JP5501146B2 - Flock formation state determination method, flock formation state determination device, agglomeration reaction tank, pH adjustment tank, and abnormality occurrence notification system - Google Patents

Description

  The present invention relates to a flock formation state determination method, a flock formation state determination device, and a floc formation state determination device for determining normality / abnormality of a flock formation state in a metal-containing wastewater treatment facility having a coagulation reaction step for forming a metal hydroxide floc, and The present invention relates to an agglomeration reaction tank provided with the floc formation state determination device, a pH adjustment tank installed in a previous process of the agglomeration reaction tank, and an abnormality occurrence notification system for reporting the occurrence of an abnormality in the aggregation reaction tank and the pH adjustment tank. .

  In the wastewater treatment of metal-containing wastewater containing zinc, manganese, iron and other heavy metals, wastewater treatment by the coagulation sedimentation method is widely adopted. In a metal-containing wastewater treatment facility that employs this wastewater treatment method, metal hydroxides in raw water (metal-containing wastewater) are colloidally deposited, and flocs of the metal hydroxide are formed in an agglomeration reaction tank. Treated water that has been treated to reduce the concentration of pollutants below the effluent standard set by the Water Pollution Control Law is discharged into public water areas such as ponds.

In this type of wastewater treatment facility, various wastewater treatment systems have been proposed in which the agglomeration reaction is normally performed so that the pollutant concentration in the treated wastewater is below a reference value.
For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2005-193203 “Water Treatment System”) describes according to the aggregation state of the water to be treated measured by the aggregation state measuring unit and the injection state of the pH adjusting agent by the pH adjusting agent injection control unit. , Which controls the injection of flocculant, especially when the pH of the water to be treated is out of the proper range, correct the control target value in the pH adjuster injection control means to make the pH of the water to be treated appropriate Then, the injection of the flocculant is controlled.
The aggregation state measuring means (aggregation sensor 11) in Patent Document 1 irradiates the minute region S with laser light guided from the light emitting unit 10 through the first optical fiber 1, and the minute colloidal particles in the minute region S are used. The generated scattered light is guided through the second optical fiber 2 directed toward the minute region S and received by the light receiving unit 20. As aggregation proceeds, the number of fine colloidal particles decreases, and the intensity of scattered light decreases. Therefore, the floc formation state is detected by measuring the scattered light intensity (paragraph number [0015]).
Details of the aggregation sensor are described in Patent Document 4 (paragraph numbers [0016], [0017], FIG. 2, FIG. 3, etc.).

  Patent Document 2 (Japanese Patent Application Laid-Open No. 2005-193204 “Water Treatment System”) provides a coagulation reaction tank with a coagulation state measuring means for detecting the state of coagulation flocs in a suspension and evaluates the quality of solid-liquid separation treated water. A water quality evaluation unit is provided, and the factor determining unit determines a factor of water quality fluctuation of the solid-liquid separation treated water in comparison with information obtained by the aggregation state measuring unit and the water quality evaluating unit. The aggregation state measuring means (aggregation sensor 11) is the same as that in the cited document 1.

In Patent Document 3 (Japanese Patent Laid-Open No. 2002-195947 “Aggregation Monitoring Device”), a laser beam irradiation unit 3 is connected to a laser oscillator 1 via a first optical fiber 2 and a scattered light receiving unit 4 is a second optical fiber. 5 is connected to the photoelectric conversion circuit 6 via 5, and the laser light output from the laser oscillator 1 is irradiated from the laser light irradiation unit 3 into the fluid to be measured (water to be treated). The scattered light scattered by the particles is received by the scattered light receiving unit 4 and converted into an electric signal by the photoelectric conversion circuit 6. Then, AM detection is performed, and the signal after this detection is taken into the minimum value detection circuit 8. The minimum value of intensity (scattered light intensity) is detected.
According to Patent Document 3, the minimum value of the fluctuating scattered light intensity is regarded as the scattered light intensity when only the minute colloidal particles (unaggregated colloidal particles) are present in the liquid. Is measured (that is, the aggregation state is measured) (paragraph numbers [0016] and [0030]).

JP-A-2005-193203 “Water Treatment System” JP-A-2005-193204 “Water Treatment System” JP 2002-195947 “Aggregation Monitoring Device” JP 2002-257715 “Particle state detection probe”

In each of the above conventional wastewater treatment systems, methods are shown to ensure that the agglomeration reaction is normally performed and the pollutant concentration in the treated wastewater is below the standard value. In the present invention, it is possible to effectively manage the concentration of pollutants at a low cost by using a relatively simple method using commercially available equipment in the existing metal-containing wastewater treatment facility in the factory. A metal-containing wastewater treatment facility, a floc-forming state determination method, a floc-forming state determination device, a coagulation reaction tank, and The purpose is to provide an anomaly reporting system.
Moreover, although the conventional aggregation sensor is immersed in the wastewater, if the sensor is immersed in the wastewater to constantly monitor the wastewater treatment, dirt is attached around the sensor and the sensor function cannot be performed. However, installing the sensor on the surface of the water solves the problem of contamination, but it causes a malfunction due to fluctuations in the surface of the water. Then, this invention is providing the method which can be measured from the surface of a water and does not cause the malfunction by the fluctuation | variation of a water surface.

The invention of claim 1 which solves the above-mentioned problem is a flock formation state determination method for determining normality / abnormality of a flock formation state in a metal-containing wastewater treatment facility having a coagulation reaction step for forming a metal hydroxide floc. And
A floc detection sensor capable of irradiating laser light toward the water surface and detecting the distance to the floc based on the reflected light from the floc in the water is disposed above the water surface of the treatment tank of the metal-containing wastewater treatment facility. and, the by flock detecting sensor detects the distance L to flock was sampled every first predetermined time T ₁ interval, the amount of change ΔL of the first set time T _each of the detection distance L is set When the step distance ΔL is greater than or equal to ₀ , an OFF signal is generated, and when it is less than the ON signal, the ON signal and the OFF signal are included within the second set time. Alternatively, the floc formation state is determined to be abnormal when the OFF signal continues for the second set time or longer.

