JP2007111698A - Method for treating waste water and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus therefor capable of stably treating waste water showing a large load fluctuation at a low cost and also reducing the influence on the environment. <P>SOLUTION: The apparatus for treating the waste water 1 comprises a first raw water tank 11 and a second raw water tank 15 connected and capable of supplying the stored water to each other when necessary, a third adjustment tank 19 receiving the stored water in the first raw water tank 11, a first adjustment tank 13, and a second adjustment tank 17 when necessary and being capable of supplying the stored water therein to the first and second adjustment tanks 11, 17 when necessary, an ozone reaction tower 65 for bringing the waste water after an aerobic treatment into contact with ozone for decolorization, a coagulation tank 69 where coagulant can be added to the waste water when necessary, a thickener 71, and a water discharging tank 10. When the quality of the waste water flowing into the ozone reaction tower 65 becomes worse, the coagulant is added to the waste water before or without the ozone treatment in the coagulation tank 69. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a drainage treatment method and drainage treatment apparatus for wastewater generated in the production of beverages, foods, and the like.

  In general, organic wastewater generated in a manufacturing plant for beverages such as coffee beverages and fruit juices is biologically processed and BOD (Biochemical Oxygen Demand), SS (Floating Substances), etc. meet certain standards, Released to rivers.

  On the other hand, there is no particular standard for the chromaticity of the discharged water, and it is left to self-regulation. However, it is desirable that the colored discharged water has a bad image for the environment and is decolorized. On the other hand, as shown in the conventional processing flow in FIG. 5, after anaerobic treatment of the wastewater, after adding the flocculant in the coagulation tank, the biological frog is precipitated and separated with a thickener, The treated water was discharged from the discharge tank through the second intermediate tank. That is, the color in the waste water was decolorized and removed by adding a flocculant.

  Moreover, the following patent document 1 and patent document 2 are well-known as a method of decoloring waste water with ozone.

JP 49-98055 A JP-A-10-128350

  However, organic wastewater generated at a manufacturing plant for beverages, for example, in the cleaning of raw material tanks and mixing tanks used for manufacturing in the factory, the drainage generated at the start of cleaning and the cleaning generated at the end of cleaning, Since the difference in concentration is greatly different, the fluctuation of the amount of drainage is also different every hour, and the load fluctuation is large, so it is not appropriate to uniformly perform subsequent biological treatment or decolorization treatment. If the wastewater is biologically treated with a large load fluctuation, it will be difficult to achieve stable wastewater treatment because the organism will grow rapidly or die, or it will hardly be treated beyond the capacity of the organism. .

  Moreover, if the coagulant is injected together when the load is high, the cost of the coagulant is high, and the chemical is used unnecessarily, which may adversely affect the environment.

  Therefore, an object of the present invention is to provide a wastewater treatment apparatus that is low in treatment cost and can reduce the influence on the environment.

  The invention according to claim 1 is an aerobic treatment unit for aerobic treatment of waste water, an ozone reaction tower for decolorizing the waste water after aerobic treatment by contacting with ozone, and a flocculant can be added as necessary. When the quality of the inflow water to the ozone reaction tower deteriorates in a wastewater treatment device equipped with a coagulation tank, a thickener that precipitates and separates the wastewater supplied from the coagulation tank, and a discharge tank that receives and discharges the treated water of the thickener. Is a wastewater treatment method characterized in that the wastewater aerobically treated in the aerobic treatment unit is caused to flow in the coagulation tank without flowing into the ozone reaction tower, and the coagulant is added in the coagulation tank.

  The invention according to claim 2 can add an aerobic treatment unit for aerobic treatment of waste water, an ozone reaction tower for decolorizing the waste water after aerobic treatment by contacting with ozone, and a flocculant as necessary. In a wastewater treatment device comprising a coagulation tank, a thickener that precipitates and separates the wastewater supplied from the coagulation tank, and a discharge tank that receives and discharges the treated water of the thickener, the wastewater treated by the aerobic treatment unit When the wastewater treated by the aerobic treatment unit is transferred to the ozone reaction tower in normal operation, and the inflow water quality to the ozone reaction tower deteriorates The waste water treatment apparatus is characterized in that the waste water treated by the aerobic treatment unit is transferred to the coagulation tank and the coagulant is added in the coagulation tank.

  The invention according to claim 3 is the invention according to claim 2, further comprising an intermediate tank between the ozone reaction tower and the coagulation tank for treating the treated water of the ozone reaction tower in contact with the biofilm. Features.

  According to a fourth aspect of the invention, there is provided the surveillance camera according to the second or third aspect, further comprising a monitoring camera for observing the decolored state of the treated water after the treatment by the thickener.

