JP2002273482A - Method and apparatus for treating night soil and / or septic tank sludge - Google Patents

Abstract

(57) [Summary] [Problem] Human waste and / or can detoxify human waste and / or septic tank sludge with a small amount of energy.
Alternatively, a method for treating septic tank sludge is obtained. SOLUTION: A solid-liquid separation step of removing a solid substance from an object to be treated consisting of night soil and / or septic tank sludge in a solid-liquid separation device 1 to obtain a liquid phase, and a concentration step of evaporating and concentrating the liquid phase in a concentration device 2 And a solid phase removed from the object to be treated and a concentrated liquid phase are mixed in a mixing tank 3, and a hydrothermal reaction step of oxidatively decomposing by a hydrothermal reaction in a supercritical or subcritical state of water in the hydrothermal reaction And

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for treating human waste and / or septic tank sludge by a hydrothermal reaction.

[0002]

2. Description of the Related Art Human waste is collected from homes and facilities by vacuum trucks, collected in a human waste treatment plant, and intensively processed. When a septic tank for urine is installed in homes, facilities, etc., the septic tank sludge is collected by a vacuum truck and collected in a sewage treatment plant, and is mixed with human waste to be treated. As a method of treating night soil and / or septic tank sludge in such a night soil treatment plant, a biological treatment method such as an anaerobic treatment and an aerobic treatment is generally used.

On the other hand, in recent years, as a method of treating organic sludge such as sewage treated sludge, a treatment method using a supercritical hydrothermal reaction has been proposed. The hydrothermal reaction is a method in which a reactant is oxidized or hydrolyzed in a supercritical or subcritical state of water to decompose waste, generate energy, or produce a chemical substance. In the case of organic sludge such as sewage sludge, an oxidation reaction is caused by reacting an oxidizing agent with a reactant containing an organic substance in a supercritical or subcritical state of water, and the organic substance in the reactant is reduced for a short time. Then, it can be almost completely decomposed.

When the organic matter in the reactant is oxidatively decomposed by the hydrothermal reaction as described above, the reactant, the oxidizing agent, and water are pressurized and heated, and supplied to the reactor to cause an oxidation reaction. In this case, when the reactant contains an appropriate amount of water in advance, it is not necessary to supply water. As a result of the reaction, organic matter is oxidized and decomposed,
A reaction product containing a high-temperature and high-pressure liquid composed of water and carbon dioxide and a solid such as ash or salt in a dried or slurry state is obtained. Solids among the reaction products are separated by a solid-liquid separator. The fluid from which the solids have been separated is recovered for energy, or cooled and decompressed, and separated into gas and liquid components.

As described above, human waste and / or septic tank sludge is generally treated by a biological treatment method at present, but sludge is generated in biological treatment.
Studies have been made on hydrothermal reaction treatments that can be completely decomposed. For example, in "Survey Report on Future Environmental Equipment System by Hydrothermal Reaction" (March 1997, Japan Society for the Promotion of Mechanical Systems), 2-10MPa under oxygen gas pressurization
When oxidized at a pressure of 300 ° C. or higher, CODMn
, A decomposition rate of 90% or more was obtained.
97% TOC for oxidation by supercritical hydrothermal reaction at 00 ° C
It is reported that the above decomposition rate can be obtained. That is, at 300 to 500 ° C., undecomposed organic components remain, and it is particularly difficult to decompose ammonia.
It is reported that a reaction temperature of at least ℃ is required. Also, Decomposition of Municipal Sludge by Supercrit
ical Water Oxidation, Goto, M. et al., Journal of Chemi
calEngineering of Japan, Vol.30, No.5, P.813-818 (1
997) reports that the decomposition of ammonia requires 600 ° C. or higher.

As described above, when treating night soil and / or septic tank sludge by a hydrothermal reaction, a high temperature is required during the hydrothermal reaction, but in the prior art, a high reaction temperature is required to achieve complete decomposition. For example, in order to carry out the reaction at 600 to 650 ° C., it is necessary to heat the reactor with an external heat source or to preheat the night soil and / or the septic tank sludge, and for this purpose, a large amount of auxiliary fuel such as kerosene is added. I needed to.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for treating human waste and / or septic tank sludge by a hydrothermal reaction, whereby the human waste and / or septic tank sludge can be decomposed and made harmless with little energy. It is to propose a method and an apparatus for treating night soil and / or septic tank sludge.

