JPH09174099A - Waste liquid treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To treat solid in waste liquid simply at low expense by a method in which the solid is caught in a filtration process which is filled with nonflammable granules, and the filtrate is supplied to a fluidized bed type heat treatment apparatus using a fluidized bed by the use of nonflammable granules and heat-treated. SOLUTION: After solid in excretory sewage 1 of excrement, purifying tank sludge, etc., being separated in a filtration process 2 by the use of nonflammable granules such as sand, the separated water 3 is introduced to a separated water treatment process 6 via storage tank 4. Besides, the separated solid 7, via a drying process 8 or directly, is stored in a gasification furnace hopper 9 and supplied to a fluidized gasification furnace heat treatment apparatus 10 to be heat-treated and gasified. The gas 11 generated, after being dedusted, is used as an energy source for a generator. In this way, the solid in waste liquid can be treated simply at low expense.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste liquid treatment method, and more particularly to human waste, sewage system wastewater such as septic tank sludge, organic wastewater such as sewage, and sludge generated in the process of treating the organic wastewater. The present invention relates to a method for treating a waste liquid, which comprises filtering and incinerating solid matter of

[0002]

2. Description of the Related Art For example, as shown in Table 1, human waste water, such as human waste and septic tank sludge, contains high concentrations of BOD and suspended solids (hereinafter simply referred to as solids). In the treatment of night soil sewage, after coarse sand is settled in a sand settler, coarse impurities are separated by a screen or the like, and biological treatment, coagulation treatment and the like are performed.
Excess sludge generated by biological treatment, coagulated sludge generated by coagulation treatment, and separated impurities are dehydrated and then dried or directly incinerated.

[0003]

[Table 1] (Note) Suspended substances are the values obtained by analyzing a sample that has passed through a 2 mm mesh sieve [Japan Environmental Sanitation Center data]

After sewage is settled in a sedimentation basin, solid matter having a relatively good sedimentation property is first settled and separated in the sedimentation basin for biological treatment. The sludge from the sedimentation basin and surplus sludge generated by biological treatment are first incinerated after passing through treatment steps such as concentration, anaerobic digestion, dehydration and drying. In addition, there is an anaerobic digestion method as one of the treatment methods of organic wastewater such as sludge, human waste, septic tank sludge, and organic wastewater such as food processing wastewater generated in the treatment process of wastewater such as sewage. Since suspended solids in wastewater are relatively biodegradable substances, they are discharged from the anaerobic digestion process as digested sludge, dehydrated, dried and incinerated. Anaerobic digestion itself is a very economical treatment method, but for the treatment of this digested sludge, a coagulant for dehydration,
A large amount of cost is required for maintenance and management costs such as heavy oil required for a drying furnace and an incinerator and electric power for operating the furnace, and construction costs for machines and furnaces.

Further, since the solid matter to be dehydrated is not gasified, the heat energy possessed by the solid matter itself cannot be effectively utilized. Further, although stirring is performed in the anaerobic digestion tank, sand is deposited on the bottom of the tank to reduce the effective volume of the tank, and thus the deposited sand is regularly removed. The settling sand settled in the sand settling tank or settling basin is mixed with other solids such as human waste sewage or sewage, and thus needs to be washed, but the washing process is complicated and the operation is complicated and unclean. In addition, since the settled sand will not be reduced even if it is incinerated, it will be landfilled, but this is a big problem because the volume of landfills in each region is currently small. The sludge generated in a small-scale wastewater treatment facility becomes inefficient in terms of human and economical efficiency if it is dehydrated and incinerated in the facility, so the concentrated sludge is transported to a specific dehydration and incineration facility for treatment. I often do it.

