JPH0673664B2 - 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).

[Prior Art] A new technology for the combined treatment of both waste and urine is disclosed in Japanese Patent Laid-Open No. 63-200881. This technology treats human waste biologically and then treats it with the biologically treated water. It was a method in which a coagulant was added and the treated water obtained by coagulation and separation was spray-supplied to the gas cooling chamber of the refuse incinerator for evaporative dispersion.

[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 (OH)
₃ or those mainly composed of Fe (OH) ₃ ] are 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 heat amount of the waste incineration exhaust gas is insufficient, so the entire amount of treated human waste water is evaporated in the gas cooling chamber. This makes it impossible to discharge some of the treated human waste water.

However, the night soil treatment water is aggregated separated water, among which Cl ^- 3000~5000mg / l as high concentrations of salt is included as further COD, since environmental pollution factors, such as chromaticity remaining Of course, not only the release of water but also the infiltration of underground causes a significant increase in the salinity of groundwater, which has a serious adverse effect on plants. Therefore, in waste incineration facilities, "no discharge of wastewater" is often required as a precondition for facility construction, and this situation is the largest in the construction and operation of the combined waste and urine treatment facility. It becomes an obstacle.

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 condition of "no discharge of wastewater" without any problems even when unbalanced.

[Means for Solving the Problems]

The present invention, after biological nitrification denitrification treatment of human waste sewage, membrane separation with an ultrapermeable membrane, and a part of the resulting ultrapermeate permeate is supplied to the gas cooling section of the refuse incineration process. While evaporating, the rest of the ultrapermeate permeate is subjected to reverse osmosis with a high desalination reverse osmosis membrane, and the concentrate obtained here is used in the waste incineration process together with the ultrapermeate permeate. It is a combined treatment method for waste and urine-based sewage, which is characterized in that it is supplied to a gas cooling section and evaporated.

[Action]

In the present invention having the above-mentioned configuration, the slurry flowing out from the biological nitrification and denitrification process of human waste is subjected to membrane separation with an ultrafiltration membrane (hereinafter referred to as UF membrane), and most of the separated sludge is treated by a conventional method. It is returned to the biological nitrification and denitrification process, the excess is dehydrated as in the conventional method, and part of the resulting UF membrane permeated water is supplied to the gas cooling part of the waste incineration process to evaporate and disperse, and the rest. Is subjected to reverse osmosis treatment with a high desalination rate reverse osmosis membrane (hereinafter referred to as RO membrane), and a small amount of the obtained concentrated liquid is supplied to the gas cooling section to be evaporated.

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 step or supplied to the gas cooling section of the refuse incineration step. The dehydrated cake obtained may be incinerated by supplying it to the refuse incineration process.

Therefore, the liquid discharged to the outside of the system can be only RO membrane permeated water, and this RO membrane permeated water is highly treated by the RO membrane with a high desalination rate to a water quality equivalent to rainwater. In addition, underground infiltration disposal is possible without any problems, and it is possible to make discharges to public water bodies without any discharge, and it is possible to easily satisfy the condition of "no discharge of wastewater".

〔Example〕

An embodiment of the present invention will be described with reference to FIG.
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, after the human waste 7 is removed by a removing device 8 such as a screen, it flows into an undiluted type biological nitrification and denitrification step 9, where BOD, COD and nitrogen components are highly removed. The slurry flowing out from the biological nitrification / denitrification step 9 flows into the UF membrane separation device 10 and is separated into a clear UF membrane permeated water 11 and SS having completely zero SS.

Most of the separated sludge 12 separated by the UF membrane separation device 10 is recycled to the biological nitrification and denitrification process 9 as return sludge 13, and the other part is removed as excess sludge 14 by the residue removal device 8. The residue 15 and the residue 15 are guided to a dehydration process 16 for dehydration, and the dehydrated cake 17 is supplied to the refuse incinerator 2 and incinerated. Further, the dehydrated separated water 18 separated in the dehydration step 16 is returned to the biological nitrification / denitrification step 9, or is introduced into the gas cooling chamber 4 of the refuse incinerator 2 and evaporated and dispersed.

