JP2000024644A - Waste water discharging section and treatment of waste water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently clean waste water by effectively utilizing energy by heat storage, reducing maintenance such as the pulling-out work of settled solid matter, enabling to reduce environmental loading and accelerating the separation of the solid matter. SOLUTION: An ice heat storage tank 3 in which waste water containing garbage or the like flows in, electrolytic electrodes 41, 42 arranged in the ice heat storage tank 3 and for flocculating the contained solid matter by electrolysis, an electrolysis control part for applying voltage to the electrodes and controlling, a heat combination supply device 6 for concentrating and separating the contained solid matter by the difference of the freezing rate by giving cold to the flocculated waste water in the ice heat storage tank 3 and for defrosting the frozen waste water and a defrosted water separation part for filtering the defrosted water generated in the ice heat storage tank 3 by the defrosting work of the heat combination supply device 6 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the purification of kitchen wastewater discharged from condominiums and the like, and in particular, ice storage using solid waste of kitchen waste as a heat storage medium by utilizing power waste heat, industrial waste heat and nighttime electric power. The present invention relates to a wastewater treatment device and a wastewater treatment method that utilize energy.

[0002]

2. Description of the Related Art With the spread of home appliances, computers, air conditioners, etc., the demand for electric power has been increasing rapidly year by year, and the peak load especially in summer has been increasing. However, there are many problems such as environmental conservation and difficulty in locating a power plant. It is also difficult to increase the power. Under these circumstances, in recent years, as a method of storing excess heat during the night by using surplus inexpensive nighttime power and leveling the peak power in the daytime, the method using ice heat storage has been mainly used for newly built commercial buildings. It has been spreading.

[0003] In the conventional ice heat storage method, cold heat is supplied via an external heat source to a coolant or heat storage material such as tap water filled in an ice heat storage tank having an adiabatic closed structure, and cooled to a temperature below ice temperature to perform a freezing process. The basic principle is that the cold energy is stored in the form of ice, and the adiabatic stored ice is melted to recover and use the cold when necessary.

On the other hand, the amount of water used is increasing year by year, and limited water resources are not polluted and drained, but are reused or purified and discharged so as not to have an adverse effect on the environment. There is increasing recognition that conserving water resources is also an important initiative. In recent years, regarding the conservation of water resources, wastewater has been treated in factories, companies, or regions, and purified water has been reused as flush water for flush toilets and sprinkling water. Similar water reuse initiatives have also begun in residential areas such as and residential complexes.

[0005] In addition, kitchen waste such as garbage generated in restaurant kitchens and home kitchens is difficult to burn at high temperature because it accounts for 30% of combustible garbage and has a large amount of water. It is one of the hated things.

[0006] In the treatment of kitchen garbage, a system for purifying kitchen garbage with water and a system for purifying the kitchen garbage together with sewage have been proposed. Therefore, it has been attracting attention as a system that can save the trouble of garbage disposal.

[0007] As described above, the leveling of energy by ice storage and the treatment of wastewater containing kitchen waste are highly effective for environmental preservation and improvement of the living environment, and both systems use or treat liquid. Have in common. Focusing on this common point, a system in which the heat storage function and the water treatment function are docked has already been proposed.For example, a heat storage method for making ice and storing ice by directly using wastewater from a building or the like has been proposed.
It has been proposed in JP-A-6-18069 and JP-A-10-73290.

An ice heat storage method described in Japanese Patent Application Laid-Open No. 6-18069 discloses a method of supplying and circulating a refrigerant from a refrigerant supply device to a heat transfer tube immersed in treated sewage introduced into an ice heat storage tank. It is configured to partially make ice around and discharge remaining unfrozen residual water to the outside of the tank. FIG.

In FIG. 4, the sewage to be treated is a sewage receiving tank 10.
1 and is taken out by the sewage feed pump 102 and sent to the screen device 103 to remove coarse dust and the like. The refuse removed by the screen device 103 is discharged to a drain tank 104. Then, the sewage to be treated from which the refuse is removed is sent to an oil-water separator 105 to separate the oil component, the oil component is discharged to a drainage tank 104, and the sewage to be treated excluding the refuse and the oil component is supplied to a treatment sewage receiving tank. Stored in 106.

In the ice heat storage tank 108, a refrigerant is supplied from the refrigerant supply device to the heat transfer tube and circulated to make ice around the heat transfer tube, and the remaining non-freezing residual water remaining thereafter is discharged out of the tank by the residual water discharge pump 109. . At the stage of discharging the unfrozen residual water from inside the ice heat storage tank 108, a part of the treated sewage is passed from the treated sewage receiving tank 106 through the heat exchanger 110 for recovering residual water cooling heat, and the ice heat storage tank 10
The non-freezing residual water discharged from 8 is subjected to cold heat exchange, and the cold stored in the non-freezing residual water is collected in the treated sewage and stored in the cold treated sewage receiving tank 111 as the cold treated sewage.