As described above, the treatment of the solid matter in the waste liquid and the solid matter generated in the treatment step of the waste liquid is extremely important including sedimentation, and the waste liquid treatment is the treatment of the solid matter (sludge). It's no exaggeration to say. In addition, as one of the sludge treatment methods with a fixed treatment cost, the sun drying method of sludge (a method of dehydrating and drying sludge in a sand layer) has been used. In the sun drying method, when scraping dehydrated dry sludge, it is necessary to prevent contact between the dehydrated dry sludge and the sand in order to prevent sand from mixing into solid matter, so scraping is insufficient. become. On the other hand, when the dehydrated and dried sludge is scraped off sufficiently, sand is mixed in the sludge, so that sand on the dry bed must be replenished, and the amount of sludge incineration residue increases.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide a waste liquid treatment method capable of treating the solid matter in the waste liquid simply and at low cost. .

[0008]

In order to solve the above problems, in the present invention, in a method for treating a waste liquid containing solids, the solids in the waste liquid are captured in a filtration step filled with non-combustible particles. The filtered material is supplied to a fluidized bed type heat treatment apparatus using a fluidized bed using non-combustible particles to perform heat treatment. In the treatment method, the non-combustible granules to be filled in the filtration step may be a part of the non-combustible granules of the fluidized bed, and the non-combustible granules of the fluidized bed are
It may be sand in the waste liquid, or non-combustible particles used in the filtration step. Further, the fluidized bed type heat treatment apparatus is an incinerator or a gasification furnace, and other organic waste may be supplied to the heat treatment apparatus together with the filtered matter captured in the filtration step. The waste liquid treated in the invention may be waste water or digested sludge generated in the anaerobic digestion process of sludge. In the present invention, the waste liquid refers to sewage such as human waste and sewage and sludge in a fluid state with a large amount of water.

[0009]

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 shows a flow process diagram in which the treatment method of the present invention is applied to the treatment of urinary wastewater. In FIG. 1, after solid matters such as human waste and septic tank sludge are separated in a filtration step 2 using sand, separated water 3 is introduced into a separated water treatment step 6 via a storage tank 4. . The separated solid matter 7 passes through the drying step 8 or is directly stored in the gasification furnace hopper 9 and introduced into the fluidized bed gasification furnace 10 to be gasified. The generated gas 11 is used as an energy source of a generator (gas turbine, gas engine, dizel engine) after dust removal, or by burning and recovering steam with a waste heat boiler to be used as an energy source for steam production of a steam turbine generator. can do. Incombustibles 12 in gasification furnace 10
When solid matter other than sand is mixed with the above, it is possible to separate the solid matter 15 other than sand by a sorting device 14 such as a specific gravity sorter, or directly circulate it as the supplementary sand 13 in the filtration step 2. it can.

The filtration material in the filtration step 2 is 0.3-
Non-combustible particles such as 3.0 mm of sand may be used. The required filtration rate in the filtration step 2 is the water temperature of the liquid (sludge), the viscosity,
Concentration of solids, properties (aggregated, non-aggregated), particle size of filter media,
Since it changes depending on factors such as the filter layer pressure, a preliminary test must be performed before determining the filtration area. The filtration may be pressure type, but if the site where the filtration process 2 is to be constructed is large and there is a margin, weight type filtration is recommended. Further, in the gravity type filtration, the sun drying method may be used. When the filtration rate is extremely low, the filtration rate can be improved by adding a coagulant such as a polymer (organic polymer coagulant) or slaked lime. As a means for removing the separated solid matter 2, it is recommended to use a scraping machine.

In the separated water treatment step 6, anaerobic digestion treatment, ammonia stripping treatment, activated sludge treatment, biological nitrification denitrification treatment, coagulation treatment, which are the techniques applied to the conventional treatment of human waste sewage, Known treatment techniques such as ozone treatment, film treatment, and activated carbon treatment can be used alone or in combination. The sludge 5 such as surplus sludge and coagulated sludge generated in the separated water treatment step 6 may be introduced into the filtration step 2 together with the night soil sewage 1. According to the present invention, it is possible to treat sludge generated from a wastewater treatment facility other than a septic tank having no sludge treatment facility together with the human waste sewage 1, and to separate separated sludge 7 from another treatment facility into a gasification furnace. It is also possible to gasify at 10.

