JP2003275720A - Garbage-containing waste water treating apparatus and operating method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a garbage-containing waste water treating apparatus in which garbage can be treated in high efficiency by saving the power consumption while reducing the volume of the solid contained in waste water without increasing the load imposed on the environment, and to provide a method for operating this apparatus. <P>SOLUTION: A means for separating the solid contained in the waste water is arranged in this waste water treating system for treating the waste water caused by organic waste with a microbe. The solid separated by the means is solubilized and treated by the action of the microbe. The conditions of a solid solubilizing part such as a residence time, the amount of air to be aerated and a control system are set as a method for promoting the solubilization of the organic solid with the microbe in the solid solubilizing part. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a kitchen wastewater treatment device for treating kitchen waste generated in homes, factories and the like, and a method of operating the same.

[0002]

2. Description of the Related Art As a method for crushing kitchen waste generated in each household by a crusher installed in a kitchen and then transferring it to a pipe to centrally process the kitchen waste, JP-A-3-89954 and JP-A-4-99954 are known.
The processing methods disclosed in Japanese Patent No. 305284 and Japanese Patent Laid-Open No. 6-55158 are known.

A method not using a crusher is disclosed in Japanese Patent Laid-Open No.
There is a method disclosed in Japanese Patent No. 208186. All of these inventions focus on the sanitary treatment of kitchen waste.

JP-A-3-89954 and JP-A-4-99954.
The kitchen waste processing apparatus disclosed in Japanese Patent No. 305284 discloses a kitchen garbage that is crushed by a crusher and transferred to a post-treatment unit, and then crushed kitchen waste is collected to treat the kitchen waste solid matter, and crushed kitchen waste is collected by solid-liquid separation. The wastewater sometimes generated is discharged into the environment as it is.

The processing method disclosed in Japanese Patent Laid-Open No. 6-55158 is such that the kitchen crusher installed in the kitchen of each house in an apartment house crushes the kitchen waste, transfers it with water and pipes it together at one place. To do. The kitchen waste treatment aims to recover kitchen waste by solid-liquid separation from wastewater containing kitchen waste, and to compost it by solid-phase fermentation to recycle it, and only treat the kitchen waste solids.

The treatment method disclosed in Japanese Unexamined Patent Publication No. 5-208186 squeezes kitchen waste with a piston to dehydrate and reduce the volume to improve handleability at the time of disposal, and oxidize the compressed waste water with ozone. Then, the odorous components and polluted components extracted in the water are oxidized.

[0007]

By crushing garbage, the organic components in the garbage are dissolved, and the BOD (biochemical oxygen demand) value, which is an index of water pollution, rises.
JP-A-3-89954 and JP-A-4-305284
In the treatment device disclosed in Japanese Patent Laid-Open No. 6-55158 or JP-A-6-55158, only the garbage solid is recovered by collecting the crushed garbage, and the polluted components dissolved in the wastewater are discharged untreated. There was a problem of increasing the load on the environment.

On the other hand, in Japanese Unexamined Patent Publication (Kokai) No. 5-208186, although wastewater after solid-liquid separation is treated, since it is ozone oxidation, starch or cells containing cells that migrate to the water side during the pressing process are incorporated. Fine particles such as glycogen, which is a substance, cannot be oxidatively decomposed, and ozone is difficult to handle due to its toxicity, and high-concentration ozone is required to treat the garbage recovery wastewater with many pollutants in the wastewater. There is a problem that the device becomes complicated due to the addition of an exhaust treatment device and the risk becomes high.

The present invention has been made to solve the above problems, and the present invention reduces the volume of solids contained in wastewater without increasing the load on the environment, resulting in high efficiency and power saving. It is an object of the present invention to provide a kitchen wastewater treatment device capable of treating kitchen waste and an operating method thereof.

