JP2008246483A - Apparatus for biological treatment of waste water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an apparatus for biological treatment of waste water capable of enhancing the treatment capacity, though requiring no more space for the installation. <P>SOLUTION: The apparatus for the biological treatment of the waste water has a biological reaction tank 101 for biologically treating inflow waste water, an upstream-side wall 106 having a water passage 108 at its bottom and a downstream-side wall 107 having a water passage 109 at its top, and an aeration room 105 is partitioned off by the wall 106 and wall 107 and has an aeration means 110 at its bottom. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a biological wastewater treatment apparatus for treating sewage such as sewage and wastewater in a single biological reaction tank, preferably in the presence of a carrier.

  An activated sludge method is often used as a conventional water treatment, and a batch activated sludge method, a high-speed aeration method, an oxidation ditch method, and the like can be given as operating methods. As one of the conventional water treatment apparatuses of this type, there is known a batch (batch) type activated sludge treatment apparatus that repeats the steps of stirring, aeration, precipitation, and discharge in a single treatment tank. In this water treatment device, an air diffuser for blowing air from the aeration blower into the sewage in the aeration process is disposed at the bottom of the treatment tank. This air diffuser uses, for example, a jet type air diffuser so that both the agitation process and the subsequent aeration process can be performed only by switching control of the aeration blower, and the air supply pipe and the water supply pipe are connected. (For example, refer to Patent Document 1).

JP-A-60-150894 (page 2, upper left column, lines 12-19 and FIG. 3)

  This conventional water treatment apparatus can improve the denitrification / dephosphorization effect by performing the precipitation / discharge process after alternately repeating the stirring / aeration process a predetermined number of times for a predetermined time in a single treatment tank. It has the advantage of being However, this water treatment apparatus has a problem that the treatment capacity is not always sufficient with respect to the increase in the amount of inflow sewage with the recent progress of sewage treatment and wastewater treatment. In addition, in order to increase the treatment capacity, it is necessary to install a new water treatment device, but it is difficult to secure an installation space for that purpose, so the treatment capacity of the existing water treatment device is limited. Increasing is a challenge. Further, when a treatment using a carrier is performed, the carrier may float, so that the carrier is mixed and discharged to be difficult to maintain, and separation of the carrier is a problem.

  This invention was made in order to solve the above-mentioned subject, The objective is to obtain the biological waste water treatment equipment which can improve a processing capability, without requiring a new installation space. It is in.

  A biological wastewater treatment apparatus according to the present invention includes a biological reaction tank for biologically treating inflow water, an upstream side wall provided in the biological reaction tank and having a water passage at a lower portion thereof, and the biological reaction tank. A downstream side wall having a water passage in the upper part, an air diffusion chamber partitioned by the upstream side wall and the downstream side wall, and an air diffuser provided at a lower part of the air diffusion chamber. To do.

  In the biological wastewater treatment apparatus according to the present invention, the biological reaction tank is an endless tank.

  In the biological wastewater treatment apparatus according to the present invention, the biological reaction tank has a carrier for holding microorganisms.

  In the biological wastewater treatment apparatus according to the present invention, the biological reaction tank is divided into a plurality of tanks by a partition plate provided with a carrier separator.

  In the present invention, in particular, an endless tank is adopted, so that an upstream side wall having a water passage at the lower part and a downstream side wall having a water passage at the upper part are provided in the biological reaction tank, and the space between the upstream side wall and the downstream side wall is scattered. If a trachea is provided, the following effects can be obtained. That is, since the biological reaction tank is an endless tank, there is no need to return the carrier, and an increase in installation space can be suppressed. In addition, a rotating brush or propeller as an aerator for supplying air that generates a circulating flow that has been used in the conventional oxidation ditch may wear the carrier when the carrier is introduced. In the invention, the water to be treated is agitated by the air lift effect to ensure the flow velocity, so that the carrier is not worn. Furthermore, since a special stirrer is not required only with the air diffusing pipe, maintenance management becomes easy. Moreover, by adding a carrier to the water to be treated, the sedimentation property of sludge is improved, that is, the SVI is lowered. Furthermore, the supply amount of oxygen can be increased by disposing a diffuser tube that generates an air lift effect at a deep position.