[0011] The remaining treated sewage from the treated sewage receiving tank 106 is stored in the chilled sewage receiving tank 111 through the middle water chilled heat recovery heat exchanger 118 and sent to the ice heat storage tank 108 by the chilled sewage feed pump 112. Cold treatment sewage receiving tank 11
After the cold treated sewage from 1 drains the unfrozen residual water from the ice heat storage tank 108, the cold water is injected into the ice heat storage tank 108 from the cold water receiving tank 116 by the cold water circulation pump 121, and the cold water is loaded. Circulating water as a circulating water through a load circulating water line including a cold heat supply heat exchanger 114 and a pump 113,
A heat exchanger 1 for supplying cold energy to the cold stored by the ice around the heat transfer tubes.
14 to a load 115.

The cold water containing the thawed water in the ice heat storage tank 108 from which the cold heat has been completely recovered in the cold heat supply heat exchanger 114 is discharged as cold cold water into the cold cold water receiving tank 116 and stored. Cold and middle water feed pump 1 from the cold and middle water receiving tank 116
The cold water is taken out by 17 and passed through a heat exchanger 118 for recovering cold water from middle water to exchange heat with the treated sewage, and the cold stored in the cold water is recovered in the treated sewage. The cold water from which the cold energy has been recovered is stored in the middle water tank 119 as middle water, and is appropriately taken out by the middle water supply pump 120 and used as toilet water.

On the other hand, the apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 10-73290 is one in which an ice producing unit and a heat storage water tank are separated from each other, and ice is not made in the ice heat storage tank. And accumulate ice in the heat storage water tank,
Wastewater other than ice is discharged from the ice machine. FIG. 5 shows the outline.

Various wastewaters from buildings and the like are stored in a drainage tank 201 and sent to an ice maker 202. Ice machine 2
Numeral 02 is for producing pure ice by nighttime electric power controlled by the monitoring control device 203. Pure ice produced by the ice making machine 202 is accumulated in an ice heat storage water tank 204. The ice maker 202 is provided with a function of separating sewage,
The sewage separated by the ice making machine 202 is supplied to a sewage treatment apparatus 205.
Will be introduced. The condensate used for the load side air conditioner 206 is also introduced into the condensate water storage tank 207, and the condensate is also periodically made into pure ice by the ice maker 202.

[0015]

However, in a conventional wastewater treatment apparatus capable of performing heat storage operation, only a part of the water in the wastewater is frozen in the ice heat storage. Therefore, the advantage of the freezing treatment in the heat storage tank is not fully utilized simply by reusing a part of the water. In addition, it is necessary to provide a wastewater treatment tank separately from the heat storage tank, which requires a complicated structure and a large installation area.

In particular, in the case of wastewater treatment of kitchen refuse and sewage, generation of settled solids is inevitable, so that it is necessary to periodically extract kitchen wastewater as final treatment. For this reason, the operating cost of the wastewater treatment increases, and water is wasted from the viewpoint of water reuse.

Further, in the conventional wastewater treatment apparatus described in the above publication, a part of water in the wastewater is recovered by using ice heat storage. However, since solid components are discharged in the form of unfrozen residual water, In the case of separating such solid matter, a coagulation additive requiring concentration control is required, so that maintenance personnel are always required, and additional equipment such as a screen or a flotation device is required. In particular, the system for dewatering sludge tends to be complicated because the components constituting the sludge are small in size and easily clogged.

As one of the latest wastewater purification techniques, there is an electrolytic purification method. In this electrolytic purification method, solid-liquid separation of the treated water after the electrolytic treatment is not sufficient, and a heavy burden is imposed on the regeneration treatment of the electrolytic electrode. There is a problem that accompanies.

Therefore, the problem to be solved in the present invention is to reduce the burden on the environment by effectively utilizing energy by heat storage, reducing maintenance such as sludge extraction work, and reducing the environmental load of discharged materials. To purify wastewater.

[0020]

According to the present invention, there is provided a wastewater treatment apparatus comprising: an ice heat storage tank into which wastewater including kitchen wastes flows; and an electrolysis system for the wastewater disposed in the ice heat storage tank to coagulate solid components contained therein. An electrolytic electrode to be treated, an electrolytic control unit for controlling by applying a voltage to the electrolytic electrode, and condensed and separated solid components contained in the ice heat storage tank by a difference in freezing rate by giving cold heat to the coagulated wastewater. In addition, it is characterized by comprising a cogeneration unit for thawing the frozen wastewater, and a molten water separation unit for filtering the molten water generated in the ice heat storage tank by the thawing operation of the cogeneration unit.

