JPS58196889A - Controlling method for quantity of oxygen supplied into aeration tank - Google Patents

Abstract

PURPOSE:To reduce disturbances and facilitate control of the quantity of oxygen supplied to water to be treated, by a method wherein the concentration of dissolved oxygen in water being treated in an aeration tank is detected, and a quantity of oxygen which quantity is set on the basis of a specified estimating formula at a new moment is supplied at a set time. CONSTITUTION:Water to be treated such as feces, town sewage and industrial waste water is supplied into the aeration tank 3 in which an aeration treatment of the water is conducted by blowing air (sucked in by a blower 1) into the water through a diffusing pipe 2. In said aeration tank 3, the quantity Fi+1 of oxygen to be supplied at a new moment is set at a set theta (e.g., 10min) by calculating on the basis of Formula I , from the concentration Ci of dissolved oxygen in the water detected by the first detector 4 and the quantity Fi of oxygen supplied which is detected by the second detector 5. A flow control valve 6 is automatically operated so as to supply the thus set quantity of oxygen, whereby the quantity of oxygen supplied is controlled so that the concentration of dissolved oxygen within the tank 3 becomes constant.

Description

[Detailed description of the invention] mA
The 1'S supply filter to 1Idl is adjusted at set time intervals to control the V-storage combined supply to the air tank.

As described in Japanese Unexamined Patent Application Publication No. 1986-1, the conventional method is to add the inflow sewage lid, floating material storage, oxygen supply lid, and stored acid search rate at each set time. 40 However, at present, the measurement accuracy of suspended solids concentration is low;
Since the measured value of the suspended solids concentration is introduced, there is a drawback that the disturbance is large and leads to poor control, and changes in the substrate concentration are ignored, making it difficult to perform good IJ. There were no drawbacks.

In view of the above points, Zero-Hatsu 1 is designed to ensure good oxygen supply with minimal disturbance, regardless of changes in the properties of sewage, by simply measuring the current level of the rope and the oxygen supply vehicle. Next, embodiments of the method of the present invention will be described with reference to illustrative drawings.

Various types of treated water such as human waste, urban F water, and industrial wastewater are supplied and sucked by a blower (fl). The aeration tank (
In 3), the dissolved acid **JJi (C) in the treated water detected by the first detector (4) and the acid supply (Fi) measured by the second detector (6) were determined. The oxygen supply ji (Fj + m adjustment valve (
6), operate the VC manually and close the acid nest supply lid so as to keep the ambient oxygen concentration in the aeration tank (3) constant.

Kuninaka (7) shows a post-processing device, such as tA:, m
Six types of treatment systems, such as water treatment, floating separation tanks, etc., are applied in consideration of the risk of fire.

In the above ml prediction formula, (SN) is saturated dissolved oxygen once,
(C) is the concentration of the drug present, which is set as a constant, and (nl) is the shape of the air tank and the
Next, this prediction formula will be explained.

Change the w book supply cliff every set time (θ), then i4j
If considered at the point of view, the amount of oxygen dissolution rate (OTR) is
@Oxygen supply into air tank (3)ff1 (Fl) and 1eiqi4
13) Nitogakawa et al. is proportional to the degree of acid deficiency (St-ct) in L is reduced by the following formula.

[0T11] i = l old ・eyes (s+-c roar)
(1) tKi: A constant determined by the aeration tank's nozzle shape, separation, sewage properties, etc.
) The above fiklk dissolution rate (OTR) i
dc1/dt ``1lci @F1 (St-C1
) −(U, hai)i (2) Setting II
If the acid uniformity of the −f plane (of
-CiJdt-L1. R month dt -t3J is attached. Then, by setting aside the set time, +1 and (υ
, R) If j is determined to be approximately constant, ``'' is added.

1. - If the oxygen transmission to the air tank (3) is set to the appropriate shielding (Fr), then during the actuation, the oxygen concentration (CA) will remain constant and reach the target value (Fr). When C) is reached, both ICdC/dt = (J. Therefore, the (21st formula t
c i-person-T and 8 ni Maki] J and 10, tKi-Fr'
f (61-C town dt; (tJ, R) i・Otb+ or boat.

From the +41 formula and (01 formula, if you remove (U, January and θ),
tKt-Fr/", (St-c") at =lKr-
pt /': (St-Cs> (1 to 1Δc +a+
Therefore, the following is given. Based on this, F is defined as shown in the following equation as an approximate value of Fr.

As a result, the sour P and supply at the i+1th set time increment are calculated using formula 81. The following equation is calculated as a prediction equation for the acid system supply at the time - (Fi+).

