JP2002162338A - Measuring device for suspension water quality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring device for water quality which can monitor microscopic particle in a suspension by separating. Especially it is useful for operation control of activated sludge process device which carries out solid-liquid separation by filter. SOLUTION: This invention is related to a measuring device for water quality of suspension which features to have the way of water intake to pull out a part of suspension, the way of solid-liquid separation which separates water and concentrated water containing high concentration suspension matter from suspension pulled out by said way of water intake, and the way of muddy ingredient detection which measures the concentration of muddy ingredient in said supernatant water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for measuring the quality of suspended water. More specifically, the present invention is capable of separating and monitoring only fine particles contained in suspension water, and in particular, water quality measurement of suspension water useful for operation control of an activated sludge treatment apparatus that performs solid-liquid separation by filtration. Related to the device.

[0002]

2. Description of the Related Art In an activated sludge apparatus for treating sewage and organic wastewater, the method of solid-liquid separation using a membrane, a filter cloth, or a nonwoven fabric instead of a settling tank is not based on gravity sedimentation. And has the advantage that solid-liquid separation can be performed. Therefore, activated sludge whose sedimentation property has deteriorated due to bulking or the like can be separated into solid and liquid and concentrated to a high concentration. However, the solid-liquid separation by these filtrations has a problem that undecomposed organic substances and metabolites of microorganisms contaminate the filtration surface and reduce the solid-liquid separation speed. For this reason, it is necessary to control the operation so as to keep the concentration of these organic components low. As these management guidelines, TOC meter,
It is monitored and managed by using a COD meter, an ultraviolet absorbance meter, or the like. In addition, by measuring the viscosity of the activated sludge mixture, the concentration of the organic component in the activated sludge mixture can be indirectly estimated. On the other hand, in the solid-liquid separation by filtration, the present inventors have found that the filtration surface is contaminated by not only metabolites of microorganisms but also fine activated sludge components. It is assumed that the fine activated sludge particles form a strong gel-like layer with the microbial metabolite on the filtration surface, and increase the filtration resistance. However, in the solid-liquid separation device having no settling tank, there is no means for separating and monitoring only the fine sludge particles in the activated sludge. The present inventors have clarified that fine sludge particles that increase filtration resistance have a strong correlation with the turbidity of a supernatant layer generated by settling and separating activated sludge, and have reached the present invention.

[0003]

SUMMARY OF THE INVENTION The present invention can separate and monitor only fine particles contained in suspension water, and is particularly useful for operation control of an activated sludge treatment apparatus for performing solid-liquid separation by filtration. The purpose of the present invention is to provide an apparatus for measuring the quality of suspended water.

[0004]

