JPH0347158B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an inflow load distribution control device for a water treatment system that purifies sewage or industrial wastewater using microorganisms.

(Prior Art) Organic wastewater such as sewage and industrial wastewater is purified by the action of microorganisms such as activated sludge and anaerobic microorganisms. Particularly in recent years, anaerobic treatment using anaerobic microorganisms has attracted attention from the viewpoint of energy conservation.

This anaerobic treatment method decomposes organic matter using the action of anaerobic microorganisms. It mainly consists of a two-step gasification process in which carbon dioxide is decomposed into carbon dioxide and methane. Bacteria that perform the liquefaction reaction are called acid-producing bacteria, and bacteria that perform the gasification process are called methane bacteria. In this way, anaerobic treatment yields fermentation gas containing 50 to 70% methane, and by utilizing it effectively, energy conservation can be promoted.

In such water treatment systems, a configuration having a plurality of reactors is common, especially when purifying a large amount of wastewater such as in sewage treatment. Conventionally, in such water treatment systems, the amount of wastewater flowing into a plurality of reactors is controlled to be equal. In this conventional example, operation management is very easy, but on the other hand,
It had the following shortcomings: That is, the purification ability of microorganisms may decrease for some reason, and this cannot be avoided with current technology. When the purification capacity decreases, it is necessary to carry out operational management to reduce the inflow load and further prevent the purification capacity from further decreasing. However, in the conventional example where the amount of inflowing wastewater is evenly distributed to multiple reactors, such measures cannot be taken. For this reason, in a reactor whose purification ability has decreased for some reason, the purification ability is further decreased and the quality of the treated water deteriorates.

(Problems to be Solved by the Invention) In other words, the amount of wastewater flowing into the reactor could not be controlled, and the quality of treated water sometimes deteriorated due to a decrease in purification ability.

Therefore, the purpose of the present invention is to grasp the processing capacity of the anaerobic reactor from the PH distribution in the height direction within the anaerobic reactor, and to control the amount of inflow wastewater according to this processing capacity, so as to always maintain a good condition. An object of the present invention is to provide an inflow load distribution control device for a water treatment device that allows treated water to be obtained.

[Structure of the invention]

(Means for Solving the Problems) The present invention relates to an inflow load distribution control device for a water treatment device in which an anaerobic reactor is provided for each of a plurality of inflow pipes branched from a wastewater inflow pipe.
A flow meter is provided to measure the flow rate of wastewater flowing into the wastewater inflow pipe, and a PH meter is provided for each of the anaerobic reactors to measure the PH distribution in the height direction inside the reactor. In addition, each of these
A means for inputting the measured value of the PH meter and determining the height at which the PH value starts to decrease as the processing capacity for each anaerobic reactor, and a means for determining the height at which the PH value starts to decrease as the processing capacity of each anaerobic reactor, and the wastewater inflow pipe according to the processing capacity determined for each anaerobic reactor. A device having means for determining the amount of inflow wastewater flowing into the anaerobic reactor to be distributed to each anaerobic reactor is used.

(Function) In the present invention, the
The PH distribution in the height direction of the reactor is measured using a PH meter, and the processing capacity of each anaerobic reactor is calculated from this. That is, organic matter in wastewater is first decomposed into volatile organic acids by the action of acid-producing bacteria. Therefore, the PH is low near the wastewater inlet of the anaerobic reactor, and gradually increases toward the treated water outlet as volatile organic acids are decomposed into methane and carbon dioxide gas. In this case, if the region with low pH is wide, volatile organic acids may flow out of the anaerobic reactor without being sufficiently gasified. In this way, the processing capacity of the anaerobic reactor is calculated based on the PH distribution in the height direction of the reactor, and then the inflow wastewater to each anaerobic reactor is distributed according to the processing capacity.

(Embodiment) FIG. 1 shows an embodiment of the present invention, and is a schematic block diagram of a water treatment facility consisting of n anaerobic reactors 6a, 6b, . . . , 6n.

In the figure, a pump 2 and a flowmeter 3 are installed in a wastewater inflow pipe 1, and the flowmeter 3 measures the flow rate of inflowing wastewater. In addition, flow meters 5a, 5b,..., 5n are installed in each of the branched wastewater inflow pipes 1a, 1b,..., 1n, and these flow meters 5a, 5b,..., 6n to each anaerobic reactor 6a, 6b,..., 6.
The amount of wastewater flowing into each of the n is measured. Furthermore, in each wastewater inflow pipe 1a, 1b,..., 1n,
Control valves 4a, 4b, . . . , 4n are provided, respectively, to adjust the amount of wastewater flowing into the corresponding reactors 6a, 6b, . . . , 6n to a desired value. Treated water pipes 10a, 10b, . . . , 10n are connected to the outflow side of each of these reactors 6a, 6b, . Further, PH meters 7a, 7b, . . . , 7n are provided in each of the reactors 6a, 6b, . Each reactor 6a, 6b,..., 6n
Fermentation gas is generated from the tank, which is led to a gas tank (not shown) through a gas pipe and is used as fuel for a heat source. Reference numeral 9 denotes a calculation device which inputs each measurement signal from the flow meter 3 and each PH meter 7a, 7b, .
Determine the amount of influent wastewater of 1n. 8a, 8b,...,
8n is a flow rate adjustment device, and each wastewater inflow pipe 1a, 1
b, ..., 1n, and in order to obtain the amount of inflow wastewater determined by the arithmetic unit 9, while inputting the values of the corresponding flowmeters 5a, 5b, ..., 5n, the corresponding control valves 4a, 5n are operated. Adjust the opening of 4b,..., 4n.