  In the present invention, the following specific effects can be obtained by adding a carrier to a single biological reaction tank. That is, since the necessary amount of microorganisms can be ensured by the carrier, the concentration of floating microorganisms outside the carrier can be kept low. Thereby, the solid load at the time of a precipitation process can be lowered | hung and the quality of treated water can be improved, and it becomes possible to increase the amount of treated water. Further, if the concentration of suspended microorganisms is set to the same level as when no carrier is added, the total amount of microorganisms can be increased, so that the load during aerobic biological treatment can be increased. On the other hand, if the load during the aerobic biological treatment is not increased, the quality of the treated water can be improved, and the amount of generated sludge can be reduced. Furthermore, since the nitrifying bacteria having a slow growth rate can be held on the carrier, the nitrification ability can be improved, and the formation of the anaerobic part on the carrier enables aerobic tank denitrification, thereby improving the denitrification ability. In addition, since the carrier separator is provided, it is possible to prevent the carrier from being discharged into the treated water, thereby facilitating maintenance.

  In addition, it is not necessary to return the carrier, and an increase in installation space can be suppressed. Moreover, since sludge residence time can be lengthened, it can respond to removal of hardly decomposable substances such as environmental hormones. Furthermore, adsorption filtration with a carrier becomes possible by aeration, precipitation, and discharge without requiring a storage tank. In summary, by adding a carrier to the water to be treated, the sedimentation of sludge can be improved, so that the load (treatment capacity) can be increased without increasing the capacity (installation space) of the biological reaction tank. be able to.

Embodiment 1 FIG.
FIG. 1 is a horizontal sectional view of a biological wastewater treatment apparatus according to Embodiment 1 for carrying out the present invention, and FIG. 2 is a vertical A sectional view. The biological wastewater treatment apparatus according to the first embodiment includes an endless tank, for example, a biological reaction tank 101 that can be treated by an oxidation ditch (OD) method. Therefore, this biological reaction tank 101 is an endless tank, and the treated water 103 including the carrier 102 is circulated. The biological reaction tank 101 has a planar oval side wall 101a and a flat bottom wall 101b. In the center of the biological reaction tank 101, a partition wall 104 is extended in the longitudinal direction, and the treated water 103 including the carrier 102 is circulated around the partition wall 104. In the biological reaction tank 101, two aeration chambers 105 are provided at positions symmetrical to the partition wall 104.

  Each diffuser chamber 105 has an upstream side wall 106 that connects the partition wall 104 and the side wall 101 a at a right angle on the upstream side of the circulated water 103 to be circulated, and a substantially vertical angle from the bottom wall 101 b on the downstream side of the upstream side wall 106. The partition 104 is partitioned by a downstream side wall 107 that extends upward and connects the partition wall 104 and the side wall 101a at a right angle. A water passage 108 is provided between the lower end of the upstream side wall 106 and the bottom wall 101b, and a water passage 109 is provided at the upper end of the downstream side wall 107 below the water surface. An air diffuser 110 is arranged at the bottom between the upstream side wall 106 and the downstream side wall 107. The inflow water inlet 111 is provided upstream of one of the diffuser chambers 105, the treated water discharge port 112 and the outflow means 113 are provided upstream of the inflow water inlet 111, and a carrier separator 114 is provided at the treated water outlet 113. is there.

  As shown in FIG. 3, when air is discharged from the diffuser tube 110 in the diffuser chamber 105, the water surface 103a of the water to be treated 103 rises due to a so-called air lift effect. Thereby, since the to-be-treated water 103 in the aeration chamber 105 flows over the upper end of the downstream side wall 107, the to-be-treated water 103 flows into the aeration chamber 105 through the water passage 108 below the upstream side wall 106, The treated water 103 containing the carrier 102 circulates in the biological reaction tank 101 as a whole. Therefore, in the seventeenth embodiment, since the water to be treated 103 can be circulated without the need for a conventional stirring blade, when the carrier 102 is used, it is not worn or crushed. . If a haunch (not shown) is provided at the corner on the downstream side wall 107 side in the diffuser chamber 105, the treated water 103 can be circulated more smoothly, and the oxygen dissolution efficiency can be improved. In addition, the bottom wall of the diffuser chamber 105 is made lower than the bottom walls of other biological reaction tanks, and the water depth to the bottom wall of the diffuser chamber 105 is deepened, so that the position where the diffuser pipe 110 is installed is lowered. Thus, the oxygen dissolution efficiency can be improved.