[0012] For the treatment of night soil sewage, conventionally, a sand setter is provided as described above at the tip of the treatment process. This is to prevent the volume of the reaction tank from decreasing due to the accumulation of sand in each treatment step and to prevent the abrasion of the machine due to the sand. In the present invention, since the sand that flows in with the waste liquid in the filtration step 2 can be captured, a tank for settling and separating pebbles (gravel) larger than sand may be installed instead of the sand settling device. Pebbles have a much higher sedimentation rate than sand, so the tank for separation is extremely small. Further, when the solid matter is scraped off in the filtering step 2, even if sand is mixed, it can be used as the fluidized sand of the gasification furnace 10, so that the solid matter can be sufficiently scraped off. Moreover, the increased fluidized sand can be circulated and reused as the supplementary sand in the sand filtration step 2 by replenishing the sand, but this sand is clean because the contaminants have been treated by the heat treatment.

As the non-combustible granular material of the present invention, in addition to sand,
Known materials such as zeolite and crushed ceramics can be used. In the filtration step 2, the sand layer is 20 to 30 cm, and the gravel layer 20 to 3 below the sand layer is formed like a known sun drying bed.
It should be 0 cm, and a water collection pipe such as a perforated pipe should be placed under the gravel layer. Since the water content of the solid content is determined by the margin of the heat quantity of the gasification furnace (heat treatment apparatus) to be treated, the water content of the solid content may be high when the heat quantity has a margin. Gasification is a method usually operated at gasifier temperature 450 to 800 ° C., by pyrolysis of the processing object, low calorie (1000~1500kcal / Nm ³⁾ or medium calorie (2500~4500kcal / Nm ³⁾ Can produce gas. At least one gasifying agent such as air, oxygen, or steam is selected and fed into the furnace bottom.

Although not shown, the gas 11 is burned in, for example, a swirling melting furnace, and the gas passing through the waste heat boiler (for steam generation) is a combustion gas having calories. Energy can be recovered. (1) After the gas that has passed through the waste heat boiler is dedusted by a dust filter such as a ceramic filter, it is supplied to the gas turbine, and after generating electric power, steam is recovered by the subsequent waste heat boiler and released to the atmosphere. To do. Steam from two waste heat boilers is supplied to a steam turbine to generate electricity. This method uses high pressure (20-40 at).
m) is suitable for low calorie gas.

(2) The gas that has passed through the waste heat boiler is purified by a gas cleaning device such as a scrubber, and then supplied to a gas engine or a diesel engine to generate electric power, and then the waste heat boiler installed in a subsequent stage. After recovering the vapor at, it is released into the atmosphere. The steam that has passed through the two waste heat boilers is supplied to a steam turbine to generate electric power. This method is suitable for low-calorie or medium-calorie gas in which flammable gas remains at normal pressure. The electric power produced by the gas 11 of the gasification furnace 10 can be used as the internal electric power of the night soil treatment facility. Further, in addition to the separated solid matter 7 in the gasification furnace 10, organic industrial waste such as organic industrial waste, paper, plastic, and general waste mainly containing garbage 1
By supplying 6, it is possible to supplement the internal power consumption of the night soil treatment facility and also supply the production power to the outside.