The invention of claim 2 is a flock formation state determination device for determining normality / abnormality of a flock formation state in a metal-containing wastewater treatment facility having a coagulation reaction step for forming a metal hydroxide floc,
A floc detection sensor capable of irradiating laser light toward the water surface and detecting the distance to the floc based on the reflected light from the floc in the water is disposed above the water surface of the treatment tank of the metal-containing wastewater treatment facility. and, the floc detection sensor detects the distance L to flock was sampled every first predetermined time T ₁ interval, the amount of change ΔL of the first set time T _each of the detection distance L It has a function of issuing an OFF signal when the set step distance ΔL is greater than or equal to ₀ , and an ON signal when the distance is less than
The flock formation state is normal when the signal generated by the flock detection sensor includes the ON signal and the OFF signal within the second set time, and the flock formation state when the same ON signal or OFF signal continues for the second set time or more. Is provided with a flock formation state determination unit for determining that the device is abnormal.

The invention of claim 3 is a flock formation state determination device for determining normality / abnormality of a flock formation state in a metal-containing wastewater treatment facility having a coagulation reaction step of forming a floc of metal hydroxide,
Both are arranged above the water surface of the treatment tank of the metal-containing wastewater treatment facility, and projecting light that irradiates the projection light, which is laser light, toward the water surface, and the reflected light reflected by the flock in the water. a light receiving section adapted to receive a flocked distance detection unit for detecting a distance L to the flock and sampled every first predetermined time T ₁ interval based on the output of the light receiving section, the detection distance which the flock distance detection unit detects A flock detection sensor comprising: an ON / OFF signal generating unit that generates an OFF signal when the change amount ΔL of the first set time T _{1 of} L is greater than or equal to a set step distance ΔL _{0 and} less than the set step distance ΔL _0. Prepared,
When the signal output from the ON / OFF signal generator of the flock detection sensor includes the ON signal and the OFF signal within the second set time, the flock formation state is normal, and the same ON signal or OFF signal is the second signal. A flock formation state determination unit that determines that the flock formation state is abnormal when it lasts for a set time or longer is provided.

Invention of Claim 4 is an agglomeration reaction tank provided with the said floc formation state determination apparatus in the case where the processing tank in Claim 2 or 3 is an agglomeration reaction tank,
A sensor installation box having an opening into the agglomeration reaction tank is installed on the upper lid of the agglomeration reaction tank, and the flock detection sensor is arranged in the sensor installation box, and the lower part of the side wall of the sensor installation box Ventilation holes are provided at positions, and ventilation towers are provided at the ceiling.

The invention of claim 5 is an agglomeration reaction tank provided with the flock formation state determination device when the treatment tank in claim 2 or 3 is an agglomeration reaction tank,
A sensor installation box having an opening into the agglomeration reaction tank is installed on the upper lid of the agglomeration reaction tank, and the flock detection sensor is arranged in the sensor installation box, and one end is located near the opening. It is characterized by providing a vent pipe that opens into the agglomeration reaction tank and the other end communicates with the outside.

Invention of Claim 6 is an agglomeration reaction tank provided with the said floc formation state determination apparatus in the case where the processing tank in Claim 2 or 3 is an agglomeration reaction tank,
The floc detection sensor is placed near the outlet for sending the treated water in the agglomeration reaction tank to the next process when viewed from above, and the area immediately below the floc detection sensor communicates only with the lower part of the agglomeration reaction tank. In this manner, a partition wall is provided that is partitioned from other regions.

The invention of claim 7 is a pH adjustment tank installed in a pre-process of the aggregation reaction tank provided with the flock formation state determination device when the treatment tank in claim 2 or 3 is an aggregation reaction tank,
A pH meter for measuring the pH of the water to be treated in the pH adjusting tank and a pH adjusting agent injection pump for injecting a pH adjusting agent according to the measured value of the pH meter are recorded, and the pH value measured by the pH meter is recorded. A pH recorder is provided, and this pH recorder has a pH pass / fail judgment unit for judging whether or not the measured pH value is within a set range.

The invention of claim 8 is a pH adjustment tank provided in a metal-containing wastewater treatment facility having an agglomeration reaction tank provided with the flock formation state determination device when the treatment tank in claim 2 or 3 is an agglomeration reaction tank. And
A pH meter for measuring the pH of the water to be treated in the pH adjusting tank and a pH adjusting agent injection pump for injecting a pH adjusting agent according to the measured value of the pH meter, and the pH value measured by the pH meter for a time A pH recorder that continuously records with the horizontal axis as the horizontal axis, this pH recorder detects the period width of the recorded waveform of the recorded pH when the pH changes periodically, and the detected period width An electrode contamination determination unit that determines that the electrode of the pH meter is clean when it is equal to or less than the first set cycle width and that the electrode is dirty when the cycle width is equal to or greater than the second set cycle width that is longer than the first set cycle width; It is characterized by having.

  A ninth aspect of the invention is characterized in that the pH adjusting tank of claim 8 is a coagulation reaction tank itself provided with a pH meter and a pH adjusting agent injection pump for injecting a pH adjusting agent according to a measured value of the pH meter. To do.

The invention of claim 10 relates to an abnormality in the agglomeration reaction tank provided with the flock formation state determination device and the pH adjustment tank of claim 7 or 8 when the treatment tank in claim 2 or 3 is an agglomeration reaction tank. An abnormality occurrence reporting system for reporting,
A sequencer incorporating the flock formation state determination unit according to claim 2 or 3, an automatic dial device controlled by the sequencer, a fixed telephone dedicated to the system, and a private branch exchange
The sequencer determines whether the flock formation state determination unit determines that the flock formation state is defective based on the ON / OFF signal from the flock detection sensor according to claim 2 or 3, and / or the pH according to claim 7 or 8. When a pH abnormality signal or electrode contamination signal is input from the recorder, the automatic dialing device is controlled to access the fixed telephone, and an abnormality occurs in the mobile phone of the designated person in charge via the private branch exchange It has a built-in automatic report processing unit that issues an alarm.

