JPH0649199B2 - Human waste system treatment equipment - Google Patents

Description

The present invention relates to a treatment device for so-called human waste sewage such as human waste, septic tank sludge, and a mixed liquid of human sewage and septic tank sludge. The present invention relates to a treatment device capable of biological treatment and highly purified.

[Conventional technology]

Human waste water has been conventionally purified by biological treatment or other treatment. Fig. 2 shows the most advanced human waste treatment device at present among the treatments.

The treatment apparatus shown in FIG. 2 is called the UF membrane separator for human waste, and is the newest human waste treatment apparatus that is currently receiving a great deal of attention because the separation of SS is always perfect.

In the treatment apparatus shown in FIG. 2, the human waste sewage 1 and the gray water 8 are first subjected to biological nitrification and denitrification treatment in the biological treatment layer 2, and then the total amount of the activated sludge slurry 6 flowing out from this biological treatment tank is ultrafiltered. The basis is the welfare for solid-liquid separation by the (UF) membrane separation device 25 and returning the separated activated sludge 26 to the biological treatment tank. The SS zero UF membrane permeate is F
After the e ³⁺ coagulant is added and COD, chromaticity, and PO ₄ ³⁻ are coagulated, the coagulation block 17 is completely separated by the second UF membrane separation device 15 to become clear permeated water 16. .

That is, the treatment apparatus shown in FIG. 2 is characterized by applying the UF membrane to two steps, one for separating activated sludge and the other for separating flocculation flocs.

[Problems to be Solved by the Invention]

However, even with a processing apparatus using this UF membrane separation device, the following problems have not been solved yet, and further excellent development is eagerly desired by users.

In order to solid-liquid separate highly viscous sludge in the UF membrane separator, the equipment cost is high, and the inside of the UF membrane module is 2 to 3 m.
A practical permeation flux (Flux) cannot be obtained without passing the liquid to be separated at a high flow rate of / sec.
As a result, there is a serious drawback in that the required head size and power of the pump are very large, in combination with the high head loss in the UF membrane module.

Since the UF membrane separator is applied to both the steps for activated sludge separation and coagulation separation, energy consumption and equipment cost will be further doubled.

Since the entire amount of activated sludge slurry flowing out from the biological treatment tank for biological nitrification and denitrification is supplied to the UF membrane to perform solid-liquid separation of the activated sludge, the required area for the UF membrane is large and the equipment cost is high. Inevitably, there is a drawback that the power cost and equipment cost of the pump for supplying the activated sludge slurry to the UF membrane are large.

Since there are multiple separation steps using the UF membrane, the chemical cleaning operation using NaOCl or the like for preventing membrane contamination becomes complicated.

Since both the surplus activated sludge and the coagulated sludge discharged from the two UF membrane separators are dehydrated, a large amount of a dehydration aid (such as carbon polymer) is required, which further increases the operating cost.

The replacement cost of the membrane is high because the service life of the UF membrane is only 2-3 years. Since the membrane area becomes large in the conventional apparatus in which the UF membrane separation process is provided in two stages, the membrane replacement cost is considerably high.

Since factors (1) to (3) above overlap, the urine-based sewage treatment apparatus using the above-mentioned UF membrane separation apparatus has a facility cost and an operation and maintenance cost before the UF membrane treatment method appears (for example, a treatment apparatus). Rather than a low-dilution oxidation treatment device), the cost burden increases for consumers.

In other words, the conventional UF membrane separation method has introduced a positive effect of improving the stability of the separation efficiency of SS by introducing the advanced technology of ultrafiltration for human waste treatment, but on the other hand, the equipment of the entire urine treatment device It caused a serious negative effect of increasing costs.

The present invention significantly improves the above-mentioned drawbacks of the UF membrane separation method, significantly reduces the equipment cost and operating cost of the night soil treatment device, and secures a high treatment efficiency as in the conventional UF membrane separation method. The challenge is to develop a treatment device that can stably obtain good treated water quality.

That is, an object of the present invention is to obtain high treatment efficiency and good water quality without using a UF membrane separation device as much as possible.

[Means for Solving the Problems]

The present invention provides a first biological treatment tank for biologically nitrifying and denitrifying human waste sewage, and a second biological treatment tank for biologically treating the activated sludge slurry flowing out from the biological treatment tank. A separation device for adding a polymer flocculant to a part of the activated sludge slurry in the first biological treatment tank or flowing out from the same tank to screen-separate the produced flocs is provided, and the separation sludge from the separation device is provided. To the first biological treatment tank and the second separation liquid from the separation device.
And a solid-liquid separator for coagulating and separating the effluent from the second biological treatment tank by adding an inorganic coagulant to the effluent from the second biological treatment tank. It is a processing device.

In this treatment apparatus, various types of wastewater (bakery car wash sewage, floor wash sewage, sludge dewatered separated water, etc.) generated along with the operation of the human waste treatment facility may be supplied to the second biological treatment tank. In the prior art, this gray water must be supplied to the first biological treatment tank.

Further, as the solid-liquid separation device for adding the inorganic coagulant to the effluent flowing out from the second biological treatment tank to separate the aggregated product, a UF membrane separation device or an MF membrane separation device, or a sedimentation separation device is used. be able to.

〔Example〕

The present invention will be specifically described below with reference to examples. However,
The invention is not limited to the examples.

Example 1 FIG. 1 shows a mode of this example.

The depleted urine 1 is supplied to a first biological treatment tank 2 for biological nitrification and denitrification. As the type of the treatment tank 2, any known type such as a nitrification solution circulation type, a step type, a one-tank type may be adopted. The illustrated example is a single tank type. Reference numeral 3 is an air race and a circulation pump for stirring in the tank, 4 is an ejector, and 5 is air to be sucked.

