JP6534568B2 - Carrier interface detection apparatus, carrier interface detection method and waste water treatment apparatus - Google Patents

Description

  The present invention relates to the technology of a carrier interface detection device, a carrier interface detection method, and a waste water treatment device.

  Anaerobic fluidized bed waste water treatment is a treatment method in which the contact efficiency between the waste water and the carrier is enhanced by allowing microorganisms to be fixed to the carrier and flowed in the reaction tank, thereby enabling stable and highly efficient treatment. However, if the flow condition of the carrier is not properly managed, the carrier may flow out of the reaction vessel, resulting in unstable treatment.

  In order to manage the flow state of the carrier, it is necessary to detect the interface of the carrier and control the flow pump and the stirrer (see, for example, Patent Document 1).

  For example, Patent Document 2 proposes a method of detecting a carrier interface using an interface meter, and Patent Document 3 discloses an interface used in anaerobic fluidized bed waste water treatment using borax as a carrier. It is disclosed that an ultrasonic interface meter is effective as a meter, and Patent Document 4 discloses a vibratory interface as an interface meter used in anaerobic fluid bed wastewater treatment using slag as a carrier. It is disclosed that the measure is effective.

  In recent years, in the case of anaerobic fluidized bed waste water treatment, not an inorganic carrier such as borax or slag but an organic carrier such as polyvinyl alcohol or polyolefin is often used. The adhesion of microorganisms, the flowability of the carrier, and the like of the organic carrier are improved as compared with the inorganic carrier, and therefore waste water can be treated with a higher volume load. In addition, the possibility of high volume loading also tends to increase the amount of gases such as nitrogen gas and biogas (methane, carbon dioxide, etc.) generated in the reaction tank by denitrification treatment and anaerobic treatment of organic wastewater. It has become.

Unexamined-Japanese-Patent No. 4-330996 Patent No. 4544583 gazette JP-A-2-63597 JP-A-4-4096

  However, it is difficult to appropriately detect the interface of the carrier in the reaction vessel with the conventional interface meter because of the utilization of the organic carrier, the improvement of the flowability of the carrier, and the increase of the gas generation amount. .

  Therefore, it is an object of the present invention to provide a carrier interface detection device and a carrier interface detection method capable of appropriately detecting the interface of the carrier in a reaction tank in waste water treatment in which waste water is anaerobically treated using a carrier holding a microorganism. And providing a waste water treatment apparatus.

(1) The carrier interface detection device of the present invention is provided in a fluidized bed reaction tank storing carriers holding microorganisms, and is provided in a bottomed measurement chamber whose upper portion is opened, and the measurement chamber, wherein a detection unit for detecting the surface of the support is formed in the fluidized bed reactor, have a, the measuring chamber has a side wall, a bottom wall which is disposed below the side wall, the said A gap is provided between the side wall and the bottom wall, the gap being less than twice the size of the carrier .

  (2) In the carrier interface detection device according to (1), it is preferable to include a cleaning means for cleaning the measurement chamber.

  (3) The carrier interface detection method of the present invention is a method for detecting the interface of the carrier in the fluid bed reaction tank using the carrier interface detection device described in (1) or (2) above.

(4) The waste water treatment apparatus according to the present invention is a waste water treatment apparatus for anaerobically treating waste water using a carrier holding a microorganism, comprising: a fluid bed reaction tank for storing the carrier; and the inside of the fluid bed reaction tank A carrier interface detection device comprising: a bottomed measurement chamber having an open top, and a detection unit provided in the measurement chamber and detecting an interface of the carrier formed in the fluidized bed reaction chamber; And the measurement chamber has a side wall and a bottom wall disposed at a lower portion of the side wall, and a gap is provided between the side wall and the bottom wall, and the gap is the carrier Less than twice the size of

  (5) In the waste water treatment apparatus according to (4), the carrier is preferably an organic carrier.

  (6) In the waste water treatment apparatus according to the above (4) or (5), it is preferable to provide a stirring device which is provided in the fluidized bed reaction tank and stirs the carrier.

  (7) In the wastewater treatment device according to any one of the above (4) to (6), the SS concentration of the wastewater is preferably 100 mg / L or more.

  (8) In the waste water treatment apparatus according to any one of the above (4) to (7), it is preferable to include a washing means for washing the measurement chamber.

