JPH0651200B2 - Combined treatment method for waste and urinary wastewater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a method of extremely rationally combining both waste and urine system wastewater (hereinafter simply referred to as human waste).

[Conventional technology]

A new technique for combining both waste and urine is disclosed in JP-A-63-200881. This technology is a method in which human waste is biologically treated, a coagulant is added to the biologically treated water, and the treated water obtained by coagulation and separation is spray-supplied to the gas cooling chamber of a refuse incinerator for evaporative disposal. Met.

[Problems to be Solved by the Invention]

However, it has been recognized that the above-mentioned conventional techniques have the following serious drawbacks and are not ideal methods.

From the human waste treatment process, a large amount of non-dehydrating cohesive sludge [Al (O
H) ₃ or Fe (OH) ₃ as a main component] is generated. A system that combines waste and urine is not ideal unless the system does not generate coagulated sludge from the night soil treatment process.

In reality, the amount of waste treated is smaller than the amount of treated human waste very often, but in this case, the amount of heat of the waste incineration exhaust gas is insufficient, so it is necessary to evaporate the entire amount of human waste treatment in the gas cooling chamber. This makes it impossible to discharge some of the treated human waste water.

However, this treated human waste water is coagulated and separated water, and in it, a high concentration of 3000-5000 mg / salt salt as Cl ⁻ is contained, and further, environmental pollutants such as COD and chromaticity remain. Not only the discharge, but the infiltration into the ground causes a remarkable increase in the salt concentration of groundwater, which has a serious adverse effect on plants. In waste incineration facilities, "no discharge of wastewater" is often required as a precondition for facility construction. Therefore, this situation is the biggest obstacle in the construction and operation of the combined waste and urine treatment facility. Become.

The present invention is intended to completely solve the drawbacks of the conventional techniques, specifically, to eliminate the generation of coagulated sludge from the night soil treatment process, and to treat the amount of waste and urine. The challenge is to establish a rational system that can satisfy the "no discharge of wastewater" condition or the discharge condition without problems, not to mention discharge, even during unbalance.

[Means for Solving the Problems]

The present invention is a step of subjecting human waste sewage to a nitrifying and denitrifying bacteria in a coexisting aeration process to nitrify and denitrify the sewage, and the effluent from the step is subjected to an ultrafiltration membrane or microfiltration membrane. A step of separating the solid content and the membrane permeate into a membrane, a step of further subjecting the membrane permeate to reverse osmosis with a reverse osmosis membrane to separate the membrane permeate into a reverse osmosis concentrate, and the reverse osmosis concentrate to a refuse incinerator. The method for combined treatment of waste and urine-based sewage is characterized by comprising a step of supplying to the exhaust gas cooling chamber and evaporating to dryness.

In the present invention, the reverse osmosis concentrated liquid is evaporated to dryness in a refuse incinerator.
The reverse osmosis concentrate is atomized into a heat source of the refuse incinerator, that is, the exhaust gas cooling chamber of the refuse incinerator, and the heat of the exhaust gas cooling chamber is used to evaporate the concentrate. The form of the evaporation treatment may be an open system or a closed system.

[Action]

In the present invention having the above-mentioned configuration, the slurry liquid flowing out from the step of biologically nitrifying and denitrifying human waste is subjected to membrane separation with an ultrafiltration membrane (hereinafter referred to as UF membrane), and most of the separated sludge is subjected to the nitrification. It can be returned to the denitrification step and the surplus can be dehydrated in the usual manner. Also, the SS of UF membrane permeated water is zero, but the chromaticity is
A considerable amount of wastewater components such as COD and salt remain. This UF membrane permeated water is subjected to reverse osmosis treatment with a reverse osmosis membrane (hereinafter referred to as RO membrane) to obtain a highly purified RO membrane permeated water and a small amount of concentrated liquid in which the above wastewater components are concentrated. An exhaust gas cooling chamber of a refuse incinerator (for example, a temperature of 700 to 750)
℃) to evaporate.

The dehydrated separated water discharged during the dehydration of the surplus of sludge separated by the UF membrane is returned to the biological nitrification and denitrification treatment step or the residue and returned to the urine storage tank, or the waste incinerator. It may be supplied to the flue gas cooling chamber for evaporating, and the resulting dehydrated cake may be supplied to the refuse incineration process for incineration.

Therefore, the liquid directly discharged to the outside of the system can be only RO membrane permeated water, and since this RO membrane permeated water is highly treated to the same water quality as rainwater, it is not only discharged but also underground. Infiltration disposal is possible without any problems, and the water can be released into public water areas without any discharge, and the condition of "no discharge of wastewater" can be easily satisfied.

〔Example〕

One embodiment of the present invention will be described with reference to FIG.
The present invention is not limited to this.

The refuse 1 is incinerated in the refuse incinerator 2, and the incineration exhaust gas 3 flows out to the dust collector 5 in the next process via the gas cooling chamber 4. Reference numeral 6 denotes incineration ash discharged from the refuse incinerator 2.

On the other hand, the human waste 7 is decontaminated by a decontamination device 8 such as a fine screen, and then stored in a decontaminated urine storage tank 9. Conventionally, the decontaminated urine storage tank 9 has a function of merely removing the decontaminated urine and literally storing the urine, and averaging the flow rate to be sent to the next process. One of the features is that nitrifying bacteria and denitrifying bacteria are artificially made to coexist, aeration is performed, and BOD removal and nitrogen removal are simultaneously performed.

