JPH0131354Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a compact treatment device for treating wastewater with activated sludge deposited on a carrier. This invention relates to a fluidized carrier biological treatment device.

[Conventional technology]

Conventionally, methods of treating wastewater using activated sludge have been widely used, but various proposals have been made regarding the treatment methods and equipment, and many attempts have been made to increase the BOD volumetric load. Activated sludge is often deposited on powdered materials such as activated carbon, coke, and calcium carbonate as carriers in order to improve the efficiency of wastewater treatment.

[Problem that the invention attempts to solve]

However, even if wastewater can be efficiently treated by depositing activated sludge on a carrier, the equipment must also be efficient. In other words, a typical cylindrical tank-type device has a small throughput compared to its space;
In addition, there is a limit to the capacity in order to treat a large amount of wastewater, and furthermore, it is not easy to expand the capacity.

[Means for solving problems]

From this point of view, the inventors of the present invention have conducted intensive studies, and found that by eliminating the cylindrical tank-type treatment tank and adopting a rectangular cylindrical tank with a rectangular or square top and tapered side walls, an extremely efficient and efficient treatment method has been developed. We have devised a compact unit-type treatment device that can treat large amounts of wastewater even if the amount of wastewater increases by connecting them in parallel or in series. That is, the present invention provides a unit-type fluidized carrier biological treatment device in which activated sludge deposited on carrier particles is circulated around an internal partition wall while blowing air and brought into contact with inflowing wastewater. The treatment equipment consists of a treatment tank for circulating carriers and wastewater, and a sedimentation separation section for separating the sludge and carriers, which are installed on both opposing sides of the treatment tank overflow, and the treatment tank has an upper cross section. has a rectangular or square shape, the two opposite side walls that are perpendicular to the overflow side walls on both sides of the rectangle fall vertically, and the lower portions of the overflow side walls are both sloped. None, the processing tank has two partition walls capable of forming a divisible air lift section in the center, and the inclined side wall forms an angle of 50° or more for the carriers floating through the air lift section to circulate and settle. This is a unit-type fluidized carrier biological treatment device, which has a tapered shape and is characterized in that each sedimentation separation section has two or more small partition walls arranged at appropriate intervals.

〔Example〕

An embodiment of the device of the present invention will be described with reference to the drawings.

Figure 1 shows an example in which the upper cross section is rectangular, and A is its plan view.The side walls, whose long sides are perpendicular to the overflow side walls 2 ₁ and 2 ₂ on both sides, stand vertically. Downward, overflow side wall 2
The lower portions 3 ₁ and 3 ₂ of ₁ and 2 ₂ both have an inclined shape. This is evident in Figure 1B. That is, wastewater W flows in from the lower part of the treatment tank 1, and the air A flows through the partition wall 4 ₁ in the center of the treatment tank.
4 becomes an air lift formed by ₂ , and floats while coming into contact with the carrier particles on which activated sludge is deposited. After floating, as shown by the arrow in the figure, the circulating fluid moves downward through the processing tank until it reaches the bottom, where it becomes an air lift again, where it is repeatedly circulated and cleaned. The carrier particles also circulate together with the circulating liquid, but because the lower portions 3 ₁ , 3 ₂ of the side walls 2 ₁ , 2 ₂ on both sides of the processing tank are tapered at an angle of 50° or more, they do not accumulate on the side walls. It is circulated to If the angle is less than 50°, part of the carrier particles that are not accompanied by the circulating fluid will remain on the side wall, creating an anaerobic state and hindering aerobic digestion of microorganisms, which is not preferable.

The location of the partition walls 4 ₁ and 4 ₂ is approximately in the center of the treatment tank, but the distance between the two partition walls is not constant depending on the amount of waste water, air amount, BOD load of waste water, BOD concentration, residence time, etc. Letting B be the interval between the partition walls and L be the distance between both side walls, they are appropriately selected so as to satisfy 1/2L≧B>0.

The air lift section formed by the partition walls 4 ₁ and 4 ₂ is such that the width of the processing tank is one section as shown in FIG. 1A, or the air lift section is divided into three sections as shown in FIG. 2. But that's fine. If the amount of air is the same when divided, the air lift effect is greater because the air does not diffuse and rises in a concentrated manner within a narrow section.

Next, the small partition walls 5 ₁ , 5 ₂ ′,...
...and 5 ₂ , 5 ₂ '... will be explained.