(9) The carrier interface detection apparatus of the present invention is provided in a fluidized bed reaction tank storing carriers holding microorganisms, and a detection unit for detecting an interface of the carrier formed in the fluidized bed reaction tank And a bottom wall disposed vertically below the detection unit, the side periphery and the top of the detection unit are open, and the distance between the bottom wall of the measurement chamber and the detection unit is the carrier Less than twice the size of

  (10) The carrier interface according to the present invention is a carrier interface detection method characterized by detecting the interface of the carrier in the fluidized bed type reaction tank using the carrier interface detection apparatus according to the above (9).

(11) The waste water treatment apparatus according to the present invention is a waste water treatment apparatus for anaerobically treating waste water using a carrier holding a microorganism, comprising: a fluid bed reaction tank for storing the carrier; and the inside of the fluid bed reaction tank A detection unit for detecting the interface of the carrier formed in the fluidized bed reaction vessel, and a carrier interface detection device having a bottom wall disposed vertically below the detection unit; The lateral circumference and the top of the part are open, and the distance between the bottom wall of the measuring chamber and the detection part is less than twice the size of the carrier .

  According to the present invention, a carrier interface detection device capable of appropriately detecting the interface of the carrier in the reaction tank, a carrier interface detection method, and a waste water treatment in which waste water is anaerobically treated using the carrier holding the microorganism. Waste water treatment equipment can be provided.

It is a schematic cross section which shows the waste water treatment apparatus which concerns on embodiment of this invention. (A) is a schematic cross section which shows an example of a structure of the detection main-body part shown in FIG. 1, (B) is a model top view which shows an example of a structure of a detection main-body part shown in FIG. It is a schematic cross section which shows the waste water treatment apparatus which concerns on other embodiment of this invention. It is a schematic cross section which shows another example of a structure of the detection main-body part used by this embodiment. It is a model top view which shows another example of a structure of the detection main-body part used by this embodiment. (A) is a schematic cross section which shows the detection main-body part used by the comparative example 1, (B) is a schematic cross section which shows the detection main-body part used by the comparative example 2. FIG.

  Embodiments of the present invention will be described below. The present embodiment is an example for implementing the present invention, and the present invention is not limited to the present embodiment.

  FIG. 1 is a schematic cross-sectional view showing a waste water treatment apparatus according to an embodiment of the present invention. The waste water treatment apparatus 1 shown in FIG. 1 is an apparatus for anaerobically treating waste water using a carrier holding a microorganism carrier. The waste water treatment apparatus 1 shown in FIG. 1 is provided with a stirring type fluid bed type reaction tank 10, and in the fluid bed type reaction tank 10, a carrier 12 holding microorganisms is stored. A drainage inflow line 14 is installed at the inlet of the fluidized bed reaction tank 10, and drainage to be treated is supplied from the drainage inflow line 14 into the tank. A treated water discharge line 16 is installed at the outlet of the fluidized bed reaction tank 10, and treated water obtained by anaerobic treatment of the waste water is discharged from the treated water discharge line 16 to the outside of the system.

  The fluidized bed reaction tank 10 shown in FIG. 1 includes a draft tube 18 installed substantially vertically in the tank and opened at the top and bottom, and a stirring device 20 for stirring the carrier 12 in the tank. The stirring device 20 shown in FIG. 1 includes a motor 22, stirring blades 24, and a shaft 26 connecting the motor 22 and the stirring blades 24. The stirring blades 24 are disposed in the draft tube 18. The stirring device 20 is not limited to the above configuration as long as it has a device configuration for stirring the carrier 12 in the fluidized bed reaction tank 10. Further, by installing the draft tube 18 and operating the stirring device 20, a downward flow is formed in the draft tube 18, and between the outer wall surface of the draft tube 18 and the inner wall surface of the fluidized bed reaction tank 10 Since the upward flow is formed, it is possible to improve the flowability of the carrier 12, but it is not necessary to install the draft tube 18.

  The wastewater treatment device 1 shown in FIG. 1 is provided with a carrier interface detection device 28. The carrier interface detection device 28 shown in FIG. 1 includes a detection main body portion 30 provided in the fluidized bed reaction tank 10 and a conversion portion 32.

  2 (A) is a schematic cross-sectional view showing an example of the configuration of the detection main body shown in FIG. 1, and FIG. 2 (B) is a schematic top view showing an example of the configuration of the detection main body shown in FIG. is there. The detection main body 30 shown in FIG. 2 includes a bottomed measurement chamber 34 whose top is open. The measurement chamber 34 shown in FIG. 2 is composed of a cylindrical side wall 34a and a bottom wall 34b that closes the lower opening of the cylindrical side wall 34a. The cylindrical side wall 34 a and the bottom wall 34 b constituting the measuring chamber 34 may be separately molded or may be integrally molded. The upper part of the measuring chamber 34 is the liquid surface side of the fluidized bed reactor 10, and the lower part (bottom part) on the opposite side is the bottom side of the fluidized bed reactor 10. In the measurement chamber 34 shown in FIG. 2, the carrier 12 flowing in the fluidized bed reaction tank 10 flows into the measurement chamber 34 from the mainly opened upper portion, and the inflow from the side and bottom surfaces is the side wall 34 a and the bottom wall Limited by 34b.

