JPH06178979A - Device for separating solid from liquid - Google Patents

Abstract

PURPOSE:To subject sludge and treated water to a sepn. of solid from liquid by effectively flocculating and settling the sludge in raw water and maintaining a membrane separator in an optimum state. CONSTITUTION:A flocculating and intimate mixing tank 1 is provided with a flow meter 5 and electrical conductivity meter 6 for the biologically treated water 3 to be admitted therein, a pH meter 9 for measuring the pH of the water 23 to be treated in the tank 1 and chemicals feeders 11, 12, 13 for flocculation. A flocculating film tank 2 is provided with the membrane separator 14, a suction pump 15, stirring vanes 17, a liquid level gate 19 and a pressure gage 18 for measuring a suction negative pressure. These devices or means are connected to a controller 7. The chemicals feeders 11, 12, 13 for flocculation, the suction pump 15 and the stirring vanes 17 are controlled and operated by this controller 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-liquid separation device used in a water treatment facility for treating sludge, such as a combined septic tank and human waste septic tank.

[0002]

2. Description of the Related Art Conventionally, in a water treatment facility as described above, a membrane separator has been used as a sludge separation technique for separating organic sludge from activated sludge and then separating the treated water. The membrane separator used as a coagulant separator for further advanced treatment by adding a coagulant is an out-of-tank type in which the membrane is installed outside the liquid to be treated, and the liquid to be treated is supplied into the membrane for permeation. It is an internal pressure type that obtains liquid.

[0003]

However, the above-mentioned conventional apparatus has a problem that it tends to be difficult to obtain proper membrane permeated water according to fluctuations in raw water.

Further, since all the liquids to be treated are solid-liquid separated by the membrane separation device, it is necessary to supply a large amount of the liquids to be treated to the membrane separation device, which results in very large power energy. There's a problem.

Further, since it is the outside of the tank, there is a problem that a large installation space is required. Further, periodical chemical cleaning is required to prevent clogging of the membrane surface of the membrane separation device, which is problematic in terms of economy and workability.

The present invention solves the above problems, and an object of the present invention is to provide a solid-liquid separation device which can cope with fluctuations in raw water and is excellent in economical efficiency and workability.

[0007]

In order to solve the above problems, the solid-liquid separation device of the present invention is a solid-liquid separation device for treating organic wastewater biological treated water with a flocculant and then separating it into activated sludge and treated water. In the separation device, a coagulation / mixing tank and a coagulation membrane tank are arranged in this order, a means for detecting the inflow amount of raw water and its characteristics, and a pH meter for measuring the pH of the treated water in the tank A coagulation chemical injection means and means for agitating and mixing the water to be treated in the tank, and a membrane separation device for solid-liquid separating activated sludge and treated water into the coagulation membrane tank, and a membrane of this membrane separation device Membrane surface cleaning means for generating a circulating flow for cleaning the surface, a suction pump for sucking the membrane-permeated water, a pressure gauge for measuring the suction negative pressure, and a liquid for measuring the liquid level in the tank. A position gauge and an air operated valve for adjusting the pressure in the membrane separation device when the suction pump is stopped. Only, further, in the mixing flocculation tank, the water to be treated and its characteristics and intracisternal inflow of raw water p
In addition to controlling the injection amount of coagulation chemicals according to the H value,
The flocculation membrane tank is provided with a control device for controlling the amount of treated water by the membrane separation device and the operation of the membrane surface cleaning means while stabilizing the treatment condition in the tank based on these measurement data.

Further, the solid-liquid separation device of the present invention controls the start and stop of the suction pump according to the suction negative pressure or the integrated amount of treated water, and controls the generation of the circulating flow by the membrane surface cleaning means. The separation device can be automatically washed.

[0009]

With the above configuration, in the coagulation / mixing tank, the inflow amount of the biological treated water that flows in and its characteristic value and the pH of the treated water in the tank are automatically measured, and the measured values are input to the control device. The sludge in the water to be treated is effectively aggregated and settled because the optimal amount of the aggregating agent as the aggregating agent and the pH adjusting agent are added based on the data.