[0010]

[Means for Solving the Problems] In order to solve the above problems,
In the kitchen waste water treatment apparatus according to the present invention, the kitchen waste crushed in the crushing unit is transferred together with water through the pipe, and then temporarily stored in the kitchen wastewater storage unit, and after the solid-liquid separation unit and the solid separation via the transfer unit. The solid matter was fed to the solid matter solubilization section for biological treatment. Furthermore, in the solid matter solubilization section, by injecting air intermittently for a residence time of 15 days or more and 180 days or less, preferably 30 days or more and 60 days or less, the solid matter in the wastewater after solid matter separation is biologically treated. did. As a result, the microorganisms prey on solid substances other than fibrous substances and inorganic substances, so that the solid substances of kitchen waste can be efficiently solubilized by biological treatment, and an increase in environmental load can be suppressed. The volume of the solid matter solubilization tank when the solid matter solubilization tank is used as the solid matter solubilization unit is 15 days or more and 180 days or less of the daily water amount Q flowing into the tank according to the above conditions, preferably Three
The condition is 0 days to 60 days.

Further, in the method for operating the kitchen drainage device according to the second aspect of the present invention, the air blowing time is 5 minutes or more and 24 hours or less, and the air stop time is 5 minutes or more and 24 hours or less, and the air is intermittently discharged. I decided to blow it. As a result, the microbial activity does not decrease and the dissolved oxygen can be consumed without waste when air is blown in. Therefore, it is possible to efficiently solubilize the solid material of the garbage and to contribute to the energy saving.

Further, in the kitchen drainage apparatus according to the third aspect of the present invention, the amount of air blown into the solid matter solubilizing tank is supplied at 1 time to 6 times the capacity of the solid material solubilizing tank per hour. As a result, it is possible to suppress excessive air blowing, prevent the block of microorganisms due to excessive air blowing from becoming fine, and since a large amount of microorganisms can be retained in the solid matter solubilization tank, the solid matter in the garbage can be reduced in volume. Oxygen can be sufficiently supplied to the microorganisms that serve to solubilize.

Further, in the kitchen drainage apparatus according to the fourth aspect of the present invention, the dissolved oxygen concentration is 0.0 mg using the dissolved oxygen meter.
/ L or more and less than 3.0 mg / L is supplied with air, and when the dissolved oxygen concentration is 3.0 mg / L or more, by stopping the supply of air, oxygen dissolved in water is regenerated by microorganisms during the respiration process. I decided to use it. As a result, instead of controlling the timing of blowing air intermittently with time, the timing of blowing air can be determined based on the result of measuring the concentration of oxygen dissolved in water, which shows the decomposition ability of microorganisms more directly. By controlling it, the operating time of the blower that blows air can be minimized, so the power consumption can be suppressed to a minimum, and since it becomes an environment-friendly wastewater treatment system, the dissolved oxygen concentration in water can be easily measured. it can.

Further, in the garbage drainage device according to the fifth invention of the present application, as in the fourth invention of the present application, the timing at which air is intermittently blown is not controlled by time, but organic compounds contained in water are microorganisms. By measuring the potential difference during the process of oxidative decomposition, the redox state in the tank can be grasped more directly, and the amount of air blown into water is adjusted by this redox state. If the redox potential (ORP) in water is -50 mV to less than 50 mV, air is supplied to the water by a blower that is an air supply means, and OR
When P is -50 mV to 50 mV or more, the blower is stopped so that the oxidation-reduction reaction of the organic compound by the microorganism can be performed with a minimum of oxygen. As a result, the operating time of the blower that blows in air can be minimized, so the power consumption can be minimized, and this is a garbage wastewater treatment device that is more environmentally friendly.