  When using a carrier for holding microorganisms in a biological reaction tank, for example, the carriers 102 and 125 are fixed by attaching microorganisms to the surface or inside, or fixed inclusive of microorganisms, and each side is 5 to 30 mm. It can be a porous material in the shape of a rectangle or a sphere with a diameter of 5 to 30 mm, for example a sponge. Materials of this type of carrier 102, 125 have fluidity, extremely low biodegradability, excellent corrosion resistance and durability, for example, plastic materials such as polyurethane, polyester and polypropylene, natural materials such as activated carbon. A material etc. can be used. However, the shape, size, material, and the like of the carriers 102 and 125 are not limited as long as the carriers 102 and 125 are capable of holding microorganisms by flowing in the water to be treated by stirring or aeration. The addition rate of the carriers 102 and 125 is preferably 20 to 50%.

  Air diffuser is provided for aerobic biological treatment in the biological reaction tank. For example, the air diffusers 110 and 127 enable high-speed aeration by discharging air from the blower at a high speed, and float the carriers 102 and 125 on the water surface. It arrange | positions at the bottom part of the bioreaction tank 101,141 so that the to-be-processed water may generate | occur | produce the swirl | flow to be treated below the surface of the water. The generation state of the swirling flow of the water to be treated can be adjusted by changing the arrangement state of the diffuser tubes 110 and 127. The diffuser tubes 110 and 127 of this type can be a flexible tube made of an elastic material such as rubber and provided with a number of air discharge holes. The flexible tube opens an air discharge hole when air is diffused, and closes the air discharge hole when air is not diffused. If the diffuser pipes 110 and 127 are cylindrical diffuser facilities (OHR type), there are no moving parts in the diffuser pipes 110 and 127. Therefore, the replacement frequency of the diffuser pipes 110 and 127 can be reduced, and the overall maintenance is maintained. Management becomes easy. If air is sent to the plurality of diffuser tubes 110, 127 via an air switch (not shown), air can be intermittently discharged from the plurality of diffuser tubes 110, 127, thereby eliminating dead space. , Processing efficiency is improved. If a plurality of air changers are installed, nitrification and denitrification can be performed while adjusting anoxic and aerobic conditions.

  When a carrier for holding microorganisms is used in the biological reaction tank, for example, the carrier separators 114 and 153 are screens that do not allow the carriers 102 and 125 to pass through. For example, punching metal having a large number of holes smaller than the outer shape of the carriers 102 and 125 (porous Board). As the carrier separators 114 and 153, in addition to the punching metal, a composite made of a mesh, a bar screen, a combination of inclined plates, or a combination of a punching metal and an inclined plate can be used. When a combination of inclined plates is used as the carrier separator 124, for example, as shown in FIG. 6, the descending speed of the carrier 125 in the vicinity of the inclined plate 121c is made larger than the rising speed of the treated water. Thus, the carrier 125 and the treated water are separated to obtain treated water. In this case, the inclination angle of the inclined plate 121c is preferably set to 45 to 90 °, more preferably 60 ° or more, in order to make the carrier 125 settle easily. . Although the hole diameters of the carrier separators 114, 124, and 153 are determined according to the outer shape of the carriers 102 and 125, it is needless to say that the carrier separators 114, 124, and 153 must always be kept in a clogged state.

  When a carrier for holding microorganisms is used in a biological reaction tank, for example, in order to prevent clogging of the carrier separators 114 and 153, a shower for washing them and equipment for vibrating them may be provided. it can. Further, when a combination of inclined plates is used for the carrier separator 139, for example, as shown in FIG. 8, a diffusion tube is provided in the vicinity of the combination of the inclined plates, and a swirling flow is caused by bubbles from the diffusion tube, and the processing is performed. It is preferable to separate the carrier 125 and the treated water by making the swirl speed faster than the water outflow speed. Then, as shown in FIG. 10, when the volume of the biological reaction tank 141 is high and the load is increased, the inside of the biological reaction tank 141 is divided into several parts, and the air diffuser is provided near the carrier separator 139 for each division. In addition to separating the carrier 125 and the treated water, it is possible to replace the carrier 125 by installing an air lift pump or the like.

  In the biological wastewater treatment apparatus of the first embodiment, since microorganisms adhere to the carrier 102 and grow, the sludge retention time is significantly increased compared to the case where floating sludge is drawn out as extra sludge. Therefore, nitrifying bacteria having a low specific growth rate and bacteria capable of degrading persistent substances can be well retained. Moreover, since it is easy to make an oxygen-free state inside the support | carrier 102, denitrification reaction can generate | occur | produce easily and nitrogen can be removed efficiently.