In the invention of claim 1 or claim 2, flock detection sensor the laser beam emitted can be detected by sampling the distance L to flocs in water for every first set time T ₁ interval by the reflected light.
If the processing tank for determining the floc formation state is described as a coagulation reaction tank, the water to be treated in the coagulation reaction tank is agitated. Exercise irregularly inside. Therefore, the laser light emitted from the floc detection sensor irradiates flocs in a shallow layer or irradiates flocs in a deep layer. The change in the detection distance (distance to the flock) L sampled and detected by the flock detection sensor at that time is not a gradual change such that the water surface is moving up and down due to stirring, but a rapid change (that is, , first set time T ₁ for each amount of change [Delta] L is sufficiently short sampling interval is set step length [Delta] L ₀ or more). At this time, an OFF signal is issued.
Further, since the floc moves irregularly, there is a case of a gradual change (that is, a case where the change amount ΔL for each first set time T ₁ is equal to or less than the set step distance ΔL ₀ ), and at that time, an ON signal is generated. Therefore, when the agglutination reaction is normally performed, the signal includes an ON signal and an OFF signal within the second set time. Usually, it is a pulse signal that repeats ON and OFF. Thus, even if the water surface is moved up and down by stirring, it is confirmed that a signal including the ON signal and the OFF signal is generated within the second set time, so that the floc is normally formed in the agglomeration reaction tank. Can be determined.
On the other hand, if the floc formation state is poor, the floc grains become fine and the fine flocs are in a dense state, so that the laser light emitted from the sensor is reflected on the water surface, or at least a dense floc near the water surface. (The diameter of the laser beam is about 1.2 mm, and cannot pass through the gap between the dense flocks near the water surface). Therefore, the change in the detection distance L detected by sampling is small (that is, the change amount ΔL for each first set time T ₁ that is the sampling interval is less than the set step distance ΔL ₀ ), and an ON signal is output.
If flocculation state is bad, followed by a state of reflected near the water surface or reflected by the water surface as described above, the output signal of the sensor is a signal of continuous ON state ON signal follows at least a second set time T ₂ or more . The sequencer 10 determines that the flock formation state is abnormal based on the signal of the continuous ON state from the sensor 9.
As described above, since the floc moves irregularly, it is probable that the OFF signal state, that is, the state where the change amount ΔL is equal to or greater than the set step distance ΔL ₀ continues for the second set time T ₂ or longer in terms of probability. it is considered, it is determined that some abnormality may OFF signal follows the second set time T ₂ or more.
The same applies to the case where the processing tank for determining the floc formation state is not an agglomeration reaction tank, for example, an agglomeration precipitation tank or a neutralization tank.

The floc detection sensor installed in the upper part of the agglomeration reaction tank has a light receiving portion that receives the reflected light from the floc, but condensation may occur on the light receiving surface of the glass on the outer surface of the sensor, especially in the morning in winter. is there. If condensation occurs, the reflected light from the flocs may be irregularly reflected and erroneously detected.
However, by providing a ventilation hole and a ventilation tower as in the agglomeration reaction tank of claim 4, it is possible to prevent erroneous detection caused by condensation.
Further, when the outside air temperature is lowered to about 10 ° C. or less, for example, the water temperature in the agglomeration reaction tank is as high as 30 ° C., for example, steam is generated from the water surface, and the reflected light (laser beam) is caught by the steam. Again, false detection may occur.
However, as in the case of the agglomeration reaction tank, steam can be removed by a simple measure of providing a vent pipe, and erroneous detection due to steam can be prevented.

  As in the agglomeration reaction tank of claim 6, the position immediately below the flock detection sensor is arranged in the vicinity of the delivery port to the next step, and the partition is separated from other regions by the partition except for the lower layer portion, thereby stirring. It is possible to prevent erroneous detection from occurring in the flock detection sensor due to bubbles generated by the above.

  The pH adjusting tank according to claim 8 detects the period width of the recorded waveform of pH recorded in the pH recorder, and determines whether the detected period width is shorter than a certain fixed period width or longer than a set time width. It detects dirt and can detect electrode dirt extremely simply and inexpensively.

  According to the abnormality occurrence notification system of claim 10, the abnormalities in the metal-containing wastewater treatment facility are accurately determined by effectively utilizing the performances of the flock formation state determination device, the agglomeration reaction tank, and the pH adjustment tank. Promptly and reliably report the occurrence to the appropriate person, making it possible to take countermeasures quickly.

It is a schematic block diagram explaining an example of the metal containing waste water treatment equipment which this invention makes object. FIG. 2 shows a schematic structure of the agglomeration reaction tank in FIG. 1, (A) is a plan view, and (B) is a cross-sectional view taken along line AA in FIG. 1. It is an enlarged view of the vicinity of the sensor installation box in FIG. It is a figure explaining the schematic block structure of the flock formation state determination apparatus of this invention (a figure is shown when the flock formation state is normal). (A) is a diagram for schematically explaining, in time series, an operation state in which a flock detection sensor detects a normal flock when the flock formation state is normal, and (B) is an output from the flock detection sensor at that time. It is a figure explaining the pattern of a signal. (A) is a diagram for schematically explaining, in time series, an operation state in which a floc detection sensor detects a minute floc near the water surface when the floc formation state is poor, and (B) is for floc detection at that time It is a figure explaining the pattern of the signal which a sensor outputs. It is a block diagram explaining the schematic structure of the said flock formation state determination apparatus and a sequencer. It is a figure explaining the pH control system which has the pH meter provided in five places in FIG. 1, and the pH recording meter 8 to which these are connected. In the pH recorder of FIG. 8, it is a figure explaining the stain | pollution | contamination judgment principle which determines the electrode stain | pollution | contamination of each pH meter, (A) is the case where an electrode is clean (normal), (B) is the case where the electrode stain | pollution | contamination has arisen. Indicates. It is a block diagram explaining the schematic structure of the abnormality generation notification system of this invention.

