JP6895302B2 - Wastewater neutralization equipment and wastewater neutralization method using oil traps - Google Patents

Description

The present invention relates to, for example, a wastewater neutralization treatment facility and a wastewater neutralization treatment method utilizing an oil trap that floats oil from wastewater discharged from a facility such as a factory to separate water and oil.

The most common method for neutralizing industrial wastewater is batch processing. Specifically, a dedicated neutralization treatment tank for putting wastewater is provided, a neutralizing agent (neutralizing agent) is added to the wastewater in the neutralization treatment tank, the mixture is stirred, and the wastewater is discharged after reaching a predetermined pH. It is a process of doing.
However, such batch processing requires a large-scale neutralization treatment tank and requires a large capital investment.
On the other hand, factories of a certain size are equipped with oil traps that collect oil before discharging wastewater to prevent oil from flowing out to the outside.

As a wastewater treatment system using the oil trap described above, for example, the wastewater treatment system described in Patent Document 1 is disclosed as a known technique.
This wastewater treatment system batch-treats wastewater to neutralize it. Specifically, the inside of the storage tank to which the wastewater is supplied is divided into a plurality of storage chambers by a partition plate, and between adjacent storage chambers. A communication pipe is provided, and a circulation pipe is provided between the storage chambers at the most downstream position and the most upstream position. In use, when the wastewater separated from the oil in the storage chamber on the upstream side and sent to the storage chamber at the most downstream position is sent to the storage chamber at the most upstream position by the circulation pipe, carbon dioxide gas is injected into the wastewater. Is neutralizing.

JP-A-2010-125386

However, in the above-mentioned wastewater treatment system, since it is necessary to form a plurality of storage chambers in the storage tank and provide communication pipes and circulation pipes connecting the storage chambers, it is necessary to drastically change the configuration of the oil trap. , Remodeling work requires labor and costs. In addition, when modifying the oil trap, the use of the oil trap may be restricted.

The present invention has been made in view of such circumstances, and is a wastewater neutralization treatment facility and wastewater neutralization treatment utilizing an oil trap that can continuously and economically carry out separation of oil from wastewater and pH adjustment of wastewater. The purpose is to provide a method.

The wastewater neutralization treatment equipment utilizing the oil trap according to the first invention according to the above object has an oil trap tank in which the inflow and outflow of wastewater are continuously performed, and the inside of the oil trap tank flows out from the inflow side. An oil trap that can float and separate oil from drainage that flows toward the side,
On the inflow side of the oil trap tank, a drainage circulation channel provided with an intake port for taking in a part of the drainage in the oil trap tank and a drainage port for returning the taken-in drainage to the inside of the oil trap tank again.
A neutralizing agent supply means capable of supplying a neutralizing agent to the wastewater taken into the drainage circulation channel according to the flow rate and pH value of the wastewater flowing through the oil trap tank.
Wherein provided on the drainage circulation path, have a mixing means for mixing the neutralizing agent fed to the waste water and drainage incorporated into drainage circulation path,
The wastewater mixed with the neutralizing agent is returned to the inflow side of the oil trap tank, and is directed toward the outflow side while securing a laminar flow region necessary for oil-water separation of the wastewater flowing in the oil trap tank. Flow, the neutralizer is diffused into the drainage in the oil trap tank .

In the wastewater neutralization treatment equipment utilizing the oil trap according to the first invention, a water absorption pump is provided at the intake port of the drainage circulation passage, and the depth position of the water absorption port of the water absorption pump is set in the oil trap tank. It is preferable that the oil trap tank is set below the upper layer of the drainage water and above the bottom of the oil trap tank.

In the wastewater neutralization treatment equipment utilizing the oil trap according to the first invention, the amount of wastewater taken into the drainage circulation channel is preferably 3 to 10% of the minimum amount of wastewater flowing into the oil trap tank.

In the wastewater neutralization treatment facility utilizing the oil trap according to the first invention, the neutralizer supply means communicates a tank capable of storing the neutralizer in a liquid state with the tank and the wastewater circulation path. It is preferable that the drug charging path has a drug charging path, and the liquid neutralizing agent is constantly filled in the drug charging path.