According to this structure, thorough separation of solid matter from kitchen wastewater by electrolytic coagulation and concentration separation, reuse of water by purification treatment, and effective use of energy by heat storage become possible.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is an ice heat storage tank into which waste water including kitchen wastes flows in, and an electrolytic treatment of the waste water disposed in the ice heat storage tank to coagulate solid components contained therein. Electrolyte electrode, and an electrolysis control unit that controls by applying a voltage to the electrolysis electrode, while concentrating and separating contained solid components by the difference in freezing rate by giving cold heat to the coagulated wastewater in the ice heat storage tank. A wastewater treatment apparatus, comprising: a cogeneration unit that thaws the frozen wastewater; and a meltwater separation unit that filters the meltwater generated in the ice heat storage tank by the thawing operation of the cogeneration unit. Therefore, there is an effect that thorough separation of solids from wastewater by electrolytic coagulation and concentration separation, reuse of water by purification treatment, and effective use of energy by heat storage can be simultaneously performed.

According to a second aspect of the present invention, there is provided the wastewater treatment apparatus according to the first aspect, further comprising a drying device for receiving a paste-like solid remaining in the ice heat storage tank and performing a drying process.
A series of processes from purification of waste water including kitchen waste to drying of solid components and effective use of energy by heat storage can be carried out in one system, and it is not necessary to pull out solid components that have been subjected to coagulation treatment. Is processed into a dried product, which facilitates storage and handling, and has the effect of reducing maintenance costs and man-hours.

According to a third aspect of the present invention, in the drying device,
3. The wastewater treatment device according to claim 2, further comprising a drain recovery unit that recovers water evaporated in the drying process, wherein the water evaporated in the drying process can be recovered as a drain. This has the effect of preventing the diffusion of the odor due to the diffusion of the steam and reducing the humidity in the drying device, so that the drying can be performed efficiently even when the drying temperature is lowered.

The invention according to claim 4 is characterized in that a heat exchanger for an electrode is provided on the electrolytic electrode, and the deposits on the surface of the electrolytic electrode are removed by heat exchange by the heat exchanger for the electrode. Since the wastewater treatment apparatus according to any one of claims 1 to 3, the electrode surface can always be kept in a clean state, and thus has the effect of stabilizing the performance of the electrolytic treatment.

According to a fifth aspect of the present invention, there is provided the wastewater treatment according to any one of the first to fourth aspects, further comprising a regeneration electrode paired with the electrolysis electrode, and controlled by an electrolysis controller. Since the device is a device, the performance of the electrolytic electrode can be recovered by performing a reverse cleaning operation between the electrolytic electrode and the regeneration electrode.

According to a sixth aspect of the present invention, when only the vicinity of the electrolysis electrode and the regeneration electrode is defrosted by the electrode heat exchanger, the electrolysis control unit supplies electricity to the electrolysis electrode and the regeneration electrode. 6. The wastewater treatment apparatus according to claim 5, wherein the wastewater treatment apparatus performs the cleaning operation by efficiently performing the cleaning of the electrolytic electrode in a narrow range without affecting the whole of the treated water in the ice heat storage tank by the backwashing. It has the effect that washing and regeneration can be performed.

According to a seventh aspect of the present invention, wastewater containing garbage or the like flows into an ice heat storage tank, and the wastewater is electrolyzed to coagulate the solid components contained therein. After that, the frozen wastewater is thawed and dewatered from the solid components that have been concentrated and separated, and filtered,
This wastewater treatment method is characterized by leaving paste-form solids and purifying filtered water.Thus, thorough separation of solids from wastewater by electrolytic coagulation and concentration separation, and reuse of water by purification treatment In addition, there is an effect that energy can be effectively used by heat storage at the same time.

[0029] The invention according to claim 8 is the wastewater treatment method according to claim 7, characterized in that the remaining paste-like solid matter is subjected to a drying treatment. A series of processes up to the drying process and the effective use of energy by heat storage can be performed by one system, and the solid component that has been subjected to agglomeration treatment is not required to be drawn out. This has the effect of facilitating maintenance and reducing costs and man-hours required for maintenance.

According to a ninth aspect of the present invention, the drying process is performed simultaneously with the freezing process of the wastewater in the ice heat storage tank, and the waste heat generated by the freezing process is used for the drying process. According to the wastewater treatment method described above, waste heat can be effectively used for energy required for drying the paste-like solid matter, and thus it has an effect of achieving energy saving.

In the present invention, the concentration separation means that when the garbage wastewater is frozen, the solid content is gradually frozen because of the difference in the freezing speed between water and the solid component. Is concentrated and denatured and agglomerated, and when thawed thereafter, the water is easily dehydrated, and finally, the solid content remains in the form of a paste.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. FIG. 1 shows an overall configuration diagram of a wastewater treatment apparatus according to an embodiment of the present invention.