  The detection main body unit 30 shown in FIG. 2 includes a detection unit 36 provided in the measurement chamber 34. The detection unit 36 detects the interface of the carrier 12 formed in the fluidized bed reaction tank 10. The detection unit 36 is electrically connected to the conversion unit 32 illustrated in FIG. 1, and the detection signal of the detection unit 36 is transmitted to the conversion unit. The interface of the carrier 12 is, for example, in the case of a stirring type reaction tank provided with a stirring device 20, the output of the stirring device 20 is increased, the interface of the carrier 12 is increased, and the output is decreased, it is decreased. For example, if the flow rate of the wastewater flowing into the reaction vessel is increased, the interface of the carrier 12 is raised, and if the flow rate is decreased, the interface of the carrier 12 is lowered.

  The detection unit 36 illustrated in FIG. 2 includes a light emitting unit 36a and a light receiving unit 36b, and is installed on the side surface in the measurement chamber 34 so that the light emitting unit 36a and the light receiving unit 36b face each other. The detection unit 36 shown in FIG. 2 is an optical sensor. The light emitted from the light emitting unit 36 a is scattered by the carrier 12 or the like. Therefore, for example, when the interface of the carrier does not rise to the measuring chamber 34 and the carrier 12 is not in the measuring chamber 34, the intensity of the transmitted light received by the light receiving unit 36b is high and the intensity of the scattered light is low A signal is output. Also, for the same reason, for example, when the interface of the carrier rises to the measuring chamber 34 and the carrier 12 flows into the measuring chamber 34, the intensity of the transmitted light received by the light receiving unit 36b is low. A detection signal with high intensity is output.

  The carrier interface detection device 28 illustrated in FIG. 1 includes a conversion unit 32 that receives a detection signal from the detection unit 36 illustrated in FIG. 2. The conversion unit 32 includes, for example, a display unit that displays the detection signal from the detection unit 36 as a numerical value, for example, the transmitted light intensity value, the scattered light intensity value, and the ratio of transmitted light intensity / scattered light intensity. Alternatively, a display unit may be provided that converts the light into an MLSS concentration, an SS concentration, or a turbidity using a transmitted light intensity / scattered light intensity ratio or the like. An operator etc. sees the numerical value displayed by the conversion part 32, and whether the detection part 36 detected the support | carrier interface, ie, the support | carrier interface rose to the measurement room 34 which installed the detection part 36. It is possible to judge

  In addition, for example, based on a detection signal from the detection unit 36, the conversion unit 32 determines whether the detection unit 36 has detected the carrier interface, that is, the carrier interface has risen to the measurement chamber 34 in which the detection unit 36 is installed. If the carrier interface rises up to the measurement chamber 34, an alarm that warns with a buzzer or the like, or a control unit that controls the output of the stirring device 20 may be provided.

  Whether or not the detection unit 36 detects the carrier interface is determined, for example, as follows. In a state where the stirring device 20 is stopped, the waste water is introduced into the fluid bed reactor 10 from the inlet of the fluid bed reactor 10. In this state, the carrier 12 is deposited at the bottom of the reaction tank, the drainage mainly flows into the measuring chamber 34, and the carrier 12 hardly flows. In this state, the conversion unit 32 determines the transmitted light intensity, the scattered light intensity value, the transmitted light intensity / scattered light intensity ratio, the MLSS concentration, the SS concentration, the turbidity, or the like detected by the detection unit 36 in this state. Set as a value. After the inflow of drainage, the stirring device 20 is operated to perform anaerobic treatment of the drainage while flowing the carrier 12 holding microorganisms, but when the carrier 12 is stirred by the operation of the stirring device 20, the interface of the carrier 12 Will rise. The conversion unit 32 compares the transmitted light intensity, the scattered light intensity value, the transmitted light intensity / scattered light intensity ratio, the MLSS concentration, the SS concentration, the turbidity, etc. detected by the detection unit 36 with the above reference value as needed. Then, it is determined whether this difference (absolute value) is larger than a threshold. And when it is large, it is determined that the detection unit 36 has detected the carrier interface, that is, the carrier interface has risen to the measurement chamber 34 in which the detection unit 36 is installed. Note that, for example, when it is determined that the carrier interface has risen to the measurement chamber 34 in which the detection unit 36 is installed, the conversion unit 32 performs warning by an alarm, output control of the stirring device 20 by a control unit, and the like. The threshold value may be set as appropriate, but for example, it is preferable to set so that the abundance ratio of the carrier (the ratio of the carrier volume per liter of treated water in the reaction tank) is in the range of 10% to 30%. For example, when the threshold is set so that the carrier abundance is 10%, if the difference (absolute value) becomes larger than the set threshold, the carrier abundance is less than 10% above the carrier interface. In the lower part of the interface of the carrier, the abundance of the carrier is more than 10%. In addition, the abundance ratio of the carrier is calculated by sampling 1 L of water to be treated and the carrier at a certain depth of the reaction tank, putting the treated water and the carrier in a measuring cylinder, and measuring the volume occupied by the carrier. Ru.

