Method and device for treating waste liquid of grease trap

Abstract

The method for treating a waste liquid of a grease trap according to the present invention can efficiently make, into a soap liquid (including a liquid in an emulsified state), an oil and fat content floating in the waste liquid, in particular in an upper portion of the waste liquid inside the grease trap, the method involving: mixing the waste liquid inside the grease trap and a saponification agent supplied to the waste liquid with ultrasonic waves oscillating inside the grease trap to obtain a mixture liquid; and stirring and mixing the mixture liquid inside the grease trap to obtain the soap liquid. The device for treating a waste liquid of a grease trap according to the present invention is provided with an ultrasonic oscillator inside the grease trap and can mix the waste liquid inside the grease trap and a saponification agent supplied to the waste liquid with oscillation of ultrasonic waves emitted by the ultrasonic oscillator to obtain a mixture liquid.

Description

Grease trap wastewater treatment method and wastewater treatment device

[0001] The present invention relates to a method for treating wastewater in a grease trap (to convert it into soapy water) and to an apparatus for treating the same.

[0002] For example, in the kitchens of food service centers, restaurants, hotels, food processing plants, supermarkets, department stores, hospitals, and restaurants, cooking oil, food waste, leftover food, chopsticks, toothpicks, paper scraps, plastic waste, and other garbage, as well as the liquids that accompany them (hereinafter referred to as "wastewater"). In Japan, it is prohibited to discharge such wastewater into sewer pipes or drainpipes, so currently, such wastewater is stored in storage tanks (grease traps), simple grease traps, and other wastewater storage tanks (hereinafter collectively referred to as "grease traps") installed inside or outside the kitchen, and the wastewater inside the grease traps is cleaned out by a cleaning company on a regular basis, for example, once a week or once a month.

[0003] The wastewater in grease traps is treated regularly, but with the current wastewater treatment method, cleaning companies must treat the wastewater, neutralize it with a neutralizing agent, and then discharge it into the sewer or septic tank. This requires secondary work and costs, resulting in high costs. In addition, the grease trap may become full with wastewater before the next scheduled cleaning date, and the wastewater may flow into the drain pipes or sewer pipes untreated, causing environmental pollution and foul odors inside and outside the kitchen.

[0004] The inventor of this application has previously developed new wastewater treatment devices for grease traps (Patent Documents 1 to 6). These wastewater treatment devices use a pump to suck out the wastewater from the grease trap, while stirring and mixing the wastewater with a saponifying agent, turning the wastewater from the grease trap into a soapy solution.

[0005] According to the wastewater treatment devices of Patent Documents 1 to 6, the wastewater in the grease trap can be turned into soapy liquid and returned to the grease trap or discharged into a drain pipe or sewer pipe, which has the advantage that the pipes are less likely to clog and the grease trap can be cleaned with the soapy liquid.

[0006] JP 2010-149101 A JP 2012-050918 A JP 2012-106247 A JP 2012-223767 A JP 2013-146686 A JP 2013-208616 A

[0007] Wastewater contains oil and fat. Oil and fat floats on water due to its specific gravity. However, the wastewater treatment devices in Patent Documents 1 to 6 described above use a hose inserted into the wastewater in the grease trap and pumped up with a pump, which inevitably pumps up a large amount of water at the bottom of the wastewater. This means that a large amount of wastewater needs to be agitated and mixed by the pump, making it difficult to efficiently turn the oil and fat in the wastewater floating at the top of the wastewater in the grease trap into a soapy solution.

[0008] The present invention provides a method and apparatus for treating grease trap effluent, which can efficiently convert effluent in a grease trap, particularly grease floating above the effluent, into soapy liquid.

[0009] The method for treating grease trap effluent of the present invention involves ultrasonically mixing the effluent in the grease trap with a saponifying agent supplied to the effluent to form a mixed liquid, which is then stirred and mixed in the grease trap to form a soapy liquid (including an emulsified state). In this case, it is desirable to introduce the effluent in the grease trap, primarily the oil and fat components, into a mixing section provided in the grease trap, where it is mixed with the saponifying agent using ultrasonic waves. In this case, the mixed liquid flowing out of the outlet of the mixing section can be stirred and mixed at the outlet side to form a soapy liquid.