[0008]

SUMMARY OF THE INVENTION The present invention relates to the following method and apparatus for treating human waste and / or septic tank sludge. (1) a solid-liquid separation step of obtaining a liquid phase by removing solid matter from a material to be treated consisting of night soil and / or septic tank sludge;
A concentration step of evaporating and concentrating the liquid phase, and a hydrothermal reaction step of oxidatively decomposing the solid matter removed from the object to be treated and the concentrated liquid phase by a hydrothermal reaction in a supercritical or subcritical state of water. A method for treating human waste and / or septic tank sludge. (2) The method according to the above (1), wherein the solid is removed by membrane separation in the solid-liquid separation step. (3) The method according to the above (1) or (2), wherein the concentration step is performed by evaporating and concentrating at a pH of 6 or less. (4) The method according to any one of the above (1) to (3), wherein the concentration step comprises evaporating and concentrating by adding a seed crystal. (5) The method according to any one of the above (1) to (4), wherein the hydrothermal reaction step performs oxidative decomposition at 600 ° C. or higher. (6) a solid-liquid separation device for removing a solid substance from an object to be treated consisting of night soil and / or septic tank sludge to obtain a liquid phase;
Including a concentrating device for evaporating and concentrating a liquid phase, and a hydrothermal reactor for oxidatively decomposing a solid removed from a treatment object and a concentrated liquid phase by a hydrothermal reaction in a supercritical or subcritical state of water Equipment for treating night soil and / or septic tank sludge. (7) The concentrator according to the above (6), wherein the condensing device circulates the heated object to be processed through a heat exchanger, compresses the generated steam and supplies it to the heat exchanger, and heats the circulating object to be processed. apparatus.

The object to be treated in the present invention is human waste and / or septic tank sludge. The night soil includes raw night soil collected from a home or facility by a vacuum truck or a pretreated product thereof. Septic tank sludge is sludge that accumulates in a septic tank installed for the treatment of night soil at home or in a facility, such as sludge collected by a vacuum truck and collected in the same manner as night soil. These human waste and septic tank sludge may be mixed at an arbitrary ratio to be treated, or may be separately treated. In addition, other organic wastewater, dust, or the like may be mixed to be processed.

[0010] Night soil and / or septic tank sludge contains solid substances such as fibers derived from human waste and toilet paper. In addition, when another organic waste liquid, dust, or the like is mixed to form a treatment target, the treatment target contains insoluble solids such as garbage. In the present invention, a liquid phase is obtained by separating the solid matter in the solid-liquid separation step from the object to be treated including human waste and / or septic tank sludge containing the solid matter. This liquid phase has a solid length of 500μ
It is preferable that an insoluble substance longer than m or having a diameter larger than 500 μm is not contained. In the solid-liquid separation step, it suffices if the separation treatment can be performed so that no solids are present in the liquid phase obtained by the solid-liquid separation, and the separated solids contain a small amount of water, and the separated solids have a certain amount. It is preferred that the treatment is carried out so as to have a fluidity. When the separated solid has fluidity, it can be easily introduced into the subsequent hydrothermal reactor.

The solid-liquid separator can be used without any particular limitation, and examples thereof include a screen, a dehydrator, a filter, and a membrane separator. As a membrane separation device, U
F membrane (ultrafiltration membrane), MF membrane (microfiltration membrane) and the like. Modules include flat membrane, spiral,
Those using a permeable membrane of any shape, such as a tubular or hollow fiber, can be used. In these modules, the concentrated liquid chamber and the permeated liquid chamber are separated by a permeable membrane, and the liquid to be treated is supplied to the concentrated liquid chamber by applying pressure by using a pump or the like to perform membrane separation. One that allows (liquid phase) to flow out and one that performs membrane separation by suctioning the permeate side can be used.

Prior to the solid-liquid separation step, the material to be treated may be pulverized by a pulverizer in advance and homogenized to be subjected to solid-liquid separation. A crushing pump, a crusher, or the like can be used as the crushing means. The solid-liquid separation can be efficiently performed by crushing the object to be processed to about 1 mm.