Further, in the flocculation membrane tank, the liquid level and suction negative pressure in the tank are measured by a liquid level gauge and a pressure gauge, and the measured values are input to the control device and stored in the data and the control device. The suction flow rate and the operating time of the suction pump are controlled based on the amount of the inflow liquid, and the generation of the circulation flow by the membrane surface cleaning means is controlled. Therefore, the membrane separation device is maintained in a suitable state and the activated sludge is maintained. It is possible to perform solid-liquid separation into water and treated water.

Further, by controlling the start / stop of the suction pump on the basis of the negative suction pressure or the integrated amount of treated water, and controlling the generation of the circulating flow by the membrane surface cleaning means, the membrane separation device can be automatically cleaned. .

[0012]

EXAMPLE FIG. 1 shows a solid-liquid separator according to an example of the present invention. The coagulation / mixing tank 1 and the coagulation membrane tank 2 are installed in this order, and the biologically treated organic wastewater, that is, the secondary treated water 3 can be introduced.

A flow meter 5 and an electric conductivity meter 6 are provided in the flow path 4 to the coagulation and mixing tank 1 and are connected to a controller 7, respectively, and data measured by these meters 5 and 6 are measured. Is automatically input to the control device 7.

The aggregating and mixing tank 1 is provided with a stirrer 8 and a pH meter 9. The stirrer 8 can be operated by a motor 10, and the pH meter 9 is connected to a controller 7 to measure a measured pH value. Can be input to the control device 7. The flocculating agent A charging device 11, the flocculant B charging device 12 and the pH adjusting chemical charging device 13 each having pumps 11a, 12a and 13a are connected to the control device 7, and these are controlled by the control device 7. The dosing devices 11, 12, 13 can be operated.

Further, the coagulation membrane tank 2 has an immersion type membrane separation device 1
4 is installed and connected to the suction pump 15, and the membrane permeate 16 can be taken out by applying a negative pressure to the membrane separation device 14 with the pump 15. A stirring blade 17 is provided below the membrane separation device 14 and can generate a stirring flow. A pressure gauge 18 is provided between the membrane separation device 14 and the suction pump 15, and the measured suction pressure data is sent to the control device 7. A liquid level meter 19 is provided in the tank 2, and the data obtained by the liquid level meter 19 is automatically input to the control device 7. The suction pump 15 and the stirring blade 17 are connected to the control device 7, and can be controlled based on the suction pressure data and the liquid level data stored in the control device 7. Further, an air actuating valve 20 capable of supplying air into the membrane separating device 14 is also provided between the membrane separating device 14 and the suction pump 15. An outlet 21 is provided in the lower part of the tank 2 and is connected to a pump 22. This pump 22 is connected to a control device 7, and the control device 7 controls the pump 22 to control the sludge removal. It is possible.

In this structure, the secondary treated water 3 is measured in the flow path 4 sent to the coagulation and mixing tank 1 by the flow meter 5 and the electric conductivity meter 6 continuously or batchwise to measure the flow rate and the electric conductivity. Then, the obtained data is automatically input to the control device 7. Here, since the electrical conductivity has a correlation with the chlorine ion concentration, it is possible to obtain information on the chlorine ion concentration in the secondary treated water 3 by measuring the electrical conductivity.

The secondary treated water 3 sent to the coagulating and mixing tank 1 is
The above data and p of the treated water 23 measured in the tank 1
The type and characteristics of the wastewater are determined based on the H data and the data and know-how accumulated in advance in the control device 7. Then, based on this judgment, the flocculating agent A charging device 1 from the control device 7
1, a flocculant B charging device 12, and a pH adjusting chemical charging device 13
Flow rate instruction is sent to the pumps 11a, 12a, 13a
Is activated and coagulant A, coagulant B or a pH adjusting chemical is added. At this time, the water 23 to be treated in the tank 1 is agitated and mixed by the agitator 8. As a result, the treated water 23 in the tank 1 is in an optimum state for coagulation, the sludge aggregates and settles, and the treated water 2 containing sludge that has not settled in the tank 1
3 is taken out from the upper part of the tank 1 and sent to the coagulation membrane tank 2.