In the wastewater neutralization treatment facility utilizing the oil trap according to the first invention, the pH value of the wastewater flowing through the oil trap tank is measured on the inflow side and the outflow side of the oil trap tank, respectively, and the pH on the inflow side is measured. The amount of the neutralizing agent supplied is determined based on the value and the flow rate of the wastewater flowing through the oil trap tank, and the amount of the neutralizing agent supplied is corrected based on the pH value on the outflow side. preferable.

The wastewater neutralization treatment method utilizing the oil trap according to the second invention according to the above object uses an oil trap provided with an oil trap tank in which the inflow and outflow of wastewater are continuously performed, and the inside of the oil trap tank. When floating and separating oil from the wastewater flowing from the inflow side to the outflow side
A part of the drainage in the oil trap tank is taken in from the intake port into a drainage circulation path provided with an intake port and a discharge port on the inflow side of the oil trap tank, and the flow rate and pH of the drainage flowing through the oil trap tank. A neutralizing agent is supplied from the neutralizing agent supply means to the wastewater taken into the drainage circulation channel according to the value, and the wastewater taken into the drainage circulation channel and the neutralizing agent supplied to the wastewater are mixed. after mixing with means to return the waste water is mixed with the neutralizing agent from the outlet on the inlet side of the oil trap tank to the oil trap tank, the oil-water separation of the waste water flowing through the oil trap tank The neutralizing agent is diffused into the wastewater in the oil trap tank by flowing toward the outflow side while securing the necessary stratified flow area .

In the wastewater neutralization treatment method utilizing the oil trap according to the second invention, the depth position of the water absorption port of the water absorption pump provided at the intake port of the drainage circulation path is set from the upper layer of the drainage in the oil trap tank. Is also preferably set below and above the bottom of the oil trap tank.

In the wastewater neutralization treatment method utilizing the oil trap according to the second invention, the amount of wastewater taken up from the drainage circulation channel is preferably 3 to 10% of the minimum amount of wastewater taken into the oil trap tank.

In the wastewater neutralization treatment method utilizing the oil trap according to the second invention, the neutralizing agent supply means communicates the tank capable of storing the neutralizing agent in a liquid state with the tank and the drainage circulation path. It is preferable that the drug charging path is provided and the liquid neutralizing agent is constantly filled in the drug charging path.

In the wastewater neutralization treatment method utilizing the oil trap according to the second invention, the pH value of the wastewater flowing through the oil trap tank is measured on the inflow side and the outflow side of the oil trap tank, respectively, and the pH on the inflow side is measured. It is preferable to determine the supply amount of the neutralizing agent based on the value and the flow rate of the waste water flowing through the oil trap tank, and further correct the supply amount of the neutralizing agent based on the pH value on the outflow side. ..

The wastewater neutralization treatment equipment and the wastewater neutralization treatment method utilizing the oil trap according to the present invention include an oil trap provided with an oil trap tank in which the inflow and outflow of wastewater are continuously performed. In this oil trap, when the drainage flows from the inflow side to the outflow side of the oil trap tank, the oil is floated and separated from the drainage, so that it is necessary to secure a laminar flow area of the drainage required for oil-water separation.
Therefore, an intake port and an outlet of the drainage circulation channel are provided on the inflow side of the oil trap tank, and a part of the drainage in the oil trap tank is taken into this drainage circulation path from the intake port, and a neutralizing agent supply means is provided to the taken-in drainage. After supplying the neutralizing agent from the oil and mixing by the mixing means, this waste water is returned to the oil trap tank from the discharge port.
In this way, by providing the intake port and the discharge port of the drainage circulation path for adjusting the pH of the drainage on the inflow side of the oil trap tank, the drainage mixed with the neutralizing agent can be collected again in the oil trap tank. Even if it flows into the oil trap tank, the area (distance) required for stratification of the wastewater in the oil trap tank can be secured, and the oil-water separation function of the oil trap tank can be maintained. In addition, by mixing the wastewater taken into the drainage circulation channel with the neutralizing agent and returning it to the oil trap tank, the neutralizing agent diffuses into the drainage in two stages, so a very small amount of chemical solution is required. Even so, the neutralizing agent can be diffused into the oil trap tank to promote the neutralization reaction of the wastewater in the oil trap tank without directly stirring the inside of the oil trap tank.
Therefore, the separation of oil from the wastewater and the pH adjustment of the wastewater can be carried out continuously and economically without blocking the wastewater (without performing batch processing).