Next, the liquid phase of the object to be treated obtained by the solid-liquid separation is concentrated by evaporation in the concentration step. The concentration device used in the concentration step is not limited as long as the liquid phase can be concentrated by evaporation, and any concentration device such as a liquid film type, a dip tube type, and a flash type can be used. It is preferable to use a circulation type in which the circulating liquid phase is heated by circulating through the heat exchange unit, compressing the generated steam by removing mist as required, and supplying the compressed mist to the heat exchange unit. Such a circulation-type concentrating apparatus is preferable if heating is performed first, and thereafter evaporation and concentration can be performed only by adding energy for compression. The heat required for heating the liquid phase can be recovered from the treated product discharged from the concentrator and / or the hydrothermal reactor and used.

In the concentration step, an acid such as hydrochloric acid or sulfuric acid or an acid salt is added to the liquid phase to adjust the pH to 6 or less, preferably 5 or less, and the concentration treatment is carried out. It is possible to reduce the amount of the antifoaming agent to be used. Although there is no lower limit of pH, pH 4 or more is preferable from the viewpoint of corrosion prevention and the amount of chemicals used,
It is most preferred to concentrate at around pH 5.

In the concentration step, evaporation of ammonia at a pH of 6 or less suppresses the evaporation of ammonia. However, part of the ammonia evaporates, part of the ammonia is transferred to condensed water, and part of the ammonia is condensed. Exhausted with gas.
In this case, provision of a device for decomposing the evaporated ammonia facilitates post-treatment. As the ammonia decomposition step, a catalyst decomposition apparatus is preferable, and ammonia can be decomposed by passing the catalyst layer in the presence of an oxidizing agent in the state of steam or condensed water. As the catalyst, a catalyst supporting a noble metal, preferably a platinum-supported alumina catalyst, is desirable. When decomposing in a vapor state, 300 to 400 ° C. is preferable, and for decomposing after aggregating, 150 to 200 ° C. is suitable. . Since organic substances and the like are also decomposed simultaneously with the decomposition of ammonia, condensed water can be reused as washing water or the like as it is.

In the concentration step, when a seed crystal is added and evaporation and concentration is performed, phosphoric acid, calcium, magnesium, etc. in the liquid phase precipitate on the seed crystal, so that corrosion and scale of the concentrator and the hydrothermal reactor are reduced. Can be prevented.
The seed crystal is not particularly limited, and calcium sulfate, calcium phosphate and the like can be used. Such seed crystals and other solids may be removed after the concentration step, or a hydrothermal reaction may be performed without removal, and then removed.

Although the concentration ratio of the liquid phase in the concentration step is arbitrary, it is preferable that the liquid phase be concentrated in the hydrothermal reaction step to a concentration at which it can be maintained at 600 ° C. or higher by oxidizing the organic substances contained therein. Can be subjected to a hydrothermal reaction. If the enrichment ratio is too high, the fluidity of the concentrate may decrease. In this case, the enrichment ratio can be lowered and auxiliary fuel can be used.

In the concentration step, the liquid phase from which solids have been removed in the solid-liquid separation step is concentrated, so that no residue or solids derived from toilet paper adhere to the heat transfer surface of the evaporator during concentration. And does not block the inside of the tube. Therefore, a decrease in concentration efficiency due to a decrease in heat conductivity can be prevented, so that the liquid phase can be concentrated efficiently and reliably.

Next, the concentrate generated from the liquid phase in the concentration step and the solid separated in the solid-liquid separation step are sent to the hydrothermal reaction step as reactants. Since impurities such as organic matter, ammonia, and solid matter are also transferred to the condensed water of the vapor evaporated in the concentration step, the organic matter and other impurities are concentrated by membrane separation using a reverse osmosis membrane, and the like.
It is preferable to send the concentrate to the hydrothermal reaction step together with the concentrate of the object to be treated. The liquid separated by membrane separation can be recovered and used by removing organic substances and other impurities by activated carbon treatment or the like.

In the hydrothermal reaction step, organic substances are oxidatively decomposed by a hydrothermal reaction. The concentrates, solids, and condensate of the condensate, which are the reactants, can be premixed or separately introduced into the hydrothermal reaction step. However, considering the processing efficiency of the hydrothermal reaction, it is preferable that they are mixed in advance and introduced into the hydrothermal reaction step. The hydrothermal reactor is configured to oxidatively decompose the introduced reactant in a supercritical or subcritical state of water by a hydrothermal reaction.