In FIG. 1, a wastewater treatment apparatus 1 is a primary storage tank 2 for temporarily storing kitchen wastewater and miscellaneous wastewater including kitchen waste and adjusting the amount of wastewater discharged from the primary storage tank 2. An ice heat storage tank 3 that exhibits an effect as a heat storage tank besides the electrolytic processing and the freeze-thaw processing, a drying device 5 that performs a drying process on solids separated in the ice heat storage tank 3, and mainly cools and heats the ice heat storage tank 3. Cogeneration device 6, which generates and uses heat energy,
It is provided with a dried product container 7 for storing the dried solid product. An air conditioning unit 8 that receives the supply of cold and hot heat from the heat cogeneration device 6 and performs air conditioning in a building or a room is connected to the heat cogeneration device 6. In addition, the primary storage tank 2
Sewage from toilets, washrooms, washing machines, and baths
A sewage pipe 10 for supplying miscellaneous wastewater is connected to the sewage pipe 10, and a flow path from a disposer 9 installed in a kitchen of a building or a home kitchen for crushing garbage is connected to the sewage pipe 10. .

In the arrangement of the above-described devices, the wastewater treatment apparatus 1 includes a wastewater supply pump 1 for controlling the transfer of wastewater stored in the primary storage tank 2 to the ice heat storage tank 3.
1, a solids discharge pump 12 for controlling the transfer of the solids separated in the ice heat storage tank 3 to the drying device 5, a liquid discharge pump 3 for controlling the transfer of the liquid separated in the ice heat storage tank 3 to the primary storage tank 2, An initial melt water discharge pump 14 for discharging the initial melt water obtained at the time of thawing in the ice heat storage tank 3, a drain discharge pump 15 for transferring and controlling the drain water after collecting water vapor generated in the drying device 5 as a drain, and a drying device Dry solid discharge pumps 16 for controlling the transfer of the solids dried in 5 to the dry matter container 7 are arranged.

Inside the ice heat storage tank 3, there is provided an initial melt water filtering section 21a for filtering the initial melt water obtained at the time of thawing, and a thaw water filter section for taking out the thawing water at the time of thawing processing and filtering and remaining solids. 21b, and a water discharge pipe 26 for distributing the purified treated water to an intermediate water utilization facility or the like is connected to the initial molten water filtration section 21a. In addition, a first electrolytic electrode 41 and a second electrolytic electrode 42 for electrolytically treating wastewater in the ice heat storage tank 3 are incorporated, and the first electrolytic electrode and the second electrolytic electrode 41 are required for electrolysis. An electrolytic power supply 43 for applying and controlling a voltage is connected.

The heat co-supply device 6 is connected to an ice heat storage tank heat exchanger 30 for freezing and thawing the electrolytically treated wastewater in the ice heat storage tank 3 and storing heat energy. As the heat cogeneration device 6, any heat cycle device that can generate and use cold and warm heat may be used. However, if waste heat in a power plant or an industrial area is used, the amount of power used can be reduced and energy can be saved. In such a case, means such as a heat pump or an endothermic refrigeration cycle that can utilize waste heat is desirable.

The drying device 5 is provided with a drain recovery cooler 31 connected to the cogeneration device 6 for recovering and separating steam generated in the drying process as drain by setting the temperature to a temperature lower than the internal dew point. The drying device 5 includes a heating heat exchanger 32 connected to the heat co-supplying device 6 for heating the solid matter, a heating and drying unit 33 for heating the solid matter with the heating heat exchanger 32, Drain recovery cooler 31
A drain collecting section 34 for separating and collecting steam as drain water 35 is provided. Reference numeral 40 denotes a power supply unit for operating the cogeneration system 6.

In the above configuration, the kitchen waste discharged is:
While being supplied with water by a disposer 9 installed in a building kitchen or a home kitchen, the water is crushed and discharged to the primary storage tank 2 as crushed garbage. At the same time, sewage from toilets and miscellaneous wastewater from washrooms and washing machines are also discharged to the primary storage tank 2 via the sewage pipe 10. After the wastewater containing solid matter in the primary storage tank 2 is primarily stored, the wastewater is supplied to the ice heat storage tank 3 by the drainage supply pump 11.

In the ice heat storage tank 3, the waste water containing the kitchen waste flowing into the ice heat storage tank 3 is cooled to a temperature below or above the ice temperature by an ice heat storage tank heat exchanger 30 connected to the cogeneration system 6. Freezing and thawing are performed. That is, the electrolytic power source 4
By applying a voltage to the first electrolysis electrode 41 and the second electrolysis electrode 42 such that the electrolysis can be performed, the wastewater stored in the ice heat storage tank 3 is electrolyzed.

