JPS63291693A - Mobile bed waste water treatment device - Google Patents

Abstract

PURPOSE:To metabolize a fine particle-filled bed by pushing up fine particles with air through a center rising pipe provided in a treatment tank with the simultaneous separation of microbes sticking to fine particles and performing separation and removal of the separated microbes after precipitation of the fine particles to a filled bed. CONSTITUTION:Waste water to be treated is supplied from below a filled bed 2 of fine particles to which aerobic microbes stick and treated waste water is extracted from the top. The above process is performed by a treatment tank 1 which consists of components such as a center rising pipe 8 a charging layer 2 surrounding the former, and a statically placed separator 9. Below the rising pipe 8, an air injection pipe having a smaller cross section area than the inner cross-section area of the rising pipe is provided with its mouth opened upward, and a suspension of waste water and fine particles is allowed to rise mainly by an ejector action generated by air supply. Also in the statically placed separator 9, the fine particles are allowed to precipitate and fall on the upper surface of the filled bed 2. After this, a top suspension containing a microbe flock separated by friction wash in the pipe 8 is extracted out of the treatment tank 1 separately from the treated waste water, and the air change to the pipe 8 is adjusted for adjustment of a surplus sludge separation amount.

Description

[Detailed Description of the Invention] Industrial Application Field: The present invention relates to a moving bed type sewage treatment device, specifically, a packed bed is created by attaching microorganisms to a filler such as silica sand, and the sewage to be treated is entirely disposed of from below to above. This relates to improvements in equipment for aerobic biological decomposition of M solids in wastewater.
.

Conventional technology: Simple aeration method, fixed bed, moving 4 & fluidized bed aeration method, and rotating disk method are methods for decomposing wastewater such as sewage, domestic wastewater, and industrial wastewater by aerobic biological treatment. etc. are being questioned.

Furthermore, in recent years, a treatment tank has been filled with relatively high specific gravity and inexpensive particles such as sand, sewage is flowed into the bottom of the packed bed, and air is blown in from the bottom of the packed bed, causing microorganisms attached to the particles to The biological decomposition method is aerobic one bed (fixed bed)
It has been developed under the name.

Problems we are trying to solve: Aerobic microorganisms (including Elephantia genus Hosoura, etc.)

) generally separates the polynaracalide to form flocs. When this is attached to a carrier (filling material), if the agitation is too vigorous, desorption will occur, microorganisms will be washed away, and biodegradation will be difficult to occur.In addition, if the agitation is too little, flocs will grow. This causes clogging of the packed bed.

Generally, aerobic microorganisms account for approximately 20 to 60% of processed organic matter.
It is known that sludge grows excessively (the multiplied portion is called surplus sludge), and steady operation cannot be maintained unless the surplus sludge is removed.

With the method of attaching microorganisms to carrier particles, excessive flow of microorganisms and clogging of the filler due to excess sludge occur! It can be said that it is important to prevent this from happening when using a box.

Means for solving the problem: In the present invention, in order to separate unnecessary surplus sludge (excess microbial flocs) and to perform metabolism of the packed bed of carrier fine particles to which microorganisms are attached, a central Install a riser pipe, force the air to push up the particles, simultaneously peel off the microorganisms attached to the particles, let the particles fall into the packed bed, set up a stationary section Mt16, and read the separated microorganisms in the upper layer. The suspension is separated off.

That is, the present invention provides: In a moving bed sewage treatment device having a treatment tank, in which sewage to be treated is supplied from the lower part of a packed bed of carrier fine particles to which aerobic microorganisms are attached, and treated sewage is taken out from the upper part: The treatment tank is roughly divided into a nearly vertical central riser pipe, a packed bed part surrounding the central riser pipe with an annular horizontal cross section, and a stationary separation part located at the upper part of the center riser pipe; By opening the air blowing nozzle upward and supplying air with a cross section smaller than its internal cross-sectional area, the S suspension consisting of sewage and fine particles rises inside the pipe mainly due to the ejector action; The fine particles are allowed to settle down and fall onto the upper surface of the packed bed, and the upper layer suspension containing microbial flocs separated by the original flow in the central rising pipe is collected outside the treatment tank separately from the treated wastewater; This fluidized bed sewage treatment apparatus is characterized in that excess sludge separation t is adjusted by adjusting the amount of air sent to the rising g.