FIG. 2 shows a flow process diagram in which the method of the present invention is applied to the treatment of sewage having a much lower concentration of pollutants (buoyant solids, BOD, etc.) than human waste. In FIG.
The sewage 19 is first introduced into the settling basin 21 via the settling basin 20 to separate solid matters such as sand 33 and organic suspended solids 34, and then the separated water 22 is subjected to the sewage treatment step 23 by the activated sludge method. After being introduced and treated, it is discharged as treated water 24. In addition, the sewage treatment step 23 can utilize a known treatment method such as a standard activated sludge method, a nitrification denitrification method, and an anaerobic aerobic method. In the case of sewage, since the solid content concentration is low as described above, it is not directly introduced into the filtration step 2 as in the case of human wastewater, sludge, etc., and solid-liquid separation is performed in the sand basin 20 and the first sedimentation basin 21, Although it is better to introduce into the filtration step 2, 19 may be bypassed and introduced when the solid load of the filtration step 2 is small. Sludge 26 generated in sewage treatment process 23
Is introduced into the filtration step 2. The separated water 27 of the filtration step 2 is transferred to the sewage treatment step 23 for treatment. Separated solids 28
Is incinerated in the fluidized bed incinerator 30 via the hopper 29, and the ash content 31 is the same as in FIG.
It is advisable to separate the solid matter 15 other than sand in 4 and then transfer it to the filtration step 2.

When gravel is mixed in the sand from the sand basin 20, it may be separated into sand and gravel by a sieve or the like, if necessary, and only the sand may be introduced into the filtration step 2. The fluidized bed incinerator 30
Since the sand filled as the heat medium flows by the air from the furnace bottom, it mixes with the separated solid matter 28 in an extremely short time and is burned. It should be noted that, for uniform mixing, the separated solid matter 28 may be finely crushed by a crusher, if necessary, and charged into the fluidized bed incinerator 30, although not shown. The exhaust gas 32 of the incinerator 30 can be treated economically by recovering the heat as steam in a waste heat boiler, supplying it to a steam turbine generator, and supplying the required electric power in the facility. .

Next, the treatment method of the present invention will be described with reference to the flow chart of FIG. 3 in which the digested sludge generated in the anaerobic digestion treatment step is applied. In FIG. 3, after separating sand and gravel in the sand settling tank 42 of the night soil system wastewater 41 such as human waste and septic tank sludge, the crushing pump 44 passes through the receiving tank 43 and the pretreatment screen 45 having an opening of 1 to 3 mm. Pumped to and sieved 4
6 and separated water 47. The sieve 46 is a sieve dehydrator 4
The dehydration furnace liquid 50 is dehydrated in 8 to a dehydration sieve 49, and the dehydration furnace liquid 50 is passed through a storage tank 51 for adjusting the water amount fluctuation together with the separated water 47, and is then agitated under anaerobic conditions.
And then flows into the second digestion tank 53 under anaerobic conditions and without stirring. As the stirring, gas stirring or mechanical stirring can be applied. Gas stirring is a stirring method in which the gas in the gas phase is pressed into the bottom of the tank via a blower, and mechanical stirring is a method of stirring the liquid in the tank by rotating stirring blades. Gas stirring has stronger stirring strength than mechanical stirring, but consumes more power.

In the digestion tanks 52 and 53, the easily decomposable organic acid promptly reacts with biogas (methane, carbon dioxide) 54.
On the other hand, the floating solid matter is also reduced to a low molecular weight after a relatively long time and decomposed into biogas 54. Floating solids are polymeric substances, and since many of them are relatively biodegradable, the amount decomposed into biogas is limited. In the second digestion tank 53, the biogas 54 is generated but the stirring is not performed, so that the solid matter is settled, so that the digested sludge 55 is discharged to the filtration step 56. In addition, even in the first digestion tank 52 in which stirring is performed, solids such as sand having a large specific gravity gradually pile up, so it is desirable to discharge the piles regularly. Since the digested desorbed liquid 57 contains nitrogen and phosphorus, it can be used as liquid fertilizer. When the digested desorbed liquid 57 is discharged into a water system, it is advisable to discharge the digested desorbed liquid 57 after performing denitrification and dephosphorization treatment in order to prevent eutrophication at the discharge destination. It is also possible to bypass part or all of the desorbed liquid 57 in order to remove suspended solids remaining in the digested desorbed liquid 57. The filtered water 59 is discharged or used as a liquid fertilizer together with the digestion / desorption liquid 57.