The hydrothermal reaction is a reaction in which a concentrate is oxidatively decomposed by an oxidation reaction in the presence of supercritical or subcritical high-temperature and high-pressure water and an oxidizing agent. Here, the supercritical state is 3
The temperature is 74 ° C. or higher and 22 MPa or higher. The subcritical state is, for example, 374 ° C. or more, 2.5 MPa or more and 22M or more.
It refers to a state of less than Pa or 374 ° C. or less and 22 MPa or more, or a high temperature and high pressure state close to a critical point even if it is 374 ° C. or less and less than 22 MPa.

Such a hydrothermal reaction is carried out by introducing a reactant in a state of being mixed with an oxidizing agent into a hydrothermal reactor, and the mixture undergoes a hydrothermal reaction inside the reactor. As oxidants, air, oxygen, liquid oxygen, hydrogen peroxide, nitric acid,
Nitrite, nitrate, nitrite and the like can be used. The oxidizing agent may be supplied by being mixed with a concentrate of the object to be treated, or may be supplied as a multi-layer flow by using a double-hole nozzle at a supply port. If necessary, a catalyst, a neutralizing agent, and the like may be added. These may be mixed with the reactant or supplied to the reactor separately.

The hydrothermal reactor used in the present invention is formed of a heat-resistant, pressure-resistant material and a substantially vertical cylindrical reactor so as to perform a hydrothermal reaction in a supercritical or subcritical state. . When the supercritical or subcritical state is not reached only by the heat of reaction, an external heating means can be provided.
The shape of the reactor may be a cylinder, an ellipsoid, or a polygonal cylinder, and the lower end may have a cone shape. When a hydrothermal reaction is performed in a supercritical or subcritical state using such a hydrothermal reactor, the organic substance to be reacted is oxidized by an oxidizing agent and is finally decomposed into water and carbon dioxide, or is reduced by hydrolysis. It is molecularized, and the inorganic substances are separated in a solid or molten state. After separating the solid, the reaction product is cooled, decompressed, and separated into a gas component and a liquid component.

The material of the hydrothermal reactor is not limited, but is preferably a corrosion-resistant material such as Hastelloy, Inconel or stainless steel. Preferably, the hydrothermal reactor is provided with a corrosion resistant liner. The corrosion-resistant liner is not particularly limited, and a corrosion-resistant liner having a gap between the corrosion-resistant liner and the pressure load wall as disclosed in JP-A-11-156186 can be used.

The hydrothermal reactor can be provided with cooling means for cooling the reaction mixture before discharging it from the outlet. The cooling means is not particularly limited, but water can be introduced into the reactor to cool it, and the inorganic salt can be dissolved to facilitate its discharge. In addition, water containing an acid or an alkali can be introduced into the reactor and cooled to neutralize the alkali or the acid. If the solid is very sticky, a mechanical removal device for removing the solid attached to the inner wall of the reactor can be provided. The mechanical removal device for removing solids is not particularly limited, but a substantially cylindrical scraper including a cutout window portion disclosed in JP-A-11-156186 is preferred.

A separation means for separating solids in the reaction fluid discharged from the hydrothermal reactor can be provided. In particular, since the inorganic salts are not dissolved but contained as a solid in the reaction fluid in a supercritical state, it is easy to reuse the treated water by separating the insoluble inorganic substances. The solid matter separating means is not particularly limited, and a container provided with an inlet for introducing a reaction fluid from a hydrothermal reactor and an outlet for discharging a fluid from which solids have been removed, and the reaction fluid provided in the container and having a One provided with a means for removing and discharging the solid contained therein can be used. In the steps of cooling and depressurization, means for solid separation or gas-liquid separation may be included.