The water to be treated 24 sent to the flocculation membrane tank 2 is subjected to liquid level measurement by a liquid level gauge 19 installed in the tank 2, and liquid level data is sent to a control device 7, and this data and control are carried out. The suction pump 15 is operated by controlling the amount of suction liquid so that the entire membrane separation device 14 is immersed in the water to be treated 24 based on the amount of inflow liquid stored in the device. Further, the suction pressure is measured by the pressure gauge 18 installed upstream of the suction pump 15, pressure data is sent to the control device 7, and the intermittent operation of the suction pump 15 and the suction liquid amount are inverter-controlled based on this data. . That is, the control device 7 determines the filtration capacity of the membrane separation device 14 using the rise in suction negative pressure obtained by the pressure gauge 18 as an index, and adjusts the flow rate so as to prevent clogging of the membrane surface due to an excessive flow rate load, The judgment at the time of cleaning the membrane is performed. The deposits on the film surface are easily separated from the film surface by alternately placing the suction negative pressure and the suction negative pressure-free state. The membrane surface can be washed. When the suction pump 15 is stopped to wash the membrane, the membrane separation device 14
The air-operated valve 20 is operated so that the inside does not become negative pressure. Based on the suction pressure data, the control device 7 controls the pump 22 to remove excess coagulated sludge 25 and wash sludge 26.
It is also possible to control the return operation.

The membrane permeate 16 taken out through the membrane separator 14 is further sent to a highly treatable facility such as activated carbon or discharged as it is as treated water.

[0020]

As described above, according to the present invention, a control device using a computer or the like effectively optimizes the membrane separation device by effectively coagulating / settling the sludge in the raw water even if the raw water varies. Since the sludge and the treated water can be separated into solid and liquid while maintaining a stable state, it is possible to save the power energy as compared with the conventional method of supplying all the raw water to the membrane separation device.

Further, since it is an in-tank type, a large installation space is not required. Furthermore, by determining the time of cleaning the membrane surface based on the suction pump pressure during membrane separation and the integrated amount of treated water, and controlling the suction pump and the agitating means, the membrane separator can be self-cleaned, so that the life of the membrane is reduced. Since it is long and the number of times of chemical cleaning is small, it is possible to improve the economy and workability.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a solid-liquid separation device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Coagulation / mixing tank 2 Coagulation membrane tank 3 Secondary treated water (raw water) 5 Flow meter 6 Electric conductivity meter 7 Control device 8 Stirrer 9 pH meter 11, 12 Coagulant injection device 13 pH adjusting chemical injection device 14 Membrane separation device 15 Suction pump 17 Stirring blade 18 Pressure gauge 19 Liquid level gauge

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C02F 3/12 S 9/00 ZAB A 7446-4D

Claims (2)

[Claims] 1. A solid-liquid separator for treating organic wastewater biological treated water with an aggregating agent and then separating it into activated sludge and treated water by arranging an aggregating and mixing tank and an aggregating membrane tank in this order, and aggregating and mixing. A means for detecting the inflow rate of raw water and its characteristics into the tank, a pH meter for measuring the pH of the treated water in the tank, a coagulation chemical injection means, and a means for stirring and mixing the treated water in the tank. The coagulation membrane tank is provided with a membrane separation device for solid-liquid separation of activated sludge and treated water, a membrane surface cleaning means for generating a circulating flow for cleaning the membrane surface of the membrane separation device, and a membrane permeated water. Suction pump for sucking air, a pressure gauge for measuring suction negative pressure, a level gauge for measuring the liquid level in the tank, and an air for adjusting the pressure in the membrane separation device when the suction pump is stopped. Further, an operating valve is provided, and further, in the coagulation / mixing tank, the inflow rate of raw water and its characteristics and And the amount of coagulation chemicals injected according to the pH value of the water to be treated in the tank, and in the coagulation membrane tank, the amount of treated water by the membrane separation device and the operation of the membrane surface cleaning means are based on these measurement data. A solid-liquid separation device comprising a control device for controlling. 2. The membrane separator can be automatically cleaned by controlling the start and stop of the suction pump according to the suction negative pressure or the integrated amount of treated water and controlling the generation of a circulating flow by the membrane surface cleaning means. The solid-liquid separation device according to claim 1.