  Hereinafter, a floc formation state determination method, a floc formation state determination device, an agglomeration reaction tank, a pH adjustment tank, and an abnormality occurrence notification system according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram for explaining a main part of a metal-containing wastewater treatment facility targeted in an embodiment of the present invention. This metal-containing wastewater treatment facility is a zinc wastewater treatment facility for treating zinc wastewater discharged from a galvanizing facility. What is shown in FIG. 1 is an essential part of an actual zinc wastewater treatment facility, and is a raw water tank 11, a first pH adjustment tank 1, a second pH adjustment tank 2, a coagulation reaction tank 3 in the entire equipment, A coagulating sedimentation tank 4, an activated carbon adsorption tower 5, and a discharge monitoring tank 6.

This zinc wastewater treatment facility performs zinc wastewater treatment by a coagulation sedimentation method. The outline of the zinc wastewater treatment by the coagulation sedimentation method will be explained. Since zinc is present in an ion state (dissolved) in the washing water discharged from the galvanizing equipment, first, the pH of the water to be treated is adjusted to a pH adjusting agent. The mixture is adjusted to an appropriate range by injection, and is precipitated in colloidal form as zinc hydroxide fine particles. The size of the colloidal particles is as fine as 0.1 to 10 μm and the sedimentation rate is slow, so that the colloidal particles flow with water without sedimentation.
Therefore, an aggregate of colloids (colloid particles) is made by agglomeration reaction using a flocculant to increase the size. Since the surface of the colloid is charged with a charge of the same sign and repels each other and is in a stable dispersed state, an electrolyte solution having an opposite charge is added to neutralize the charge on the surface of the colloid. Since uncharged colloids attract each other by intermolecular attraction, colloid aggregates (small aggregates) are created. Furthermore, by the action of adsorption crosslinking of the agglomeration aid, small aggregates of colloids are gathered to form larger aggregates, that is, flocs having a size of about 1 cm. When flocs are normally formed, the sedimentation speed is increased, the sediment can be settled without flowing into the treated water, and the particles and water can be easily separated. In this way, the precipitated colloidal particles are collected by an agglomeration reaction to form a large-sized floc that is likely to precipitate.

  In this embodiment, caustic liquid (pH adjusting agent) is injected in two pH adjusting tanks, a first pH adjusting tank 1 and a second pH adjusting tank 2, which follow the raw water tank 11 storing the washing water discharged from the galvanizing facility. To control the pH. A pH of 8 to 10 is set as an appropriate pH range for generating zinc hydroxide, and is adjusted to be maintained within the range. The proper pH range is not limited to pH 8 to 10, and may be appropriately set according to various conditions and situations.

The water to be treated whose pH is adjusted is sent to the agglomeration reaction tank 3. In the agglomeration reaction tank 3, an aggregating agent such as ferric chloride is added, and an agglomerating aid is added.
The fact that the agglutination reaction is normally performed in the agglomeration reaction tank 3 means that flock formation is normally performed. That is, the colloidal particles of zinc hydroxide precipitated by appropriate pH adjustment become aggregates of colloidal particles due to the action of the aggregating agent and aggregating aid, and the aggregates are combined into, for example, a lump having a diameter of about 1 cm. When a certain flock is formed, the flock formation is normal.
However, the aggregation reaction may not be performed normally.
When caustic soda is injected into the pH adjustment tanks 1 and 2, the zinc hydroxide colloidal particles are not only in the process from the second pH adjustment tank 2 to the aggregation reaction tank 3 but also after entering the aggregation reaction tank 3. In addition, an aggregate of colloidal particles is generated, but when caustic sorter (pH adjuster) is excessively added in the second pH adjusting tank and the pH rises, in the process from the second pH adjusting tank 2 to the aggregation reaction tank 3 Alternatively, there are cases where the aggregate of colloidal particles is re-dissolved in the agglomeration reaction tank 3 and no floc is formed.
In addition, when the water to be treated becomes, for example, pH 11 or more by pH adjustment in the pH adjusting tanks 1 and 2 and the water to be treated does not enter a colloidal state (zinc hydroxide does not precipitate as particles), the aggregates as well as flocs I can't.
Such an abnormality in the flock formation state is detected by a flock formation state determination method described later.

The to-be-processed water which formed the floc in the coagulation reaction tank 3 is sent to the next coagulation sedimentation tank 4 from the delivery pipe in the lower part.
In the coagulating sedimentation tank 4, the floc sinks quickly, so that the floc sinks and accumulates at the bottom of the sedimentation tank without flowing into the treated water flow. The accumulated floc is treated as sludge.
However, colloidal particles and small flocs that have not become flocs carry over and flow into the next activated carbon adsorption tower 5 together with the treated water.
In the activated carbon adsorption tower 5, those colloidal particles and small flocs are collected with sand or activated carbon.
Only clean water separated from the pollutants flows into the discharge monitoring tank 6, and in the discharge monitoring tank 6, it is confirmed that the pH is within a predetermined range with a pH meter. In this way, only clean water from which contaminants have been removed is discharged into the public water area as treated water.

The pH meters 7 are installed at five locations of the first and second pH adjusting tanks 1 and 2, the aggregation reaction tank 3, the aggregation and precipitation tank 4, and the discharge monitoring tank 6. The five pH meters 7 are connected to a pH recorder 8 described later in detail.
The agglomeration reaction tank 3 is provided with a flock detection sensor 9 which will be described in detail later.
The pH recorder 8 and the flock detection sensor 9 are connected to a sequencer 10 which will be described in detail later.