The trapped sludge 60 in the filtration step 56 is the dehydrated sieve 4
9. After being put into the hopper 62 together with the sand 61 in the sand settling tank 42, it is incinerated in the fluidized bed incinerator 63. Incineration exhaust gas 6
The ash 66 in 4 is removed by a dust remover 65 such as an electrostatic precipitator or a bag filter. Although not shown, in order to utilize the heat of the incineration exhaust gas 64, installing a waste heat boiler for steam recovery is an effective means of energy recovery. A heat recovery pipe may be inserted into the fluidized bed incinerator 63 to recover water vapor as energy. When scraping off the sand separated in the process of treating the night soil-based wastewater 41 and the sludge 60 captured in the filtration step 56, the mixed sand increases the sand in the fluidized bed of the fluidized bed incinerator 63, so A part of the sand 67 is separated from the foreign matter 69 directly or in the fluidized sand by a separating device 68 such as a screen or a specific gravity separating machine, and then a filtering step 56.
It can be reused as replenishing sand. This sand is
Clean because the contaminants are treated by heat treatment.

In addition to sand, gravel with a particle size of about 10 mm is also mixed in the settling sand 61 of the settling tank 42, so it is desirable to separate it with a screen or the like before putting it into the fluidized bed incinerator 63. Further, the settling sand 61 may be transferred to the filtering step 56 and used as the filtering sand. In addition, the screen 46 of the screen 45
Is transferred to the filtration step 56 and filtered, the dehydrator 48 can be omitted. Crushing pump 44 to screen 4
5. It is also possible to directly transfer the urine system wastewater to the first digestion tank 52 without passing through the storage tank 51. In this case, since the solid matter concentration of the wastewater flowing into the digestion tank 52 becomes high,
It is necessary to intensify the stirring of the first digestion tank 52 so that the mixing is sufficiently performed, and to pay attention to the fluctuation of the water amount. Regarding the water temperature of the first digestion tank 52, medium-temperature fermentation at around 38 ° C. can stably perform gasification of organic substances. The heating is
It is convenient to directly inject the steam produced by the heat generated in the fluidized bed incinerator 63 into the liquid in the first digestion tank 52. The effective volumes of the digestion tanks 52 and 53 may be constructed so that the number of days of retention of the separated water 47 is 15 days.

Although not shown, the biogas 54 can be appropriately desulfurized with an iron-based desulfurizing agent and then stored in a gas tank to be used as an auxiliary fuel for the fluidized bed incinerator 63 or a fuel for another combustion device. The filtering material in the filtering step 56 is 0.
Known non-combustible particles such as 3-3.0 mm sand, crushed waste ceramics, molten slag of waste, and zeolite may be used. The required filtration rate in the filtration step 56 is the water temperature of the liquid (sludge),
It depends on factors such as viscosity, concentration of solids, properties (aggregated and non-aggregated), particle size of filter media, filter layer pressure, etc. Therefore, a preliminary test must be performed before determining the filtration area. I won't. The filtration may be performed by pressure, but if there is a large site for constructing the filtration process 42 and there is a margin, weight filtration is recommended. In gravity filtration, if the sun drying method is used, dehydration can be efficiently performed by filtration and transpiration, so it is recommended to use sun in high temperature areas. A known example of the sun drying device may be referred to.

In the filtration step 42, it is preferable that the sand layer is 20 to 30 cm, the gravel layer is 20 to 30 cm below the sand layer, and a water collecting pipe such as a perforated pipe is provided below the gravel layer, as in a sun-dried bed. Gasification furnace (heat treatment equipment) to treat the water content of solids
The water content of the solid content may be high when there is a margin in the amount of heat, since it is determined by the margin of the amount of heat. To improve the filtration rate, polymer (organic polymer flocculant),
The addition of a flocculant such as slaked lime can improve the filtration rate. Although not shown, after the digestive desorption solution 57 is subjected to aerobic aeration treatment or aerobic biological treatment,
The liquid may be introduced into the filtration step 56 directly or sludge separated from the liquid. This is because by performing aerobic treatment (oxidation treatment), fine solids remaining in the digestion / desorption liquid 57 aggregate to form coarse flocs, which facilitates filtration. A scraper is recommended as a means for removing the separated solid matter 42.