In order to decompose oxygen into the sewage to be treated, it is best to install a bath decomposition tank upstream of the treatment tank, but in some cases, air may be introduced into the treatment tank, for example, at the bottom of the packed bed, to eliminate air bubbles. It's okay to change it.

Action: The mechanism by which the suspension rises in the central riser is much stronger than the normal air lift action. That is,
Since the blown air blows upward, it can be used as a type of pump to forcibly transport the S turbid liquid in conjunction with the ejector structure (the law of conservation of momentum is used in the ejector design calculations). This is well known.

). Most of the added energy is consumed by friction inside the liquid and between the liquid and the pipe wall;
Current action occurs, and the microbial flocs attached to the particles are peeled off. At this time, fine particles with a large amount of microbial flocs attached tend to peel off. Furthermore, by increasing or decreasing the excess amount of air (blow air pressure), the liquid flow rate and original flow level can be increased or decreased (adjusted).

The wastewater to be treated is supplied to the lower part of the particulate packed bed, and as it rises through the particulate bed, it undergoes biological decomposition by attached political organisms. This packed bed can also be called a fluidized bed, but
Since the lower suspension is withdrawn to the central riser 2, the moving bed can be said to be a fluidized bed type moving bed.

The treated wastewater that passes through the 44th layer upwards overflows the overflow weir and is discharged outside the system.

Example: In FIG. 1, the upright cylindrical process f! (1) is, for example, a bottomed cylindrical structure with an inner diameter of about 80011 iJ, and is filled with a filler, for example, silica sand with a particle size of about 0.8 to 1.2 nm, to form a packed bed (2). The sewage to be treated is stored in the sewage tank (3)
The oxygen-containing gas (e.g., air) is blown into the blower (6) in the oxygen dissolution tank (5) to dissolve the oxygen, and then the oxygen is dissolved by the pump (7). ,
charged at the bottom of the treatment layer (instead of the pump (7)
The decomposition tank may be provided at a high location and sewage to be treated with oxygen dissolved therein may be charged using potential energy. ). Processing - In the center of (1), a central riser f(8) is installed, and compressed air is blown into f(8) by a compressor (8y) to perform an ejector action (unfortunately). The filling in the packed bed is raised mainly by air lift action.The outlet pressure of the compressor is higher than that of normal F-soft, for example, the blowing pressure is about 0.5~S
ky/d is desirable, and is usually about 3 kg/d or more (this pressure is consumed to overcome the frictional force with the pipe wall and to stir the liquid containing the filler). When the liquid containing the filler rises through the central riser, flocs of fine particles adhering to the filler peel off from the filler.

The packed bed in the treatment tank (1) is sucked up from the bottom (1a) into the central riser pipe (8), and is raised to the upper end (8).
a], falls down the annular cylinder (9), and reaches the upper surface of the packed bed (2a) through the distributor αQ. The packed bed (2) is a moving bed with some fluidity. The annular cylinder (9) is provided with a protrusion (9a) so that the liquid containing the filler falling down this part is agitated. In the upper swollen part (9b) of the annular cylinder (9), the flow rate of the liquid containing the filler decreases, so solid-liquid separation occurs, forming peeled At11 bodies (in the case of activated sludge, polysaccharide flocs are formed). are doing.

) The upper layer liquid containing 1f passes through the overflow '1f (11) and enters the concentration 1@. Here, the supernatant liquid and the lower layer of thickened sludge (one body)
The 0-thickened sludge, which is roughly divided into 1 and 2, is discharged from the pipe (12a), and the upper liquid d overflows and is returned to the sewage tank (3). The treated fr liquid is discharged out of the outlet system.

11! Elementary dissolution・4 (5) 1r, instead of installing separately,
As shown in Figure 2, air (oxygen-containing gas in a broad sense) may be blown directly into the lower part of the treatment tank (1) (with
(a) corresponds to the blower (6) in FIG. 1). It should be noted that in the case of the configuration shown in FIG. 2, unlike the configuration shown in FIG. 1, an oxygen dissolution tank is not used.