Further, in the kitchen waste drainage device according to the sixth invention of the present application, when the oxidative decomposition of the organic compound by the microorganisms is progressing favorably, the pH of the water is controlled to be near neutral so that the pH is controlled. As a method for maintaining the optimum oxidative decomposition process, the pH is preferably 5.5 to 6.5 or less, preferably 6.0 or less, and 8.0 to 9.0 or more, preferably 8.
When it is 5 or more, air is constantly blown in, and it is 5.5 to 6.5.
Higher, preferably higher than 6.0, 8.0 to 9.0
If less than 8.5 is desirable, it is decided to maintain a good environment by blowing air intermittently. As a result, the microorganism has an optimum pH for oxidative decomposition of the organic compound, so that the decomposition of the organic substance can be accelerated.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION After the kitchen waste is crushed by a crusher and transferred by piping with water to separate the kitchen waste solid matter and the waste water, the kitchen waste solid matter is finally subjected to aerobic biological treatment or dry distillation treatment. The volume of waste materials is reduced, and the wastewater is treated by aerobic biological treatment to remove pollutants in the water, thus suppressing the increase of environmental load as a whole. In that case, in order to stably treat the solid waste and the wastewater, the wastewater with large fluctuations in water amount is temporarily stored in the wastewater storage unit, and the wastewater is transferred to the subsequent processing unit via the transfer means. By ensuring that a stable amount of water in the pipe is flowed through the pipe with a specified amount of water that has been crushed by the crusher, the amount of water and waste crushed product that will be the target of wastewater treatment in the subsequent stage is adjusted to the specified concentration. By setting the range, the efficiency of biological treatment of wastewater will be improved.

Further, when the sedimentation separation tank is used for separating the kitchen waste solids and the waste water, the tank volume is set to a predetermined size and a residence time suitable for the separation of the crushed kitchen waste, so that solids in solid-liquid separation can be obtained. (Garbage) Maintain a high recovery rate and reduce the environmental load released into the environment via the wastewater treatment equipment. Even when a sieving device is used in the solid-liquid separation unit, in order to increase the solid (garbage) recovery rate, the size of the opening of the sieve and its treatment speed should be within the specified range, and the operation method should be the same as the previous day. It is controlled by the water level and the time in the kitchen wastewater storage unit, which has a predetermined capacity for the amount of wastewater.

According to the present invention, there is provided a kitchen wastewater treatment apparatus and its operating method for improving hygiene in a work place such as a kitchen, ensuring stable operation, and harmonizing the environment.

[0019]

Example As an example of the present invention, BOD of crushed kitchen waste drainage,
Table 1 shows the SS concentration (concentration of solids), and Table 2 shows the particle size of crushed garbage and the BOD particle size distribution. In addition, the first of the present application
1 to 2 show a process and a device diagram of a kitchen wastewater treatment device of a wastewater transfer system including solid matter using the technology according to the sixth to sixth inventions.

It is clear from the comparison with kitchen drainage that the load of drainage becomes extremely large when the crushed kitchen waste drainage shown in Table 1 is caused to flow into sewers or the like. In addition, Table 2 shows the particle size distribution of crushed kitchen waste and the particle size distribution of BOD. Considering that the size of solids that can be collected by solid-liquid separation is submillimeters or more, solid-liquid separation allows solids to be collected from kitchen wastewater. It can be seen that even if the substances are separated and collected, the pollution of the wastewater due to the elution of the soluble component from the crushed garbage cannot be removed, and the wastewater also needs a treatment for removing the pollution. It should be noted that the pollutant components in the wastewater are extremely diverse, including fine particle components having a particle diameter of several microns to several tens of microns and components having a molecular weight of several hundreds to several hundreds of thousands.

[0021]

[Table 1]

[0022]

[Table 2]

Further, as shown in FIGS. 1 and 2, the crusher 1 has a transfer water supply port capable of supplying transfer water, and kitchen cooking kitchen waste is crushed and water is used for normal kitchen drainage to dispose of kitchen waste. Pour to the storage tank 2. The crushed garbage may be transferred by a pressure-feeding pipe via a pressure-feeding pump. The stored waste kitchen wastewater is transferred to the sedimentation separation tank 5 by the quantitative transfer pump 3, and the crushed kitchen waste separated by sedimentation is separated into the solid matter solubilization tank (aerobic solubilization tank) 7 by the kitchen waste pump 6, and the wastewater is separated by sedimentation. The supernatant liquid in the tank is transferred to a wastewater biological treatment tank (contact aeration tank) 8 and treated therein. The fixed-quantity transfer pump 3 and the garbage pump 6 may be air lift pumps. In the fixed-quantity transfer pump 3, the pump discharge liquid is partly branched and the garbage drainage storage tank 3 is used.
It may be returned to and used for stirring in the storage tank. Further, a detector 13 is installed in the aerobic solubilization tank 7, and dissolved oxygen, redox potential and pH in the tank are measured, and the result is controlled by the controller 14.
Then, the operation of the blower 15 as the oxygen supply means is controlled, and the air is continuously or intermittently discharged from the air diffuser 16.

