increase in cost due to the replenishment due to the above.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing high concentration SS.

FIG. 3 is a configuration diagram showing a modified embodiment of the present invention.

FIG. 4 is a simplified diagram showing a structure of a conventional anaerobic treatment apparatus.

[Explanation of symbols]

 1 Processing Container 6 SS Extracting Tube 7 SS Extracting Means 8 Magnetic Powder Collecting Means J Magnetic Powder

Claims (2)

[Claims] 1. An organic industrial wastewater containing soluble organic matter,
Introduced from the lower end and flowing in an upward flow, overflowing from the upper end, inside the processing container, in the anaerobic processing apparatus containing anaerobic microorganisms for decomposing organic matter in the organic industrial wastewater, the processing container, A magnetic powder that densifies the suspension in the organic industrial waste water (hereinafter referred to as SS) is mixed therein, and an SS extraction pipe for extracting the SS accumulated in the processing container is provided on the side surface of the magnetic powder. Connect by branching diagonally upward, and then connecting the above S
Anaerobic treatment, characterized in that SS extraction means for air-lifting and extracting S and magnetic powder recovery means for adsorbing and recovering the magnetic powder in SS extracted by this SS extraction means are provided. apparatus. 2. The magnetic powder recovery means comprises an electromagnet surrounding the SS extraction tube and a cleaning means for causing a part of the treated water overflowing from the processing container to flow back into the SS extraction tube. Claim 1 characterized by the above-mentioned.
Anaerobic treatment device described.