  Generally, when the carrier interface rises to the detection unit 36 in a state in which the flowability of the carrier 12 in the reaction tank is high, the speed of the carrier 12 passing through the detection unit 36 also increases, and the generated by the anaerobic treatment Since a large amount of gas passes through the detection unit 36, the detection accuracy of the carrier 12 tends to decrease. That is, even if the carrier 12 is made to flow, the interface of the carrier 12 rises, and the interface of the carrier 12 reaches the detection portion 36, the interface of the carrier 12 can not be detected or the interface of the carrier 12 is detected Even if the gas does not reach the portion 36, it may be determined that the interface of the carrier 12 is erroneously detected because a large amount of gas passes through the detection portion 36 or the like. However, in the waste water treatment apparatus 1 shown in FIG. 1, since the detection unit 36 is provided in the bottomed measuring chamber 34 whose upper part is open, the inside of the tank is moved up to the measuring chamber 34 with the carrier interface raised. The fluid carrier 12 flows into the measuring chamber 34 in the sedimentation state from the mainly open top. Since the flowability of the carrier 12 flowing into the measurement chamber 34 in the sedimentation state from the top is lower than the flowability of the carrier 12 outside the measurement chamber 34, the detection unit 36 can appropriately detect the carrier 12 Become. In addition, the side wall 34a and the bottom wall 34b of the measurement chamber 34, for example, limit the entry of gas generated by the anaerobic treatment or reduce the influence of the water flow generated by stirring or the like. The flowability of the carrier 12 that has flowed in is lower than the flowability of the carrier 12 outside the measurement chamber 34, and the detection unit 36 can appropriately detect the carrier 12.

  FIG. 3 is a schematic cross-sectional view showing a waste water treatment apparatus according to another embodiment of the present invention. In the waste water treatment apparatus 2 shown in FIG. 3, the same components as those of the waste water treatment apparatus 1 shown in FIG. 1 are given the same reference numerals, and the description thereof will be omitted. The waste water treatment apparatus 2 shown in FIG. 3 includes an upward flow type fluidized bed reaction tank 38, and in the fluidized bed reaction tank 38, a carrier 12 holding microorganisms is stored. The fluidized bed type reaction tank 38 shown in FIG. 3 has a drainage supply unit 40 provided near the bottom in the tank, and a drainage inflow line 14 is connected to the drainage supply unit 40, and the drainage inflow line 14 and drainage supply Drainage flows into the tank through the portion 40. Further, the fluidized bed type reaction tank 38 shown in FIG. 3 includes an overflow type treated water extraction unit 42 provided in the upper part in the tank, and the treated water extraction unit 42 is connected to the treated water discharge line 16. The treated water obtained by anaerobic treatment of the waste water is discharged to the outside of the system through the treated water extraction unit 42 and the treated water discharge line 16. The fluid bed reactor 38 shown in FIG. 3 includes a circulation line 44 and a circulation pump 46. One end of the circulation line 44 is connected to the fluid bed reactor 38, and the other end is a drainage inflow line 14 The waste water in the tank is circulated through the circulation line 44.

  In the waste water treatment apparatus 2 shown in FIG. 3, waste water is introduced from the waste water supply unit 40 into the fluidized bed reaction tank 38, and is circulated through the circulation line 44 by the operation of the circulation pump 46 while microorganisms are Anaerobic treatment is performed by the carrier 12 etc. held. And with the flow of this drainage, the carrier 12 in the tank also flows, and the carrier interface in the tank rises. The interface of the carrier 12 formed in the upward flow type fluidized bed reactor 38 is detected by the carrier interface detector 28. The detection method of the carrier interface detection device 28 is as described above.