The inventor of the present invention has conducted intensive studies to solve the above-mentioned problems. As a result, the present inventor has found that a water intake means for extracting a part of the suspension water and a solid solution for separating the supernatant of the extracted suspension water. By means of a device provided with a liquid separating means and a means for measuring the concentration of a turbid component contained in the supernatant, it is possible to easily and accurately measure the turbid component concentration by separating only fine particles contained in the suspension water. And completed the present invention on the basis of this finding. That is, the present invention relates to (1) a water quality measuring device for a suspension water, wherein a water intake means for extracting a part of the suspension water, and the suspension water extracted by the water intake means containing a supernatant and a high concentration of suspended substances. (2) a water quality measuring device for a suspended water, comprising: a solid-liquid separating means for separating into a concentrated water to be separated; and a turbid component detecting means for measuring a turbid component concentration contained in the supernatant. ) Suspended water forms a microfiltration membrane, an ultrafiltration membrane, or a coarse filter cloth, or a dynamic filtration layer on the surface of a filter made of non-woven fabric to capture suspended particles in sewage, 3. The water quality measuring device for suspended water according to claim 1, which is the water to be treated by a filtration means comprising at least one of a dynamic filtration body for extracting filtered water, (3) the suspended liquid, wherein the suspended water is an activated sludge mixed solution or The water quality measuring device for suspended water according to Item 2, and ( ) Turbid component detecting means, there is provided a water quality measuring device, aqueous suspension as claimed in any one of items 1 to 3, wherein the surface light scattering type turbidity detector. Further, as a preferred embodiment of the present invention, (5) the water quality measuring device for suspended water according to item 1, wherein the water intake means is an intake pipe and a transfer pump provided with an intake port in the suspension water, and (6). Item 2. The apparatus for measuring water quality of suspended water according to item 1, wherein the solid-liquid separation means is a sedimentation separation column.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The water quality measuring apparatus of the present invention comprises a water intake means for extracting a part of the suspension water, and the suspension water extracted by the water intake means containing a supernatant and a high concentration of suspended substances. The apparatus comprises a solid-liquid separation means for separating into a concentrated water and a turbid component detecting means for measuring the concentration of a turbid component contained in the supernatant. According to the apparatus of the present invention, only fine particles contained in the suspension water can be separated and monitored. The device of the present invention is a microfiltration membrane, an ultrafiltration membrane,
Or, a filtration cloth comprising coarse filtration cloth, or a dynamic filtration layer that forms a dynamic filtration layer on the surface layer of a filtration body made of a non-woven fabric to capture suspended particles in sewage, and removes filtration water. It can be applied to the treated water of the means. By using the apparatus of the present invention, the microbial metabolites contained in the activated sludge mixed solution, form a strong gel-like layer with the microbial metabolites on the filtration surface, it is assumed that the fine activated sludge particles are assumed to increase filtration resistance The concentration can be measured and used effectively for operation management of the activated sludge treatment device. In the apparatus of the present invention, there is no particular limitation on a water intake means for extracting a part of the suspension water, for example, a combination of an intake pipe and a transfer pump provided with an intake port in the suspension water, and the suspension water overflowing from the suspension water tank. Examples include a water guide pipe that guides the water, a water intake pipe that takes in the suspension water through a water head provided with a water intake port on the wall or bottom surface of the suspension water tank, and the like. Among these, the combination of an intake pipe with an intake port in the suspension water and a transfer pump allows the start and stop of intake to be easily controlled by operating and stopping the pump, and always allows intake under constant conditions. Therefore, it can be particularly preferably used.

In the apparatus of the present invention, there is no particular limitation on the solid-liquid separation means for separating the suspended water extracted by the water intake means into a supernatant and a concentrated water containing a high concentration of suspended substances.
For example, a sedimentation separation column, a centrifuge, a membrane separation device and the like can be mentioned. Among these, the sedimentation separation column is particularly preferable because it has a simple structure and is easy to maintain and can be used by directly connecting to a suspension water tank, and can always perform solid-liquid separation under constant conditions. Can be used.
There is no particular limitation on the size and shape of the sedimentation separation column.However, when the activated sludge mixture is transferred by the transfer pump and introduced into the sedimentation separation column, the size of the sedimentation separation column is determined from the pump flow rate so that sludge does not settle. It is preferable to set the shape and shape. In the apparatus of the present invention, there is no particular limitation on the turbid component detecting means for measuring the turbid component concentration contained in the supernatant. For example, a surface scattered light turbidity detector, a visual turbidity measuring instrument, a transmitted light turbidity Meter, scattered light turbidity meter, integrating sphere turbidity meter and the like. Also, the intensity of turbidity can be detected by detecting the intensity of light reflected or blocked by fine particles in the supernatant using laser light.
Among these, the surface scattered light type turbidity detector is particularly preferably used because it can perform continuous measurement in a non-contact type, has resistance to dirt, and does not require the preparation of a standard solution. Can be.