  According to the first and second aspects of the present invention, in normal operation, waste water after aerobic treatment is decolorized by contacting ozone with an ozone reaction tower and no flocculant is used. Cost can be reduced.

  On the other hand, only when the decolorization state is not sufficient due to load fluctuations, operational troubles, etc., the minimum flocculant is used and decolorization is performed by coagulation sedimentation. The decolorization can be performed reliably.

  According to the invention described in claim 3, the same effect as that of the invention described in claim 2 is achieved, and in the ozone reaction tower, the dissolved oxygen becomes high, so that the second intermediate tank is brought into contact with the biofilm as it is. Therefore, the biological treatment can be promoted, and the treatment efficiency is good.

  According to invention of Claim 4, while having the same effect as invention of Claim 2 or 3, the decoloring state of waste water is observed with the monitoring camera provided downstream of the thickener, and the decoloring state before discharge Therefore, it is possible to prevent the drainage from being discharged accidentally with insufficient decolorization.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 to 3 are piping diagrams of a waste water treatment apparatus, and FIGS. 3 and 4 are flow charts showing a waste water treatment flow.

  First, the piping of the waste water treatment apparatus 1 according to the present embodiment will be described. The wastewater treatment apparatus 1 is for treating wastewater in a beverage manufacturing factory, and includes a raw water adjustment unit 3, an anaerobic treatment unit 5, an aerobic treatment unit 7, and a decolorization treatment unit 9, and a decolorization treatment. After the unit 9 is treated, the treated water is discharged from the discharge tank 10 to a river or the like.

  The raw water adjustment unit 3 includes a first raw water tank 11 for high concentration drainage, a first adjustment tank 13 that receives drainage from the first raw water tank 11, a second raw water tank 15 for low concentration raw water, and a second raw water tank. A second adjustment tank 17 that receives drainage from 15 and a third adjustment tank 19 are provided. A first raw water pipe 2 that supplies high-concentration waste water is connected to the first raw water tank 11, and a second raw water pipe 4 that supplies low-concentration waste water is connected to the second raw water tank 15. The high-concentration wastewater and the low-concentration wastewater are distinguished from each other by high density or low concentration by comparison between them, and are not limited by numerical values.

  In addition, the high-concentration wastewater and the low-concentration wastewater are distributed by switching the valve at the time of operation. For example, when starting the cleaning of the raw water tank in the manufacturing facility, the drainage is poured into the first raw water pipe 2 and the cleaning is about to end. The valve is switched so that the washing wastewater flows into the second raw water pipe 4. In addition, the electrical conductivity of the wastewater discharged from the production facility may be measured without operating with a valve, and the wastewater may be automatically distributed to the high-concentration wastewater and the low-concentration wastewater according to the measured value. .

  In the first raw water tank 11, the drainage pumped up by the pump is supplied to the first adjustment tank 13 by the pipe 21 and is connected to the third adjustment tank 19 by the switching valve 23 so as to be supplied to the first adjustment tank 13. The raw water tank 15 can be supplied.

  In the second raw water tank 15, the drainage pumped up by the pump is supplied to the second adjustment tank 17 through the pipe 27, and is connected to the first raw water tank 11 through the pipe 29.

  The first adjustment tank 13 can supply drainage pumped up by the pump to the first heat exchanger 31 and can be supplied to the second adjustment tank 17 and the third adjustment tank 19 through the pipes 35 and 37.

  The 2nd adjustment tank 17 can supply the 3rd adjustment tank 19 with the piping 41 and the piping 35 mentioned above while supplying the waste_water | drain pumped up with the pump to the 2nd heat exchanger 39. FIG. Moreover, the 2nd adjustment tank 17 and the 3rd adjustment tank 19 are connected so that a stored water can be supplied mutually.

  Thus, the 1st raw | natural water tank 11, the 2nd raw | natural water tank 15, the 1st adjustment tank 13, the 2nd adjustment tank 17, and the 3rd adjustment tank 19 can mutually be connected, and stored water can be distributed as needed. Therefore, it is possible to easily cope with the fluctuation of the inflow amount in each tank, and the capacity to absorb the fluctuation can be dealt with with a capacity about three times the normal capacity. Furthermore, each of the high-concentration wastewater and the low-concentration wastewater can be distributed to three tanks at all times, so that the capacity of each tank can be reduced and installed using the dead space of the site, and the installation cost of each tank Can also be reduced.

  The first adjustment tank 13 is agitated in water, the second adjustment tank 17 is agitated by air blow, the third adjustment tank 19 is capable of agitating in water and air blow, and in the third adjustment tank 19, The case where it is used as a reserve tank for anaerobic treatment and the case where it is used as a reserve tank for aerobic treatment can be accommodated.