Here, it is a well-known technique to coagulate and precipitate fine particles such as solids contained in the wastewater by subjecting the wastewater to electrolytic treatment. For example, when the first electrolytic electrode 41 is made of aluminum and the electrolytic power supply 43 is operated so as to be positive with respect to the second electrolytic electrode 42, the aluminum of the first electrolytic electrode 41 melts as aluminum ions to form aluminum hydroxide. Further, fine particles such as solids contained in the wastewater can be aggregated by the action of zeta potential or the like.

Further, in particular, electrolysis is performed without using aluminum or the like as the first electrolytic electrode 41, for example, the first electrolytic electrode 4
When the electrolytic power supply 43 is operated so that 1 becomes plus,
In the vicinity of the first electrolytic electrode 41, the pH decreases and becomes acidic,
Fine particles such as solids contained in the wastewater can be aggregated by the action of zeta potential or the like.

It is to be noted that soluble organic substances and the like can also be subjected to a reductive decomposition treatment with hydrogen generated during the electrolytic treatment or an oxidative decomposition treatment with oxygen. The casing of the ice heat storage tank 3 may be used as a conductor instead of the second electrolytic electrode 42 which is a counter electrode of the first electrolytic electrode 41. Also, the first electrolytic electrode 41 and the second electrolytic electrode 42
The polarity of the voltage to be applied may be changed so as to switch the polarity or apply an AC voltage at regular intervals in order to prevent deposits on the electrolytic electrode 43.

As described above, in the ice heat storage tank 3, the electrolytic power source 4
The wastewater is subjected to electrolytic treatment by the first electrolytic electrode 41 and the second electrolytic electrode 42 connected to 3, thereby causing aggregation of the fine particles in the wastewater. Accordingly, relatively large aggregates settle down below the ice heat storage tank 3, thereby performing wastewater treatment.

Next, when a certain amount of wastewater is accumulated in the ice heat storage tank 3, the co-heating device 6 is operated to send cold heat to the ice heat storage tank heat exchanger 30, and the freezing process is started. Freeze. Then, on the next day, when the frozen wastewater is thawed, cold heat can be recovered and supplied by the ice heat storage tank heat exchanger 30 provided in the ice heat storage tank 3, and this cold heat is supplied to the air conditioning unit 8 installed in the building or the room. Turn to use as a heat source for cooling.

When such freeze-thaw treatment is performed, the aggregated particles contained in the electrolytically treated wastewater are denatured at the same time as the heat is stored by freezing, so that the solids are more easily aggregated. In addition, the ice storage tank heat exchanger 3
When the position of 0 is arranged in the upper part of the ice thermal storage tank 3, pure water ice is formed on the upper side by the effect of the freezing point of water, and water ice with more solid components is formed on the lower side. . For this reason, at the time of thawing the next day, the initial molten water dissolves out as water having a small solid component, and can be discharged from the discharge pipe 26 by the initial molten water discharge pump 14 from the initial molten water filtration unit 21a. Therefore, the ice thermal storage tank 3
The wastewater inside is concentrated and reduced by the amount of clean water released.

When the thawing process is further performed, the water in the ice heat storage tank 3 is transferred to the primary storage tank 2 via the liquid discharge pump 13 through the gap of the thawing water filtration unit 21b. At this time,
Since the solids are sufficiently agglomerated in the ice heat storage tank 3, the gap between the thawed water filtration units 21b can be made coarser than in the case where the wastewater is directly filtered, and the occurrence of clogging is reduced. Even if some of the solids pass through the thawed water filtration unit 21b, they are returned to the primary storage tank 2 and do not pose a problem. In addition, by improving the performance of the thawed water filtration 21b, the thawed water filtration unit is improved. The thawed water that has passed through 21b may be discharged from the water discharge pipe 26.

By such an operation, the liquid component is separated at the time of melting, and the solid matter remains in the bottom of the ice heat storage tank 3 in an agglomerated state, so that it can be easily discharged to the subsequent stage.

In the above example, as the operation in the ice heat storage tank 3, the electrolytic purification treatment is first performed, and then the freeze-thaw treatment is performed. However, depending on the solid component concentration of the wastewater, the solid component concentration during the electrolytic treatment is determined. May be higher. In this case, a freeze-thaw process may be performed first, and an electrolytic purification process may be performed after discharging the initial melt water. Conversely, when it is desirable to lower the solid component concentration during the electrolytic treatment, first perform freeze-thaw treatment to lower the solid component concentration of the wastewater near the electrolytic treatment without discharging the initial molten water, and then perform the electrolytic purification treatment. May be performed. Alternatively, the electrolytic purification process may be performed after a plurality of freeze-thaw processes, or a synergistic effect of the processes may be obtained by performing the electrolytic purification process and the freezing or thawing process.