The means for initiating the reaction by the hydrothermal reactor is not particularly limited. Usually, the reactor is preheated to near a predetermined reaction temperature at the start of the reaction. Preheating can be performed by providing a heating device in the reactor, or by introducing heated water or air provided in the reactant and / or oxidant supply passage. In addition, usually, water or an oxidizing agent is supplied to the reactor, and the reactor is pressurized to a predetermined pressure by a normally provided pressure regulating valve. After the temperature and pressure are adjusted to the predetermined values, the fluid containing the reactant is supplied to start the hydrothermal reaction. Organic substances are decomposed by the reaction, and heat of reaction is generated. If a mixing reaction zone with a backflow is provided in the upper part of the hydrothermal reactor (upper part of the reactor), the reactant, oxidizing agent and contents of the reactor are sufficiently mixed by the mixing action with the backflow. The temperature of the fluid increases. As a result, the object to be supplied immediately starts a hydrothermal reaction, and a stable reaction is continued. The reaction fluid moves downward in the reactor, continuously reacts in the plug flow reaction zone, and is discharged from the outlet. The length: diameter ratio of the reactor is preferably from 1: 1 to 100: 1.

The reaction fluid exiting the hydrothermal reactor is separated into solids, cooled, decompressed, and separated into gas and liquid. When a liquid is generated by cooling in the reactor, the liquid is separated from the liquid together with the solid upon exiting the reactor, and if necessary, further cooling and gas-liquid separation are performed. The finally generated water, gas, and solid are directly recovered for energy, reused as a substance, or disposed as they are or additionally processed.

The reactants of the hydrothermal reaction are the solid separated in the solid-liquid separation step, the liquid phase reliably concentrated in the concentration step, and the concentrated condensed water. Ammonia can be decomposed by raising the temperature inside the reactor of the hydrothermal reactor easily to 600 ° C or higher by combustion heat, and it is possible to decompose organic substances and ammonia at a high decomposition rate by reducing the amount of heat added from the outside. become.

[0030]

According to the hydrothermal reaction method of the present invention, night soil and / or septic tank sludge are previously separated into solid and liquid phases in a solid-liquid separation step, and the liquid phase is concentrated in a concentration step. Since the liquid phase does not contain solid matter, solid matter adheres to the heat transfer surface of the evaporator in the concentration step and does not reduce the concentration efficiency. Can be obtained. The concentrated liquid phase and solids are oxidatively decomposed by a hydrothermal reaction in a supercritical or subcritical state, so that human waste and / or septic tank sludge can be oxidatively decomposed at a high decomposition rate by a hydrothermal reaction with little energy. Can be made harmless.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are flowcharts of the processing apparatus according to the embodiment.

In FIG. 1, 1 is a solid-liquid separator, 2 is a concentrator, 3 is a mixing tank, 4 is a hydrothermal reactor, and 5 is an oxidizer tank. The solid-liquid separator 1 is connected to a system path 10 a extending from the processing object tank 10. The processing object tank 10 has a processing object supply path 7 having a crusher 7a for crushing and supplying a processing object composed of night soil and / or septic tank sludge, a pH adjusting agent supply path 8a and a seed crystal supply path. 8b is in contact. In addition, a system path 10 a communicates with the solid-liquid separation device 1 from the processing object tank 10.

The solid-liquid separation device 1 is a membrane separation device, which is composed of a module and a permeable membrane 1a provided therein, and is divided into a concentrated liquid chamber 1b and a permeated liquid chamber 1c by the permeable membrane 1a. I have. A system path 10a extending from the processing object tank 10 communicates with the concentrated liquid chamber 1b, and the permeated liquid chamber 1b.
A system line 11a extends from c and communicates with the lower part of the concentrator 2 via a heat exchanger 12. A system path 11b extending from the concentrate chamber 1b communicates with the mixing tank 3.

The concentrating device 2 is a circulation type evaporating and concentrating device, and a main body 1 for accommodating a liquid phase 13 and a vapor 14 of an object to be treated.
5 has a heat exchange section 17 in which a plurality of heat exchange tubes 16 are vertically arranged, and further has a distribution section 18 thereon. To the distributor 18 and the distributor 22
Thus, the object to be processed is configured to flow down and circulate in the form of a film along the inner wall of the heat exchange tube 16. Also the main body 15
Mist removal member 2 provided between the upper part of
3, the steam is sucked from the upper part of the main body 15 into the system passage 24, compressed by the compressor 25, and supplied to the outside of the heat exchange pipe 16 of the heat exchange unit 17. Route 1
A line 26 branching from 9 communicates with the mixing tank 3.