With the device configured as shown in Figure 1, the volume of the particle packed bed was set to 0°811.
/ The average BOD is used as wastewater to be treated.
= 186Mg/L S S =48q/l, NH;
LM nitrogen = 41jf# sewage (above the first settling tank of activated sludge equipment (iH) k 9.6 d/day,
Q velocity f The inflow o 4 treated water is in the oxygen dissolution tank (5),
0286 Arrogance Make sure to bring the gas into liquid contact with enriched air so that the amount of available oxygen is 7.0 to 8.0 l/j. 2 treatment tanks (1
The inner diameter of > is 3QOag, and the inner diameter d of the central rising pipe is 22m.
g, the height is 2.58m. The filling material used has a typical diameter of approximately 0.
．． With silica sand of 8 to 1.2111, the filling M1 forms a liquid-solid moving bed, ascends through the central riser and descends in the packed bed section, so it can also be called a fluidized moving bed or moving fluidized bed.

Now, the outlet of the compressor <81 jE purple 7kq/d
1, the 4 turbidity rising up the central riser is about 8.8 (1/mte, in suspension i 1 Kt) 0.5 # -t'.

An example of the experimental results for the remaining 20 days after 80 days of continuous operation under these conditions, excluding the initial transient state of 10 days, shows that the average effluent water quality was BOD = 12W/Ic fluctuation 8. 8-14.8 cape/4), S S = 11.6
da/l (Rsh1鴫9.8~ta, 9v#), NH;
m Nitrogen J 8.4 q/g <changed 4.9 to 10.6
da/g), and stable and good results were obtained.

Effects of the invention: The advantages of the moving bed wastewater burial device of the present invention compared to the conventional S#L are that the packed bed of fine particles to which aerobic microorganisms are attached is
Since it is a type I moving bed, the suspension in the packed bed is well stirred: The suspension at the bottom of the packed bed is constantly pumped up into the central riser, so there is a turbulent flow effect. Particles in the packed bed to which prolific microbial flocs are attached are preferentially peeled off, and it is difficult for fine particles rich in floc gold to exist in the packed bed.

Sky A*Cg flowing into the lower part of the central riser pipe! It is possible to adjust the microbial removal layer (sludge layer to be removed as surplus sludge) within the same pipe by increasing or decreasing the atmospheric pressure.

[Brief explanation of the drawing]

FIG. 1 is a schematic factory diagram illustrating the structure of the apparatus of the present invention. Figure @2 is a schematic structural diagram specifically illustrating the lower structure of the processing tank regarding a modification of the present invention in which air is blown into the processing tank and no oxygen dissolving tank is used. (1)...Treatment tank, (2)...Filled bed, (3)...
・Sewage tank, (5)...Oxygen solution #fl, (8)...
・Central rising pipe, (9)...annular tube, 4...distributor,
(6)... Overflow pipe, (to)... Treated liquid outlet. Processing 51 Main Case Figure 1

Claims (1)

[Scope of Claims] 1. In a moving bed active water treatment device having a treatment tank which supplies wastewater to be treated from the lower part of a packed bed of fine particles to which aerobic microorganisms are attached and takes out the treated wastewater from the upper part: The treatment tank has: It is roughly divided into an almost vertical central riser, a filling layer surrounding it with an annular horizontal section, and a stationary separation located at the top of the center riser; An air blowing pipe with a cross-sectional area smaller than the area is opened upward, and air is supplied to cause a suspension consisting of sewage and particulates to rise inside the pipe mainly due to the ejector action; in the static separation section, the particulates are allowed to settle and descend. The upper layer suspension containing microbial flocs, which has been separated by abrasion in the central riser pipe, is taken out of the treatment tank separately from the treated wastewater and the amount of air sent to the central riser pipe. A moving bed sewage treatment device characterized in that the amount of excess sludge separated is adjusted by adjusting the amount of excess sludge separated. 2. The moving bed sewage treatment device according to claim 1, wherein oxygen is dissolved before the sewage to be treated is supplied to the treatment tank. 3. The moving bed sewage treatment apparatus according to claim 1, wherein the oxygen supply is carried out in the treatment tank in the form of bubbling air.