In addition, a flocculant A such as a cationic polymer is placed in front of the residue removing device 8.
Is also suitable for the present invention.

Then, the slurry that is debris removed and flows out from the urine storage tank 9 is
After flowing into the UF membrane or MF membrane separation device 10, SS is separated into clear UF membrane permeated water 11 and separation sludge 12 which are completely zero.

Most of the separated sludge 12 separated by the UF membrane separation device 10 is
Waste sludge 13 is removed and recycled as waste sludge 9, and the other part is recycled as excess sludge 14 with waste residue 15 removed by the residue removal device 8 to the dehydration process 16 for dehydration, and dehydrated cake 17 is a waste incinerator. It is supplied to No. 2 and incinerated. Also, the dehydration process 16
The dehydrated separated water 18 separated in (1) is returned to the human waste storage tank 9 or is guided to the gas cooling chamber 4 of the refuse incinerator 2 and evaporated and dispersed.

Then, the SS zero UF membrane permeate 11 (biological nitrification and denitrification treated water) is guided to the RO membrane device 19 and undergoes reverse osmosis treatment, and a large amount of chromaticity remains in the UF membrane permeate 11. , CO
D, PO ₄ ^3-, salt and the like are highly removed, the RO membrane permeate 20 shown rainwater equivalent water, concentrate 21 (RO membrane apparatus 19
It is reduced to about 1/6 to 1/8 of the amount of water supplied to).

The concentrated liquid 21 obtained by the RO membrane device 19 is supplied to the gas cooling chamber 4 of the refuse incinerator 2 and evaporated and dispersed, and the salt, organic substances, etc. contained in the concentrated liquid 21 and the like become dried products, and the dust collector 5 and is discharged together with dust 22 in the incineration exhaust gas 3,
It is disposed of together with incineration ash 6.

Further, the RO membrane permeated water 20 from the RO membrane device 19 has a water quality equivalent to that of rainwater, so that there is no problem even if rainwater permeates underground, by means such as deep well or surface permeation or surface watering. , It is possible to easily infiltrate the grounds of the facility underground and dispose of it, and to release it into public water areas without discharge.

In addition, when there is a margin in the heat quantity of the waste incineration exhaust gas 3, U
A part of the F membrane permeated water 11 can be supplied to the exhaust gas cooling chamber 4 for evaporative dispersion. In this case, since the amount of water flowing into the RO membrane device 19 is reduced, there is an effect that the operating cost of the RO membrane treatment can be saved.

The biological nitrification and denitrification is preferably carried out in a storage tank as in the example, but it may be carried out thereafter as in the conventional case.

〔The invention's effect〕

As described above, according to the present invention, the following important effects can be achieved, and an ideal garbage / human waste combined treatment method is completed.

Since the complete treatment can be performed by omitting the coagulation / separation step in the human waste treatment step, it is possible to reduce the generation of coagulated sludge, which is a difficult dehydration sludge and a troublesome matter in sludge treatment.

Even when the amount of waste and the amount of urine treated are unbalanced,
The treated sewage treated water can be discharged without any problems, and a combined waste / human sewage treatment facility that is extremely flexible in operation can be constructed and operated. Further, since the amount of water supplied to the RO membrane treatment can be automatically controlled according to the enthalpy fluctuation of the exhaust gas of the refuse incinerator, flexible operation becomes possible.

Since the amount of sludge generated from the human waste treatment process is reduced, it becomes easier to mix waste with sludge. This is because the calorific value of the sludge dewatering cake is about ⅓ of the calorific value of the garbage, and thus the smaller the sludge dewatering cake, the better the combustibility at the time of incineration of the waste.

Compared to the case where separate human waste and waste treatment facilities are installed,
The number of operation managers is small and the labor cost can be greatly reduced.

Sludge incinerators, exhaust gas treatment equipment, etc. can be omitted from the human waste treatment facility, and construction costs and operating costs are significantly reduced.

If a new concept is adopted in which artificially high concentration of nitrifying and denitrifying bacteria coexist in the decontamination urine storage tank and aeration process is performed to perform the two functions of storage and nitrogen removal at the same time, Generation of concentrated odor can be prevented, and concrete corrosion due to hydrogen sulfide can be prevented. In addition, the biological nitrification and denitrification tank (which is provided after the decontamination and urine storage tank), which was indispensable in the conventional human waste treatment process, is completely eliminated, and significant construction cost and installation area can be saved. As a result, the urine treatment facility can be easily installed on the premises of the waste treatment facility.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a flowchart of a method for combining waste and urinary wastewater of the present invention. Explanation of symbols: 1: garbage, 4: gas cooling chamber, 7: human waste, 9: decontamination waste urine storage tank, 10: UF membrane or MF membrane separation device, 11: UF membrane permeated water, 12: separated sludge, 19: RO membrane device, 20: RO membrane permeated water, 21: Concentrated liquid

Claims (1)

[Claims] 1. A step of nitrifying and denitrifying sewage by subjecting human waste sewage to aeration treatment in the presence of nitrifying bacteria and denitrifying bacteria, and the effluent from the step is subjected to an ultrafiltration membrane or a microfiltration membrane. At the step of separating the solid content and the membrane permeated water into a membrane, a step of further subjecting the membrane permeated water to a reverse osmosis treatment by reverse osmosis to separate the membrane permeated water and a reverse osmosis concentrate, and incinerating the reverse osmosis concentrate. A combined treatment method for waste and urine-based sewage, comprising the step of supplying to an exhaust gas cooling chamber of a furnace and evaporating to dryness.