  The anaerobic treatment unit 5 includes an initial sedimentation tank 43, an acid generation tank 45, and an anaerobic treatment tank 47 downstream of the first heat exchanger 31, and the treated water in the anaerobic treatment tank 47 is supplied via a pipe 49. It is supplied to the raw water tank 15. That is, the high-concentration wastewater is anaerobically treated and then supplied to the second raw water tank 15 so as to be aerobically treated together with the low-concentration wastewater. The acid generation tank 45 is supplied with predetermined nutrients from the nutrient source 51 and the micronutrient source 53. Further, the sludge in the anaerobic treatment tank 47 is drawn out to the granule storage tank 56.

  The waste water whose temperature has been adjusted by the second heat exchanger 39 is subjected to aerobic treatment by the aerobic treatment unit 7. The aerobic treatment unit 7 includes a neutralization tank 55, an aeration tank 57, and a precipitation tank 59 downstream of the second heat exchanger 39, and after the neutral pH is adjusted in the neutralization tank 55, the aeration tank After aerobic treatment with activated sludge at 57, precipitation is performed in a sedimentation tank 59, and treated water is supplied to the first intermediate tank 63.

  A decolorization processing unit 9 is provided downstream of the first intermediate tank 63. The decolorization processing unit 9 includes an ozone reaction tower 65, a second intermediate tank (intermediate tank) 67, a coagulation tank 69, and a thickener 71. Pumped water from the first intermediate tank 63 is supplied to the coagulation tank 69 through a pipe 73. The supply can be switched.

  The flocculant 69 can be supplied with the flocculant from the flocculant supply device 75, but the flocculant is not supplied in the normal operation.

  A white board is attached to the outlet of the thickener 71 that supplies the treated water of the thickener 71 to the discharge tank 10, and the color of the treated water is monitored by the monitoring camera 79 from above. That is, the color of the wastewater transferred from the thickener 71 to the discharge tank 10 is made visible, and the decolorization state of the wastewater is confirmed from the control room or the like by the monitoring camera 79.

  The thickened sludge in the thickener 71 is stored in the excess sludge storage tank 81 together with the excess sludge in the settling tank 59 and is post-processed by the dehydrator 83 and the hopper 85.

  Next, the effect | action of the waste water treatment apparatus concerning this Embodiment is demonstrated. In normal operation, high-concentration wastewater flows into the first adjustment tank 13 from the first raw water tank 11, and the high-concentration wastewater is anaerobically treated from the first adjustment tank 13 by the anaerobic treatment unit 5, and the treated water is low. It is supplied to the second raw water tank 15 for concentration drainage.

  The low-concentration wastewater flows into the second adjustment tank 17 from the second raw water tank 15, and the low-concentration wastewater is aerobically processed from the second adjustment tank 17 by the aerobic treatment unit 7.

  Here, the flow volume fluctuation | variation of the waste_water | drain flowing into the 1st and 2nd raw | natural water tanks 11 and 15 is demonstrated. When the amount of high-concentration wastewater flowing into the first raw water tank 11 increases and cannot be dealt with by the first adjustment tank 13 alone, the wastewater of the first raw water tank 11 is supplied to the third adjustment tank 19. . In addition, if it still cannot be covered, the drainage of the third adjustment tank 19 is supplied to the second adjustment tank 17. Further, in some cases, the waste water from the first raw water tank 11 is also supplied to the second raw water tank 15 to cope with an extreme flow rate fluctuation of the high concentration waste water. Similarly, the fluctuation of the inflow amount of the low-concentration waste water can be received in the three tanks of the first adjustment tank 13, the third adjustment tank 19, and the first raw water tank 11, and the fluctuation of the inflow amount can be easily performed. In addition to being able to cope with it, the capacity to absorb fluctuations can be covered by three tanks, and wastewater with large inflow fluctuations can be treated stably. There may be a significant difference, and such flow rate fluctuations can be easily addressed.

  In the aerobic treatment unit 7 provided downstream of the second adjustment tank 17, the temperature of the waste water is adjusted by the second heat exchanger 39, the pH is adjusted to be approximately neutral by the neutralization tank 55, and then activated in the aeration tank 57. Biological treatment with sludge is performed, and after a certain residence time has elapsed, activated sludge is settled and separated in the settling tank 59 and supplied from the first intermediate tank 63 to the decolorization processing unit 9.