The garbage treatment using the above-mentioned garbage wastewater treatment equipment will be described below. Figure 3 shows the change over time in the inflow and outflow of an apartment house with a garbage treatment device as an average value for 6 months.

It is understood that the kitchen drainage and the kitchen waste pulverization drainage are discharged only during the cooking work time, so that the change with time is extremely large. Therefore, without the kitchen wastewater storage tank, stable solid-liquid separation was not possible at the time of peak inflow even if it was set to twice the daily capacity Q of the sedimentation separation tank, and wastewater containing kitchen waste solids was aerated. It flowed into the tank and could not be treated sufficiently.

Tables 3 and 4 show the solid-liquid separation performance of the sedimentation separation tank and the biological treatment performance of the contact aeration tank, respectively, when the inflow fluctuation was alleviated in the kitchen wastewater storage tank. In the sedimentation tank, the capacity is more than 1/24 times the daily discharged water quantity Q, preferably 1 /
It has been found that a sufficient solid-liquid separation performance can be obtained with 12 times or more. If the volume becomes too large, the residence time in the tank will become longer, and the pollutant components (BOD amount) that migrate to the drainage side due to the elution of pollutant components from the crushed garbage and the disintegration of particle components such as rice grains will progress. Become. Therefore, it was also clarified that the capacity should be twice or less, preferably 1 or less times the daily discharged water amount Q.

[0027]

[Table 3]

[0028]

[Table 4]

In the contact aeration tank, the residence time is 1 hour or more,
It has been found that the BOD in the wastewater can be removed to a concentration at which it can be discharged into the sewer, preferably in two hours or more, as in ordinary domestic wastewater. If the residence time is long, the tank becomes large and the power consumption for aeration increases, so as an index of the economically viable size, the residence time of the contact aeration tank is 2 days or less, preferably 1 day or less. Good to do. It is necessary to reduce the volume of the kitchen waste collected by sedimentation and to reduce the amount of waste that is ultimately discarded to reduce the environmental load.

In the solid matter solubilization tank (aerobic solubilization tank) which is the solid matter solubilization section, as shown in Table 5, the residence time is 15
It has been found that a sufficient garbage decomposition rate can be obtained by setting the time to be at least one day, preferably 30 days or more. It should be noted that, if the retention time of the tank is lengthened, the tank becomes larger and the power consumption for aeration increases, so that the retention time of the aerobic solubilization tank is preferably 180 days or less as an index of the economically viable size. Is 60 days or less. The aeration in the aerobic solubilization tank may be continuous or intermittent, but intermittent aeration is desirable in order to reduce the power cost and remove the nitrogen component in the garbage. Further, by adjusting the time for blowing air, it is possible to suppress filamentous fungi having poor sedimentation properties among microorganisms that contribute to solubilization and decomposition of organic substances, and stabilize the treatment performance of the aerobic solubilization tank 7.

[0031]

[Table 5]

As shown in Table 6, the time period of the air blown into the aerobic solubilization tank 7 is 5 minutes or more 2
By setting the period of 4 hours or less and the period of stopping the air to 5 minutes or more and 24 hours or less, the sedimentation property of the microorganisms that contribute to the solubilization and decomposition of the organic solid matter in the aerobic solubilization tank 7 becomes high. The effect is to blow air for 5 minutes to 24 hours,
The time to stop blowing air is set to 5 minutes or more and 24 hours or less, but if the combination of time is too short or too long, the settling property of microorganisms is reduced or the treatment performance is reduced due to anaerobicization in the tank. Therefore, it is desirable to repeat the air blowing for 30 minutes or more and 60 minutes or less and the stop of the air blowing for 30 minutes or more and 60 minutes or less.