FIG. 1 is an explanatory view of one embodiment of the apparatus for measuring the quality of suspended water according to the present invention, and FIG. 2 is a partially enlarged view thereof. The apparatus of this embodiment includes an activated sludge aeration tank 1, an intake port 2 installed in an activated sludge mixture, an intake pipe 3, a transfer pump 4,
A valve 5 and a sedimentation separation column 6 are provided. A diffuser pipe 7 and a filtration unit 8 are provided in the activated sludge aeration tank, and a filtered water discharge trough 9 is provided outside the activated sludge aeration tank. The filtration unit and the filtered water discharge trough are connected by a filtered water discharge siphon tube 10. Raw water is supplied to the activated sludge aeration tank, aerated air is released from the air diffuser, and oxidative decomposition of organic substances proceeds in the activated sludge mixture in the aeration tank. The filtered water discharge siphon pipe is filled with filtered water by reducing the pressure through the pressure reducing pipe 11. The liquid level of the activated sludge aeration tank is kept higher than the water level of the filtered water discharge trough, and the activated sludge mixture is filtered by the filtration unit due to the head difference between the two liquid levels, and the filtered water flows out to the filtered water discharge trough. . When the filtration unit is a microfiltration membrane or an ultrafiltration membrane, an air diffuser is installed almost immediately below the filtration unit as shown in FIG. 1, and the flow of the activated sludge mixture on the membrane surface of the filtration unit is directed upward. It is preferable that the cross-flow flow is as follows. In the case where the filtration unit is a dynamic filtration body that forms a dynamic filtration layer on the surface layer of a filtration body made of a coarsely-clothed filter cloth or a nonwoven fabric, captures suspended sludge particles in the activated sludge mixture, and takes out filtered water. Preferably, a diffuser is installed at the bottom of the aeration tank on the side where the filtration unit is not present, and the flow of the activated sludge mixture on the membrane surface of the filtration unit is a downward cross flow. If necessary,
A partition plate can be provided between the filtration unit side and the side where no filtration unit is present in the activated sludge aeration tank.

[0008] In the apparatus of the present invention shown in FIG.
The activated sludge mixture is withdrawn from the water inlet 2 through the water intake pipe 3 by the transfer pump 4 and sent into the sedimentation column through the inlet 12 at the bottom of the sedimentation column 6. At the upper part of the sedimentation separation column, the activated sludge mixture liquid uniformly overflows the overflow trough 13 from around the column, and is discharged from the overflow trough. The liquid level of the activated sludge mixture is formed at the uppermost part of the settling separation column, and the turbidity of the liquid level is detected by the surface scattered light type turbidity detector including the light irradiation unit 14 and the light receiving unit 15. . In the measurement, the activated sludge mixture is transferred to a sedimentation separation column and overflowed from the upper part of the column. Next, the transfer pump 4 is stopped, the valve 5 is closed, the transfer of the activated sludge mixture is stopped, and the mixture is allowed to stand for a certain period of time. This standing time is
About 5 to 30 minutes is preferable. After stopping for a certain period of time, the activated sludge mixture is again transferred to the sedimentation column.
FIG. 3 is an example of a turbidity detection curve in this step.
When the activated sludge mixture is continuously transferred to the settling separation column at a constant flow rate, the turbidity detection intensity on the liquid surface maintains a constant value. Then
When the transfer of the activated sludge mixture is stopped and the process proceeds to the standing step, the turbidity detection intensity on the liquid surface slightly changes. It is assumed that the fluctuation of the turbidity detection intensity is caused by disturbance of the liquid level due to the stop of the transfer. When the transfer of the activated sludge mixture to the sedimentation separation column is resumed, the turbidity detection intensity on the liquid surface starts to decrease, and after returning to the minimum turbidity detection intensity point, the turbidity detection intensity returns to the initial constant value of the turbidity detection intensity. By obtaining the minimum turbidity detection intensity from such a turbidity detection curve, the concentration of the turbid component contained in the supernatant can be measured. If fresh water is used instead of the activated sludge mixture as a means to push out and overflow the liquid in the sedimentation separation column after sedimentation separation, the turbidity detection intensity does not show a clear minimum value, and the supernatant turbidity is measured. It will be difficult to do. In addition, auxiliary means such as fresh water supply means and a scraper or a brush may be provided for cleaning the sedimentation separation column. By using the apparatus of the present invention, only the fine particles contained in the suspension water can be separated and monitored, and can be utilized for operation management of an activated sludge treatment apparatus that performs solid-liquid separation by filtration.