As shown in FIGS. 2 (a) and 2 (b), the agglomeration reaction tank 3 has a tank body 3a having a square shape with a side of about 1 m and a height of about 1.2 m as viewed from above, and one corner portion thereof. A delivery pipe 12 for sending the treated water in the agglomeration reaction tank 3 to the next agglomeration sedimentation tank 4 is connected to the upper part of the tank body in the vicinity, and the opposite corner on the diagonal line with the corner having the delivery port 12a. A stirrer 13 that stirs the water to be treated with a stirring propeller is disposed in the vicinity of.
In the vicinity of the delivery port 12a, that is, in the vicinity of the corner opposite to the stirrer 13, a partition wall 14 is provided that partitions the corner portion side from other regions in such a manner that only the tank body lower layer portion communicates.
As shown in FIG. 3, a sensor installation box 15 is installed in the upper lid 3 b of the agglomeration reaction tank 3 in the vicinity of the corner portion partitioned by the partition wall 14, and the flock detection sensor 9 is installed in the sensor installation box 15. (9a) is accommodated. The distance Ls from the light projecting / receiving surface of the flock detection sensor 9 to the water surface (water surface when stationary) is 200 mm.

In a wastewater treatment facility using the coagulation sedimentation method, it is extremely important that floc formation is normally performed in the coagulation reaction tank 3 in order to ensure the quality of the treated wastewater to be discharged. Therefore, a floc formation state determination device that determines whether floc formation is normally performed in the agglomeration reaction tank 3 is provided.
The flock formation state determination device will be described. As schematically shown in FIG. 4, a flock detection sensor 9 including a sensor main body 9a and a signal processing unit 9b and a flock detection sensor 9 based on the output of the flock detection sensor 9 are described. A flock formation state determination unit 27 (to be described later) built in the sequencer 10 that determines whether the formation state is normal or abnormal is provided.
The flock detection sensor 9 and the flock formation state determination unit 27 in the sequencer 10 constitute a flock formation state determination device 17.

As shown in FIG. 7, the flock detection sensor 9 is disposed above the water surface of the agglomeration reaction tank and irradiates the projection light, which is laser light, toward the water surface and the irradiated projection light. A light receiving unit 22 that receives reflected light reflected by an underwater floc, and a flock distance detecting unit that samples and detects the distance L to the floc at intervals of the first set time T ₁ based on the output of the light receiving unit 22 23 and an ON signal that generates an OFF signal when the change amount ΔL of the detection distance L detected by the flock distance detection unit 23 for each first set time T ₁ is equal to or greater than the set step distance ΔL ₀ and ON. / OFF signal generator 24.
25 set step length memory for storing a set step length data, 26 is a first set time memory for storing the T ₁ first set time.
The floc detection sensor 9 includes a sensor main body 9a including a light projecting unit 21 and a light receiving unit 22, and a signal processing unit 9b that processes an output signal of the light receiving unit 22 of the sensor main body 9a.

The sequencer 10, signals output from the ON / OFF signal generating unit 24 of the flock detection sensor 9 is normal flocculation state when within the second set time T ₂ and a ON signal and the OFF signal, the same flocculation state when oN signal or the OFF signal continues the second set time T ₂ or higher and a determining floc formation state determination unit 27 and abnormality. Reference numeral 28 denotes a second set time memory for storing second set time data.

A specific determination procedure of the flock formation state by the flock formation state determination device 17 will be described.
FIG. 5 is a diagram schematically illustrating, in time series, an operation state in which the flock detection sensor 9 detects a flock when the flock formation state is normal. S is the water surface, and the horizontal axis is time. Sensor and detects the flock as shown in the first sampling interval of the set time T _1.
Since the water to be treated in the agglomeration reaction tank 3 is agitated, when the agglutination reaction is normally performed, the generated flocs move irregularly in the water tank. Therefore, the laser light emitted from the sensor 9 irradiates flocs in a shallow layer or irradiates flocs in a deep layer. The change in the detection distance (distance to the floc) L detected by sampling by the sensor 9 at that time is not a gradual change such that the water surface is moving up and down due to agitation, but a rapid change (that is, sufficient short first set time T ₁ for each amount of change [Delta] L is the sampling interval is set step length [Delta] L ₀ or more). At this time, an OFF signal is issued (ΔL ₁ , ΔL ₃ , ΔL ₄ , ΔL ₅ , ΔL ₇ ).
Further, since flocs at positions close to the depth may be continuously detected, when the change in the detection distance L is moderate (that is, the change amount ΔL for each first set time T ₁ is equal to or less than the set step distance ΔL ₀ ). In this case, an ON signal is issued (ΔL ₂ , ΔL ₆ , ΔL ₈ ).
Therefore, if the agglutination reaction is normally performed, the signal is as shown in FIG. 5 (b), so that the second set time T in ₂ and a ON signal and the OFF signal. Usually, it is a pulse signal that repeats ON and OFF.
Thus, even if water is not vertically by stirring, by confirming that the signal including the ON signal and the OFF signal in the second set time T ₂ set to the appropriate length is generated, It can be determined that flocs are normally formed in the agglomeration reaction tank.

FIG. 6 is a diagram schematically illustrating, in time series, an operation state in which the flock detection sensor 9 detects a flock when the flock formation state is defective.
When the floc formation state is poor, as shown in the figure, the floc grains become fine and the fine flocs are in a dense state. Therefore, the laser light emitted from the sensor 9 is reflected on the water surface or at least near the water surface. Reflected by the dense flocs (the beam diameter of the laser light is about 1.2 mm and cannot pass through the gaps between the dense flocs near the water surface). Therefore, the change in the detection distance L detected by the sensor is always small. Accordingly, the difference ΔL between the detection distance at a certain time point detected at the sampling interval and the detection distance at another time point after the first set time T ₁ from that time point is at least less than the set step distance ΔL ₀ , and the ON signal is put out.
When the flock formation state is poor, the state of reflecting on the water surface or reflecting near the water surface as described above continues, and as shown in FIG. 6 (b), the ON signal of the sensor output signal is at least the second set time T. It becomes a signal of a continuous ON state lasting ₂ or more (ΔL ₂ ′, ΔL ₃ ′,... (Not shown). The sequencer 10 determines that the flock formation state is abnormal based on the signal of the continuous ON state from the sensor 9.
As described above, since the floc moves irregularly, it is probable that the OFF signal state, that is, the state where the change amount ΔL is equal to or greater than the set step distance ΔL ₀ continues for the second set time T ₂ or longer in terms of probability. it is considered, it is determined that some abnormality may OFF signal follows the second set time T ₂ or more.
As described above, even if the water surface moves up and down by stirring, the flock formation state can be determined without being affected by the water surface up and down movement.
The set step distance ΔL ₀ and the second set time T ₂ are appropriately set according to the specific situation. In the embodiment, for example, the set step distance ΔL ₀ is set to 5 mm, and the second set time T ₂ is set to 7 seconds. It was possible to determine the flock formation state appropriately.

