JPH07144192A - Operating method of night soil treating device using filter membrane - Google Patents

Abstract

PURPOSE:To restore the performance of filter membranes without installing special devices by decreasing the supply rates of the biologically treated liquid to be supplied at specified flow rates to filter membrane devices for the specific period of time at every specific time, at the time of biologically treating night soil with a biological treating device, then separating the biologically treating liquid to concd. sludge and treated water with the filter membrane devices. CONSTITUTION:This night soil treating device is constituted to separate the night soil to the concd. sludge and the treated water by the filter membrane devices 6, 9 after biologically treating the night soil with the biological treating device 3. The supply flow rates of the biologically treated liquid supplied at a specific flow rate to the filter membrane devices 6, 9 are decreased for 10 to 60 seconds at every 60 to 120 minutes. Consequently, there is no need for providing this device with the special devices and the contaminations of the filter membranes are easily removed. The number of washing times by liquid chemicals is drastically decreased and the amts. of the liquid chemicals to be used are decreased. In addition, the deterioration of the filter membranes by the liquid chemicals is lessened and the life of the filter membranes is prolonged. The danger of clogging of the inside of the filter membranes with the sludge is prevented and the higher operating efficiency than heretofore is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation method for removing contaminants adhering to the surface of a filtration membrane to recover the performance of the filtration membrane in a urine treatment apparatus using a filtration membrane, and particularly to a tuber type limiter. The present invention relates to an operation method suitable for an outer filtration membrane device.

[0002]

2. Description of the Related Art Conventionally, as a method for treating human waste, a biological treatment liquid after treating human waste with a biological treatment device such as activated sludge treatment, nitrification and denitrification treatment is used with an ultrafiltration membrane or a reverse osmosis membrane. The method of separating concentrated sludge and treated water by the filtration membrane device, and circulating the concentrated sludge to the biological treatment tank to efficiently treat human waste by high load operation is used.

In the above-mentioned method for treating human waste, an appropriate filtration membrane is selected, and a multistage ultrafiltration membrane device or a combination of an ultrafiltration membrane device and a reverse osmosis membrane device is appropriately arranged to obtain S
Of course, the removal of S content and the like has been widely used in recent years because clear treated water in which pollutants such as COD, BOD, and chromaticity are significantly reduced can be easily obtained.

However, in the urine treatment apparatus using the above-mentioned filtration membrane, high molecular substances such as sludge and proteins in the biological treatment liquid supplied to the filtration membrane apparatus at a constant set flow rate are not filtered by the filtration membrane. The scale easily adheres to the surface to form scales and slimes, and the amount of the membrane permeated liquid is gradually reduced, which may cause normal operation to become impossible.

[0005] It should be noted that, if the filtration membrane surface is fouled with a polymeric substance such as protein, the amount of permeated water is not so affected if the previous biological treatment is carried out well, but the scale generation by sludge is As long as the treatment liquid circulates at a constant flow rate, the amount of permeated water formed is reduced with the progress of operation regardless of the flow rate.

Therefore, conventionally, when the scale adheres to the surface of the filtration membrane and the amount of permeated water becomes less than the set permeated water, a sponge ball is circulated to scrape off the contamination, an acid, an alkali or an oxidizing agent. The performance of the filtration membrane is recovered by the method of washing with the above chemical solution.

[0007]

The above-mentioned washing operation is performed once at least once every 1 to 2 months after stopping the filtration membrane device, which causes a decrease in operating efficiency and sponge boring. -It is sure to scale by cleaning with only
However, the chemical cleaning has the drawbacks of shortening the life of the filtration membrane due to chemicals and increasing the cost of chemicals.

Therefore, according to the present invention, the performance of the filtration membrane can be recovered without the need to install a special device, the frequency of cleaning can be greatly reduced as compared with the conventional one, and the amount of the chemical liquid used can be reduced, and the filtration membrane can be reduced. It was made for the purpose of providing a driving method capable of extending the life of the vehicle.

[0009]

Means for Solving the Problems The gist of the present invention for achieving the above-mentioned object is to provide a biological treatment liquid obtained by biologically treating human waste with a biological treatment device by using a filtration membrane device with concentrated sludge and treated water. In the human sewage treatment apparatus which is separated into two, the amount of the biological treatment liquid supplied to the filtration membrane device at a constant flow rate is 60 to 12
It is a method of operating a urine treatment apparatus using a filtration membrane, which is characterized by decreasing the flow rate every 0 minutes for 10 to 60 seconds.