Further, the depth position of the water intake of the water absorption pump provided at the intake of the drainage circulation passage is set below the upper layer of the drainage in the oil trap tank and above the bottom of the oil trap tank. In this case, it is possible to suppress or even prevent the suction of oil that has floated in the oil trap tank and sludge that has accumulated on the bottom of the oil trap tank.

When the amount of drainage taken in from the drainage circulation channel is 3 to 10% of the minimum amount of drainage into the oil trap tank, the drainage in the oil trap tank due to the drainage returned from the drainage circulation channel to the oil trap tank It is possible to efficiently diffuse the neutralizing agent into the wastewater in the oil trap tank while suppressing the turbulence of the flow.

Further, when the neutralizing agent in a liquid state is constantly filled in the chemical input passage of the neutralizing agent supply means, for example, even if the pH value of the wastewater changes suddenly, the neutralizing agent is taken into the drainage circulation passage. However, it can be quickly supplied to wastewater.

Further, when the supply amount of the neutralizing agent obtained based on the pH value on the inflow side and the flow rate of the wastewater is further corrected based on the pH value on the outflow side, the accuracy of the neutralization treatment is further improved.

It is explanatory drawing of the wastewater neutralization treatment equipment utilizing the oil trap which concerns on one Embodiment of this invention.

Subsequently, an embodiment embodying the present invention will be described with reference to the attached drawings, and the present invention will be understood.
As shown in FIG. 1, the wastewater neutralization treatment equipment (hereinafter, also simply referred to as wastewater neutralization treatment equipment) 10 utilizing the oil trap according to the embodiment of the present invention is, for example, from wastewater discharged from a factory. It has an oil trap 11 capable of separating oil (oil component), and the oil trap 11 is provided with a pH adjusting function. The details will be described below.

The oil trap 11 includes an oil trap tank 12.
The oil trap tank 12 is a tank in which drainage flows in and out continuously, and the oil trap 11 flows from the inflow side (upstream side) to the outflow side (downstream side) of the oil trap tank 12 (FIG. In No. 1, the oil is floated and separated from the wastewater (flowing from the left side to the right side). An auxiliary tank 13 is attached to the outflow side of the oil trap tank 12, and the drainage (treated water) after oil separation that has flowed out of the oil trap tank 12 is discharged to the sea via the auxiliary tank 13. It has become. The length (distance) of the drainage of the oil trap tank 12 in the flow direction is, for example, about several meters to several tens of meters.

A plurality of partition plates 14 and 15 are provided at positions in the middle of the oil trap tank 12 in the flow direction of the drainage. One of the partition plates 14 is arranged on the liquid surface (bath surface) side of the drainage in the oil trap tank 12, and the other partition plate 15 is arranged on the bottom side of the oil trap tank 12, and the partition plate 14 and the partition plate 15 are arranged. Are arranged alternately (in a zigzag shape) with an interval in the flow direction of the oil trap tank 12. The partition plate 14 on the liquid surface side has a configuration in which the upper end portion thereof protrudes from the liquid surface and can block the floating oil content, and the oil content on the liquid surface blocked by the partition plate 14 is. Collected by a suction pump (not shown).

On the inflow side of the oil trap tank 12 (position on the upstream side of the partition plates 14 and 15), an intake port and a discharge port of the drainage circulation passage 16 are provided.
The drainage circulation passage 16 is composed of pipes, and a part of the drainage in the oil trap tank 12 is drained and circulated by the water absorption pump 17 provided at the intake side end (upstream side end portion) of the drainage circulation passage 16. It is taken into the road 16 and the taken-in drainage is returned to the oil trap tank 12 from the discharge port of the drainage side end portion (downstream side end portion) of the drainage circulation passage 16 again. The water absorption pump 17 is arranged on the upstream side of the discharge port.
The drainage circulation passage 16 is sequentially provided with an on-off valve 18, a check valve 19, a circulation flow meter 20, and an on-off valve 21 from the intake port to the discharge port.