  And conventionally, in order to distribute the carrier uniformly in the biological reaction tank, water to be treated in the biological reaction tank is circulated by a jet-type air diffuser or an air lift pump. In the first embodiment, the carrier 102 is circulated by the flow of the water to be treated 103 generated by the air from the air diffusing pipe 110, and a conventional jet type air diffuser or an air lift pump for returning the carrier becomes unnecessary. And maintenance costs can be reduced. Further, the carrier separator 114 can prevent the carrier 102 from flowing out, and the carrier 102 can be made to flow uniformly in the biological reaction tank 101. Furthermore, when the volume of the biological reaction tank 101 is high and the load is increased, as described in paragraph [0019], the inside of the biological reaction tank 101 is divided into several parts, and an aeration tube is provided for each division. In addition to separating the carrier and treated water, an air lift pump or the like can be installed instead of returning the carrier.

Further, since the necessary amount of microorganisms can be secured by the carrier 102, the concentration of floating microorganisms other than the carrier 102 can be kept low. Therefore, it is possible to improve the quality of the treated water by reducing the solid load of the precipitation portion, and to increase the amount of treated water. Furthermore, if the concentration of airborne microorganisms is set to the same level as when no carrier is added, the load during aerobic organism treatment can be increased. Conversely, if the load during aerobic biological treatment is not increased, the quality of treated water can be improved and the amount of generated sludge can be reduced. That is, by using the carrier 102 in the biological reaction tank 101, it is possible to cope with an increase in load without increasing the volume of the biological reaction tank 101. And sludge sedimentation ability, nitrification ability, and denitrification ability can be improved, and even in a type of operation that removes only BOD, there is room for dissolved oxygen, so it can be expected to remove nitrogen. Further, since an endless tank, for example, the oxidation ditch method is adopted, there is no need to return the carrier 102, and an increase in installation space can be suppressed. Furthermore, since the sludge residence time can be increased, it is possible to cope with the removal of persistent substances such as environmental hormones.

Embodiment 2. FIG.
4 is a horizontal sectional view of a biological waste water treatment apparatus according to Embodiment 2 for carrying out the present invention, and FIG. 5 is a vertical B sectional view. The same reference numerals are given to the same portions as those in FIGS. Therefore, duplicate explanation is omitted. In the first embodiment, two aeration chambers 105 are provided, but in this second embodiment, four aeration chambers 105A are provided on each side of the partition wall 104 in the biological reaction tank 101A. And the space | interval of the upstream side wall 106 and the downstream side wall 107 of each diffuser chamber 105A is made narrower than the case in Embodiment 1, and the diffuser tube 110A is arrange | positioned in each diffuser chamber 105A. Then, the two aeration chambers 105A located on one side of the partition wall 104 are spaced apart. Note that the number of diffuser tubes 110 and the number of diffuser chambers 105A are limited by the size and depth of the biological reaction tank 101A, and the number and position of installation are restricted to the second embodiment if a good circulation flow is obtained. It is not something that can be done. In the second embodiment, the same effect as in the first embodiment can be obtained.

Embodiment 3 FIG.
FIG. 6 is a cross-sectional view of a biological waste water treatment apparatus according to Embodiment 3 for carrying out the present invention. The biological waste water treatment apparatus according to the third embodiment includes a single biological reaction tank 121 having a side wall 121a and a bottom wall 121b. An outer inclined plate 121c extends outward and upward on the upper side wall 121a on the downstream side of the biological reaction tank 121, and an outer vertical plate 101d extends vertically upward from the upper end of the outer inclined plate 121c. The upper end of the outer vertical plate 101d is made to coincide with the height of the other side wall 121a of the biological reaction tank 121. Further, the inner inclined plate 122 extends in the direction opposite to the inclination direction of the outer inclined plate 121c inside the outer inclined plate 121c, and between the lower end of the inner inclined plate 122 and the outer inclined plate 121c. An advection port 123 is provided. These inner inclined plate 121c and outer inclined plate 122 constitute a carrier separator 124. In such a biological reaction tank 121, water to be treated 126 containing a carrier 125 is accommodated. In the biological reaction tank 121, an air diffuser 127 is arranged at a corner on the opposite side of the carrier separator 124. In the biological waste water treatment apparatus in the third embodiment, the treated water 126 is swung in the clockwise direction by the air from the diffuser tube 127, so that the carrier 125 flows downward along the upper inclined plate 122, and the advection port 123 does not flow out.