In wastewater treatment facilities using the coagulation sedimentation method, pH control at each stage is also extremely important. As shown in FIG. 8 and FIG. 1 described above, each of the first and second pH adjusting tanks 1 and 2, the aggregation reaction tank 3, the aggregation and precipitation tank 4, and the discharge monitoring tank 6 are provided in five tanks. pH meters 7a, 7b, 7c, 7d, and 7e are installed, and each pH meter 7 (7a,...) is connected to a pH recorder 8 that records the pH value measured by each pH meter.
In this pH recorder, the pH value measured by each pH meter 7 is individually recorded continuously with time as a horizontal axis, and the pH value measured by each pH meter 7 is set as an appropriate pH range. The pH acceptance / rejection determination unit for determining whether or not it is within the set range includes an 8b and an electrode contamination determination unit 8c described later. The pH meter electrode is shown in 7s.
Each of the first pH adjusting tank 1 and the second pH adjusting tank 2 includes a pH adjusting agent injection pump 30, and each of the pH meters 7a and 7b of the two pH adjusting tanks 1 and 2 is made of caustic soda or the like according to the measured pH value. A pH indicating controller for instructing the injection of the pH adjusting agent. The pH adjusting agent injection pump 30 is operated to control the injection of the pH adjusting agent, and the water to be treated in the first and second pH adjusting tanks 1 and 2 is controlled. The pH is maintained in the appropriate pH range of 8 to 10 described above.

In particular, the electrode contamination determination unit 8c determines the electrode contamination of the pH meters 7a and 7b of the first and second pH adjusting tanks 1 and 2 that perform pH adjuster injection control.
When the measured pH value of the water in the tank detected by the pH meter reaches a set value (pH), the injection pump 30 injects the caustic liquid, so that the pH increases. However, since the raw water having a low pH is constantly fed from the raw water tank 11 and the pH is lowered, the pH is adjusted by repeatedly injecting the caustic liquid, so that the pH value recorded by the pH recorder 8 is periodic. Make fluctuating.
When the electrode becomes dirty, the pH meter becomes less sensitive to changes in pH. If the reaction is slow, the measured value of the pH meter does not reach the proper value even if the pH actually reaches the proper value, so the stop instruction to the infusion pump is delayed and excessive caustic liquid is added. The pH of deviates from the appropriate pH range (becomes higher). This causes a poor agglutination reaction.
Therefore, the electrode contamination determination unit 8c detects the slowness of the reaction of the pH meter with respect to the change in pH to detect the presence or absence of electrode contamination. The recording waveform of the pH recorded by the pH recorder 8 is detected. When the period width is detected and the detected period width is equal to or less than the first set period width, the pH meter electrode is clean (normal), and the period width is equal to or greater than the second set period width longer than the first set period width. In this configuration, the electrode is determined to be dirty at a certain time. In this embodiment, as a periodic width to be detected, a time width of a portion where pH exceeds a certain set value (pH 9 in the illustrated example) in the pH recording waveform is defined as a periodic width t.
FIG. 9A shows a case where the electrode is clean (normal), and the period width t is short. On the other hand, FIG. 9B shows a case where the electrode is soiled beyond the limit, and the period width t becomes longer. In the embodiment, for example, when the cycle width at the level of pH = 9.0 is shorter than the first set cycle width (for example, 20 seconds), clean (normal), and when the cycle width is longer than the second set cycle width (for example, 30 seconds), Judgment.
In the embodiment, the electrode contamination determination is performed on the electrodes of the pH meters installed in the first pH adjustment tank 1 and the second pH adjustment tank 2, but this electrode contamination determination means includes a pH meter and intermittently adjusts the pH adjusting agent. If it is a tank provided with the means to inject automatically, it can apply to the pH meter.

By the way, even in the range where the agglomeration reaction is normal in the agglomeration reaction tank 3, all the colloidal particles such as zinc are not completely flocked, and usually only a small part is from the agglomeration sedimentation tank 4 to the next activated carbon adsorption tower 5. However, the colloidal particles are adsorbed by the activated carbon, so that the final treatment wastewater zinc concentration can be kept below the regulation value.
However, when the colloidal particles adsorbed on the activated carbon in the activated carbon adsorption tower 5 become saturated, zinc gradually precipitates in the treated water even if the floc formation state is normal in the agglomeration reaction tank 3, and the treated water having a high zinc concentration is discharged. There is a fear.
On the other hand, even when an agglomeration reaction failure occurs in the agglomeration reaction tank 3 and the flocs are not sufficiently formed, the colloidal particles flowing out from the agglomeration precipitation tank 4 are adsorbed on the activated carbon in the next activated carbon adsorption tower 5. In some cases, the zinc concentration in the final treated wastewater is not so high. Therefore, it is necessary to sufficiently monitor the discharge monitoring tank 6 as well as to keep the floc formation state in the aggregation reaction tank 3 normal.