The water absorption pump 17 is a submersible pump arranged in the drainage in the oil trap tank 12. Although one water absorption pump 17 may be provided, it is preferable to provide a plurality of water absorption pumps 17 at intervals in the width direction of the oil trap tank 12 (direction orthogonal to the drainage flow direction).
The depth position of the water suction port of the water absorption pump 17 is set below the upper layer of the drainage in the oil trap tank 12 and above the bottom of the oil trap tank 12. As a result, the water absorption pump 17 does not suck the oil that has floated in the oil trap tank 12 (while avoiding the suction of the oil contained in the wastewater), and also sucks the sludge accumulated at the bottom of the oil trap tank 12. The drainage in the oil trap tank 12 can be taken into the drainage circulation passage 16 while suppressing the above.
Further, although the position of the discharge port of the drainage circulation passage 16 is set above the liquid level of the drainage in the oil trap tank 12, it may be submerged in the drainage in the oil trap tank 12. Although the number of outlets may be one, it is preferable to provide a plurality of outlets at intervals in the width direction of the oil trap tank 12.

The drainage circulation channel 16 is provided with supply ports for two neutralizing agent supply means 22 and 23.
One neutralizing agent supplying means 22 supplies liquid sulfuric acid (an example of a neutralizing agent) to the alkaline wastewater in the drainage circulation channel 16, and the other neutralizing agent supplying means 23 is A liquid caustic soda (an example of a neutralizing agent) is supplied to the acidified wastewater in the drainage circulation channel 16. As described above, the neutralizing agent supplying means 22 and the neutralizing agent supplying means 23 differ only in the type of the neutralizing agent (chemical solution) used, and their configurations are substantially the same. Therefore, the neutralizing agent supplying means 23 Regarding the reference numerals of the constituent members of the above, "a" is added to the reference numerals of the constituent members of the neutralizing agent supply means 22, and description thereof will be omitted.

The neutralizing agent supply means 22 has a tank 24 capable of storing sulfuric acid, and a drug input path 25 communicating the tank 24 with the drainage circulation path 16.
The concentration of sulfuric acid stored in the tank 24 is adjusted to about 5 to 15%, and the concentration of caustic soda stored in the tank 24a is adjusted to about 5 to 15%. , Can be changed as needed.
Reference numeral 26 is a water level gauge provided in the tank 24.
The chemical input passage 25 is composed of pipes, and is connected to the drainage circulation passage 16 between the check valve 19 provided in the drainage circulation passage 16 and the circulation flow meter 20.

A transfer pump 27, a flow meter 28 for charging, a back pressure valve 29, an electric valve 30, and a check valve 31 are sequentially provided in the chemical charging passage 25 from the tank 24 side to the drainage circulation passage 16 side. There is. Reference numeral 32 is a maintenance flow path for returning sulfuric acid to the tank 24 and circulating it to prevent solidification of sulfuric acid, and reference numeral 33 is an electric valve provided in the flow path 32.
Sulfuric acid is constantly filled in the drug input path 25. As a result, sulfuric acid can be quickly supplied to the wastewater taken into the drainage circulation channel 16, but if necessary (for example, depending on the length of the drug input path), sulfuric acid can be supplied into the drug input path 25. Does not have to be filled.

The drainage circulation channel 16 is provided with a static mixer (an example of mixing means) 34 that mixes the drainage in the drainage circulation channel 16 with sulfuric acid (or caustic soda, the same applies hereinafter) supplied to the drainage.
The static mixer 34 is a conventionally known static mixer having no drive unit, and is provided between the circulation flow meter 20 of the drainage circulation path 16 and the on-off valve 21 (downstream from the drug input path 25). ..
If the wastewater in the drainage circulation passage 16 and sulfuric acid can be mixed, a mixer other than the static mixer described above, for example, a mixer provided with a drive unit can also be used.

With the above configuration, sulfuric acid can be supplied and mixed with the wastewater taken into the drainage circulation passage 16, but the amount of wastewater taken up by the drainage circulation passage 16 is 3 to 10% of the minimum inflow amount of the wastewater flowing into the oil trap tank 12. (Preferably, the lower limit is 5% and the upper limit is 8%).
Here, when the drainage intake amount of the drainage circulation channel 16 is less than 3% of the minimum inflow amount, the drainage intake amount becomes small, and when the wastewater mixed with sulfuric acid is returned to the oil trap tank 12, the oil trap tank The efficiency of diffusion of sulfuric acid into the wastewater in 12 tends to decrease. On the other hand, when the drainage intake amount of the drainage circulation channel 16 exceeds 10% of the minimum inflow amount, the drainage intake amount becomes large, and when the wastewater mixed with sulfuric acid is returned to the oil trap tank 12, the oil trap tank 12 The flow of drainage inside tends to be disturbed.
Normally, a constant flow rate of water is taken within the range of 3 to 10% of the minimum inflow rate.