[0033]

[Table 6]

When the amount of air blown is small, the inside of the aerobic solubilization tank 7 may be anaerobicized, and when the amount of air blown is large, coagulant microorganisms become fine and water quality deteriorates. However, it also leads to higher power costs. Therefore, a good treatment state can be ensured by supplying air in an amount of 1 to 6 times the volume of the solid matter solubilizing tank per hour.

Next, as a method for ensuring optimum habitation conditions for aerobic microorganisms that contribute to the solubilization of solids, a dissolved oxygen measuring sensor is installed as a means for measuring dissolved oxygen, DO (Dissolve Oxygen, dissolved oxygen) is linked with the result and the blower 15, which is an air supply means, so that the DO concentration in the aerobic solubilization tank 7 is 0.0 mg / L or more and 3.0 mg / L.
When it is less than the above, the blower 15 is operated to supply air into the solid matter solubilization tank 7 in order to increase the oxygen concentration. Next DO
When the concentration is 3.0 mg / L or more, the blower 15 is stopped and the supply of excess air is stopped, so that it is possible to find the effect of reducing the power cost.

Further, as another method, the redox potential is measured in order to grasp the degree of oxidative decomposition of the organic compound contained in the water in the aerobic solubilization tank 7. Specifically, an ORP (oxidation-reduction potential) sensor is installed in the aerobic solubilization tank 7, and a blower 1 which is an air supply means via an ORP measuring device.
5 is interlocked, and if the ORP value is −50 mV to less than 50 mV, the blower operates and air is sent into the tank to accelerate the oxidative decomposition of organic compounds by microorganisms. When the ORP value becomes high due to the blowing of air, the blowing of excess air is suppressed, and the state in which the oxidative decomposition of the organic compound is promoted is maintained without excess air.

Further, as another method, the pH of the aerobic solubilization tank 7 is measured to confirm the blowing condition of air. That is, when the amount of air blown in is small, the state becomes anaerobic, the organic compound begins to decompose, and the pH is lowered due to conversion to the organic acid. Therefore, when the pH becomes 5.5 to 6.5 or less, preferably 6.0 or less, air is constantly blown in to suppress the generation of organic acid and the pH can be prevented from lowering.
In addition, in the case of solid wastewater containing a large amount of protein, ammonia may be generated in an anaerobic state and the pH may increase.
Is adjusted from 8.0 to 9.0 or more, preferably 8.5 or more, so that air is constantly blown in. Therefore, when it is higher than 5.5 and higher than 6.5, preferably higher than 6.0, and lower than 8.0 and lower than 9.0, it is preferable to blow air intermittently to reduce the power cost. Maintain aerobic condition.

Thus, the dissolved oxygen meter, ORP meter, pH
The detector 13 such as a meter controls the operation operation of the blower 15 via the controller 14 based on the detected value.

In order to operate the kitchen wastewater treatment device in a stable manner, it is necessary to reliably transfer the kitchen waste crushed by the crusher to the post-treatment section. The operation of the kitchen wastewater treatment system enabled stable pipe transfer. That is, kitchen weight 1
It was clarified that the crushed garbage can be flowed without staying in the pressure-feeding pipe or the ordinary natural-flowing kitchen pipe by flowing 3 L or more, preferably 5 L or more of water per kg. It shows in Table 7. If the amount of water increases, it will be stored in the kitchen wastewater storage tank at a low concentration, and the elution of pollutant components from the kitchen waste will increase. In addition, the increase in the amount of water used causes the size of the aftertreatment device to increase in size, resulting in a decrease in economic efficiency. Therefore, the amount of water is 1k of garbage
It is 80 L or less, preferably 40 L or less per g.

