JP2000254680A - Waste water treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate a microorganism tank under the condition of the highest microorganism activity and to increase a water draining capacity by regulating the supply rate of the raw water to be supplied to the microorganism tank for the purpose of executing the treatment of the raw water according to the quality of the cleaned water after cleaning in the microorganism tank at the time of the waste water treatment by an activated sludge method. SOLUTION: At the time of the waste water treatment in a food related factory, etc., where the fluctuation of the quality of the inflow waste water is large, the raw water stored in a raw water tank 2 is supplied through a supply pump 3 by a supply pump 4 to the microorganism tank 1 deposited with the microorganisms. A discharge pipe 6 is connected to the microorganism tank 1 and the purified water resulted from the cleaning of the raw water in the microorganism tank is discharged through this discharge pipe 6. The discharge pipe 6 is provided with a cleaned water quality measuring instrument 7 for measuring the quality of the cleaned water and the measured value thereof is inputted to a controller 5. If the measured value is larger than the upper limit value of a set range, a signal is outputted to the supply pump 4 to the controller 5 to decrease the supply rate of the raw water by the supply pump 4, by which the supply of the raw water of the microorganism tank 1 is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is applied to the treatment of organic wastewater, especially human waste in a human waste treatment plant where the quality of inflow wastewater varies greatly, and the treatment of wastewater in food-related factories and storage facilities.

[0002]

2. Description of the Related Art Conventionally, in a wastewater treatment method using the active body method, as shown in FIG. ORP (redox potential), DO (dissolved oxygen), pH, etc. are measured with each of the instruments c to e, and the state of the microbial vessel a with the change in the BOD amount (microbiological oxygen demand) is measured. Blower g by control device f based on
, The amount of air supplied to the microorganism tank a is changed, and stable operation is expected.

[0003]

However, the above-mentioned conventional waste water treatment method using the active body method has the following problems.

[0004] First, the scale of the microbial tank is designed with reference to the amount of BOD per unit time in the raw water supplied to the microbial tank based on the highly contaminated raw water. When deciding the scale of the processing equipment from experience, the scale is inevitably too large considering the safety factor.

[0005] In the operation of the actual apparatus, even if the operation state in the microbial vessel is in a stable state, the inflow B
Depending on the increase or decrease of the OD amount, a change in the microorganism tank is required. The countermeasures will be taken by increasing or decreasing the amount of air blown by the blower. However, the effect obtained by this operation usually does not appear until 4 to 6 hours have elapsed. Therefore, the operation condition of the microorganism tank during that time is extremely unstable, and the deterioration of the purified water quality and the excessive aeration phenomenon are inevitable.

As a result, the operator of the wastewater treatment facility requires a high degree of experience and skill, and it is necessary to check the indication of each instrument and, if necessary, analyze the purified water to perform an appropriate operation.

That is, as in the conventional wastewater treatment method, in which the raw water supply speed is fixed and the amount of the blown air is adjusted in response to the change in the inflow BOD amount, as described above, the rapid change of the microorganism tank is performed. Was not enough.

[0008] The present invention has been made in view of the above problems, and in order to stabilize the operation state of a microorganism tank, the supply amount of raw water to the microorganism tank is changed according to the state of the microorganism tank. It is an object of the present invention to enable the operation of the microbial tank in an environment with the highest microbial activity.

[0009]

According to a wastewater treatment method of the present invention, in a wastewater treatment method based on the active body method, a supply amount of raw water supplied to a microorganism tank for treating raw water is purified by the microorganism tank. It is adjusted according to the quality of the purified water after the cleaning.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of equipment for carrying out the wastewater treatment method of the present invention.

The raw water stored in the raw water tank 2 is supplied through the supply pipe 3 into the microorganism tank 1 on which the microorganisms have been implanted.
Is supplied by the supply pump 4 provided in the first stage.

The raw water stored in the raw water tank 2 is, for example, human waste processed in a human waste processing plant, and wastewater discharged from a food-related factory or a storage facility.

As the supply pump 4, a variable flow rate pump is used. The supply pump 4 is driven and controlled based on a control signal from a control device 5 to be described later. The supply of raw water is regulated.

A discharge pipe 6 is connected to the microorganism tank 1, and discharges purified water obtained by purifying raw water in the microorganism tank 1 through the drain pipe 6.

The discharge pipe 6 is provided with a purified water quality measuring device 7 for measuring the quality of the purified water. The object to be measured by the purified water quality measuring device 7 is appropriately determined according to the quality of the raw water, and for example, the amount of NH3-N (ammonia nitrogen),
Examples include the amount of TN (total nitrogen) and the amount of TC (total carbon), and it is also conceivable to refer to the reference water quality of purified water discharge.