The oil trap tank 12 is provided with pH meters 35 to 37 at three locations.
The pH meter 35 is installed on the inflow side of the oil trap tank 12 (position on the upstream side of the water absorption pump 17 provided at the intake of the drainage circulation passage 16) and measures the pH value of the drainage flowing into the oil trap tank 12. It is possible.
The pH meter 36 is installed at a position downstream of the partition plates 14 and 15, and is used for monitoring (reference value) the pH value of the wastewater flowing in the oil trap tank 12.
The pH meter 37 is installed on the outflow side of the oil trap tank 12 (position on the downstream side of the pH meter 36) and is used for monitoring the pH value of the wastewater flowing out from the oil trap tank 12.

As described above, the pH meters 35 to 37 were installed at three locations in the oil trap tank 12, but they may be installed at least on the inflow side of the oil trap tank 12, and may be installed at two or four or more locations as necessary. It may be installed in a plurality of places. The number of pH meters installed at each location may be one or a plurality of two or more.
At the outflow position of the drainage of the oil trap tank 12 (the outflow side end of the oil trap tank 12), a weir type flow meter 38 capable of measuring the flow rate of the drainage flowing through the oil trap tank 12 (outflowing from the oil trap tank 12) 38 Is installed. Of course, if the flow rate of wastewater can be measured, it is possible to use a flow meter other than the weir type flow meter.

The three pH meters 35 to 37 and the weir type flow meter 38 described above are provided with indicators 39 to 42, respectively, and each numerical value (pH value and flow rate of wastewater) of the indicators 39 to 42 is a calculation processing unit. It is transmitted to 43. Further, each flow rate measured by the circulation flow meter 20 and the input flow meters 28, 28a is also transmitted to the arithmetic processing unit 43.
Using the transmitted data described above, the arithmetic processing unit 43 performs each process described later by a preset program, calculates the amount of sulfuric acid or caustic soda supplied to the drainage circulation channel 16, and transfers the pumps 27 and 27a. It is a computer that can control the operation of. The computer is a conventionally known computer including a RAM, a CPU, a ROM, an I / O, and a bus connecting these elements, but the computer is not limited thereto.

The arithmetic processing unit 43 has a chemical solution output determination SEQ unit, a reference magnification determination SEQ unit, and a chemical solution gain determination SEQ unit.
In the chemical output determination SEQ section, the flow rate of drainage measured by the weir type flow meter 38 (flow rate of the indicator 42) and the pH value measured by the pH meter 35 on the inflow side of the oil trap tank 12 (indicator 39). The pH value of) and is input respectively.
The amount of sulfuric acid (or the amount of caustic soda, the same applies hereinafter) required to neutralize the wastewater in the oil trap tank 12 is calculated from the flow rate and pH value of the wastewater.

The amount of sulfuric acid calculated by the chemical output determination SEQ section is output to the reference magnification determination SEQ section. In the reference magnification determination SEQ section, the pH value measured by the above-mentioned pH meter 35, the pH meter 36 located downstream from the partition plates 14 and 15, and the pH meter 37 located downstream from the pH meter 36 are used. The measured pH values (each pH value of the indicators 40 and 41) are input respectively.
Further, the pH value measured by the above-mentioned pH meter 35 and each flow rate measured by the circulation flow meter 20 and the input flow meters 28 and 28a are input to the chemical solution gain determination SEQ unit, respectively. , These are output to the reference magnification determination SEQ section.

As a result, the reference magnification determination SEQ section corrects the amount of sulfuric acid calculated by the chemical solution output determination SEQ section based on the pH value (measured value) measured by the pH meter 37, and operates the transfer pumps 27 and 27a. Control.
Although the case where the sulfuric acid amount calculated by the chemical solution output determination SEQ section is corrected has been described here, each of them is based on the sulfuric acid amount calculated by the chemical solution output determination SEQ section without correction as necessary. The operation of the transfer pumps 27 and 27a can also be controlled.