Embodiment 4 FIG.
FIG. 7 is a cross-sectional view of the biological waste water treatment apparatus according to Embodiment 4 for carrying out the present invention. The same parts as those in FIG. The biological waste water treatment apparatus in the fourth embodiment is basically the same as the biological waste water treatment apparatus in the third embodiment, but instead of the flat inner inclined plate 122 of the third embodiment, an inner side is provided. The inner inclined plate 128 has an inclined portion 128a and an inner vertical portion 128b. Therefore, in the fourth embodiment, the carrier separator 129 is configured by the outer inclined plate 121c and the inner inclined portion 128a of the inner inclined plate 128. In the fourth embodiment, the same effect as in the third embodiment can be obtained.

Embodiment 5. FIG.
FIG. 8 is a cross-sectional view of the biological waste water treatment apparatus according to Embodiment 5 for carrying out the present invention. The same parts as those in FIG. The biological waste water treatment apparatus according to the fifth embodiment includes a single biological reaction tank 131 having a side wall 131a and a bottom wall 131b. Inside this bioreaction tank 131, a partition plate 132 is disposed on the downstream side thereof in parallel with the side wall 131a, and a mud collection box 133 is formed between the downstream side of the partition plate 132 and the side wall 131a. An advection port 134 is provided between the lower end of the partition plate 132 and the bottom wall 131b. In the vicinity of the lower end portion of the partition plate 132, an inner inclined plate 135 and an outer inclined plate 136 that are inclined upwardly away from the partition plate 132 are provided in pairs with respect to the partition plate 132. Further, in the vicinity of the advection port 134, the upstream vertical plate 137 extends substantially perpendicularly from the bottom wall 131b on the upstream side, and the downstream vertical plate 138 extends substantially perpendicularly from the bottom wall 131b on the downstream side. The air diffuser 127 is disposed in the vicinity of the upstream side of the upstream vertical plate 137. Therefore, the carrier separator 139 is constituted by the inclined plates 135 and 136 and the vertical plates 137 and 138.

The carrier separator 139 has a function of transferring the coagulated sludge to the mud collection box 133 and a function of separating the carrier 125 from the sludge. The carrier separator 139 is provided slightly above the diffuser tube 127 so that the carrier 125 can be prevented from adhering to the carrier separator 139 when the air from the diffuser tube 127 rises in the vicinity of the carrier separator 139. is there.
In the fifth embodiment, the same effect as in the third embodiment can be obtained, and the treated water 126 swirls counterclockwise because the air diffusion tube 127 is provided in the vicinity of the carrier separator 139. Therefore, the carrier 125 rises along the inner inclined plate 135 and does not flow out into the mud collection box 133.

Embodiment 6 FIG.
FIG. 9 is a cross-sectional view of a biological waste water treatment apparatus according to Embodiment 6 for carrying out the present invention. The same parts as those in FIG. In the biological wastewater treatment apparatus in the sixth embodiment, the partition plate 132, the inclined plates 135 and 136, and the vertical plates 137 and 138 in the fifth embodiment are vertically inverted, and the advection port 134 is at the upper part. It is located. The air diffuser 127 is arranged at the corner on the opposite side of the carrier separation 139. In the sixth embodiment, the same effect as that of the third embodiment can be obtained, and the treated water 126 swirls clockwise, so that the carrier 125 moves along the upstream vertical plate 137 and the inclined plate 135. It descends and does not flow out to the mud collection box 133 side.