Next, the treatment method of the present invention in which the treatment method for human waste water is made simpler than that in FIG. 3 and the filtered solid matter is gasified in the gasification furnace will be described with reference to FIG. In FIG. 4, the human waste sewage 41 is put into the digestion tank 72 after the large solid matter is removed by the screen 71. It is suitable that the opening of the screen 71 is 1 to 10 mm for the rotating screen and 5 to 20 mm for the bar screen. In order to separate the gravel and the waste sanitary goods, the screen may be about 3 to 7 or 8 mm. As compared to the embodiment of FIG. 3, the anaerobic digestion tank 72 has a relatively large inflow amount of gravel, sand, and organic suspended solids. Good to do.

For gas agitation, the gas in the gas phase portion 73 of the digestion tank 72 is sucked by the blower 74, and is pressed into the bottom of the digestion tank 73 via the pipe 75 and stirred. Since the digestion tank 72 is a single tank, the effective volume may be constructed so that the number of days of retention of the urine system wastewater 41 is 20 days or more for safety. Since the solid matters are suspended in the digestion tank effluent 76 by stirring, the digestion tank effluent 76 is introduced into the total amount filtration step 56 and filtered. Further, since the sand settling tank is not provided here, the amount of sand deposited in the digestion tank 72 becomes larger than that in FIG. Therefore, it is necessary to pull out the sand 77 more frequently than in FIG. Although not shown,
By aerating the effluent 76 in the aeration tank for several days, the filtering property of the digestion tank effluent 76 can be improved as described in FIG.

The trapped sludge 78 of the filtration step 56 is introduced into the hopper 80 together with the sieve 79 of the screen 71, and is gasified in the fluidized bed gasification furnace 81. The fluidized sand in the gasification furnace 81 is
Since it increases due to the sand that flows in together with the human waste system sewage 41 and the sand that is mixed in during the scraping of the sludge 78 captured in the filtration step 56, the part 83 of the fluid sand directly or screens the foreign matter 85 in the fluid sand. After being separated by a sorting device 84 such as a specific gravity sorting machine, it can be circulated and used as make-up sand for the filtration step 56. The generated gas 82 is dust-removed and then used as an energy source of a generator (gas turbine, gas engine, dizel engine) or burned to recover steam with a waste heat boiler and used for a steam turbine generator. Further, although not shown, the fuel gas is still present in the gas that has partially burned the gas 82, for example, in a swirling melting furnace and passed through a waste heat boiler (for steam generation). The energy can be recovered in the same manner as the generated gas 11.

The electric power produced by the gas 82 of the gasification furnace 81 can be used as the internal electric power of the human waste treatment facility. In the present invention, organic waste liquid 86 such as food waste liquid and separated sludge of other treatment facilities is used.
It is possible to treat the wastewater with the urine system wastewater 41.
In addition, organic waste such as organic industrial waste, paper, plastic, general waste mainly containing kitchen waste, and dehydrated sludge 87
By additionally gasifying the gas in the gasification furnace 80, it is possible to supplement the internal power consumption of the human waste system wastewater treatment facility and also supply the production power to the outside. The biogas 54 can be used as an energy source together with the gas 82 of the gasification furnace 81.