Subsequently, a wastewater neutralization treatment method using an oil trap according to an embodiment of the present invention will be described with reference to FIG.
The wastewater generated at the factory is treated by the wastewater neutralization treatment facility 10, oil is removed from the wastewater, the pH of the wastewater is adjusted, and then the wastewater is discharged to the sea. The details will be described below.

In the oil trap 11 of the wastewater neutralization treatment facility 10, the inflow of wastewater into the oil trap tank 12 and the outflow from the oil trap tank 12 are continuously performed. At this time, if the drainage contains oil, the oil floats and separates from the drainage in the process of flowing the drainage from the inflow side to the outflow side of the oil trap tank 12.
The floating oil is blocked by the partition plate 14 on the liquid surface side, and is therefore recovered by the suction pump.

Further, the pH value of the wastewater flowing into the oil trap tank 12 is measured at each location by a pH meter 35 to 37, and the flow rate is measured by a weir type flow meter 38. The measured pH value and flow rate are sequentially transmitted to the arithmetic processing unit 43.
Then, when the wastewater becomes alkaline due to the influence of rainwater, or becomes acidic due to an abnormality in the factory (for example, damage to equipment or leakage of chemicals), a part of the wastewater in the oil trap tank 12 is used. Is continuously taken into the drainage circulation passage 16 by the water absorption pump 17.

The water absorption pump 17 may be operated intermittently only when the pH value measured by the pH meter is alkaline or acidic. For example, the water absorption pump 17 is always operated regardless of the fluctuation of the pH value, and the drainage circulation path 16 is operated. The wastewater may be taken into the water continuously.
At this time, the depth position of the water suction port of the water absorption pump 17 is set below the upper layer of the drainage in the oil trap tank 12 and above the bottom of the oil trap tank 12, so that the drainage circulation is performed. It is possible to suppress the infiltration of oil and the like into the road 16. Further, the amount of wastewater taken into the drainage circulation channel 16 is preferably 3 to 10% of the minimum amount of wastewater taken into the oil trap tank 12.

Here, a case where the calculation processing unit 43 determines that the wastewater is alkaline from the pH value measured by the pH meter 35 will be described below.
In the chemical output determination SEQ unit of the arithmetic processing unit 43, the flow rate of drainage measured by the dam type flow meter 38 (flow rate of the indicator 42) and the pH value measured by the pH meter 35 on the inflow side of the oil trap tank 12 From (pH value of indicator 39), the amount of sulfuric acid required to neutralize the wastewater in the oil trap tank 12 is calculated. The calculated amount of sulfuric acid is output to the reference magnification determination SEQ section.

In the reference magnification determination SEQ unit of the arithmetic processing unit 43, the amount of sulfuric acid calculated by the chemical solution output determination SEQ unit from the pH value measured by the pH meter 37 on the outflow side of the oil trap tank 12 (pH value of the indicator 41). Is corrected.
The operation of the transfer pump 27 is controlled so that the corrected amount of sulfuric acid can be supplied to the drainage circulation passage 16. The operation of the transfer pump 27 is performed based on each flow rate measured by the circulation flow meter 20 and the input flow meter 28 transmitted to the chemical solution gain determination SEQ unit of the arithmetic processing unit 43.
At this time, the transfer pump 27a for supplying caustic soda is in a stopped state.

Since the chemical input passage 25 of the neutralizing agent supply means 22 is constantly filled with sulfuric acid, the sulfuric acid can be quickly supplied to the wastewater taken into the drainage circulation passage 16.
Further, since the amount of sulfuric acid supplied from the neutralizing agent supply means 22 is an amount necessary for neutralizing the drainage in the oil trap tank 12, the alkaline wastewater taken into the drainage circulation passage 16 is , It becomes acidic due to the supplied sulfuric acid.

The drainage in the drainage circulation passage 16 described above and the sulfuric acid supplied to the drainage are mixed by the static mixer 34, and then returned to the oil trap tank 12 from the discharge port of the drainage circulation passage 16.
By adjusting the pH of the drainage on the inflow side of the oil trap tank 12 in this way, the distance required for forming the laminar flow in the oil trap tank 12 of the oil trap 11 can be secured, and the original oil-water separation function of the oil trap 11 can be secured. Appropriate addition of sulfuric acid is possible without inhibiting the above.