Embodiment 7 FIG.
10 is a cross-sectional view of a biological wastewater treatment apparatus according to Embodiment 7 for carrying out the present invention. The same parts as those in FIG. The biological waste water treatment apparatus in the seventh embodiment is basically the same as that in the fifth embodiment, but the biological reaction tank 141 in the seventh embodiment is the biological reaction tank 131 in the fifth embodiment and has a volume load. The biological reaction tank 141 is partitioned into a biological reaction tank 141A and a biological reaction tank 141B by a partition plate 132 equipped with a carrier separator 139. As in the fifth embodiment, the partition plate 132, the mud collection box 133, the advection port 134, the inclined plates 135 and 136 are the same as those in the fifth embodiment in the vicinity of the side wall 141a on the downstream side of the biological reaction tank 141. , And vertical plates 137, 138 are provided to constitute a carrier separator 139. In addition, a similar partition plate 132, advection port 134, inclined plates 135 and 136, and vertical plates 137 and 138 are provided in the biological reaction tank 141 to constitute a further carrier separator 139. In the biological reaction tank 141, a plurality of diffuser tubes 127 are arranged at the corners. In the seventh embodiment, the same effect as in the fifth embodiment can be obtained, and the treated water 126 can be swung counterclockwise by providing the air diffusion tube 127 in the vicinity of the upstream side of the carrier separator 139. Therefore, the carrier 125 does not flow out to the advection port 134. Furthermore, since the treated water 126 turns clockwise by providing the diffuser tube 127 in the vicinity of the downstream side of the carrier separator 139, the carrier 125 does not flow to the advancing port 134. Further, in the biological reaction tank 141A and the biological reaction tank 141B partitioned by the carrier separator 139 of the biological reaction tank 141, the carrier 125 does not move from the respective sections. Therefore, there is no need to send it back to the upstream side, so there is less energy.

  When the carrier separator 139 uses a combination of inclined plates and is provided with a diffuser tube that generates air in the vicinity thereof, the lowering (upward) speed of the carrier 125 is processed in the vicinity of the carrier separator 139. It becomes larger than the rising (falling) flow rate of water, so that the carrier 125 can flow uniformly into the biological reaction tank 101 and the carrier 125 and treated water can be separated. Further, by using a combination of inclined plates as the carrier separator 139, the suspended sludge in the treated water settles along the inclined plates, and good treated water is obtained.

Embodiment 8 FIG.
FIG. 11 is a cross-sectional view of a biological waste water treatment apparatus according to Embodiment 8 for carrying out the present invention. The same parts as those in FIG. Similarly to the seventh embodiment, this eighth embodiment is preferably used when the biological reaction tank 141 is large. The biological reaction tank 141 is separated from the biological reaction tank 141A and the biological reaction tank by the partition plate 151 provided with the carrier separator 153. It is partitioned into 141B. In the eighth embodiment, the partition plate 151 including the carrier separator 153 instead of the partition plate 132, the mud collecting box 133, the advection port 134, the inclined plates 135 and 136, and the vertical plates 137 and 138 of the seventh embodiment is provided. As an example, a mud collecting box 152 is formed between one partition plate 151 and the side wall 141a. The partition plate 151 is provided with an upper vertical portion 151a, an intermediate inclined portion 151b, and a lower vertical portion 151c. The lower vertical portion 151c is positioned upstream of the upper vertical portion 151a. Further, the carrier separator 153 is configured by forming a large number of holes 151d in the intermediate inclined portion 151b. A single or a plurality of diffuser tubes 127 are arranged below the carrier separator 153, and a diffuser tube 127 is also arranged in the vicinity of the lower vertical portion 151c of the partition plate 151 on the upstream side of the carrier separator 153. It is. In addition, a similar partition plate 151 and carrier separator 153 aeration tube 127 are provided in the biological reaction tank 141. In the eighth embodiment, the same effect as in the seventh embodiment can be obtained, and the air from the air diffuser 127 arranged below the carrier separator 153 can be surely prevented from clogging the carrier separator 153. can do. Further, in the biological reaction tank 141A and the biological reaction tank 141B partitioned by the partition plate 151 having the carrier separator 153 of the biological reaction tank 141, the carrier 125 does not move from the respective sections. It is not necessary to return the carrier 125 to the upstream side using power, and the energy can be reduced. Moreover, it is possible to satisfactorily retain, for example, nitrifying bacteria having a small specific growth rate and bacteria that degrade hardly-degradable substances, which are suitable for each compartment.

