JPS5875061A - Measuring apparatus for concentration of floating matter of activated sludge - Google Patents

Abstract

PURPOSE:To find the concentration of floating matters of activated sludge (MLSS) by measuring the volume (SV) of a sludge precipitation part and the concentration (D) of the sludge after standing still for a prescribed time in a measurement pipe and multiplying said measured values. CONSTITUTION:A sludge precipitation part 21 is formed in a SV measuring pipe 5 and ultrasonic waves are projected successively from the lower side ultrasonic transmission element 40 by controlling an oscillation circuit 45 by a controlling circuit 44. Then, the height of the sludge precipitation part 21 is measured by deciding the intensity of the ultrasonic waves received by a reception element 41 through a level deision circuit 43 and the SV value is found through a conversion circuit 46. The ultrasonic waves are projected from one of transmission elements 40 located lower than a precipitation boundary face 23 and the concentration is measured from the intensity of the ultrasonic waves received by the element 41 through a sludge concentration measuring circuit 47. The SV(%) value and precipitated sludge concentration D(%) are inputted into a multiplication circuit 49 and (SV)XD=MLSS(%) is found.

Description

DETAILED DESCRIPTION OF THE INVENTION l) Inventive technology minute hand The present invention relates to an activated sludge suspended matter concentration measuring device for determining a management index for activated sludge treatment in a sewage treatment plant, and particularly relates to a direct ML
This invention relates to a device for simply determining MLSS without measuring 88 concentration.

2) Conventional technology “C
: As a control index, water temperature in the treatment tank (aeration tank), P
In addition to H, dissolved oxygen, etc., the concentration of the activated sludge treated product (hereinafter referred to as ML88) and the settled sludge volume it (
Hereinafter T1 (hereinafter referred to as 8■) is measured. Also,
Recently, as a management index for activated sludge, the ratio of 8V/ML88 is taken and the sludge capacity index (hereinafter referred to as Moleman index) is used.
This is commonly referred to as 8VI) and is being measured.

Therefore, this type of device automatically measures the ML88 concentration and SV, and further calculates the SVI value by calculating sV/MLSS.

Hereinafter, a series of operations of the conventional apparatus will be explained step by step with reference to FIG.

■ Sampling process...First, open valve 1.2 and three-way valve 3, operate air pump 4,
Constant w 5 Oyo i: J: Ml, 8811 constant cell 6 O Reduce the pressure inside and vent! Sludge liquid 8 in II 7 is sucked through pipe 9 and collected into MLS88111 constant cell 6 and Sv measuring tube 5. This sampled amount is set to a predetermined capacity (IJ
), the level meter 10 is generally truncated, and S
v When the sludge liquid has been collected to a predetermined level in the measuring pipe 5, the valve 1
Then, the three-way valve 3 is closed, the abo pump 4 is stopped, and the atmosphere release valve 11 is opened to set the inside of the 8V measuring tube 5 to atmospheric pressure.

(2) ML88 measurement process...Next, the air introduction valve 13 is opened and air is blown into the gt, ss@1 constant cell 6 to stir the collected sludge liquid. This is because the sludge suspension settles as soon as the sludge liquid collection is completed, so the sludge liquid is stirred in the MLSS measurement to ensure uniform decomposition of the sludge suspension and to avoid measurement errors.

When the stirring of the sludge liquid is completed, the air introduction valve 13 and the valve 2 are closed to begin one MLSM measurement. To measure MLS of 89 degrees, a light emitter 14 and a light receiver 15 are placed across an MLSS measurement cell 6 made of a transparent material such as glass, and these devices 14 and 15 are operated at a predetermined timing.
The L88 measurement circuit 16 measures the MLSS concentration.

That is, the light from the projector 14 passes through the sludge in the measurement cell 6 and is received by the light receiver 15. Since the amount of transmitted light has a certain relationship with the sludge suspended solids concentration, the amount of light received is used as the MLS 8. Concentration can be measured. The MLSS concentration value measured here is the ML8S value data hold circuit 17.
is held.

■ SV measurement process...Next (-1 SV of the same transparent body
When the sludge liquid in the ill fixed tube 5 is allowed to stand still for a predetermined period of time (for example, 30 minutes), it is divided into a sludge settling portion 21 and a supernatant liquid portion 22', and a boundary surface 23 is formed. The position of this boundary surface 23 is detected by an optical intensity switch consisting of an SV@1 regular emitter 25 and a light receiver 26 connected to a servo mechanism 24, and a position signal is generated from a subsequent button V yometer 27. Therefore, this position signal is measured and output as an 8V value by the SVI measurement circuit 28.

■ SvI value calculation ratio calculation 1 - S measured as in F
The V value and the MLS8 value enter an 8V1 value calculation circuit 30, where an 8V1MLSS calculation is performed to determine and output the SVI value.