After the melting process is completed in the ice heat storage tank 3,
The solid is discharged to the drying device 5 by the solid discharge pump 12. The operation and operation of the drying device 5 are as follows.

The heating / drying section 33 in the drying apparatus 5 has a heating heat exchanger 32 connected to the cogeneration unit 6 for heating and drying solids containing water. The drain recovery unit 34 in the drying device 5 includes a drain recovery cooler 31 capable of adjusting the temperature to the internal dew point temperature or lower.
The water vapor from the solid material heated in the step is drained and collected as drain water 35. This makes it possible to eliminate or extremely reduce the amount of water vapor exhaustion accompanying the drying process discharged to the outside of the drying device 5. During the drying process, the odor is prevented from leaking to the outside, and the internal humidity can be adjusted to be low, so that the solid can be dried even when the heating temperature is low.

When the drying operation is performed simultaneously with the freezing operation of the ice heat storage tank 3, the waste heat generated during the ice heat storage operation can be used, and a part of the cold heat sent to the ice heat storage tank 3 can be collected by drain recovery. Since it can be used for the cooler 34, a system with high energy saving can be obtained without using energy only for drying the solid matter.

The solid matter which has been dried so that it can be easily handled is sent to the dry matter container 7 by the dry solid matter discharge pump 16 and stored until reaching a predetermined amount. On the other hand, the drain water 35 recovered by the drain recovery unit 34 is sent to the water discharge pipe 26 by controlling the operation of the drain discharge pump 15 and discharged.

In addition, when there is power generation waste heat or industrial waste heat, if the solid matter can be directly heated as a drying heat source, it may be operated separately from the above-mentioned freezing operation. In addition, the drain collecting section 34 may be omitted when the external environment permits or when there is a separate deodorizing device or drain collecting device.

As described above, according to the present invention, a mixed solution containing solid matter such as kitchen garbage and sludge generated in wastewater purification processing can be used as a heat storage material to be used as a cold storage tank, and by simultaneously performing freeze-thaw processing. By modifying the solid, the solid-liquid separation performance is improved, and by performing the electrolytic purification, more efficient wastewater purification can be performed. Therefore, the wastewater treatment equipment is very simple and compact, eliminating the need to remove sludge water as waste in wastewater treatment, increasing the effective use of water, and recovering and using waste heat as refrigeration heat. Waste heat can be used effectively.

Further, according to the present invention, the garbage can be denatured and coagulated in the freezing and thawing treatment of wastewater containing garbage,
Solid-liquid separation can be facilitated. Here, the metamorphic aggregation of kitchen waste in drainage will be described.

In a state in which the crushed solid such as garbage is in a suspended state, pore water having a weak binding force is present around the particles of the crushed solid such as garbage. When freezing garbage wastewater containing solid matter such as crushed garbage containing pore water, it starts freezing from water with high purity and a high freezing point, and freezes as the ice grows. I do. As a result, the pore water existing between the solids is easily sucked out by the growing ice and disappears, and as a result, the solids such as the crushed garbage approach and aggregate. When the freezing temperature is further lowered and the freezing proceeds, the internal water inside the cells of the solid matter such as crushed garbage is frozen, the cell wall is broken, and the internal water is also sucked out. This further improves cohesion and dehydration.

As described above, as a result of the freeze-thaw treatment, solids such as kitchen garbage that have been in a suspended state are easily aggregated and dehydrated, so that solid-liquid separation can be easily performed.
Conventionally, there is no technical idea about such solid-liquid separation by denaturing aggregation, and concentration and separation can be easily and effectively obtained by freezing operation and denaturing aggregation.

FIG. 2 shows an overall configuration diagram of a wastewater treatment apparatus according to another embodiment of the present invention. In the example of FIG. 2, the first electrode heat exchanger 44 is disposed inside the first
The second electrode heat exchanger 45 is disposed inside the electrolytic electrode 42, and the other configuration is the same as the example of FIG. The same components as those in FIG. 1 are designated by the same reference numerals.

When freezing waste water in the ice heat storage tank 3, cold heat is fed from the cogeneration unit 6 to the first electrode heat exchanger 44 and the second electrode heat exchanger 45, and the first electrolytic electrode 41 and the second The operation is performed so that the surface of the electrolytic electrode 42 freezes. Then, due to the volume change when the drainage near the surfaces of the first and second electrolytic electrodes 41 and 42 starts freezing and turns into ice, and due to the denaturation of the deposits adhering to the surfaces of the electrolytic electrodes 41 and 42, there is a problem. The kimono is easily peeled off from the electrolytic electrode surface.
Also, due to the effect of freezing point depression, an ice layer having a relatively small solid component is formed in the vicinity of the first and second electrolytic electrodes 41 and 42.