The treated wastewater passes through the gaps at the bottom of the small partitions 5 ₁ , 5 ₁ ′, . . . and _{5 2} , 5 _{2 ′} , . Eventually, the sludge overflows and is discharged outside the system, but at this time, the carrier and the sludge separated from the carrier are separated in a settling section provided before the overflows 2 ₁ and 2 ₂ . In other words, the settling speed of the carrier depends on the carrier particle size, porosity, apparent specific gravity and amount of adhered sludge, but it is generally 5 to 15 cm/min, so the carrier does not flow out of the system and the sludge In order to allow only the treated wastewater to flow out together with the treated wastewater, the area between the small partition walls 5 ₁ , 5 ₂ and the overflow parts 2 ₁ , 2 ₂ must not be affected by turbulent flow due to aeration in the treatment tank, and the water in this area must be The rate of rise must be smaller than the rate of sedimentation. The simplest means for realizing this are the small partition walls 5 ₁ , 5 ₂ and the overflow parts 2 ₁ , 2 _{2 .}
The distance between the small partition walls 5 ₁ ,
If only one 5 ₂ is provided, it will be affected by turbulent flow due to aeration, so to avoid this effect, the gap between the lower part of the small partition walls 5 ₁ and 5 ₂ and the side walls 3 ₁ and 3 ₂ should be made small. However, if this gap is made too small, the rising speed of the water will increase, and the carrier will float in the treated water reservoirs 6 ₁ and 6 ₂ due to the effect of turbulent flow due to aeration, making sedimentation separation impossible. In addition, if this gap is made larger, the effect of preventing turbulent flow by the small partition walls 5 ₁ and 5 ₂ will be reduced, and the carrier will be washed away.As a way to prevent these phenomena, the small partition walls 5 ₁ and 5 ₂ and the overflow part 2 ₁ , 2 There is a way to make the gap between ₂ large enough, but this requires a fairly wide gap, so
Even if it could be implemented, it would be economically disadvantageous for the equipment.

Therefore, these problems can be solved by providing two small partition walls 5 ₁ and 5 ₂ each. In this case, the turbulent flow caused by aeration is considerably attenuated by the first small partition walls 5 ₁ and 5 ₂ , and by providing the second small partition walls 5 ₁ ′ and 5 ₂ ′, sedimentation and separation of the carrier becomes possible.
In addition, if the effect of turbulence is large and sedimentation separation is insufficient even with the two small partition walls 5 ₁ , 5 ₁ and 5 ₂ , 5 ₂ ′, one or more small partition walls 5 ₁ ″, . . . and 5 ₂ ″…
By providing ..., the distance between the small partition wall and the overflow part can be kept small, and the sedimentation and separation of the carrier can be carried out efficiently.

The circulating carrier particles fill approximately 10% of the volume of the treatment tank. Also, the amount of air blown is determined by the amount of air that is blown into the wastewater to be treated.
Select and determine the larger of the BOD and the amount required to flow the carrier particles by airlift.

On the other hand, the wastewater to be treated may flow in from the upper or lower part of the treatment tank.

The processing apparatus of the present invention is easiest to operate when it has a capacity of 2 to 60 m ³ (for example, a rectangular top surface of 5 m x 1.5 m and a height of 4 to 5 m), and a small capacity smaller than this becomes rather complicated in actual operation. In addition, if a larger capacity is required, at least within each unit, three units of this unit type processing equipment can be installed in series or the required number of units can be added in parallel as shown in Figure 3. Air distribution and dispersion can be easily and uniformly carried out, and overflow of treated water can also be made uniform, so operation is easy and a large amount of wastewater can be treated.

[Results of the idea]

The processing device of the present invention may be made of iron or concrete, and in particular, if it is made of concrete, the manufacturing cost will be extremely low. By setting a constant capacity, this device forms an air lift within the range of the air amount according to the inflow amount of waste water and the required amount of air, which differ depending on the type of waste water, and the number and spacing of small partition walls can be adjusted. If appropriate selection is made, wastewater can be treated economically. Furthermore, if the capacity of the device is insufficient, it can be solved by adding the necessary number of units.In this case, the shape of the device is rectangular or square on the top, making it convenient to add units, so it can be installed compactly, so the installation location does not require a large area. It has the advantage of not being necessary.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the unit type fluidized carrier biological treatment apparatus of the present invention, in which A is a plan view and B is a longitudinal sectional view. FIG. 2 is a plan view of an embodiment in which the air lift section is divided, and FIG. 3 is a plan view of a case in which a unit type processing apparatus of the present invention is added. DESCRIPTION OF SYMBOLS 1...Processing tank, ₂₁ , ₂₂ ...Overflow part (side wall), ₃₁ , ₃₂ ...Tapered part, _{41,42 ...}
Partition wall, 5 ₁ , 5 ₁ ′, 5 ₁ ″, ... 5 ₂ , 5 ₂ ′, 5 ₂ ″...
Small partition wall, 6 ₁ , 6 ₂ ... treated water reservoir, 7 ... carrier particles, A ... air, W ... wastewater.

Claims (1)

[Scope of utility model registration request] In a unit-type fluidized carrier biological treatment equipment, activated sludge deposited on carrier particles is circulated around an internal partition wall while blowing air, and brought into contact with inflowing wastewater for treatment. and a treatment tank for circulating wastewater, and a sedimentation separation section for separating sludge and carriers provided on opposite sides of the overflow side of the treatment tank, and the treatment tank has a rectangular or square upper cross section. The two opposite side walls that are perpendicular to the overflow side walls on both sides of the rectangle fall vertically, and the lower portions of the overflow side walls are both sloped. The tank has two partition walls capable of forming a divisible air lift section in the center thereof, and the inclined side wall has a tapered shape having an angle of 50° or more for the carriers floating through the air lift section to circulate and settle. None, a unit type fluid carrier biological treatment device, characterized in that each sedimentation separation section has two or more small partition walls arranged at appropriate intervals.