A description will be given of an abnormality occurrence reporting system for reporting an abnormality when the aggregation reaction in the aggregation reaction tank 3 is abnormal or when there is a pH abnormality in the first and second pH adjusting tanks 1 and 2.
As shown in FIG. 10, the abnormality occurrence notification system 35 is designated by the sequencer 10 described above, the automatic dial device 31 controlled by the sequencer 10, the fixed telephone 32 dedicated to the system, and the private branch exchange 33. For example, in the illustrated example, the mobile phone 34 includes three mobile phones 34 held by three persons in charge.
As described above, the output of the flock detection sensor 9 and the output of the pH recorder 8 are input to the sequencer 10. The sequencer 10 includes the flock formation state determination unit 27 described above, and includes a reception unit 28 that receives determination result signals from the pH pass / fail determination unit 8b and the electrode contamination determination unit 8c of the pH recorder 8, It incorporates an automatic notification processing unit 29 that performs automatic notification processing based on signals from them.
The sequencer 10 detects that the flock formation state determination unit 27 determines that the flock formation state is defective based on the ON / OFF signal from the flock detection sensor 9 or that a pH abnormality signal or an electrode contamination signal is received from the pH recorder 8. When entered, the automatic notification program of the automatic notification processing unit 29 operates to control the automatic dialing device 31, access the dedicated fixed telephone 32, and via the private branch exchange 33, the designated person in charge 3 The mobile phones 34a, 34b, and 34c are sequentially connected in rotation, and this is repeated until one of the mobile phones responds. As a result, the person in charge can immediately go to the site, check the content of the abnormality, and deal with it. Note that the rotation order is set in the automatic notification processing unit 29 by operating the duty selection switch 36.

As shown in FIG. 3, the floc detection sensor 9 is arranged in a sensor installation box 15 having an opening 15 a into the agglomeration reaction tank, which is installed on the upper lid 3 b of the agglomeration reaction tank 3. In winter, especially in the morning, condensation may occur on the light receiving surface (projecting / receiving surface (window)) of the outer surface of the sensor facing the light receiving unit. If condensation occurs, the reflected light from the flocs may be irregularly reflected and erroneously detected.
Therefore, as shown in the figure, a plurality of ventilation holes 15b are provided in the lower position of the side wall of the sensor installation box 15, and a ventilation tower 15c is provided in the ceiling.
The ventilation hole 15b and the ventilation tower 15c reduce the temperature difference between the inside and outside of the sensor installation box 15, can prevent condensation on the light receiving surface of the flock detection sensor 9, and can prevent erroneous detection caused by condensation.

When the outside air temperature drops to about 10 ° C. or less, for example, the water temperature in the agglomeration reaction tank 3 is as high as 30 ° C., for example, steam is generated from the water surface and enters the sensor installation box 15. Then, the reflected light (laser beam) to the light receiving unit is caught by steam, and erroneous detection may still occur.
Therefore, a vent pipe 16 is provided in the vicinity of the opening 15a, one end of which opens into the aggregation reaction tank (opening 16a) and the other end communicates with the outside.
In this way, steam can be removed with a simple measure of providing the vent pipe 16, and erroneous detection due to steam can be prevented. Although not shown, a blower fan may be attached to the other end side (external side) of the vent pipe 16.

Although the above-described embodiment has been described for a zinc wastewater treatment facility whose content metal is zinc, not only zinc but also a metal-containing wastewater treatment facility containing manganese, iron, copper, nickel, chromium and other metals. Can be applied.
Moreover, in the Example, although pH adjustment of metal containing waste_water | drain is performed with two pH adjustment tanks of the 1st pH adjustment tank and the 2nd pH adjustment tank installed as another process before the aggregation reaction tank 3, one pH The adjustment tank may be used, and it is also possible to adjust the pH in the aggregation reaction tank 3 itself without using a separate process.
Moreover, although the method by pH adjustment is employ | adopted as a means to precipitate a metal hydroxide from a metal containing waste_water | drain, another method is employable.
In the embodiment, the target processing tank for determining the floc formation state is a coagulation reaction tank. For example, when it is necessary to determine the floc formation state in a coagulation sedimentation tank or a neutralization tank, the processing is performed. It can also be applied to tanks.

DESCRIPTION OF SYMBOLS 1 1st pH adjustment tank 2 2nd pH adjustment tank 3 Aggregation reaction tank 3a Tank main body 3b Top cover 4 Aggregation sedimentation tank 5 Activated carbon adsorption tower 6 Discharge monitoring tank 7 (7a, 7b, 7c, 7d, 7e) pH meter 7s Electrode 8 pH recording Total 8a pH recording unit 8b pH pass / fail judgment unit 8c Electrode contamination judgment unit 9 Flock detection sensor 9a Sensor body 9b Signal processing unit 10 Sequencer 12 Delivery pipe 12a Outlet 13 Stirrer 14 Bulkhead 15 Sensor installation box 15a Opening 15b Ventilation hole 15c Ventilation tower 16 Ventilation pipe 16a Opening portion 17 Flock formation state determination device 20 Receiving portion 21 Light emitting portion 22 Light receiving portion 23 Flock distance detecting portion 24 ON / OFF signal generating portion 25 Set step distance memory 26 First set time memory 27 Flock formation State determination unit 28 Second set time memory 29 Automatic notification processing unit 30 pH adjusting agent injection pump 31 Automatic Dial apparatus 32 dedicated fixed telephone 33 private branch exchange 34 (34a, 34b, 34c) mobile phone 35 abnormality notification system _{T 1} First set time (sampling interval)
T ₂ Second set time L Detection distance (distance from sensor to floc)
ΔL Change amount (for each sampling interval of detected detection distance) ΔL ₀ Step difference distance t Period width

Claims (10)