Further, the drainage mixed with sulfuric acid by the static mixer 34 is returned to the oil trap tank 12 from the discharge port of the drainage circulation passage 16, and this drainage is flowed from the upstream side to the downstream side of the oil trap tank 12, so that the drainage becomes an oil trap. The neutralization reaction proceeds while moving in the tank 12, and the neutralization treatment can be continuously performed in the flow of wastewater. At this time, the oil-water separation function is not affected.

Then, the wastewater (treated water) from which the oil content has been separated and the pH has been adjusted is discharged to the sea via the auxiliary tank 13.
The above method describes the case where the calculation processing unit 43 determines that the wastewater is alkaline, but when the calculation processing unit 43 determines that the wastewater is acidic, it is neutralized. Using the agent supply means 23, caustic soda is supplied to the drainage circulation channel 16 by the same method as described above.

From the above, by using the wastewater neutralization treatment equipment and the wastewater neutralization treatment method utilizing the oil trap of the present invention, the separation of oil from the wastewater and the pH adjustment of the wastewater can be continuously performed without blocking the wastewater. And it can be implemented economically.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the configuration described in the above-described embodiments, and the matters described in the claims. It also includes other embodiments and variations that may be considered within the scope. For example, when a wastewater neutralization treatment facility and a wastewater neutralization treatment method utilizing the oil trap of the present invention are constructed by combining some or all of the above-described embodiments and modifications, the scope of rights of the present invention also applies. included.
Further, the scope of rights of the present invention is not limited to the case where a wastewater neutralization treatment facility utilizing an oil trap is newly installed (newly installed), for example, to an existing oil trap used in a conventional factory. It is also applied to the case where a wastewater circulation channel, a neutralizing agent supply means, and a mixing means are installed to configure a wastewater neutralization treatment facility utilizing the oil trap of the present invention.

Then, in the above-described embodiment, the case where the wastewater neutralization treatment equipment is installed in the factory has been described, but especially if the facility contains oil and discharges wastewater that requires pH adjustment. It is not limited.
Further, in the above-described embodiment, the wastewater neutralization treatment equipment is provided with two systems of acid and alkali as a neutralizing agent supply means, and the wastewater neutralization treatment equipment is made a facility capable of responding to a wide range of pH changes. If the value varies from acidic only or alkaline only, only one of the acid and alkaline strains may be used. The acidic neutralizing agent is not limited to the above-mentioned sulfuric acid, and may be, for example, hydrochloric acid. Also, the alkaline neutralizer is not limited to the caustic soda described above.

10: Wastewater neutralization treatment equipment utilizing oil traps, 11: Oil traps, 12: Oil trap tanks, 13: Auxiliary tanks, 14, 15: Partition plates, 16: Drainage circulation channels, 17: Water absorption pumps, 18: Opening and closing Valve, 19: Check valve, 20: Circulation flow meter, 21: On-off valve, 22, 23: Neutralizer supply means, 24, 24a: Tank, 25, 25a: Drug inlet, 26, 26a: Water level meter , 27, 27a: Transfer pump, 28, 28a: Input flow meter, 29, 29a: Back pressure valve, 30, 30a: Electric valve, 31, 31a: Check valve, 32, 32a: Flow path, 33, 33a: Electric valve, 34: Static mixer (mixing means), 35 to 37: pH meter, 38: Weir type flow meter, 39 to 42: Indicator, 43: Arithmetic processing unit

Claims (10)