  The fluidized bed type reaction tank used in this embodiment is higher in contact efficiency between the waste water and the carrier 12, and can be treated even with waste water having a high oil and fat concentration and SS concentration, etc. Stirred fluidized bed reactors are preferred. Further, the fluidized bed type reaction vessel is not limited to the upward flow type and the stirring type, and is not particularly limited as long as the carrier 12 flows. Further, the upward flow type fluidized bed reaction tank is not particularly limited as long as it is an apparatus configuration for anaerobically treating the waste water in the upward flow, and the apparatus configuration of the fluidized bed reaction tank 38 shown in FIG. It is not limited. Further, the stirring type fluidized bed type reaction tank is not particularly limited as long as it is an apparatus configuration for anaerobic treatment while stirring the drainage, and is limited to the apparatus configuration of the fluidized bed type reaction tank 10 shown in FIG. It is not a thing.

  The detection unit used in the present embodiment is not limited to the optical detection unit 36 shown in FIG. 2 as long as it can detect the carrier 12. For example, an ultrasonic type, a vibration type, etc. Can be mentioned. The ultrasonic detection unit includes, for example, a transmission unit and a reception unit of ultrasonic waves, and detects the carrier 12 by measuring the reception intensity of the ultrasonic waves. In the ultrasonic detection unit, the reception intensity is high when the carrier 12 is not present, and the reception intensity decreases when the carrier 12 reaches the detection unit. The vibration-type detection unit detects, for example, the presence or absence of a carrier interface by measuring the vibration intensity of the detection unit. In the vibration type detection unit, the vibration strength is high when the carrier 12 is not present, and the vibration strength decreases when the carrier interface contacts the detection unit. Moreover, the detection part used by this embodiment may be a sensor etc. which can measure sludge concentration, SS concentration, turbidity, etc. which used the principle of an optical type and an ultrasonic type, for example.

  The measuring chamber 34 used in the present embodiment is not limited to the shape in which only the upper part is open as shown in FIG. 2 as long as the upper part is open and closed. FIG. 4 is a schematic cross-sectional view showing another example of the configuration of the detection main body used in the present embodiment. For example, as in the measurement chamber 34 shown in FIG. 4, a predetermined gap may be provided between the cylindrical side wall 34 a and the bottom wall 34 b disposed below the cylindrical side wall 34 a. In the case where a gap is provided between the side wall 34a and the bottom wall 34b, it is desirable to make the gap between the side wall 34a and the bottom wall 34b such that the penetration of the carrier 12 is limited, for example, the size of the carrier 12 used. It is preferable to set to 2 times or less. The cross-sectional shape of the cylindrical side wall 34a is not limited to a circle, and is not particularly limited, such as a polygon. The side wall 34 a and the bottom wall 34 b of the measurement chamber 34 may be plate-like or may be mesh-like or the like in which a plurality of holes are formed. In the case of mesh shape, the size of the holes is preferably such that the penetration of the carrier 12 is limited, and for example, it is preferable that the size is set to twice or less the size of the carrier 12 used. . FIG. 5 is a schematic top view showing another example of the configuration of the detection main body used in the present embodiment. The side wall 34 a does not have to be provided on the entire side surface of the measurement chamber 34, and may be provided on a part of the side surface of the measurement chamber 34 as shown in FIG. 5. The side walls 34 a shown in FIG. 5 are a pair of arc-shaped side walls disposed opposite to each other at a predetermined interval. In any case, the bottomed measuring chamber whose upper portion is open enables the carrier to flow from the upper portion, which is mainly open, into the measuring chamber in a precipitated state, and also the carrier or gas from the side or bottom surface In addition, the influence of the water flow generated by stirring or the like is reduced, so that the detection unit 36 can appropriately detect the carrier 12. Also, if the SS concentration of the waste water is high, the detection accuracy of the carrier tends to decrease, but in the present embodiment, for example, even if the SS concentration of the waste water is 100 mg / L or more, the detection unit 36 appropriately It is possible to detect.