The system 27 extending from the heat exchange section 17 of the concentrator 2 is connected to the concentrator 2 of the membrane separation device 28 via the heat exchanger 12.
Contact 9 The membrane separation device 28 is divided into a concentration chamber 29 and a permeation chamber 32 by a reverse osmosis membrane 31 provided inside. A system path 33 extending from the concentration chamber 29 communicates with the mixing tank 3. A system path 34 extending from the permeation chamber 32 communicates with the outside of the system via an adsorption tank 36 filled with activated carbon 35.

A system 38 having a high-pressure pump 37 for supplying the concentrate 30 extending from the mixing tank 3 is connected to an injection device 41 provided above the hydrothermal reactor 4. A system 43 having a pump 42 is connected to the injection device 41 from the oxidant tank 5 for supplying air. The injector 41 is attached to the reactor 40 so as to inject a mixed flow of the oxidant, the concentrate and the solid into the hollow reactor 40.

The hydrothermal reactor 4 has a heat insulating material 46 as necessary.
Is provided. From the lower part of the reactor 40, a system path 47 communicates with a cooler 49 via a solid separator 48, and a system path 51 from the cooler 49 communicates with a gas-liquid separator 52. From the solid separator 48, a solid discharge path 50 communicates with the outside of the system, and the gas-liquid separator 5
From 2, a gas discharge path 53 and a liquid discharge path 54 communicate with the outside of the system. A cooling water channel 55 communicates with the cooler 49. Although a pump, a valve, and the like are required in the above-described apparatus, they are omitted in the figure.

The processing in the above device is performed as follows. First, an object to be treated consisting of night soil and / or septic tank sludge is supplied from the object to be treated supply channel 7, crushed by a crusher 7 a, and introduced into the object to be treated tank 10. The pH adjusting agent is supplied from the pH adjusting agent supply passage 8a to the processing object tank 10 so that the
It is adjusted as follows, and the seed crystal is supplied from the seed crystal supply path 8b and mixed with the workpiece 6.

The processing object 6 in the processing object tank 10 is
The liquid is pressurized and introduced into the concentrated liquid chamber 1b of the solid-liquid separation device 1 via a. Here, only the liquid component of the water to be treated permeates through the permeable membrane 1a and moves to the permeated liquid chamber 1c, and the solid content stays in the concentrated liquid chamber 1b. The liquid component of the object to be processed that has passed through the permeable membrane 1a is sent to the concentration step as a liquid phase through the system path 11a. On the other hand, the solid content retained in the concentrate chamber 1b is sent to the mixing tank 3 through the system path 11b.

The liquid phase obtained by the solid-liquid separation is passed through the system 11
a through the heat exchanger 12 and the concentrator 2
Is introduced into the lower part of the main body 15a. In the concentration device 2, the pump 21 is driven to drive the liquid phase 1 through the system line 19.
3 to the distribution unit 18 and the heat exchanger tubes 16 by the distributor 22.
The water is evaporated by distributing and flowing down in a film form on the inner wall of the main body, and the vapor and the concentrate are circulated to the main body 15.

On the other hand, the steam 14 removes mist through the mist removing member 23, is compressed by the compressor 25, and is supplied to the heat exchange section 17 from the system line 24. The steam whose temperature has risen due to the compression reaches the outside of the heat exchange tube 16 and the heat exchange tube 1
The object to be processed, which flows down in the form of a film on the inner wall of 6, is heated and evaporated, and itself is condensed to form condensed water. Enter device 28. In the present invention, the liquid phase to be concentrated does not contain a solid, and the solid does not precipitate on the heat exchange tube 16 to be heated, and does not lower the thermal conductivity or block the tube. . Therefore, the concentration process can be performed efficiently and reliably.

In the enrichment step, when the operation is started, a heat source such as steam is supplied to the heat exchanger 12 to heat the liquid phase 13 to start evaporation, and thereafter the temperature is increased by the compression of the compressor 25. The liquid phase 13 can be efficiently concentrated by performing evaporation. The concentrate is sent from the system line 26 to the mixing tank 3. The mist removed by the mist removing member 23 returns to the main body 15 as it is to prevent the condensed water from being contaminated.