[0028]

The present invention will be described below in more detail with reference to examples. Example 1 4.5 m ² of concentrated sludge (sludge concentration 3 to 5%) of three small-scale sewage treatment plants dispersed in each area was used as a sand filter tank with an area of 20 m ² (sand diameter 1 mm, sand thickness 30 cm, Gravel layer 3 below the sand layer
(0 cm) for 5 days after filtration and dehydration to obtain an average water content of 82%, and then mixes organic waste (2t) from households mainly consisting of paper, plastic, and garbage and crushed old tires (1t). Then, it was gasified by the processing flow of FIG. The gasification temperature was 700 ° C., and a gas of 3500 kcal / Nm ³ could be obtained.

[0029]

According to the present invention, the following effects can be obtained. (1) By performing the fluidized bed incineration treatment and the fluidized bed gasification treatment, the inflow sand, which has been a troublesome material in the past, can be recycled and reused as the fluid sand and the filter material. (2) Since the sand in the incinerator and gasifier ash that had to be landfilled as non-combustible waste in the past can be effectively used, it is possible to extend the life of landfills that are currently under pressure. (3) The filling sand of the fluidized bed gasification furnace and the fluidized bed incinerator can be internally supplied. (4) Scraping from a conventional sand filtration bed Sludge can be sufficiently scraped off even if sand is mixed with sludge.

(5) The conventional sand settling process can be eliminated or the sand can be easily treated, so that the troublesome and unclean sand settling operation can be improved. (6) When solid wastes are treated together with solid wastes using a fluidized bed incinerator or a fluidized bed gasification furnace for industrial wastes, sand generated during the wastewater treatment process can be used. (7) Soluble organic matter and insoluble organic matter (floating solid matter) in wastewater and sludge, that is, wastewater and organic matter in sludge, which have been impossible by the conventional anaerobic digester and gasifier, are used as energy. It can be converted to high-quality gas.

[Brief description of the drawings]

FIG. 1 is a flow process chart showing an example of a processing method of the present invention.

FIG. 2 is a flow chart showing another example of the processing method of the present invention.

FIG. 3 is a flow chart showing another example of the treatment method of the present invention.

FIG. 4 is a flow chart showing another example of the processing method of the present invention.

[Explanation of symbols]

1, 41: Night soil sewage, 2, 56: Filtration process, 3, 2
7, 59: separated water, 4: storage tank, 6: separated water treatment step,
7, 28, 60, 78: separated solid matter, 8: drying step:
9, 29, 62, 80: Hopper, 10, 30, 63,
81: fluidized bed gasification furnace, 11, 32, 64, 82: generated gas, 12, 31, 67, 83: incombustible material, 13: supplementary sand, 14, 68, 84: fractionation device, 15: separated solid matter,
19: sewage, 20, 42: sand basin, 21: first sedimentation basin,
23: Sewage treatment process, 52, 53, 72: Digestion tank

Claims (7)

[Claims] 1. A method for treating a waste liquid containing a solid matter, wherein the solid matter in the waste liquid is captured in a filtration step filled with non-combustible particles, and the filtrate is a fluidized bed using a fluidized bed using the non-combustible particles. A method for treating waste liquid, characterized in that the waste liquid is supplied to a heat treatment apparatus for heat treatment. 2. The method for treating waste liquid according to claim 1, wherein the non-combustible granular material filled in the filtration step is a part of the non-combustible granular material of the fluidized bed. 3. The method for treating waste liquid according to claim 1 or 2, wherein the non-combustible granular material in the fluidized bed is sand in the waste liquid. 4. The method for treating waste liquid according to claim 1, 2 or 3, wherein the non-combustible granular material in the fluidized bed is the non-combustible granular material used in the filtration step. 5. The method for treating waste liquid according to claim 1, wherein the fluidized bed heat treatment apparatus is an incinerator or a gasification furnace. 6. The method for treating waste liquid according to claim 1, wherein the waste liquid is digested sludge generated in an anaerobic digestion treatment step of waste water or sludge. 7. The fluidized bed heat treatment apparatus is supplied with other organic waste together with the filtered material captured in the filtering step. Waste liquid treatment method.