  In another embodiment, the detection main body 30 may be provided without the measurement chamber 34 disposed around the side of the detection unit 36. That is, the detection main body 30 may be provided with the detection unit 36 and the bottom wall 34 b disposed vertically below the detection unit 36, and the side periphery and the top of the detection unit 36 are open. A predetermined distance may be provided between the detection unit 36 and the bottom wall 34b, or the detection unit 36 may be provided on the bottom wall 34b. When a space is provided between the detection unit 36 and the bottom wall 34b, it is desirable that the gap be such that entry of the carrier 12 is restricted from below the detection unit 36, for example, twice the size of the carrier 12 used. It is preferable to set to the following. Even with such a configuration, the carrier can pass through the detection unit 36 in the sedimentation state from the open top, so the detection main body with the top and bottom of the detection unit open and the top of the detection unit It is possible to appropriately detect the carrier in the detection unit from the detection main body unit that is covered and opened at the lower part. The bottom wall 34b is installed vertically below the detection unit 36, and the detection body with the side circumference and the top open of the detection unit 36 is, for example, a flow of water and gas mainly from the bottom of the tank toward the water surface It is desirable to be installed in a fluidized bed type reaction tank (for example, a stirring type and an upflow type reaction tank in which a draft tube is installed).

  The material of the measurement chamber 34 is not particularly limited, but is preferably a material which does not cause corrosion or deterioration in the fluidized bed reaction tank, and examples thereof include coated iron, plastic, stainless steel and the like.

  The carrier interface detection device 28 according to the present embodiment fixes the measurement chamber 34 and the detection unit 36 at a specific location in the tank, and detects whether the interface of the carrier 12 has reached the fixed location. Alternatively, it may be attached to a drive unit for moving the measurement chamber 34 and the detection unit 36 up and down to detect the position of the interface of the carrier 12 which is fluctuating. When the measurement chamber 34 and the detection unit 36 are fixed to a specific location in the tank, 1 to 4 of the water surface height in the tank from the viewpoint of the flowability of the carrier 12, contact with drainage, and prevention of carrier outflow. It is preferable to fix the measurement chamber 34 and the detection unit 36 at a height of three quarters.

  In the carrier interface detection device 28 of the present embodiment, since the carrier 12 and the like easily accumulate in the measurement chamber 34, it is desirable to include a cleaning device for cleaning the inside of the measurement chamber 34. The cleaning apparatus is not particularly limited as long as it can remove the carrier 12 and the like accumulated in the measurement chamber 34. For example, the cleaning apparatus and the like provided with a mechanism for injecting water or gas into the measurement chamber 34 preferable.

  The carrier 12 used in the present embodiment is not particularly limited as long as it is a carrier conventionally used in anaerobic biological treatment, and, for example, organic carriers such as plastic carriers, sponge carriers, gel carriers, etc. And inorganic carriers such as borax and slag. From the viewpoint of the flowability of the carrier, it is preferable to use an organic carrier rather than an inorganic carrier. In particular, by using a gel-like carrier, methane fermenting bacteria that do not produce a high molecular weight polymer easily enter the pores of the three-dimensional network structure of the gel-like carrier, or adhere easily due to the shape of the gel-like carrier, charge, etc. In addition, since the flowability of the carrier by agitation is high, high-load processing is possible compared to plastic carriers and sponge-like carriers.

  The gel-like carrier is not particularly limited, and examples thereof include water-absorbent polymer gel-like carriers comprising polyvinyl alcohol, polyethylene glycol, polyurethane and the like.

  The shape of the carrier 12 is not particularly limited, but is preferably spherical or cubic (cube-like), rectangular, cylindrical or the like having a diameter of about 0.5 mm to 20 mm. In particular, a spherical or cylindrical gel-like carrier having a diameter of about 3 to 8 mm is preferable. If the diameter of the carrier 12 is less than 0.5 mm, clogging easily occurs in a separator such as a screen for separating the carrier 12 and the treated water. When the diameter of the carrier 12 exceeds 10 mm, the surface area may be reduced and the processing speed may be reduced.

  In order to form the flow state of the support 12 inside the fluidized bed reactor, for example, the specific gravity of the support 12 is at least greater than 1.0, and the true specific gravity is 1.1 or more, or the apparent specific gravity is 1.01 or more Is preferred.

  The amount of the carrier 12 charged into the fluidized bed reactor is preferably in the range of 10 to 50% with respect to the volume of the fluidized bed reactor. If the amount of the carrier 12 is less than 10% of the volume of the fluidized bed reactor, the reaction rate may be reduced, and if it exceeds 50%, the carrier 12 becomes difficult to flow, and clogging with sludge in long-term operation Raw water may be short-passed due to water treatment, etc., resulting in poor treated water quality.

  The sedimentation velocity of the carrier 12 is preferably 100 to 500 m / hr. When the sedimentation velocity of the carrier 12 is less than 100 m / hr, the carrier 12 floats up and tends to flow out of the fluidized bed reactor, and the separation screen may be clogged. If it exceeds 500 m / hr, the fluid state may be deteriorated, and the carrier 12 may short pass or the energy of stirring may be increased.