In the concentration step, the vaporization of ammonia can be prevented by evaporating water from the liquid phase 13 under the condition of pH 6 or less. However, since a part of ammonia is vaporized, the solid matter passing through the mist removing member 23 The membrane is separated by the membrane separation device 28 together with impurities such as organic substances. In the membrane separation device 28, the condensate is supplied from the system 27 to the concentration chamber 29 at a high pressure, water is passed through the reverse osmosis membrane 31 to the permeation chamber 32, and the concentrate is sent from the system 33 to the mixing tank 3. The permeate is supplied to an adsorption tank 36, and organic matter and other impurities are removed by activated carbon 35, discharged from a system 34, and used as recovered water if necessary.

The mixing tank 3 stores a concentrate 30 obtained by mixing a solid obtained by solid-liquid separation, a concentrated liquid phase, and a concentrated liquid of the flocculated liquid. This concentrate 30
Is sent from the system 38 to the injection device 41 of the hydrothermal reactor 4 by the high-pressure pump 37, where the pump 42
Oxidant (eg, air,
(Hydrogen peroxide solution), and the mixed stream is jetted downward into the reactor 40 to perform a hydrothermal reaction. In the reactor 40, a preheater (not shown) provided in the system path 38 or 43 at the start of the reaction
To carry out a hydrothermal reaction while maintaining the supercritical or subcritical state.

The mixed stream injected from the injection device 41 undergoes oxidative decomposition in the reactor 40. In this hydrothermal reaction step, the concentrate having a high calorific value which is concentrated in the preceding concentration step is oxidized. Therefore, the reaction temperature should be maintained at 600 ° C. or higher with only the calorie of the concentrate or with a small amount of auxiliary fuel. Can be. Therefore, the reaction can be performed at a high temperature to decompose ammonia at a high decomposition rate.

The reactant in the reactor 40 is introduced into the solid separator 48 from the system line 47 to separate the solid, and the separated solid is discharged from the solid discharge passage 50. The separated reactant is cooled 49
And cooled by cooling water supplied from a cooling water passage 55,
Gas-liquid separation is performed by a gas-liquid separator 52, gas is discharged from a gas discharge path 53, and treated water is discharged from a liquid discharge path 54.

FIG. 2 is a flowchart showing a processing apparatus according to another embodiment. In this embodiment, the basic configuration is substantially the same as that of FIG. 1, and the difference is that heat exchangers 56 and 57 and a catalyst reaction tank 58 are provided in a system path 27 for taking out condensed water from the concentrator 2. That is, the membrane separation device 28, the adsorption tank 36, and the channels 33 and 34 in FIG. 1 are omitted.

The treatment method using the apparatus shown in FIG. 2 is performed in substantially the same manner as in FIG. 1, except that the condensed water taken out of the concentrator 2 is heated in the heat exchanger 56 and then is supplied to the steam supply path in the heat exchanger 57. Ammonia and organic matter are decomposed by heating with steam supplied from 60 and passing through the catalyst layer 59 in the catalyst reaction tank 58, and the heat exchanger 56,
The difference is that the condensed water is discharged from the system path 39 through 12. Thereby, the operation of membrane separation is omitted.

In the above embodiment, the circulation type evaporating and concentrating device is shown as the concentrating device 2. However, other evaporating type evaporating and concentrating devices such as a liquid film type, a dip tube type and a flash type may be used. For the treatment of the condensed water obtained from the concentrator, other treatment means such as ion exchange, coagulation, biological treatment and the like can be employed in addition to the membrane separation and catalytic oxidation shown in FIGS.

[0050]

Embodiments of the present invention will be described below. Example 1 A human urine concentration test was carried out using an evaporative concentration test apparatus, in which a solid was roughly removed with a 1-mm metal shell. As a result, when the concentration could be increased to 3.7 times (292 L → 80 L) in 27.6 hours, the evaporation and concentration stopped.

Comparative Example 1 The human urine without solid-liquid separation treatment was concentrated using an evaporative concentration test apparatus. As a result, when the concentration was about 2.5 times, the evaporation and concentration stopped.

In Example 1 and Comparative Example 1, after the respective devices were stopped, the can was opened and the inside was observed. As a result, the surface of the heat transfer tube was covered with concentrated urine containing a large amount of a substance considered to be toilet paper. Turned out to be not enough. However, as compared with Comparative Example 1, in Example 1, the concentration ratio was higher, and the effect of solid-liquid separation could be confirmed.