In the above equation, the saturated dissolved acid wood TIk degree (St) varies with time, but the fact that the dissolved oxygen concentration (St) is smaller in the straw than in the dissolved oxygen content (DO) When combined in the b-hi joint test, the saturated dissolved tJlt elemental degree (
Assuming that the difference is constant, therefore, saturated dissolved acid 5I#
Assign the degree (Sl) to a constant and a predetermined numerical value.

As mentioned above, the dissolved oxygen concentration (CI) at that point, which can be detected by the first detection 11+4), is converted into electric No. 41 and inputted from the generator e4 (8) to the calculator (9)K,
The current oxygen supply M (Fi) detected by the second detector (6) is input to the calculator (9) K, and the constants -, (C), (θ) are input from the setting device (lO). Performance performance (9) K
When manually analyzed based on equation 111 (11), the axis I
! Based on this, the operation circuit for the 111th Arrival 11I4 valve (6) is given full power to the command E, and adjustments are made to supply the calculated amount of oxygen to the child. 1. As a result of controlling the amount of oxygen supplied as described above while reducing or increasing the substrate #ash and changing the properties of the wastewater to straw, *sg
Guku 7 as shown in the figure was obtained.

That is, the dissolved oxygen concentration (Ci) is 1lIllJ Omoku Keyaki value (
In a stable state close to C☆), both the oxygen supply amount (Fl), the saturated dissolved oxygen concentration (St), and the dissolved oxygen concentration (CI) remain almost constant with little change.

And 1. When the MS concentration decreases, the activated sludge oxygen @ reserve decreases, and the dissolved oxygen concentration (Ct) and the saturated dissolved oxygen concentration (S) increase, or the oxygen supply (Fi ) is adjusted in stages, and accordingly, the j-4th stage adjustment allows the dissolved oxygen concentration (C1) to shift to a stable state close to the control strain value (C), while the JK concentration increases. Even when the dissolved oxygen concentration (C and saturated dissolved oxygen fiK (Si) decreases), the oxygen supply jt (F) is maintained in step #1 to protect against the above control.
It is clear (7) that the dissolved acid system # degree (C1) can be transferred to a stable stage close to the secondary deviation at the s-j stage.
) 1J Therefore, even if there is a large change in the concentration in the water, if the set time is set to 10 minutes, stable sewage treatment can be performed over a period of time.

The present invention is applicable not only to a shallow m-air tank (3) of approximately 10 to J□θm, but also to a deep submersion type tank (3) that extends over 100 m, and a type that performs air treatment while flowing treated water in a zig-deg shape. Also, in the above ml prediction formula, an unreasonable number of sleeves is multiplied depending on the shape and type of the A bond (, 5), or the size of the treated water. In carrying out the present invention, the upper 6-pin setting time (θ) is not limited to 70 minutes, but may be adjusted between 1 and 1 as appropriate. Official setting 1J14! , is.

In summary, the present invention provides a method for controlling the amount of oxygen supplied that is officially registered, by detecting the concentration of sour candy remaining in the m-air tank]3),
Oxygen supply 1 (Fi + s) at a new time is expressed as 'Fjf' own prediction formula FI: Oxygen supply 1 at that time C1: Detected dissolved Flllk yield rate S at that time:
The limit of dissolved oxygen concentration that is considered to be fixed is 1. 1, which is characterized by a warning set in advance, that is, the dissolved oxygen concentration at that point (C1) and the oxygen supply fi (Fl) for the scheduled time/batch at that time are calculated using a predictive formula. Although it is bamboo, it is a lees w nest supply jt (FI
+1) can be set, thereby eliminating the need for large disturbances to the measuring element itself, such as measured values such as suspended solids concentration and suspended solids concentration, and regardless of columnar changes in sewage, the above-mentioned In response to these changes, M
! I am now able to supply 1ulJ evenly to the nest without any problem.

[Brief explanation of drawings]

The drawing is a complete example of a method of supplying acid to the water valve JK keeping 1 Qi bonds, and Figure 1 is a 70-sheet showing the Qi elm,
The second cause is Guku 7, which indicates the experimental results. Aerated cypress - Maki dI straw peeling r

Claims (1)

[Claims] @An oxygen supply m IIJ method to the air tank (3) in which the oxygen supply lid to the air tank (3) is adjusted at set intervals, and the dissolved oxygen in the aeration 4m +31 is Get used to concentration, new F1
= Il at that time * Supply cap C1: Detected dissolved M at that time Once saturated dissolved oxygen, which is regarded as a ridge in S ☆ C: Dissolved fR concentration set as a number in H Oxygen supply to the air tank, which is characterized by being set according to the condition and type of the air condition.
1tilJ hunger method.