  In normal operation, as shown in FIG. 4, the waste water after treatment in the aerobic treatment unit 7 is decolorized by contacting ozone with the ozone reaction tower 65, and then the second intermediate tank 67, the coagulation tank 69, the thickener 71, the discharge It is discharged through the tank 10, but the coagulant is not injected into the coagulation tank 69. Therefore, since the flocculant is not used, the cost for the flocculant and the flocculent sedimentation sludge treatment can be reduced. Note that, in the second intermediate tank 67, the organic matter having been reduced in molecular weight through the ozone reaction tower 65 is processed.

  On the other hand, when the decolorization state is not sufficiently achieved due to load fluctuations, driving troubles, or the like, the processing of the flow indicated by “abnormality handling 1” in FIG. In this “abnormality response 1”, drainage is not supplied from the first intermediate tank 63 to the ozone reaction tower 65 but is supplied to the condensation tank 69 via the pipe 73, and a flocculant is added to the aggregation tank 69 and agglomerated by the thickener 71. Perform precipitation. That is, only when a flocculant is required, decolorization is achieved by agglomeration precipitation using the minimum necessary amount of flocculant.

  The processing flow indicated by “abnormality handling 2” in FIG. 4 is a combination of coagulation precipitation with a coagulant and the treatment with ozone. In this “abnormality response 2” process, the waste water from the first intermediate tank 63 is supplied to the coagulation tank 69, and after adding the coagulant, coagulation sedimentation treatment is performed by the thickener 71, and the treated water of the thickener 71 is passed through the pipe 72. Then, it is supplied to the ozone reaction tower 65 and brought into contact with ozone. In the “abnormality response 2”, the coagulant and the ozone treatment are used in combination, and reliable decolorization can be performed.

  As described above, in the present embodiment, the processing flow can be switched to “normal processing”, “abnormal response 1”, and “abnormal response 2”, and usually only by ozone reaction without using a flocculant. Decolorization treatment is performed, and decolorization with a flocculant can be performed only when necessary.

  The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the scope of the invention. For example, in the present embodiment, drainage treatment in the production of beverages has been described as an example, but it may be used for wastewater treatment in the production of foods and the like.

It is a piping diagram of the waste water treatment equipment concerning an embodiment of the invention. It is a piping diagram which extracts and shows the raw | natural water adjustment unit shown in FIG. It is a piping diagram which extracts and shows the decoloring unit shown in FIG. It is a flowchart which shows the process flow for every driving | running state in the waste water treatment apparatus shown in FIG. It is a flowchart which shows the process flow in the conventional waste water treatment equipment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waste water treatment equipment 2 1st raw water pipe 3 Raw water adjustment unit 4 2nd raw water pipe 5 Anaerobic treatment unit 7 Aerobic treatment unit 9 Decolorization processing unit 10 Discharge tank 11 1st raw water tank 13 1st adjustment tank 15 2nd raw water tank 17 Second adjustment tank 19 Third adjustment tank 63 First intermediate tank 65 Ozone reaction tower 67 Second intermediate tank (intermediate tank)
69 Coagulation tank 71 Thickener 79 Surveillance camera

Claims (4)

An aerobic treatment unit for aerobic treatment of waste water, an ozone reaction tower for decolorizing the waste water after aerobic treatment by contacting with ozone, a coagulation tank to which a coagulant can be added if necessary, and a coagulation tank In the wastewater treatment equipment equipped with a thickener that settles and separates the wastewater and a discharge tank that receives and discharges the treated water of the thickener, the aerobic treatment unit will A wastewater treatment method characterized by flowing the treated wastewater into a coagulation tank without flowing into the ozone reaction tower and adding a coagulant in the coagulation tank. An aerobic treatment unit for aerobic treatment of waste water, an ozone reaction tower for decolorizing the waste water after aerobic treatment by contacting with ozone, a coagulation tank to which a coagulant can be added if necessary, and a coagulation tank Wastewater treatment equipment equipped with a thickener that separates and separates the wastewater discharged and a discharge tank that receives and discharges the treated water of the thickener, and transfers the wastewater treated by the aerobic treatment unit to a piping and agglomeration tank In normal operation, wastewater treated by the aerobic treatment unit is transferred to the ozone reaction tower, and when the quality of the inflow water to the ozone reaction tower deteriorates, the wastewater treated by the aerobic treatment unit The waste water treatment apparatus characterized by transferring a flocculant to a coagulation tank and adding a coagulant | flocculant in a coagulation tank. The waste water treatment apparatus according to claim 2, further comprising an intermediate tank between the ozone reaction tower and the agglomeration tank for treating the treated water of the ozone reaction tower in contact with the biofilm. The wastewater treatment apparatus according to claim 2 or 3, further comprising a monitoring camera for observing a decolorized state of the treated water after treatment with a thickener.

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