■ Discharge/cleaning process...The above measurement operations have been completed. If so, open the valves 1 and 2 and the three-way valve 31, operate the air pump 4, pressurize the air from the -E section of the Sv measurement tube 5, and then open the Sv measurement tube 5 and the ML88 measurement cell 6.
(The sludge liquid is discharged through pipe 9.

Next, when the discharge of the sludge liquid is completed, the valve 1 is closed and the wash water valve 32 is opened to introduce fresh water and collect the fresh water in the SV measuring tube 5 and the ML88 measuring cell 6. Then, the air introduction valve 13 is opened to introduce air, and the measurement tube 5 and measurement cell 6 are cleaned by sniffing. After cleaning, the cleaning water is discharged by an operation similar to the discharge process described above.

3) Problems with the Prior Art The conventional example of the sludge volume JIA measuring device has been described above with reference to FIG. 1, but it is a fairly complicated and expensive device.

That is, (1) two measurement units, an ML88 measurement unit and an SV measurement unit, are required. (2) ML from an electrical circuit perspective
S S measurement circuit, ML8S value data hole F circuit, 8■
Measurement measurement M, SVI (, = 8V (*) / MLSSWb
)) Requires an arithmetic circuit (3) MLS8, 8V
Since both methods use an optical measurement method, cleaning water must be introduced into the SV measurement tube and the MLSS measurement cell after each measurement, and further cleaning must be carried out by bubbling air. Must be.

Therefore, the structure is simple and it is easy to use svt,
A device that can obtain sv and ML588 is desired.

4) Object and structure of the invention The present invention has been accomplished in response to the above request 1.
V #I Measures the SV and the sludge concentration in the settling part after a predetermined period of time in a fixed pipe, and calculates the MLSS by multiplying the SV value and the sludge concentration. The aim is to provide inexpensive equipment.

5) Examples of the invention An embodiment of the present invention will be described with reference to FIG.

Note that in FIG. 2, 2 to 5 degrees, 7 to 11 degrees, 21 to 23 degrees, and 31.32 are the same as in FIG. @1 of the conventional example, so a detailed explanation thereof will be omitted.

40 is a plurality of ultrasonic transmitters arranged and attached in the vertical direction (2) on the side wall of the measuring tube 5;
; A long ultrasonic receiver (a combination of a plurality of ultrasonic receivers may be used) is attached to the side wall of the measuring tube 5, facing the ultrasonic transmitter 40. 42 is an amplifier for amplifying the received signal from the ultrasonic receiver 41; 43 is a level determination circuit for determining whether the received signal is at a certain level or higher; 44 is an oscillation circuit 45t for controlling and level This is a control circuit that receives the 4IT signal from the determination circuit 43 and sends to the conversion circuit 46 a signal indicating from which ultrasonic transmitter the ultrasonic wave was received with an intensity equal to or higher than a certain value.

47 is a sludge concentration measuring circuit for receiving a signal from the multiplier 42 and determining the sludge concentration (9%) based on the magnitude C of the signal; 48 is a circuit for calculating sludge concentration (100/i); This is a reciprocal calculation circuit.

Further, 49 is a multiplication circuit for multiplying the Sv′ value obtained by the conversion circuit 46 and the concentration D (%) obtained by the sludge concentration measurement circuit 47.

The definition of Sv■ is It is.

The sludge floating matter dispersed in the predetermined line (11) of the 8V measuring tube (-) of the sampled sludge liquid is measured for the predetermined Sv measurement time (3
After 0 minutes), tk precipitates at the bottom of the measuring tube, i.e., the precipitate part (- is concentrated, and its am degree is lOO/5
v(aIb) Theal.

Therefore, the sludge concentration D (%) in the settling part is as follows. Therefore, 5vS) SVI is required.

In addition, as shown in equation (4), the ML
You can also find 8B.

As described above, conventionally, 5VI5 was determined by determining Sv and ML88, but the apparatus of the present invention is characterized in that 8VI and 1viL88 are determined by measuring sludge 11f and Sv in the sedimentation part.

Next, the series of operations will be explained step by step.

■ Sampling process First, open the valve 2 and the three-way valve 3, operate the air pump 4, reduce the pressure inside the measuring tube 5, and sludge liquid 8 in the aeration tank 7.
is sucked through the pipe 9 and collected in the Sv measurement 5. A level meter 10 is provided to make this collection basket have a predetermined volume of 1 t (1/), and when the sludge liquid is collected to the predetermined level of the 8V measuring tube 5, the valve 2 and the three-way valve 3 are closed, and the air pump 4 is stopped. Then, open the atmospheric release valve 11 to bring the inside of the S① measuring tube 5 to atmospheric pressure.