[0040]

[Table 7]

[0041]

[Effects of the Invention] As a method of treating food waste generated from business systems such as homes, restaurants, factory cafeterias, and food factories by a disposer, it is known that wastewater is purified by treating wastewater using microorganisms. There is. However, the disposer wastewater has a lot of organic solids, and when it is directly treated by the typical activated sludge method of microorganism treatment method or methane fermentation method, it is generated as deterioration of treatment performance and a large amount of excess sludge. There was a problem such as a large amount of power consumption. In the present invention, it is possible to provide a technology for reducing the environmental load by proposing conditions for efficiently solubilizing many organic solids contained in the disposer wastewater.

[Brief description of drawings]

[Fig. 1] Kitchen wastewater treatment process diagram

[Fig. 2] Kitchen wastewater treatment equipment

[Fig. 3] Change over time in the amount of wastewater flowing into the kitchen wastewater treatment equipment

[Explanation of symbols]

1 ... Crusher, 2 ... Kitchen wastewater storage tank, 3 ... Transfer pump, 4
… Agitation discharge port, 5… sedimentation separation tank, 6… garbage pump, 7…
Solid matter solubilization tank (aerobic solubilization tank), 8 ... Wastewater biological treatment tank (contact aeration tank), 13 ... Detector 14, Controller 15, Blower 16 ... Air diffuser

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasutoshi Shimizu             2-1-1 Nakajima, Kokurakita-ku, Kitakyushu City, Fukuoka Prefecture             No. Totoki Equipment Co., Ltd. F-term (reference) 4D003 AA01 AB02 BA02 CA03 CA07                 4D004 AA03 CA04 CA13 CA19 CA42                       CB04 CB13 CB45 DA01 DA20                 4D059 AA07 BA04 BE31 BF13 BK11                       BK12 CA22 CB01 CB27 EA05                       EA20 EB20

Claims (6)

[Claims] 1. A crushing unit for crushing kitchen waste, a water supply unit for supplying water to the crushing kitchen waste, a kitchen waste water storage unit for storing kitchen waste water composed of a mixture of water and crushing kitchen waste, and a kitchen waste water storage unit. A transfer unit that sends the stored waste kitchen wastewater to the solid-liquid separation unit, a solid-liquid separation unit that separates the stored kitchen wastewater into garbage and solid wastewater, and a wastewater biological treatment unit that biologically treats the wastewater after solid matter separation. And has a solid matter solubilization section for biologically treating solid matter in wastewater after solid matter separation by intermittently blowing air with a residence time of 15 days to 180 days, preferably 30 days to 60 days. A kitchen wastewater treatment device characterized in that 2. The solid solubilizing section is characterized in that the time for blowing air is 5 minutes or more and 24 hours or less and the time for stopping the air is 5 minutes or more and 24 hours or less, and air blowing and stopping are repeated. Item 3. A method for operating the kitchen wastewater treatment device according to item 1. 3. The garbage drainage according to claim 1 or 2, wherein air is blown into the solid matter solubilizing unit in an amount of 1 time to 6 times the capacity of the solid matter solubilizing unit per hour. How to operate the processor. 4. The dissolved oxygen concentration in the solid matter solubilizing section is measured by a dissolved oxygen concentration measuring means, and the dissolved oxygen concentration is 0.1 mg / L or more and less than 3.0 mg / L. At that time, air is blown in and 3.0 mg /
The method for operating the kitchen wastewater treatment device according to claim 1, wherein the blowing of air is stopped when the value is L or more. 5. In the solid matter solubilization section, the redox potential in water is measured by a redox potential measuring means, and when the redox potential is -50 mV to less than 50 mV, air is blown in to measure -50 mV to 50 mV. The method for operating the kitchen wastewater treatment device according to claim 1, wherein the air blowing is stopped at the above time. 6. In the solid matter solubilizing section, p in water is added.
H is measured by a pH measuring means, and the pH is 5.5 to 6.5 or less (desirably 6.0 or less) or 8.0.
To 9.0 or more (preferably 8.5 or more), air is constantly blown in and 5.5 to higher than 6.5 (desirably higher than 6.0) or 8.0 to less than 9.0 (desirable). Is less than 8.5), the air is blown intermittently, the method for operating the kitchen wastewater treatment device according to claim 1 or 3.