Example 2 Using an evaporative concentration test apparatus, a solid substance was roughly removed with a 1-mm metal pad, and the solid substance was removed with a filter cloth to concentrate urine. As a result, it was possible to evaporate and concentrate to about 8 times in about 20 hours without any problem. In Example 2, no decrease in the evaporative concentration efficiency due to the attachment of the solid matter in the night soil to the heat transfer surface was observed.

[Brief description of the drawings]

FIG. 1 is a flowchart of a processing apparatus according to an embodiment.

FIG. 2 is a flowchart of a processing apparatus according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solid-liquid separation apparatus 2 Concentrator 3 Mixture tank 4 Hydrothermal reactor 5 Oxidizer tank 6, 13 Workpiece 7 Workpiece supply path 7a Pulverizer 8a pH adjuster supply path 8b Seed crystal supply path 10 Workpiece Vessel 12, 56, 57 Heat exchanger 14 Steam 15 Main body 16 Heat exchange tube 17 Heat exchange part 18 Distribution part 21, 42 Pump 22 Distributor 23 Mist removing member 25 Compressor 28 Membrane separation device 29 Concentration room 30 Concentrate 31 Reverse osmosis Membrane 32 Permeation chamber 35 Activated carbon 36 Adsorption tank 37 High-pressure pump 40 Reactor 41 Injector 46 Insulation material 48 Solid separator 49 Cooler 50 Solid discharge path 52 Gas-liquid separator 53 Gas discharge path 54 Liquid discharge path 58 Catalyst reaction tank 59 Catalyst layer 60 Steam supply path 61 Cooling area 62 Injection port 63 Injection nozzle 64 Mixing section 67 Liner 68 Scraper 71 Driving machine 72 cooling water passage

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[Procedure amendment]

[Submission date] March 23, 2001 (2001.3.2)
3)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 11/06 C02F 11/06 A 11/12 11/12 C (71) Applicant 598124412 General Atomics Inc. United States San Diego, California General Atomics Coat 3550 (72) Inventor Hironori Kaku 3-4-7 Nishi-Shinjuku, Shinjuku-ku, Tokyo Inside Kurita Industrial Co., Ltd. (72) Inventor Masaaki Wakita Nishi, Shinjuku-ku, Tokyo 3-4 Shinjuku Kurita Kogyo Co., Ltd. F-term (reference) 4D006 GA06 GA07 HA01 HA21 HA41 HA61 PB08 4D034 AA16 AA26 BA01 CA12 DA02 4D059 AA01 AA02 BC01 BC02 BE42 BE49 BK11 CA21 DA31 DA44 DA47 EB06

Claims (7)

[Claims] 1. A solid-liquid separation step of removing a solid substance from an object to be treated consisting of night soil and / or septic tank sludge to obtain a liquid phase; a concentration step of evaporating and concentrating the liquid phase; A hydrothermal reaction step of oxidatively decomposing the solid matter and the concentrated liquid phase by a hydrothermal reaction in a supercritical or subcritical water state, and a method for treating human waste and / or septic tank sludge. 2. The method according to claim 1, wherein the solids are removed by membrane separation in the solid-liquid separation step. 3. The method according to claim 1, wherein the concentration step comprises evaporating and concentrating at a pH of 6 or less. 4. The method according to claim 1, wherein the concentration step comprises evaporating and concentrating by adding seed crystals. 5. The method according to claim 1, wherein the hydrothermal reaction step performs oxidative decomposition at a temperature of 600 ° C. or higher. 6. A solid-liquid separation device for removing a solid substance from an object to be treated consisting of night soil and / or septic tank sludge to obtain a liquid phase, a concentration device for evaporating and concentrating the liquid phase, An apparatus for treating human waste and / or septic tank sludge, comprising: a hydrothermal reactor for oxidatively decomposing a solid matter and a concentrated liquid phase by a hydrothermal reaction in a supercritical or subcritical state of water. 7. The concentrating device circulates a heated object to be processed through a heat exchanger, compresses generated steam and supplies it to the heat exchanger to heat the circulating object to be processed. Equipment.