0 Grass measurement process (A) 8 V m Constant S ■ When the sludge liquid in the measuring tube 5 is allowed to stand still for a predetermined time (30 minutes), it is divided into a sludge settling part 21 and an F clear liquid part 22, and a boundary surface 23 is formed. Sanru. Control circuit 4
4 Control the oscillation circuit 45 from G2 to sequentially emit ultrasonic waves from the lower side of the ultrasonic transmitter 40, receive the ultrasonic waves with the ultrasonic receiver 41, and transmit the received ultrasonic waves. A level judgment circuit 4 determines whether the sound wave intensity is above a certain value.
3 and sends a determination signal to the control circuit 44.

Since the ultrasonic waves emitted from the ultrasonic transmitter located at the height of the sludge sediment 21 are attenuated by the sludge, the reception intensity is set by the level determination circuit 43.
It is below the fixed value. And above the precipitation boundary surface 23 (
: Since the ultrasonic waves emitted from the located ultrasonic transmitter are not subject to sludge attenuation, the reception intensity is equal to or higher than a certain value set by the level determination circuit 43. In this way, the height of sludge precipitation can be measured by detecting which number of light sources the ultrasonic waves emitted from are received with an intensity above a certain value, and the SV value can be determined through the conversion circuit 46. .

(b) Since the height of sludge sedimentation was measured in the 8V measurement of sedimentation sludge concentration measurement (1), the control circuit 44 controls the oscillation circuit 45 to transmit the ultrasonic transmitter located below the sedimentation viewing surface 23. An ultrasonic wave is emitted from one, and the concentration of the settled sludge is measured from the intensity of the ultrasonic wave received by the ultrasonic receiver 41 by the sludge measurement circuit 47.

(2) Calculation of SVI value The sludge concentration in the sedimentation section 21 measured as described above is inputted to the reciprocal calculation circuit 48, and 100/l)=svi value is determined and output.

■SV<@ value from MLS8 calculation conversion circuit 46 and settled sludge result f D from sludge concentration measurement circuit 47 (*) is multiplication circuit 49-
Two people are forced (SV) xt) = MLSS (punishment is sought and output.

■When the discharge process and above operations are completed, open the valve 2 and the three-way valve 31, operate the air pump 4, pump air from the upper part of the Sv measuring pipe 5, pressurize it, and discharge the sludge liquid in the Sv measuring pipe through the pipe 9. do.

In addition, since the ultra-high wave measurement method is not affected by the effects of dirt like the optical measurement method, there is no need to introduce clean water to clean the inside of the SV measurement pipe after each measurement. therefore,
The cleaning operation of opening the cleaning water valve 32 and introducing cleaning water may be performed every certain period.

In addition, in this Example C2, the sludge strength was determined based on the intensity of the ultrasonic waves from the ultrasonic transmitter that determined the SV value, so the concentration distribution of the sediment was not uniform in the height direction. In some cases, measurement errors occur. A means for solving this problem will be explained using FIG. 3.

To measure the settled sludge concentration, ultrasonic waves are sequentially emitted from all the ultrasonic transmitters located below the settling boundary surface 23, and the ultrasonic intensity received by the ultrasonic receivers is measured at each height position. The settled sludge of D is measured once, and the average value of D is determined by an averaging circuit 50. By determining the average concentration of C in this way, the influence of the concentration distribution at the interface can be removed.

6) Effects of the Invention The conventional device required two measurement sections, an MLS8 measurement cell section and an 8V measurement tube section, and also required an MLBS value data hold circuit, making the device complicated and expensive.

On the other hand, according to the present invention 1, an 8V measuring tube is required, and 8V, SVI, Ml, 88
It is possible to provide an activated sludge suspended solids-l measuring device which has a simple configuration and is inexpensive, which can determine the values of the three measurement items.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional measuring device, FIG. 1J42 is a block diagram showing one embodiment of the present invention, and FIG. 3 is a circuit diagram showing another embodiment of the present invention. 40... Ultrasonic transmitter 45... Oscillation circuit 41...
- Ultrasonic receiver 46... Conversion circuit 42... Amplifier 47... Sludge concentration measurement circuit 43... Level judgment circuit 48... Reciprocal conversion circuit 44... Control circuit 49... Multiplier circuit Agent Patent Attorney Gansuke Norichika
(1 other person) Figure 2 Figure 3

Claims (1)

[Claims] Collect the sludge liquid with a predetermined content (for example, 11) in the measurement pipe, and after allowing it to stand for a predetermined period of time (for example, 30 minutes), measure the volume (SV) and sludge concentration (D) of the sludge settling part formed, By multiplying this sludge volume (8V) and sludge concentration (L), activated sludge suspended matter (Ml, 88)11
An activated sludge suspended matter concentration measuring device characterized in that it measures 1 degree.