[0010] The grease trap wastewater treatment device of the present invention has an ultrasonic oscillator installed inside the grease trap, which mixes the wastewater in the grease trap and the saponifying agent supplied to the wastewater using ultrasonic waves emitted from the ultrasonic oscillator to form a mixed solution, and then agitates and mixes the mixed solution with an agitator to form a soapy solution.The ultrasonic oscillator can be installed on the partition plate, the peripheral wall, the bottom, or other locations inside the grease trap.The ultrasonic oscillator can also be installed on both or either the inner and outer surfaces of the peripheral wall of a mixing section installed inside the grease trap.An agitator can be installed on the outlet side of the mixing section, and the wastewater in the grease trap or the mixed solution flowing into the grease trap from the outlet of the mixing section can be agitated and mixed at the outlet side using the agitator to form a soapy solution.

[0011] The method for treating grease trap effluent of the present invention has the following effects: (1) The effluent in the grease trap, mainly the oils and fats and the saponifying agent, is mixed with ultrasound to form a mixture, and the mixture is then stirred and mixed with an agitator, which promotes the liquefaction of the effluent into soap. (2) When the oils and fats and the saponifying agent are mixed in the mixing section, the oils and fats and the saponifying agent are more easily mixed.

[0012] The grease trap wastewater treatment device of the present invention has the following advantages: (1) Because an ultrasonic oscillator is provided inside the grease trap, the wastewater in the grease trap and the saponifying agent supplied to the wastewater can be mixed by the ultrasonic waves generated by the ultrasonic oscillator, making it easier for the wastewater and the saponifying agent to mix. (2) When ultrasonic waves are generated in a mixing section provided inside the grease trap, the wastewater and the saponifying agent in the mixing section are efficiently mixed.

[0013] The present invention relates to a method for treating wastewater from a grease trap, ...

[0014] [General-Purpose Grease Trap] Typically, wastewater B from a kitchen or other facility is poured into grease trap A (Figure 3). This wastewater B typically contains grease E and debris. The debris is collected in basket C inside grease trap A, while wastewater B containing grease E accumulates inside grease trap A. Grease trap A is divided into sections by several partitions D1 and D2. The spaces below partitions D1 and D2 are open, allowing wastewater B to pass through. The flow rate of wastewater B flowing into grease trap A is slowed by partition D1, and the grease E accumulates on top of the water F (which usually contains sludge) due to its specific gravity. Wastewater B inside grease trap A is gradually discharged from the outlet of trap G into a sewer or septic tank K outside grease trap A. The grease E that accumulates above the water F inside grease trap A is primarily a combination of glycerin and fatty acids.

[0015] (Embodiment of the method for treating effluent from a grease trap) The method for treating effluent from a grease trap of the present invention is a method for efficiently converting effluent from grease traps of various shapes and structures, particularly the oils and fats contained in the effluent, into a soapy solution. An embodiment of the method for treating effluent will be described below with reference to Figures 1 and 2.

[0016] The method for treating effluent from a grease trap of the present invention involves mixing effluent B in grease trap A with saponifying agent H supplied to effluent B using ultrasonic vibrations to form a mixed solution, and then stirring and mixing the mixed solution in grease trap A to form a soapy solution. Mixing of effluent B and saponifying agent H using ultrasonic waves can be carried out anywhere in grease trap A, but the embodiment in Figure 1 shows a case where a pipe 1 is placed in grease trap A to form a passage (mixing section) 2, and mixing is carried out in mixing section 2.

[0017] In the embodiment of Figure 1, waste liquid B from grease trap A flows into mixing section 2 from inlet 3 of mixing section 2. Saponifying agent H is supplied from saponifying agent container 8 into mixing section 2, and the saponifying agent H and waste liquid B that has flowed into mixing section 2 are mixed with ultrasonic waves generated by ultrasonic oscillator 5 provided in mixing section 2 to form a mixed liquid. Furthermore, the mixed liquid flowing out from outlet 6 of mixing section 2 is stirred and mixed by rotating agitator 7 provided near outlet 6 to form a soapy liquid. The soapy liquid is discharged from outlet 6 of mixing section 2 into grease trap A by the rotation of agitator 7.

[0018] It is desirable that the waste liquid B flowing into the mixing section 2 mainly consists of oils and fats floating on the water of the waste liquid B in the grease trap A. The saponifying agent H can be supplied to the waste liquid B inside the mixing section 2 or to the waste liquid B outside the mixing section 2.