[0009]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Example 1 The turbidity detection intensity of the supernatant of the activated sludge mixture was measured by the apparatus shown in FIG. Activated sludge aeration tank is 1m effective capacity
^{In 3} , ^three filtration units having a filtration module with a side area of 400 mm × 400 mm are arranged. Sewage of BOD 180 mg / L and SS 130 mg / L was used as raw water, and the residence time in the aeration tank was set to 6 hours. The sedimentation separation column has a conical bottom and is provided with an activated sludge mixture inlet, and has a cylindrical shape with an inner diameter of 100 mm and a height of 500 mm. A surface scattered light type turbidity detector [Electrochemical Instrument Co., Ltd., TUF-5] for measuring the turbidity of the liquid surface to be prepared is provided. The activated sludge mixture was fed into the settling separation column at a rate of 50 mL / min by a transfer pump from an intake port installed in the activated sludge aeration tank. In this transfer step, the turbidity detection intensity of the liquid surface was 2,100 mg / L. Next, the transfer pump was stopped, the valve was closed, and the container was kept still for 20 minutes. During the standing step, the detection intensity of turbidity on the liquid surface slightly changed, but was approximately 2,000 mg / L. Open the valve again and operate the transfer pump to bring the activated sludge mixture to 50 mL /
When sent to the sedimentation separation column at the speed of min, the turbidity detection intensity decreased rapidly, and reached the minimum turbidity detection intensity of 30 mg / L 11 minutes after resumption of the transfer. Thereafter, the turbidity detection intensity gradually increased and returned to 2,100 mg / L 46 minutes after the transfer was resumed. FIG. 3 shows the obtained turbidity detection curve. In the figure, the time on the horizontal axis indicates 0 at the start of the standing process.

[0010]

According to the apparatus for measuring the quality of suspended water of the present invention, it is possible to simply and accurately separate and monitor only fine particles contained in suspended water, and to perform activated sludge which performs solid-liquid separation by filtration. It is particularly useful for the operation management of the processing apparatus.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of one embodiment of a water quality measuring device for suspended water of the present invention.

FIG. 2 is a partially enlarged view of FIG. 1;

FIG. 3 is an example of a turbidity detection curve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Activated sludge aeration tank 2 Intake port 3 Intake pipe 4 Transfer pump 5 Valve 6 Sedimentation separation column 7 Diffusion pipe 8 Filtration unit 9 Filtration water discharge trough 10 Filtration water discharge siphon pipe 11 Decompression pipe 12 Inlet 13 Overflow trough 14 Light irradiation Unit 15 Light receiving unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 1/44 C02F 3/12 ZABP 3/12 ZAB G01N 21/49 Z G01N 21/49 21/59 Z 21 / 59 33/18 A 33/18 B01D 29/04 510E 510F 530A

Claims (4)

[Claims] 1. A water quality measuring device for a suspension water, comprising: a water intake means for extracting a part of the suspension water; a supernatant water and a concentrated water containing a suspended substance in a high concentration; 1. A water quality measuring device for a suspended water, comprising: a solid-liquid separating means for separating the suspension; and a turbid component detecting means for measuring a turbid component concentration contained in the supernatant. 2. A method for producing suspended particles in sewage by forming a dynamic filtration layer on the surface of a filter made of a microfiltration membrane, an ultrafiltration membrane, a filter cloth having coarse openings, or a nonwoven fabric. The suspension water quality measuring device according to claim 1, wherein the water quality of the suspended water is at least one of a dynamic filtration body that captures and removes filtered water. 3. The suspension according to claim 1, wherein the suspension is an activated sludge mixture.
Or the water quality measuring device of the suspension water according to claim 2. 4. The water quality measuring device according to claim 1, wherein the turbid component detecting means is a surface scattered light type turbidity detector.