A flock formation state determination method for determining normality / abnormality of a flock formation state in a metal-containing wastewater treatment facility having a coagulation reaction step for forming a metal hydroxide floc,
A floc detection sensor capable of irradiating laser light toward the water surface and detecting the distance to the floc based on the reflected light from the floc in the water is disposed above the water surface of the treatment tank of the metal-containing wastewater treatment facility. and, the by flock detecting sensor detects the distance L to flock was sampled every first predetermined time T ₁ interval, the amount of change ΔL of the first set time T _each of the detection distance L is set When the step distance ΔL is greater than or equal to ₀ , an OFF signal is generated, and when it is less than the ON signal, the ON signal and the OFF signal are included within the second set time. Alternatively, when the OFF signal continues for the second set time or more, the flock formation state is determined to be abnormal. A flock formation state determination device for determining normality / abnormality of a flock formation state in a metal-containing wastewater treatment facility having a coagulation reaction step for forming a metal hydroxide floc,
A floc detection sensor capable of irradiating laser light toward the water surface and detecting the distance to the floc based on the reflected light from the floc in the water is disposed above the water surface of the treatment tank of the metal-containing wastewater treatment facility. and, the floc detection sensor detects the distance L to flock was sampled every first predetermined time T ₁ interval, the amount of change ΔL of the first set time T _each of the detection distance L It has a function of issuing an OFF signal when the set step distance ΔL is greater than or equal to ₀ , and an ON signal when the distance is less than
The flock formation state is normal when the signal generated by the flock detection sensor includes the ON signal and the OFF signal within the second set time, and the flock formation state when the same ON signal or OFF signal continues for the second set time or more. Provided with a flock formation state determination unit for determining that the flock is abnormal. A flock formation state determination device for determining normality / abnormality of a flock formation state in a metal-containing wastewater treatment facility having a coagulation reaction step for forming a metal hydroxide floc,
Both are arranged above the water surface of the treatment tank of the metal-containing wastewater treatment facility, and projecting light that irradiates the projection light, which is laser light, toward the water surface, and the reflected light reflected by the flock in the water. a light receiving section adapted to receive a flocked distance detection unit for detecting a distance L to the flock and sampled every first predetermined time T ₁ interval based on the output of the light receiving section, the detection distance which the flock distance detection unit detects A flock detection sensor comprising: an ON / OFF signal generating unit that generates an OFF signal when the change amount ΔL of the first set time T _{1 of} L is greater than or equal to a set step distance ΔL _{0 and} less than the set step distance ΔL _0. Prepared,
When the signal output from the ON / OFF signal generator of the flock detection sensor includes the ON signal and the OFF signal within the second set time, the flock formation state is normal, and the same ON signal or OFF signal is the second signal. A flock formation state determination device comprising a flock formation state determination unit that determines that a flock formation state is abnormal when it continues for a set time or longer.
When the treatment tank in claim 2 or 3 is an agglomeration reaction tank, the agglomeration reaction tank provided with the flock formation state determination device,
A sensor installation box having an opening into the agglomeration reaction tank is installed on the upper lid of the agglomeration reaction tank, and the flock detection sensor is arranged in the sensor installation box, and the lower part of the side wall of the sensor installation box A coagulation reaction tank provided with a ventilation hole at a position and a ventilation tower at a ceiling. When the treatment tank in claim 2 or 3 is an agglomeration reaction tank, the agglomeration reaction tank provided with the flock formation state determination device,
A sensor installation box having an opening into the agglomeration reaction tank is installed on the upper lid of the agglomeration reaction tank, and the flock detection sensor is arranged in the sensor installation box, and one end is located near the opening. An agglomeration reaction tank provided with a vent pipe that opens into the agglomeration reaction tank and communicates with the other end to the outside. When the treatment tank in claim 2 or 3 is an agglomeration reaction tank, the agglomeration reaction tank provided with the flock formation state determination device,
The floc detection sensor is placed near the outlet for sending the treated water in the agglomeration reaction tank to the next process when viewed from above, and the area immediately below the floc detection sensor communicates only with the lower part of the agglomeration reaction tank. An agglomeration reaction tank characterized in that a partition wall is provided that is partitioned from other regions in such a manner as to be caused. When the treatment tank in claim 2 or 3 is an agglomeration reaction tank, a pH adjustment tank installed in a pre-process of the agglomeration reaction tank provided with the flock formation state determination device,
A pH meter for measuring the pH of the water to be treated in the pH adjusting tank and a pH adjusting agent injection pump for injecting a pH adjusting agent according to the measured value of the pH meter are recorded, and the pH value measured by the pH meter is recorded. A pH adjusting tank comprising a pH recording meter, wherein the pH recording meter includes a pH pass / fail determination unit that determines whether or not the measured pH value is within a set range. A pH adjustment tank provided in a metal-containing wastewater treatment facility having an agglomeration reaction tank equipped with the floc formation state determination device when the treatment tank in claim 2 is an agglomeration reaction tank,
A pH meter for measuring the pH of the water to be treated in the pH adjusting tank and a pH adjusting agent injection pump for injecting a pH adjusting agent according to the measured value of the pH meter, and the pH value measured by the pH meter for a time A pH recorder that continuously records with the horizontal axis as the horizontal axis, this pH recorder detects the period width of the recorded waveform of the recorded pH when the pH changes periodically, and the detected period width An electrode contamination determination unit that determines that the electrode of the pH meter is clean when it is equal to or less than the first set cycle width and that the electrode is dirty when the cycle width is equal to or greater than the second set cycle width that is longer than the first set cycle width; A pH adjusting tank characterized by comprising:   9. The pH adjustment according to claim 8, wherein the pH adjusting tank is a coagulation reaction tank itself provided with a pH meter and a pH adjusting agent injection pump for injecting a pH adjusting agent according to a measured value of the pH meter. Tank. In the abnormality reaction reporting system which reports the abnormality in the aggregation reaction tank provided with the said floc formation state determination apparatus in case the processing tank in Claim 2 or 3 is an aggregation reaction tank, and the pH adjustment tank of Claim 7 or 8. There,
A sequencer incorporating the flock formation state determination unit according to claim 2 or 3, an automatic dial device controlled by the sequencer, a fixed telephone dedicated to the system, and a private branch exchange
The sequencer determines whether the flock formation state determination unit determines that the flock formation state is defective based on the ON / OFF signal from the flock detection sensor according to claim 2 or 3, and / or the pH according to claim 7 or 8. When a pH abnormality signal or electrode contamination signal is input from the recorder, the automatic dialing device is controlled to access the fixed telephone, and an abnormality occurs in the mobile phone of the designated person in charge via the private branch exchange An anomaly reporting system that includes an automatic report processing unit that issues an alarm.

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