[0019] The mixture mixed by ultrasonic vibration in the mixing section 2 is stirred and mixed by the agitator 7 provided on the outlet 6 side of the mixing section 2 to form a soapy solution. The rotation of the agitator 7 makes it easier for the waste liquid B in the grease trap A to flow (be drawn) into the mixing section 2. The rotation speed of the agitator 7 is a speed suitable for forming a soapy solution, for example, around 1000 rpm.

[0020] The soapy liquid flowing out from the outlet 6 of the mixing section 2 into the grease trap A hits the partition plate D2 and diffuses within the grease trap A. The diffused soapy liquid flows into (is drawn into) the mixing section 2 from the inlet 3 of the mixing section 2 together with wastewater B flowing into the grease trap A from outside, such as a kitchen. The flowing wastewater B is vibrated by ultrasonic waves in the mixing section 2 and mixed with the saponifying agent H to form a mixed liquid. This mixed liquid is stirred and mixed in the agitator 7 to form soapy liquid. By repeatedly liquefying the wastewater in the mixing section 2 and stirring and mixing in the agitator 7, the wastewater B in the grease trap A is turned into soapy liquid.

[0021] The saponifying agent H in the present invention is a general-purpose saponifying agent that can convert the fat and oil content and water in grease trap A into fatty acids (separating from glycerin) through a chemical reaction to produce a soap solution. It includes various processing agents such as emulsifiers, detergents, and surfactants. The amount of saponifying agent H added to wastewater B can be set as desired depending on the amount of wastewater B in grease trap A, the amount of fat and oil content, and the composition of the fat and oil (nature: plant-based, animal-based), etc. By converting the fat and oil content into fatty acids, biodegradability is much higher than that of the fat and oil content itself. The soap solution in the present invention does not necessarily have to be fully soaped, and also includes an emulsified state.

[0022] The operation timing and operation time of the agitator 7, the timing and amount of saponifying agent H to be added, etc. can be set, adjusted, and controlled as desired depending on the amount and properties of the wastewater B in the grease trap A, the type and properties of the saponifying agent H, etc. The start and stop of the operation of the agitator 7 is automatically performed at a predetermined time, for example, once a day or several times a day. The operation time for each operation can be set as desired and can be changed. The saponifying agent H is automatically added at a predetermined time, for example, once a day or several times a day. The amount added each time can be set as desired.

[0023] The mixing ratio of the waste liquid B to the saponifying agent H is preferably about 5:1 in terms of saponification efficiency, cost, etc., but this ratio can be changed depending on the degree of dirtiness of the waste liquid B, the amount of oil and fat, and the components of the oil and fat. When the waste liquid B is significantly dirty or the amount of oil and fat is large, the amount of saponifying agent H can be made larger than the above ratio, and when the waste liquid B is not dirty or the amount of oil and fat is small, the amount of saponifying agent H can be made smaller than the above ratio.

[0024] The soapy solution in the grease trap A is discharged from the outlet of the grease trap A into an external sewer or septic tank K.

[0025] In the present invention, as long as the wastewater B and the saponifying agent H can be mixed by the ultrasonic waves generated from the ultrasonic oscillator 5, the ultrasonic oscillator 5 does not necessarily have to be provided inside the mixing section 2. For example, it can be provided on the peripheral wall or bottom surface of the grease trap A, or on the partition plates D1 and D2. It can also be provided on the entire surface.

[0026] In the present invention, microorganisms (microbial preparations: liquid, solid, etc.), EM bacteria, enzymes, etc. can also be added to grease trap A or mixing section 2. Suitable microorganisms are those that can contribute to the saponification of wastewater B in grease trap A, such as soil microorganisms and other microorganisms. These microorganisms can be commercially available. Liquid microbial preparations are suitable for supplying into grease trap A or wastewater B in mixing section 2. Commercially available enzymes can be used. Adding these microbial preparations, EM bacteria, enzymes, etc. promotes the decomposition and saponification of the oils and fats in wastewater B in grease trap A.

[0027] (Embodiment of Grease Trap Wastewater Treatment Device) An embodiment of a grease trap wastewater treatment device of the present invention will be described below with reference to Figures 1 and 2. This wastewater treatment device includes a mixing section 2 provided within the grease trap A, a saponifying agent container 8 containing a saponifying agent H, an ultrasonic oscillator 5 that ultrasonically vibrates and mixes the wastewater B and the saponifying agent H in the mixing section 2, and an agitator 7 provided on the outlet 6 side of the mixing section 2. The agitator 7 is driven to rotate by a motor M.