[0010]

[Operation] The human waste after decontamination is introduced into the biological treatment apparatus, and the biological action of microorganisms decomposes the organic matter in human waste to produce BO.
After reducing D, COD, N compounds, etc., they are separated into concentrated sludge and treated water by a filtration membrane device.

The concentrated sludge is partially supplied to the sludge dewatering device and discharged as excess sludge after the dewatering process, but the rest is circulated to the biological treatment device and provided as high-load operating sludge in the biological treatment device.

When the operation for filtering the biological treatment liquid with the filtration membrane device is continued, sludge adheres and remains on the surface of the filtration membrane to form a scale, and the set amount of permeate cannot be secured and the washing operation is performed. Is required.

However, by performing the operation of decreasing the supply amount of the biological treatment liquid supplied to the filtration membrane device every 60 to 120 minutes for 10 to 60 seconds, the flow rate is changed at the stage when a small scale is formed. Since it changes abruptly, the scale is peeled off and the performance of the filtration membrane is restored to obtain the original amount of permeate.

When the supply time of the biological treatment liquid is reduced for 10 seconds or less, it is difficult to obtain the effect, and for 60 seconds or more, the treatment amount is decreased, and the effect cannot be improved.

[0015]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a system diagram of a human waste treatment device used in an operating method according to an embodiment of the present invention.

Reference numeral 1 denotes a removing device for receiving and removing residue in urine. A drum screen or the like is used. After removing the residue, it is introduced into a human waste excrement storage tank 2 and once stored, it is quantitatively stored. To the biological treatment device 3.

The residue removed by the residue removal device 1 is screwed.
The residue is dehydrated by a screen residue dehydrator 4 such as a press, and the screen residue after dehydration is processed by a sludge treatment device such as a sludge incinerator (not shown),
The removed water is supplied to the biological treatment device 3 and processed.

Reference numeral 3 accommodates an underwater aerator 11, and this aerator 1
By introducing air from 1 to supply oxygen, oxygen is removed to oxidize organic matter in urine, and further supply of oxygen is stopped to make it anaerobic, thereby reducing NO _x and removing it as nitrogen gas. , BOD, COD, N compounds, etc. are reduced.

The above-mentioned biological treatment apparatus 3 may be an apparatus in which a plurality of treatment tanks are divided or a plurality of treatment tanks are separately arranged to combine aerobic and anaerobic treatments to biologically improve denitrification and dephosphorization effects. Well, the decontamination urine supplied to the processing apparatus 3 is usually processed by high-load processing operation without dilution, but it may be appropriately diluted and supplied.

The biological treatment liquid after being treated by the biological treatment device 3 is temporarily stored in the biological treatment liquid tank 5 and then is supplied to the first filtration membrane device 6 to be treated water that permeates the concentrated sludge and the filtration membrane. And separated.

As the first filtration membrane device 6, a flat membrane type module, a tuber type module or the like is used, but it is preferable to use a tuber type module, and the filtration membrane is a cellulose acetate. -Membranes made of materials such as G-based, aromatic polyamide-based, and polyphonic-based materials are selected, and microfiltration membranes with a pore size of 1 to several μ, ultrafiltration membranes with a molecular weight cutoff of tens of thousands to hundreds of thousands, or reverse osmosis. Although a membrane or the like is used, it is preferable to use an ultrafiltration membrane.

The treated water obtained by the first filtration membrane device 6 is once stored in the treated water tank 7 and then supplied to the coagulation treatment tank 8.
Contaminants such as chromaticity that have passed through the filtration membrane of the first filtration membrane device 6 are aggregated and separated and removed as concentrated sludge in the second filtration membrane device 9 to obtain further purified clarified water.

If a plurality of modules are connected in series to the first filtration membrane device 6 so as to obtain extremely clarified treated water with a single filtration membrane device, the second filtration device will be described later. The filtration membrane device 9 and devices associated therewith may be unnecessary.

The second filtration membrane device 9 is the first filtration membrane device 6
However, it may be a combination of devices having different configurations, for example, a combination of an ultrafiltration membrane device and a reverse osmosis membrane device.