The measured value measured by the purified water quality measuring device 7 is input to a control device 5, which outputs a drive signal to the supply pump 4 based on the measured value. Adjust the feed rate of the feed.

More specifically, if the measured value measured by the purified water quality measuring device 7 is within a preset setting range, the control device 5 controls the supply pump 4 without changing the drive of the supply pump 4. Continue supplying raw water.

On the other hand, if the measured value is larger than the upper limit of the set range, a signal is output from the control device 5 to the supply pump 4 so that the supply speed of the raw water by the supply pump 4 is reduced, and Reduce the supply of raw water.

If the measured value is smaller than the lower limit of the set range, the controller 5 outputs a signal to the supply pump 4 to increase the supply speed of the raw water by the supply pump 4,
The supply amount of raw water to the microorganism tank 1 is increased.

The adjustment of the amount of raw water supplied to the microbial tank 1 by controlling the drive of the supply pump 4 by the control device 5 is obtained empirically, and the data obtained through this experience is used as the control device. Is programmed to

By adjusting the supply amount of the raw water to the microbial tank 1 in this manner, the purification processing is performed in the microbial tank 1 with the highest microbial activity. Ability can be greatly improved.

Further, each of the instruments 8 to 8 for measuring the values of ORP, DO, pH, etc. of the raw water in the microbial tank 1 as auxiliary instruments.
By providing 10, the values measured by the meters 8 to 10 are also added to the flow rate change program of the supply pump 4 in the control device 5 together with the measurement values measured by the water quality measuring device 7, so that the control device 5 can improve control accuracy.

Reference numeral 11 in FIG. 1 denotes a blower for supplying air necessary for the activity of microorganisms to the microorganism tank 1.

The above-described wastewater treatment method of the present invention can be easily implemented by providing a purified water quality measuring instrument 7 in existing equipment and making the supply pump 4 variable.
This is a great advantage in implementing the wastewater treatment method of the present invention.

The means for adjusting the supply amount of raw water to be supplied to the microbial tank 1 is not limited to the one that drives and controls the variable supply pump 4 as in the present embodiment.
It is needless to say that any means capable of adjusting the amount of raw water supplied to the plant can be applied. For example, the above means can also be achieved by providing a variable flow control valve in the supply pipe 3.

[0027]

Next, specific examples in which the wastewater treatment method of the present invention and the conventional wastewater treatment method are performed will be described. The example described here was performed at a human waste treatment plant,
The scale and operation status of the urine treatment plant are as follows.

The equipment design value is that the inflow BOD amount is 6250 mg
/ L, treatable amount is 130 kl / day, BOD removal rate is 9
9%.

In this equipment, the above-mentioned additional equipment is installed, and as a specific method of performing the wastewater treatment method of the present invention, purified water is collected every 30 minutes, and the amount of NH3-N is analyzed. The operation was performed by adjusting the supply speed of the supply pump 4 so that the value was 5 mg / l or less.

Table 1 shows general ORP values and DO values which are a rough guide in the microbial tank during the operation.

[0031]

[Table 1]

In the method of the present invention, the ORP value, D
The operation was performed with reference to maintaining the O value and pH at the values shown in Table 2.

[0033]

[Table 2]

As a result, as shown in Table 3, the wastewater treatment method of the present invention has a treatment capacity of about 1.
8 times.

[0035]

[Table 3]

That is, even if the raw water state changes, in the wastewater treatment method of the present invention, the load on the microorganism tank 1 is constant, so that the microorganism tank 1 is stable and the purified water quality is also constant.

In addition, since the operation management can be automatically performed by each instrument, the management is simplified, and it is not necessary to require the driver to have a high level of skill. Further, the quality of purified water is stabilized, so that the number of times of analysis is reduced. Costs can be reduced in this respect. For example, according to the conventional method, the analysis is performed three times a week. However, according to the method of the present invention, the analysis can be performed once a week.

[0038]

As described above, according to the wastewater treatment method of the present invention, the supply of raw water to the microbial tank is changed according to the state of the microbial tank, whereby the operation of the microbial tank can be controlled by the microbial activity. Can be operated under the highest conditions, thereby increasing the capacity of existing equipment and reducing the size of new equipment.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of equipment for carrying out a wastewater treatment method of the present invention.

FIG. 2 is a diagram showing a schematic configuration of equipment for performing a conventional wastewater treatment method.

[Explanation of symbols]

 Reference Signs List 1 Microbial tank 4 Supply pump 5 Control device 7 Purified water quality measuring instrument

Claims (1)

[Claims] 1. A wastewater treatment method according to an active body method, wherein a supply amount of raw water supplied to a microorganism tank for treating raw water is adjusted according to the quality of purified water purified by the microorganism tank. A wastewater treatment method.