An oil trap having an oil trap tank in which the inflow and outflow of wastewater are continuously performed, and an oil trap capable of floating and separating oil from the drainage flowing from the inflow side to the outflow side in the oil trap tank.
On the inflow side of the oil trap tank, a drainage circulation channel provided with an intake port for taking in a part of the drainage in the oil trap tank and a drainage port for returning the taken-in drainage to the inside of the oil trap tank again.
A neutralizing agent supply means capable of supplying a neutralizing agent to the wastewater taken into the drainage circulation channel according to the flow rate and pH value of the wastewater flowing through the oil trap tank.
Wherein provided on the drainage circulation path, have a mixing means for mixing the neutralizing agent fed to the waste water and drainage incorporated into drainage circulation path,
The wastewater mixed with the neutralizing agent is returned to the inflow side of the oil trap tank, and is directed toward the outflow side while securing a stratified region necessary for oil-water separation of the wastewater flowing in the oil trap tank. A wastewater neutralization treatment facility utilizing an oil trap, characterized in that the flow and the neutralizing agent are diffused into the wastewater in the oil trap tank. In the wastewater neutralization treatment equipment utilizing the oil trap according to claim 1, a water absorption pump is provided at the intake port of the drainage circulation passage, and the depth position of the water absorption port of the water absorption pump is set in the oil trap tank. A wastewater neutralization treatment facility utilizing an oil trap, which is characterized in that it is set below the upper layer of wastewater and above the bottom of the oil trap tank. In the wastewater neutralization treatment facility utilizing the oil trap according to claim 1 or 2, the amount of wastewater taken into the drainage circulation channel is 3 to 10% of the minimum amount of wastewater flowing into the oil trap tank. Wastewater neutralization treatment equipment that utilizes an oil trap. In the wastewater neutralization treatment facility utilizing the oil trap according to any one of claims 1 to 3, the neutralizing agent supply means includes a tank capable of storing the neutralizing agent in a liquid state and the tank. A wastewater neutralization treatment facility utilizing an oil trap, which has a chemical injection passage communicating with the drainage circulation passage and is characterized in that the chemical injection passage is constantly filled with the neutralizer in a liquid state. .. In the wastewater neutralization treatment facility utilizing the oil trap according to any one of claims 1 to 4, the pH value of the wastewater flowing through the oil trap tank is measured on the inflow side and the outflow side of the oil trap tank, respectively. The supply amount of the neutralizing agent is determined based on the pH value on the inflow side and the flow rate of the drainage flowing through the oil trap tank, and the supply amount of the neutralizing agent is set to the pH value on the outflow side. A wastewater neutralization treatment facility that utilizes an oil trap, which is characterized by being corrected based on the above. When using an oil trap equipped with an oil trap tank in which drainage flows in and out continuously, oil is floated and separated from the drainage flowing from the inflow side to the outflow side in the oil trap tank.
A part of the drainage in the oil trap tank is taken in from the intake port into a drainage circulation path provided with an intake port and a discharge port on the inflow side of the oil trap tank, and the flow rate and pH of the drainage flowing through the oil trap tank. A neutralizing agent is supplied from the neutralizing agent supply means to the wastewater taken into the drainage circulation channel according to the value, and the wastewater taken into the drainage circulation channel and the neutralizing agent supplied to the wastewater are mixed. after mixing with means to return the waste water is mixed with the neutralizing agent from the outlet on the inlet side of the oil trap tank to the oil trap tank, the oil-water separation of the waste water flowing through the oil trap tank A wastewater neutralization treatment method utilizing an oil trap , which comprises flowing toward the outflow side while securing a necessary stratified flow region and diffusing the neutralizing agent into the wastewater in the oil trap tank. In the wastewater neutralization treatment method utilizing the oil trap according to claim 6, the depth position of the water intake of the water absorption pump provided at the intake of the drainage circulation passage is set to be higher than the upper layer of the drainage in the oil trap tank. A wastewater neutralization treatment method utilizing an oil trap, which is characterized in that it is set below and above the bottom of the oil trap tank. In the wastewater neutralization treatment method utilizing the oil trap according to claim 6 or 7, the amount of wastewater taken up from the drainage circulation channel is 3 to 10% of the minimum amount of wastewater taken into the oil trap tank. Wastewater neutralization treatment method using the oil trap. In the wastewater neutralization treatment method utilizing the oil trap according to any one of claims 6 to 8, the neutralizing agent supply means has a tank capable of storing the neutralizing agent in a liquid state, and the tank. A wastewater neutralization treatment method utilizing an oil trap, which has a chemical injection passage communicating with the drainage circulation passage and constantly fills the chemical injection passage with a neutralizing agent in a liquid state. In the wastewater neutralization treatment method using the oil trap according to any one of claims 6 to 9, the pH value of the wastewater flowing through the oil trap tank is measured on the inflow side and the outflow side of the oil trap tank, respectively. Then, the supply amount of the neutralizing agent is obtained based on the pH value on the inflow side and the flow rate of the wastewater flowing through the oil trap tank, and the supply amount of the neutralizing agent is set to the pH value on the outflow side. A wastewater neutralization treatment method that utilizes an oil trap, which is characterized by making corrections based on.

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