  In this embodiment, in biological treatment of organic matter-containing wastewater, the pH of the wastewater is preferably in the range of 6.0 to 8.0, and more preferably in the range of 7.0 to 8.0. The pH adjustment of waste water is performed, for example, by supplying a pH adjuster to a raw water tank (not shown) from a pH adjuster supply line (not shown). If the pH of the organic matter-containing wastewater is outside the above range, the decomposition reaction rate of the organic matter by the biological treatment may decrease.

  The pH adjuster is not particularly limited, for example, an acid agent such as hydrochloric acid, an alkali agent such as sodium hydroxide, and the like. In addition, the pH adjuster may be, for example, sodium bicarbonate having a buffer action, a phosphate buffer, or the like.

  In the present embodiment, at least 1,000 mg / L or more of digested sludge, anaerobic granules, etc. are preferably introduced into the fluid bed reactor together with the carrier 12 at the time of startup of the apparatus, preferably 1,000 to 10,000 mg / L. It is more preferable to introduce it. When the sludge concentration in the fluidized bed reaction tank exceeds 10,000 mg / L, granular sludge or the like does not easily adhere to the carrier 12, and the effect of charging the carrier 12 may be reduced.

  In the present embodiment, it is preferable to add a nutrient, for example, to the waste water, from the point of maintaining the decomposition activity of the anaerobic biological sludge well, etc., in the anaerobic treatment of the waste water. The nutrient is not particularly limited, and examples thereof include carbon sources, nitrogen sources, other inorganic salts (Ni, Co, Fe, etc.) and the like.

  In the present embodiment, it is preferable to adjust the temperature of the water temperature in the fluidized bed reaction tank to 20 ° C. or more. In general, when the temperature is less than 20 ° C., the decomposition reaction rate tends to decrease. The method for adjusting the temperature of the water temperature in the fluidized bed reaction tank is not particularly limited. For example, a heating apparatus such as a heater is installed in the fluidized bed reaction tank, and the fluidized bed reaction is performed by heat such as a heater. The water temperature in the tank may be adjusted.

  The waste water to be treated in the present embodiment is, for example, food processing plant waste water, chemical plant waste water, semiconductor plant waste water, machine plant waste water, organic waste water containing biodegradable organic matter such as sewage, manure and the like.

  Hereinafter, the present invention will be described in more detail by way of examples and comparative examples, but the present invention is not limited to the following examples.

(Comparative example 1)
The test was conducted using a stirring type fluidized bed reactor shown in FIG. As waste water to be treated biologically, organic matter-containing waste water discharged from a food manufacturing plant was used. The CODcr concentration of the organic matter-containing wastewater was 1,500 to 3,000 mg / L, and the SS concentration was 50 to 1,800 mg / L. Next, a spherical polyvinyl alcohol gel carrier (pore diameter 4 to 20 μm, diameter 4 mm, specific gravity 1.025, sedimentation rate 4 cm / sec) was added to a 60 L acrylic reaction tank having a draft tube inside, 30% of the volume of the A stirring blade was placed in the draft tube, and the carrier was made to flow by stirring at 400 to 500 rpm. The support interface was maintained at about half the height of the reaction vessel.

  FIG. 6A shows the detection main body (detection unit and measurement chamber) used in Comparative Example 1. The detection main body 50 used in the comparative example 1 is an MLSS meter as an optical detection unit having a light emitting unit 54 a and a light receiving unit 54 b in a measuring chamber 52 of a cylindrical body whose upper and lower portions are open (Yokogawa Product name: SS400G) is installed. The measuring chamber 52 in which the MLSS meter was installed was installed in the part where the carrier interface exists. As a result of stopping a stirrer and measuring it in the state which made the support | carrier stand still at the tank lower part, the numerical value of MLSS meter showed 110-190 mg / L. Next, the stirrer was operated (400 to 500 rpm) to allow the carrier interface to reach the detection main unit 50, but the value of the MLSS meter remained at a slight increase of 240 to 350 mg / L. Generally, the drainage SS concentration fluctuates in the range of 50 to 1,800 mg / L, so depending on the treatment status, the value of the MLSS meter may indicate 200 mg / L or more without the carrier interface, It can be said that detection of the carrier interface may be difficult.