[0028] The mixing section 2 is the location within the grease trap A through which the waste liquid B passes, and can be formed, for example, by laying a pipe 1 within the grease trap A. The inner diameter of the pipe 1 depends on the size of the grease trap A, but a diameter of, for example, several centimeters to several tens of centimeters is suitable so that the waste liquid B can easily pass through without clogging. The pipe 1 is preferably made of a material that is resistant to corrosion by the waste liquid B, for example, a stainless steel pipe.

[0029] In Figure 1, the ultrasonic oscillator 5 is fixed to the inside (inner wall surface) of the mixing section 2, but it can also be fixed to the outside (outer wall surface) of the mixing section 2, or to both the inside and outside. Moreover, it can be provided not in one place in the mixing section 2, but in two or more places in the longitudinal direction of the mixing section 2 (the direction in which the waste liquid B flows). A general-purpose ultrasonic oscillator can be used as the ultrasonic oscillator 5. The oscillation frequency and oscillation power are preferably such that the waste liquid B and the saponifying agent H can be mixed efficiently. Although not shown, the ultrasonic oscillator 5 is equipped with lead wires for power supply.

[0030] 1 has an inlet 3 that is raised higher than the middle section 9, and is set at the position of the grease floating above the wastewater B in the grease trap A, making it easier for the grease to flow in through the inlet 3. The outlet 6 is also raised higher than the middle section 9, so that the mixed liquid flowing out from the outlet 6 flows above the wastewater B in the grease trap A and hits the partition plate D2 to be dispersed within the grease trap A. Furthermore, the inner portion (upward protruding portion) 6a of the peripheral wall of the outlet 6 is raised higher than the outer portion 6b, so that the soapy liquid agitated by the agitator 7 is discharged mainly toward the partition plate D2, and is easily dispersed within the grease trap A by hitting the partition plate D2.

[0031] The inlet 3 and outlet 6 are raised, and the position of the middle section 9 of the mixing section 2 is lowered (towards the bottom of the grease trap A), and the ultrasonic oscillator 5 is fixed to the inner surface of the peripheral wall of this middle section 9. By making the middle section 9 lower than the inlet 3 and outlet 6, the waste liquid B and saponifying agent H tend to remain in the middle section 9, and the time for which they are vibrated by ultrasonic waves is extended, making it easier for the waste liquid B and saponifying agent H to mix.

[0032] Although the inner surface of the pipe 1 in Fig. 1 is smooth, the pipe 1 can also be a bellows-shaped pipe (a pipe with an uneven inner surface) as shown in Fig. 2. In this case, microorganisms introduced into the wastewater B can easily live in the uneven parts of the bellows inner surface, facilitating the proliferation of the microorganisms, and the soap formation is also promoted by the microorganisms.

[0033] The pipe 1 forming the mixing section 2 can also be arranged to meander in the depth direction of the bottom surface of the grease trap A. In this case, the mixing section 2 becomes longer by the amount of meandering, so that many ultrasonic oscillators 5 can be fixed to the mixing section 2, and the wastewater B and the saponifying agent H can be vibrated and mixed by the ultrasonic waves generated from those many ultrasonic oscillators 5. The ultrasonic oscillators 5 may be fixed at locations other than those shown in the figure.

[0034] The mixing section 2 is not formed by arranging a tube 1, but can be provided with an ultrasonic oscillator 5 attached thereto, and may have any other shape or structure, such as a small chamber, as long as the ultrasonic waves emitted from the ultrasonic oscillator 5 can easily mix the waste liquid B and the saponifying agent H.

[0035] The agitator 7 rotates so as to agitate and mix the waste liquid B and the saponifying agent H. It may be a propeller type, or may be of another shape or structure, such as a submersible pump. The agitator 7 may be installed at a location other than near the outlet 6 of the mixing section 2, as long as it can agitate and mix the mixed liquid flowing out from the outlet 6.

[0036] 1, a saponifying agent container 8 is provided so that the saponifying agent H in the saponifying agent container 8 can be supplied into the mixing section 2. The saponifying agent H may be supplied to a location other than the mixing section 2, for example, it may be supplied to the waste liquid B in the gluten trap A outside the mixing section 2.