The human waste 1 is subjected to nitrification and denitrification treatment without dilution in the biological treatment tank 2, and then most of the activated sludge slurry 6 flowing out from the same tank 2 is discharged.
(MLSS 8000-15000 mg / about) is made to flow into the 2nd biological treatment tank 7 following from a flow path.

On the other hand, a part 18 of the activated sludge is extracted from the biological treatment tank 2, and a polymer flocculant is injected into the activated sludge from a chemical injection device 19. As the polymer flocculant, a cation type or a cation type anion type is used in combination, or with these,
You may use together with a 1-type flocculant. The activated sludge slurry forms a block in the stirring tank 20 by adding a polymer flocculant,
The screen separating device 21 separates the blocks.
The screen separating device 21 is preferably a wet wire type slanting type or rotating drum type having an opening of about 0.5 to 1.0 mm. In this example, a slanted wedge wire screen was used. The separation flocks 22 are recycled to maintain the concentration of activated sludge in the first biological treatment tank 2 at a predetermined value. SS separated by the screen separation device 21
The liquid 23 containing almost no is mixed with the activated sludge slurry 6 flowing out from the biological treatment tank 2 and sent to the second biological treatment tank 7.

The waste water 8 generated from the site is made to flow into the second biological treatment tank 7. The biological treatment tank 7 has a function of biologically removing a small amount of nitrogen content remaining in the mixed liquid of the activated sludge slurry 6 and the screen separation liquid 23, BOD and nitrogen components in the gray water 8. The type of the biological treatment tank 7 can be any type capable of performing nitrification and denitrification, but in this embodiment, the air 9 is turned on and off, and anaerobic and aerobic conditions are alternately set in the tank. A one tank type was used.

Then, the activated sludge slurry 10 flowing out from the biological treatment tank 7 is guided to the storage tank 11, and the inorganic flocculant 12 and the alkaline agent 13 for adjusting the flocculation pH 13 are added and flocculated. As the inorganic coagulant, FeCl ₃ , polyferric nitrate, PAC, Alum, etc. can be used, and as the alkaline agent, NaOH, Ca
OH, Mg (OH) ₂ or the like can be used. The coagulated slurry is supplied into the UF membrane separation device 15 by the pump 14, the coagulated flocs are completely filtered and separated, and separated into separated water 16 and separated sludge 17. This solid-liquid separation can be performed not by the UF membrane separation device but by an MF membrane separation device, sedimentation separation, floating separation, or centrifugation. The separated water 16 can be discharged as it is as a highly-treated water of night sewage, but when it is further treated, it is discharged through an activated carbon adsorber 24.

On the other hand, most of the sludge separated by the UF membrane separation device 15 is circulated to the storage tank 11 as the circulation sludge 17 ′, and the rest is supplied to the sludge dewatering step (not shown) as the excess sludge 17 ″ for dehydration treatment. It

In addition, in the example, an example in which a chemical such as an inorganic coagulant was added to the activated sludge slurry flowing out from the second biological treatment tank (biological treatment tank 7) was obtained, but the activated sludge slurry was obtained by solid-liquid separation. It may be added to the separated water and treated.

〔The invention's effect〕

 The processing device of the present invention has the following effects.

Since it is not necessary to install a UF membrane separation device for returning activated sludge after the first biological treatment tank, operating costs,
Equipment costs can be greatly reduced compared to conventional equipment.

As a new device for returning the activated sludge to the first biological treatment tank, a polymer flocculant is added to the activated sludge to perform screen separation, so that the power for the activated sludge separation is significantly reduced.

The mixed solution of the separated liquid from the screen separation device for returning sludge and the activated sludge slurry flowing out from the first biological treatment tank is led to the second biological treatment tank, and the waste water is discharged to this tank. Since it can be supplied and treated, it is not necessary to put gray water into the first biological treatment tank.
In the biological treatment tank, the water temperature and MLSS can be prevented from lowering due to the mixing of miscellaneous waste water, and thus, efficient nitrification and denitrification can be performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a treatment apparatus of the present invention, and FIG. 2 is a schematic diagram of a conventional human waste treatment apparatus. 1 ... Human waste, 2 ... First biological treatment tank 6 ... Activated sludge slurry, 7 ... Second biological treatment tank 11 ... Storage tank, 12 ... Inorganic coagulant 15 ... UF membrane separation device, 17 ...... Separation sludge 21 …… Screen separation device, 22 …… Separation block 23 …… Separation liquid

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiyuki Ichiki 6-27 Konan, Minato-ku, Tokyo Ebara-in Filco Co., Ltd. (72) Inventor Norio Yamada 1-6-27 Konan, Minato-ku, Tokyo No. within EBARA Infilco Co., Ltd. (56) References JP 62-44996 (JP, A)

Claims (1)

[Claims] 1. A first biological treatment tank for biologically nitrifying and denitrifying human waste sewage, and a second biological treatment tank for biologically treating activated sludge slurry flowing out from the biological treatment tank. At the same time, a polymer coagulant is added to a part of the activated sludge slurry in the first biological treatment tank or flowing out of the same tank, and a separation device for screen-separating the produced flocs is provided. A system path for returning the sludge to the first biological treatment tank and a system path for supplying the separated liquid from the separation device to the second biological treatment tank are provided, and the effluent from the second biological treatment tank is aggregated with an inorganic system. An apparatus for treating human waste sewage, comprising a solid-liquid separation device for adding an agent and performing coagulation separation.