  The endless tank in Embodiment 1 shown in FIGS. 1 to 3, for example, the biological reaction tank 101 of the oxidation ditch method, the amount of treated water was 1,000 m 3 / day, and the addition rate of the carrier 102 was 20%. As other implementation conditions, the carrier retained sludge amount is 15,000 mg / L, the capacity of the biological reaction tank 101 is 1,000 m3, the suspended MLSS concentration is 3,153 mg / L, and the BOD-SS load is 0.05 kg-BOD / kg. -SS · day, HRT was 17.4 hours, the required oxygen amount was 449 kg-O2 / day, and the output of the blower was 15 kW (1 unit). Then, 46 ultrafine air cylinder type (Newflex M type) diffuser tubes 110 were used, and the amount of air per one was 350 L / min. In the first embodiment, the diffuser tubes 110 are installed at a plurality of locations so as to produce an air lift effect, and a circulation flow having a speed of approximately 0.1 m / s (10 cm / s) is maintained in the entire biological reaction tank 101. did it. In addition, the amount of treated water could be increased by about 380 m 3 / day without increasing the BOD-SS load with the same tank capacity, and the concentration of activated sludge could be kept stable. In the fifth embodiment, since the water to be treated 103 is circulated by the air lift effect, a special stirrer is not required and the maintenance management becomes easy.

  The endless tank in Embodiment 2 shown in FIGS. 4 and 5, for example, the biological reaction tank 101A of the oxidation ditch method, the amount of treated water was 1,000 m 3 / day, and the addition rate of the carrier 102 was 30%. As other implementation conditions, the carrier holding sludge amount is 15,000 mg / L, the capacity of the biological reaction tank 101A is 1,000 m3, the suspended MLSS concentration is 2,500 mg / L, and the BOD-SS load is 0.05 kg-BOD / kg. -SS · day, HRT was 16 hours, required oxygen amount was 488 kg-O2 / day, and blower output was 18.5 kW (1 unit). Then, 50 ultrafine air cylinder type (Newflex M type) diffuser tubes 110 were used, and the amount of air per one was 350 L / min. Also in the second embodiment, it is possible to install the diffuser tubes 110 at a plurality of locations so as to produce an air lift effect, and to maintain a circulating flow with a speed of approximately 0.1 m / s (10 cm / s) in the entire biological reaction tank 101A. did it. In addition, the amount of treated water could be increased by about 500 m 3 / day without increasing the BOD-SS load with the same tank capacity, and the concentration of activated sludge could be kept stable. Also in the second embodiment, since the water to be treated 103 is circulated by the air lift effect, a special stirrer is not required and the maintenance management becomes easy.

It is a horizontal sectional view of the biological waste water treatment apparatus according to Embodiment 1 of the present invention. It is vertical A sectional drawing of the biological waste water treatment apparatus by Embodiment 1 of this invention. FIG. 3 is a partially enlarged view of FIG. 2. It is a horizontal sectional view of the biological waste water treatment apparatus according to Embodiment 2 of the present invention. It is vertical B sectional drawing of the biological waste water treatment equipment by Embodiment 2 of this invention. It is sectional drawing of the biological waste water treatment apparatus by Embodiment 3 of this invention. It is sectional drawing of the biological waste water treatment apparatus by Embodiment 4 of this invention. It is sectional drawing of the biological waste water treatment apparatus by Embodiment 5 of this invention. It is sectional drawing of the biological waste water treatment apparatus by Embodiment 6 of this invention. It is sectional drawing of the biological waste water treatment apparatus by Embodiment 7 of this invention. It is sectional drawing of the biological waste water treatment apparatus by Embodiment 8 of this invention.

Explanation of symbols

101, 101A, 121, 131, 141, 141A, 141B Bioreactor 103, 126 Water to be treated 102, 125 Carrier 110, 110A, 127 Air diffuser 133, 152 Mud collection box 132, 151 Partition plate 123, 134 Advection port 105 Aeration chamber 106 Upstream side wall 107 Downstream side walls 108 and 109 Water passage 110 Aeration pipe (aeration means)
114, 124, 129, 139, 153 Carrier separator

Claims (4)

A biological reactor for biologically treating the incoming water;
An upstream side wall provided in the biological reaction tank and having a water passage at the bottom;
A downstream side wall provided in the biological reaction tank and having a water passage at the top;
A diffuser chamber partitioned by the upstream side wall and the downstream side wall;
A biological wastewater treatment apparatus comprising a diffuser provided in a lower portion of the diffuser chamber. The biological wastewater treatment apparatus according to claim 1, wherein the biological reaction tank is an endless tank. The biological wastewater treatment apparatus according to claim 1 or 2, wherein a carrier for holding microorganisms is present in the biological reaction tank. The biological reaction tank is
The biological wastewater treatment apparatus according to claim 3, wherein the biological wastewater treatment apparatus is partitioned into a plurality of tanks by a partition plate provided with a carrier separator.

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