At the time of the thawing process, the deposits adhering to the surfaces of the first electrolytic electrode 41 and the second electrolytic electrode 42 and hindering the electrolytic purification process are melted together with the thawing water to remove the first and second electrolytic electrodes. It is removed from the surface of the electrolytic electrodes 41 and 42.

As described above, the first and second electrolytic electrodes 41,
42, a first electrode heat exchanger 4 and a second electrode heat exchanger 4
4, 45, the first and second electrolytic electrodes 41, 4
The wastewater can be freeze-thawed from the surface of the second electrode 2, and as a result, the effect of removing the deposits on the surfaces of the first and second electrolytic electrodes 41 and 42 can be obtained.

FIG. 3 shows an overall configuration diagram of a wastewater treatment apparatus according to still another embodiment of the present invention. This example includes a first regeneration electrode 46 as a counter electrode used for reverse current regeneration of the first electrolytic electrode 41, and a second regeneration electrode as a counter electrode used for reverse current regeneration of the second electrolytic electrode 42. 47, and the other configuration is the same as the example of FIG.

In this configuration, no voltage is applied to the first regeneration electrode 46 and the second regeneration electrode 47 in a normal electrolytic purification operation. When deposits adhere to the first electrolytic electrode 41 and the second electrolytic electrode 42 and the electrolytic performance deteriorates, the first electrolytic electrode 41 and the first regeneration electrode 46 and the second electrolytic electrode 42 and the second The regeneration electrodes 47 and the second regeneration electrodes 47 are combined with each other in pairs so that the voltages of the first electrolytic electrode 41 and the second electrolytic electrode 42 are opposite to those in a normal electrolytic purification operation. 47.

Alternatively, when the alkaline cleaning operation is performed, the first electrolytic electrode 41 and the second electrolytic electrode 42 are both negative, the first regeneration electrode 46 and the second regeneration electrode 47 are both positive, or the acidic cleaning operation is performed. When the first and second electrolytic electrodes 41 and 42 are both positive,
A voltage is applied so that both the reproducing electrode 46 and the second reproducing electrode 47 become negative.

As described above, the first and second electrolytic electrodes 41, 4
When the electrode regeneration cleaning operation is performed using the second and first and second regeneration electrodes 46 and 47, the deposits and deposits on the surface of the first and second electrolytic electrodes 41 and 42 are peeled or redissolved. The surfaces of the first and second electrolytic electrodes 41 and 42 are cleaned, and the electrolytic performance is restored.

The electrode regeneration cleaning operation is performed by the following: the freezing treatment of the ice heat storage tank 3, the first electrode heat exchanger 44 of the first electrolytic electrode 41 and the second electrode heat exchanger 45 from the heat co-supply device 6. And the first electrolytic electrode 41 and the second electrolytic electrode 42
It is to be implemented when only the area around is thawed. As a result, only the vicinity of the surfaces of the first and second electrolytic electrodes 41 and 42 is isolated from the surrounding ice layer as an area for the electrode regeneration cleaning operation, and the drainage of the entire ice heat storage tank 3 is melted. In comparison, the degree of pH change of the solution in the electrode regeneration cleaning operation and the activity during electrolysis are large, and a high cleaning effect can be obtained.

On the other hand, the effect of the electrode regeneration cleaning operation can be suppressed to a small effect on the entire drainage of the ice heat storage tank 3, so that the electrode regeneration cleaning operation does not adversely affect the performance of the original electrolytic purification treatment. Or can be reduced.

As described above, the first electrolytic electrode 41 and the second
If the electrode regeneration cleaning operation is performed when only the vicinity of the electrolytic electrode 42 is thawed, a high cleaning effect can be obtained, and at the same time, the adverse effect on the performance of the electrolytic purification process can be prevented or reduced.

[0069]

According to the present invention, thorough separation of solids from wastewater by electrolytic coagulation and concentration separation, reuse of water by purification treatment, and effective use of energy by heat storage can be performed simultaneously.

According to the second aspect of the present invention, a series of processes from purification treatment of waste water including kitchen waste to drying treatment of solid components and effective use of energy by heat storage can be performed by one system, and coagulation treatment is performed. The solid component is not required to be pulled out, and the solid component is processed into a dried product, so that storage and handling are easy, and the cost and the number of man-hours required for maintenance can be reduced.

According to the third aspect of the present invention, it is possible to prevent the odor from being diffused due to the diffusion of the steam during the drying process, and to reduce the humidity in the drying device, so that the drying can be performed efficiently even when the drying temperature is lowered. .

According to the fourth aspect of the present invention, the electrode surface can always be kept clean, so that the performance of the electrolytic treatment can be stabilized.