The concentrated sludge separated by the first filtration membrane device 6 and the second filtration membrane device 9 is extracted as a part of excess sludge, supplied to a sludge dehydrator 10 and subjected to a dehydration treatment, and then shown together with a screen residue. Not supplied to sludge treatment equipment.

The sludge dehydrator 10 is mainly a decanter type centrifugal separator, but is not limited to this. The membrane permeated water separated by the first filtration membrane device 6 is supplied to the treated water tank 7, and the membrane permeated water separated by the second filtration membrane device 9 is discharged as clarified treated water.

Even when the treated water of the first filtration membrane device 6 is directly discharged or the clarified treated water of the second filtration membrane device is discharged, it is discharged to the river after disinfection. And when it is necessary to further purify the clarified water,
An aggregating treatment tank, an activated carbon adsorption tank, etc. are optionally provided in the subsequent stage.

When the human waste treatment operation is continued, sludge adheres to the surfaces of the filtration membranes of the filtration membrane units 6 and 9 and the amount of permeated liquid gradually decreases, but the sludge is supplied to the filtration membrane units 6 and 9. Valves 13a, 13 attached to the bypass flow paths 12a, 12b for a part of the biological treatment liquid or a portion of the treated water after the coagulation treatment, once every 60 to 120 minutes for 10 to 60 seconds, preferably 10 to 20 seconds.
By opening b and extracting the sludge as excess sludge, the flow rate of supply to the filtration membrane devices 6 and 9 is reduced.

After that, the valves 13a, 13 of the bypass flow path
By performing the operation of closing b and returning to the original flow rate, the adhered sludge is easily peeled off by the shearing force due to the fluctuation of the supply flow rate of the filtration membrane devices 6 and 9 and the abrupt change of the flow rate accompanying it, so that the permeated liquid amount is easily separated. Can always be maintained at the set amount.

In the above, the bypass passage 12
Although a and 12b are provided to adjust the supply amount of the biological treatment liquid or the like to the filtration membrane, it is also appropriate to use other methods, for example, adjustment of the valve opening degree or pump output.

A part of the data obtained by treating human waste with a tuber type ultrafiltration membrane device in which a plurality of modules are connected in series is shown in FIG. 2. This data shows that the flow rate in the pipe is 3 m. / S, normal operation is performed once per hour for about 20 seconds, the amount of supply liquid is reduced from that of normal operation, the flow velocity in the pipe is reduced to 2.5 m / s, and then the operation is returned to the normal operation supply flow rate. It is repeated.

FIG. 2A shows the change in the amount of the supplied liquid and B shows the change in the amount of the permeated liquid. It can be seen that the amount of the permeated liquid which has been slightly lowered can be restored to the original flow rate by changing the amount of the supplied liquid. . Conventionally, a cleaning operation with a chemical solution was required about once a month, but in the present operating method, the initial amount of permeated liquid could be maintained without cleaning the chemical solution for 10 months or more.

[0033]

According to the method of operating a urine treatment apparatus using a filtration membrane of the present invention, it is possible to easily remove the contamination of the filtration membrane without providing a special device and to greatly reduce the number of times of cleaning with a chemical solution. As a result, the amount of the chemical solution used can be reduced, the deterioration of the filtration membrane due to the chemical solution can be reduced, and the life of the filtration membrane can be extended. In addition, the risk of blockage due to sludge in the filtration membrane device is also prevented, and a constant amount of permeate is always obtained.
The operation efficiency can be improved as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is a system diagram of a human waste treatment device used in an embodiment of the present invention.

FIG. 2 is a graph showing data of one example.

[Explanation of symbols]

 1: Decontamination device 2: Human waste storage tank 3: Biological treatment device 4: Human residue dehydrator 5: Biological treatment liquid tank 6: First filtration membrane device 7: Treatment water tank 8: Coagulation treatment tank 9: Second filtration membrane device 10: Sludge dewatering device 11: Underwater aerator 12a, 12b: Bypass flow path 13a, 13b: Valve

Claims (1)

[Claims] 1. A human sewage treatment apparatus in which a biological treatment liquid after biological treatment of human sewage by a biological treatment apparatus is separated into concentrated sludge and treated water by a filtration membrane apparatus, and is supplied to the filtration membrane apparatus at a constant flow rate. A method for operating a urine treatment apparatus using a filtration membrane, characterized in that the supply amount of the biological treatment liquid to be treated is reduced every 60 to 120 minutes for 10 to 60 seconds.