Most of the SS zero UF membrane permeate 11 (biological nitrification and denitrification treated water) is spray-supplied for cooling to the gas cooling chamber 4 of the refuse incinerator 2 and is evaporated and dispersed. On the other hand, the remaining portion of the UF membrane permeated water 11 is guided to the RO membrane device 19 and subjected to reverse osmosis treatment, and a large amount of chromaticity, COD, P
O ₄ ³⁻ , salt, etc. are highly removed, that is, RO membrane permeated water 20 that has been treated with a reverse osmosis membrane with a high desalination rate and shows water quality equivalent to rainwater, and concentrate 21 (supply to RO membrane device 19) It has been reduced to about 1/6 to 1/8 of the amount of water).

Although the amount of water evaporated and scattered in the gas cooling chamber 4 varies depending on the enthalpy fluctuation of the incinerator exhaust gas 3 generated in the refuse incinerator 2, the amount of UF membrane permeate 11 introduced to the RO membrane device 19 is automatically controlled. Just drive.

The concentrated liquid 21 obtained by the RO membrane device 19 is supplied to the gas cooling chamber 4 of the refuse incinerator 2 together with the UF membrane permeated water 11 and is evaporated and dispersed, and is contained in the UF membrane permeated water 11 and the concentrated liquid 21 and the like. Salts, organic substances, and the like become dried substances, are captured by the dust collector 5, are discharged together with the dust 22 in the incinerator exhaust gas 3, and are disposed of together with the incinerated ash 6.

Further, since the RO membrane permeated water 20 from the RO membrane device 19 has a water quality equivalent to that of rainwater because salts and the like are highly removed, so that there is no problem even if rainwater penetrates underground, deep wells or surface It is possible to easily infiltrate the site of the facility underground and dispose of it by means such as infiltration or water sprinkling on the ground, and release it into the public water area without discharge.

〔The invention's effect〕

As described above, according to the present invention, the following important effects can be achieved, and an ideal waste / urine merging processing method is completed.

Night soil treatment by omitting the coagulation and separation steps in the process can be complete process Moreover, human waste treated water extremely high quality i.e. chromaticity, COD, PO ₄ ^3-, salt or the like highly removed rainwater equivalent It can be used as RO membrane permeate that shows water quality, can be discharged as treated water, and can also perform groundwater infiltration treatment without problems, and part of the UF membrane permeate can be evaporated by using the incineration heat of waste. As a result, the amount of water treated with the RO membrane is significantly reduced, which can greatly save energy and reduce the contamination of the membrane of the RO membrane device, while the concentrated solution in the RO membrane process is treated in the waste incineration process, which is difficult. It is possible to reduce the generation of coagulated sludge, which is a dewatering sludge and a troublesome matter in sludge treatment.

Even when the amount of waste treated and the amount of treated urine are unbalanced, treated sewage treated water can be discharged without any problems, and it is possible to construct and operate a combined waste / human waste treatment facility that is extremely flexible in operation. it can. Moreover, since the amount of water supplied to the RO membrane treatment can be automatically controlled according to the enthalpy fluctuation of the waste incineration exhaust gas, 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 1/3 of the calorific value of the garbage, and the smaller the sludge dewatering cake, the better the combustibility when incinerating the waste.

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

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

[Brief description of drawings]

FIG. 1 is a system explanatory view showing an embodiment of the present invention. 1 ... Garbage, 2 ... Garbage incinerator, 3 ... Incinerator exhaust gas, 4 ... Gas cooling chamber, 5 ... Dust collector, 6 ... Incinerator ash, 7 ... Human waste, 8 ... Decontamination device, 9 ... Biological nitrification and denitrification Process, 10 ... UF membrane separator, 11 ... UF membrane permeate, 12 ... Separation sludge, 13 ... Return sludge, 14
… Excess sludge, 15… Screen residue, 16… Dehydration process, 17… Dehydrated cake, 18… Dehydrated separated water, 19… RO membrane device, 20… RO membrane permeated water,
21 ... Concentrated liquid, 22 ... Dust.

Claims (1)

[Claims] A method for biologically nitrifying and denitrifying human waste sewage, and then performing membrane separation with an ultrafiltration membrane, and supplying a part of the obtained ultrapermeated water to a gas cooling section in a refuse incineration process. On the other hand, the rest of the ultrapermeate permeate is subjected to reverse osmosis with a high desalination reverse osmosis membrane, and the concentrate obtained here is treated with the ultrapermeate permeate to the waste incineration process. Method for combined treatment of waste and urine-based sewage, characterized in that it is supplied to the gas cooling section of the plant and evaporated