[0037] 1, a control panel 10 is provided. The control panel 10 can set and adjust the timing of starting and stopping the operation of the agitator 7, the rotation speed, the operation time, the timing and amount of saponifying agent H to be added, the timing and amount of microorganisms to be added, and the like, and can also check the remaining amount of saponifying agent H. In addition, the control panel 10 can notify the results of the checks and adjustments to a control room or a control department such as a manager.

[0038] The operation timing of the agitator 7 is, for example, once a day or several times a day, when it automatically starts operating at a predetermined time, and the operation time is one continuous operation time. The timing of adding the saponifying agent H is, for example, once a day or several times a day, when it automatically starts adding at a predetermined time, and the amount added is a single amount. These timings can be set at a fixed time every few days, or when a sensor detects that the effluent B from the grease trap A has reached a predetermined amount. The timing and amount of microorganism addition are adjusted depending on the amount of effluent B from the grease trap A, the components of the oil and fat, etc. The control panel 10 can set, adjust, and control other conditions.

[0039] The above-described embodiment is a main example for solving the problem of the present invention. The present invention can be modified in design as long as the problem can be solved, and other devices can be added or changed to other devices.

[0040] 1 Pipe 2 Mixing section (passage) 3 Inlet (of mixing section) 5 Ultrasonic oscillator 6 Outlet (of mixing section) 6a Inner part (upward protruding part) 6b ​​Outer part 7 Agitator 8 Saponifying agent container 9 Middle part (of mixing section) 10 Control panel A Grease trap B Drainage C Basket D1, D2 Partition plate E Grease F Moisture G Trap H Saponifying agent K Sewer or septic tank M Motor

Claims

1. A method for treating grease trap effluent, comprising: ultrasonically mixing the effluent in the grease trap with a saponifying agent supplied to the effluent to produce a mixed liquid within the grease trap; and then stirring and mixing the mixed liquid within the grease trap to produce a soapy liquid.

2. A method for treating effluent from a grease trap, comprising the steps of: causing effluent from the grease trap to flow into a mixing section provided within the grease trap; mixing the effluent that has flowed in with a saponifying agent supplied to the effluent in the mixing section using ultrasound to form a mixed liquid; and stirring and mixing the mixed liquid that flows out from the mixing section into the grease trap to form a soapy liquid.

3. A method for treating effluent from a grease trap, comprising: causing effluent in the grease trap to flow into a mixing section provided within the grease trap; mixing the effluent that has flowed in with a saponifying agent supplied to the effluent in the mixing section using ultrasound to form a mixed liquid; stirring and mixing the mixed liquid that flows out from the mixing section into the grease trap to form a soapy liquid; and introducing microorganisms into the grease trap that can contribute to turning the effluent into a soapy liquid.

4. A grease trap wastewater treatment device characterized in that an ultrasonic oscillator is provided inside the grease trap, and ultrasonic waves generated from the ultrasonic oscillator enable the wastewater in the grease trap to be mixed with a saponifying agent supplied to the wastewater.

5. A grease trap drainage treatment device comprising an ultrasonic oscillator provided on one or both of a partition plate in the grease trap and the peripheral wall or bottom surface of the grease trap, and capable of mixing the drainage liquid in the grease trap with a saponifying agent supplied to the drainage liquid by ultrasonic waves emitted from the ultrasonic oscillator to produce a mixed liquid, and further comprising an agitator for agitating and mixing the mixed liquid within the grease trap to produce a soapy liquid.

6. A grease trap effluent treatment device comprising: a mixing section provided within the grease trap; an ultrasonic oscillator fixed within the mixing section; and an agitator provided within the grease trap; the ultrasonic oscillator oscillates ultrasonic waves to vibrate and mix the effluent in the grease trap and the saponifying agent supplied to the effluent; and the agitator agitates and mixes the mixture of the effluent and the saponifying agent within the grease trap or near the outlet of the mixing section to turn the mixture into soapy liquid.

7. A grease trap wastewater treatment device according to claim 6, characterized in that the mixing section is formed by arranging a pipe inside the grease trap, and an ultrasonic oscillator is fixed to the peripheral wall of the mixing section.

8. A grease trap wastewater treatment device as claimed in claim 6, characterized in that the mixing section is formed by arranging a bellows-shaped tube inside the grease trap, and an ultrasonic oscillator is fixed to the peripheral wall of the mixing section.

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