According to the fifth aspect of the present invention, the performance of the electrolytic electrode can be recovered by performing a reverse cleaning operation between the electrolytic electrode and the regenerating electrode.

According to the sixth aspect of the present invention, the whole of the treated water in the ice thermal storage tank is not affected by the backwashing, and
Washing and regeneration of the electrolytic electrode can be efficiently performed in a narrow range.

According to the present invention, thorough separation of solid matter from wastewater by electrolytic coagulation and concentration separation, reuse of water by purification treatment, and effective use of energy by heat storage can be performed simultaneously.

According to the eighth aspect of the present invention, a series of processes from purification treatment of wastewater including kitchen garbage to drying treatment of solid components and effective use of energy by heat storage can be performed by one system, and coagulation treatment is performed. The solid component is not required to be pulled out, and the solid component is processed into a dried product, so that storage and handling are easy, and the cost and the number of man-hours required for maintenance can be reduced.

According to the ninth aspect of the present invention, since waste heat can be effectively used for energy required for drying the paste-like solid, energy can be saved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a wastewater treatment apparatus according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a wastewater treatment apparatus according to another embodiment of the present invention.

FIG. 3 is an overall configuration diagram of a wastewater treatment apparatus according to still another embodiment of the present invention.

FIG. 4 is a diagram showing a conventional example described in JP-A-6-18069.

FIG. 5 is a diagram showing a conventional example described in JP-A-10-73290.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wastewater treatment device 2 primary storage tank 3 ice heat storage tank 5 drying device 6 cogeneration device 7 dry matter container 8 air conditioning unit 9 disposer 10 sewage pipe 11 drainage supply pump 12 solids discharge pump 13 liquid discharge pump 14 initial melt water discharge pump 15 Drain discharge pump 16 Dry solids discharge pump 17 Thawing water storage tank 18 Drainage adjusting pump 21a Initial melting water filtration unit 21b Thawing water filtration unit 26 Drainage pipe 30 Ice heat storage tank heat exchanger 31 Drain recovery cooler 32 Heat for heating Exchanger 33 Heat drying unit 34 Drain recovery unit 35 Drain water 40 Power supply 41 First electrolytic electrode 42 Second electrolytic electrode 43 Electrolytic power supply 44 First electrode heat exchanger 45 Second electrode heat exchanger 46 First regeneration electrode 47 Second regeneration electrode

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F24F 5/00 102

Claims (9)

[Claims] 1. An ice heat storage tank into which waste water including kitchen wastes flows, an electrolytic electrode disposed in the ice heat storage tank for electrolyzing the waste water and coagulating a solid component contained therein, and applying a voltage to the electrolytic electrode. An electrolysis controller for applying and controlling, and a co-heat supply device for applying cold to the coagulated wastewater in the ice heat storage tank to concentrate and separate solid components contained therein depending on a difference in freezing speed, and to thaw the frozen wastewater. A wastewater treatment apparatus, comprising: a meltwater separation unit configured to filter meltwater generated in the ice heat storage tank by a thawing operation of the cogeneration unit. 2. The wastewater treatment device according to claim 1, further comprising a drying device for receiving a paste-like solid remaining in the ice heat storage tank and performing a drying process. 3. The wastewater treatment device according to claim 2, wherein the drying device is provided with a drain recovery unit for recovering water evaporated in the drying process. 4. An electrolytic electrode is provided with an electrode heat exchanger,
The wastewater treatment apparatus according to any one of claims 1 to 3, wherein the deposits on the surface of the electrolytic electrode are removed by heat exchange by the electrode heat exchanger. 5. The wastewater treatment apparatus according to claim 1, further comprising a regeneration electrode paired with the electrolysis electrode, and controlled by an electrolysis controller. 6. An electrolysis controller controls the electrolysis electrode and the regeneration electrode to conduct a cleaning operation when only the vicinity of the electrolysis electrode and the regeneration electrode is thawed by the electrode heat exchanger. The wastewater treatment apparatus according to claim 5, wherein 7. A wastewater containing kitchen waste and the like flows into an ice thermal storage tank, and the wastewater is electrolyzed to coagulate solid components contained therein. Further, cold heat is applied to concentrate and separate the wastewater according to a difference in freezing speed. A wastewater treatment method characterized by dewatering and filtering out a solid component that has been thawed and concentrated and separated to leave a paste-like solid and purify filtered water. 8. The wastewater treatment method according to claim 7, wherein the remaining paste-like solid is dried. 9. The wastewater treatment method according to claim 8, wherein the drying treatment is performed simultaneously with the freezing treatment of the wastewater in the ice heat storage tank, and waste heat generated in the freezing treatment is used for the drying treatment.