JP3452162B2 - Water quality control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, water quality control system of batch-type activated sludge process to remove the nitrogen your <br/> by beauty Li down in the wastewater biologically It is about. [0002] The nitrogen Motoma other in conventional wastewater quality control system for batchwise activated sludge method in which phosphorus removal, stirring and aeration process time operation administrator set manually by a timer or the like Had control. However, due to fluctuations in the amount of water flowing into the batch tank and its components, it has been difficult to always perform optimal control only by timer control. [0003] Further, when control is performed using a water quality measuring device such as a dissolved oxygen concentration (DO) or an oxidation-reduction potential (ORP), the DO value is controlled by a DO meter and the DO and ORP meters are controlled by a constant value. ORP upper limit control was performed. However, also in this case, the control is one-input and one-output, in which one value is controlled by one measuring device, so that it is difficult to control when the measuring device or the like is abnormal. Japanese Patent Application Laid-Open No. 3-284398 discloses a fuzzy inference of the air flow rate and the target value of DO in an aeration tank by an ORP meter and a pH meter in an activated sludge method of sewage treatment in a continuous flow continuous aeration system. An apparatus to be used and controlled is shown. Further, Japanese Patent Application Laid-Open No. 5-31488 discloses that, in an activated sludge method for continuous-flow intermittent aeration type night soil treatment, the amount of air blown and the aeration time are determined by fuzzy inference using DO, pH, ORP, and ammonium or oxidized nitrogen. A control method is shown. However, these techniques have been described for a continuous flow activated sludge process, not for a batch activated sludge process, and have no mention of controlling the stirring step time. [0005] Since INVENTION Problems to be Solved conventional nitrogen Motoma other water quality control system for batchwise activated sludge method involving phosphorus removal is constructed as described above, performs optimum control in timer control This is difficult, and when control is performed using a water quality measuring device, it is difficult to control when the measuring device or the like is abnormal. In addition, there is a device that performs fuzzy control using a water quality measuring device, but there is a problem that the device is based on a continuous flow activated sludge method and is not intended for a batch activated sludge method. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides a water quality control device that optimally controls a stirring process time and an aeration process time by performing fuzzy control using a water quality measuring device. The purpose is to: [0007] A water quality control apparatus for a batch type activated sludge method according to the present invention comprises:
Based on a measurement sensor that measures pH and oxidation-reduction potential, and fuzzy inference based on the above three measured values,
A fuzzy controller for turning on and off the blower for aeration and controlling the stirring process time and the aeration process time in the batch tank, respectively , is provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment Hereinafter, an embodiment of the present invention will be described. Figure 1 is a block diagram showing a water quality control system for batchwise activated sludge method involving nitrogen and Li emissions removed according to the first embodiment of the present invention. In the figure, 1 is batch tank provided in wastewater treatment facilities , 2 are provided in the batch tank 1 and the dissolved oxygen concentration (D
O), pH, a measurement sensor for measuring the oxidation-reduction potential (ORP), 3 turns on / off the blower 4 by fuzzy inference based on the measurement value of the measurement sensor 2, and agitates the batch tank 1 and aeration process time. it is a fuzzy controller to control. Na us, measuring sensor 2, the water level of the added batch tank 1 to these measured values are measured, may be added to the control. Further, when the amount of water flowing into the batch tank 1 is small and cannot be controlled only by the aeration step time, the amount of air blown may be controlled. Next, the operation will be described. FIG. 2 shows stirring and aeration of the batch tank 1 when the fuzzy controller 3 controls the blower 4 on / off by fuzzy inference based on three kinds of measured values of DO, pH and ORP measured by the measuring sensor 2. It shows the process time. FIG. 3 is a comparison of experimental results of timer control and fuzzy control in the batch activated sludge method. Compared with timer control and fuzzy control, the nitrogen removal rate is greatly improved from 67% to 91%. And the phosphorus removal rate is 58% to 79%.
%. As described above, the fuzzy controller 3 optimally controls the stirring and the aeration process time of the batch tank 1, so that nitrogen and phosphorus removal can be performed with higher efficiency. Further, it goes without saying that the apparatus of this embodiment can be applied to a case where only nitrogen removal or phosphorus removal is required. Incidentally, in this embodiment, because of the use of continuous measurement possible measuring sensor 2, it is possible to fuzzy inference stirring and aeration process time of the fuzzy controller 3 by batch tank 1, for example every minute, also, 3
Since the stirring and aeration step times of the batch tank 1 are controlled based on the measured values of the species , the stirring and aeration step times could be more finely and optimally controlled. As described above, according to the present invention, fuzzy inference is performed based on three types of measurement values of a measurement sensor for measuring dissolved oxygen concentration, pH and oxidation-reduction potential in a batch tank. since it is configured to include a fuzzy controller for controlling each of the agitation and aeration process time, be varied inflow water and its components to the batch tank, it is possible to optimally control the agitation and aeration process time, the waste water Nitrogen and phosphorus can be more efficiently removed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a water quality control system for batchwise activated sludge method involving nitrogen and Li emissions removed according to a first embodiment of the invention. FIG. 2 is a characteristic diagram showing a control situation by a fuzzy controller. FIG. 3 is a table chart comparing experimental results of timer control and fuzzy control in the batch activated sludge method. [Explanation of symbols] Single batch tank 2 Measurement sensor 3 Fuzzy controller

Continuation of front page       (56) References JP-A-5-31488 (JP, A)                 JP-A-6-91294 (JP, A)

Claims (1)

(57) [Claims] [Claim 1] A measurement sensor for measuring the concentration of dissolved oxygen, pH, and oxidation-reduction potential in a batch tank, and aeration is performed by fuzzy inference based on the above three measured values. the use blower are turned on and off, batch tank stirring process time and the aeration process time quality control system for batchwise activated sludge method in which nitrogen and phosphorus removal and a fuzzy controller for controlling each of the.