(Comparative example 2)
The detection main-body part (a detection part and a measurement chamber) used by the comparative example 2 is shown to FIG. 6 (B). In the comparative example 2, it tested on the same conditions as the comparative example 1 except having covered the upper part with the top plate and having used the detection main-body part 60 which has the measurement chamber 58 of the cylindrical body which opened the lower part. As a result of measuring in a state where the stirrer interface is operated (400 to 500 rpm) and the carrier interface reaches the detection main body 60, the numerical value of the MLSS meter is the same as the measurement result in the state where the carrier is kept stationary 110-190 mg / L. In the measuring chamber 58 in which the upper part is covered with a top plate and the lower part is opened, the carrier does not flow into the measuring chamber 58, and detection of the carrier interface is difficult. It is considered that this is because the water flowing into the measuring chamber 58 is repelled by the top plate, and the water flowing out of the measuring chamber 58 is generated.

(Example)
As shown in FIG. 2, it tested on the same conditions as the comparative example 1 except having used the detection main-body part 30 which has the bottomed measurement chamber 34 by which the upper part was open | released. As a result of measurement in a state where the carrier interface has reached the detection main body 30, the numerical value of the MLSS meter shows a value of 6,000 to 19,000 mg / L. This is a value three times higher or more than 1,800 mg / L, which is generally the maximum value of the drainage SS concentration. Therefore, it can be said that it is possible to appropriately detect the interface of the carrier formed in the reaction tank in the system in which the waste water is treated in the fluidized bed reaction tank.

  1, 2 waste water treatment equipment, 10, 38 fluid bed type reaction tank, 12 carriers, 14 drainage inflow lines, 16 treated water discharge lines, 18 draft tubes, 20 stirring devices, 22 motors, 24 stirring blades, 26 shafts, 28 carriers Interface detection device 30, 50, 60 detection main body part 32, 32 conversion parts, 34, 52, 58 measuring chamber, 34a side wall, 34b bottom wall, 36 detection part, 36a, 54a light emitting part, 36b, 54b light receiving part, 40 drainage Supply part, 42 Treated water take-out part, 44 Circulation line, 46 Circulation pump.

Claims (11)

A bottomed measuring chamber provided in a fluid bed type reaction tank for storing a carrier holding a microorganism and having an open top,
The measurement provided in the indoor, have a, a detector for detecting the interface of the support is formed in the fluidized bed reactor,
The measuring chamber has a side wall and a bottom wall arranged at the lower part of the side wall,
A gap is provided between the side wall and the bottom wall, and the gap is equal to or less than twice the size of the carrier.   The carrier interface detection apparatus according to claim 1, further comprising a cleaning unit configured to clean the inside of the measurement chamber.   A carrier interface detection method comprising: detecting the interface of the carrier in the fluidized bed reaction vessel using the carrier interface detection device according to claim 1 or 2. A wastewater treatment apparatus for anaerobically treating wastewater using a carrier holding a microorganism,
A fluid bed reactor for storing the carrier;
A bottomed measuring chamber provided in the fluidized bed reaction vessel and having an open top, a detection unit provided in the measuring chamber, and detecting an interface of a carrier formed in the fluidized bed reaction vessel; and a carrier surface detection apparatus having,
The measuring chamber has a side wall and a bottom wall arranged at the lower part of the side wall,
A clearance is provided between the side wall and the bottom wall, and the clearance is equal to or less than twice the size of the carrier .   The waste water treatment apparatus according to claim 4, wherein the carrier is an organic carrier.   The waste water treatment apparatus according to claim 4 or 5, further comprising a stirring device provided in the fluidized bed reaction tank for stirring the carrier.   The waste water treatment apparatus according to any one of claims 4 to 6, wherein the SS concentration of the waste water is 100 mg / L or more.   The waste water treatment apparatus according to any one of claims 4 to 7, further comprising cleaning means for cleaning the measurement chamber. A detection unit provided in a fluidized bed reaction tank storing a carrier holding microorganisms, and detecting an interface of the carrier formed in the fluidized bed reaction tank;
A bottom wall disposed vertically below the detection unit;
The side circumference and the top of the detection unit are open ;
The carrier interface detector according to claim 1, wherein a distance between the bottom wall and the detector is equal to or less than twice a size of the carrier.   A carrier interface detection method comprising: using the carrier interface detection apparatus according to claim 9 to detect the interface of the carrier in the fluidized bed reaction vessel. A wastewater treatment apparatus for anaerobically treating wastewater using a carrier holding a microorganism,
A fluid bed reactor for storing the carrier;
Carrier interface detection device having a detection unit provided in the fluidized bed reaction vessel and detecting an interface of the carrier formed in the fluidized bed reaction vessel, and a bottom wall disposed vertically below the detection unit And
The side circumference and the top of the detection unit are open ;
The distance between the bottom wall and the detection unit is equal to or less than twice the size of the carrier .