Here, each anaerobic reactor 6a, 6b,..., 6n
The PH meters 7a, 7b, ..., 7n installed inside the reactors 6a, 6b, ..., 6 correspond to
Measure the PH distribution in the height direction within n. in this case,
A plurality of PH meters may be installed in one anaerobic reactor, or one PH meter may be moved vertically for measurement. When the treatment is carried out well, there is almost no PH distribution within the reactor as shown in Figure 2a, but if the treatment capacity of methane bacteria decreases or the inflow load is too large, , as shown in Figure 2 b and c, the pH gradually decreases from the bottom of the reactor. Therefore, the processing capacity of an anaerobic reactor can be evaluated based on the height of the reactor at which the PH begins to decrease. The calculation unit 9 has each PH
A total of 7a, 7b, . . . , 7n signals are inputted, and are compared with preset values for each height inside the reactor to determine the reactor height at which the PH starts to decrease. The processing capacity of each anaerobic reactor 6a, 6b, . . . , 6n is determined based on the height at which the pH starts to decrease. Next, based on this result, distribution ratios w ₁ , w _{2 ,} . The following equation is shown as an example of a method for calculating this distribution ratio.

w ₁ =H ₁ /H ₁ +H ₂ +…+H _o w ₂ =H ₂ /H ₁ +H ₂ +…+H _o 〓 w _o =H _o /H ₁ +H ₂ +…+H _o where w _1~o : Distribution ratio H1 _~o : Reactor height at which PH starts to decrease (height from the top of the reactor) Next, based on the above distribution ratio w and the output Q _T of the flow meter 3 installed in the wastewater inflow pipe 1, Target values Q ₁ , Q ₂ for the amount of wastewater flowing into each anaerobic reactor according to the following formula:
..., calculate Q _o .

Q ₁ =w ₁ ×Q _T Q ₂ =w ₂ ×Q _T 〓 〓 Q _o =w _o × _Q TTarget value of inflow wastewater amount obtained in this way Q ₁ ,
Q ₂ ..., Q _o are output to each regulating device 8a, 8b, ..., 8n, and the wastewater inflow pipe 1 is adjusted so that the target value is achieved.
Valve 4 installed at a, 1b, ..., 1n
The opening degrees of a, 4b,..., 4n are adjusted.

In addition, although the above-mentioned example explained an upward flow type reactor, it is not limited to an upward flow type, and can be similarly applied to a downward flow type reactor.

〔Effect of the invention〕

As described above, according to the present invention, the amount of inflowing wastewater can be controlled according to the processing capacity of the anaerobic reactor, so that good quality treated water can be obtained at all times, and water treatment facilities can be operated and managed in a stable manner. be able to. Furthermore, since the processing capacity is determined by measuring the pH inside the anaerobic reactor, the processing capacity of the anaerobic reactor can be directly grasped and highly accurate control can be performed.

[Brief explanation of drawings]

Fig. 1 is a schematic block diagram showing an embodiment of the inflow load distribution control device for a water treatment equipment according to the present invention, and Fig. 2 a, b, and c are characteristic diagrams showing the PH distribution in the height direction of the anaerobic reactor. . 3...Flowmeter, 4a, 4b, ~, 4n...Valve, 5a, 5b, ~, 5n...Flowmeter, 6a, 6
b, ~, 6n...anaerobic reactor, 7a, 7b,
~, 7n... PH meter, 8a, 8b, ~, 8n... Adjustment device, 9... Arithmetic device.

Claims (1)

[Scope of Claims] 1. In an inflow load distribution control device for a water treatment device in which each of a plurality of inflow pipes branched from a wastewater inflow pipe is provided with an anaerobic reactor, the flow rate of wastewater flowing into the wastewater inflow pipe is The system is equipped with a flow meter that measures the pH distribution of each anaerobic reactor, and a PH meter that is installed in each of the anaerobic reactors and measures the PH distribution in the height direction inside each anaerobic reactor. means for determining the height at which the PH value begins to decrease as a treatment capacity, and distribution of inflow wastewater flowing into the wastewater inflow pipe to each anaerobic reactor according to the treatment capacity determined for each anaerobic reactor. An inflow load distribution control device for a water treatment device, comprising: a calculation device having means for determining an amount.