JP6472125B2 - Disposal method of organic waste - Google Patents

Description

  The present invention relates to a processing method and a processing system for organic substance-containing waste.

  In recent years, it has been proposed to treat livestock manure or food residues as organic matter-containing waste by anaerobic digestion (for example, Non-Patent Document 1). On the other hand, a method of hydrothermally treating food residue, wood waste, paper waste, raw garbage, food waste, etc. with subcritical water vapor has been proposed (for example, Patent Document 1).

Research on performance comparison of medium temperature and high temperature methane fermentation of manure and food residues, Journal of Waste Management, 16, 45-54, 2005.

Japanese Patent No. 4898970

  By the way, even if it is in sewage sludge, it should not be changed to waste containing organic matter and should be subjected to anaerobic digestion treatment, but the amount of sludge to be treated is enormous, so anaerobic digestion treatment in a short period of time There is room for improvement in the selection of processing substrates that allow progress. Although the technique proposed in Patent Document 1 reduces the molecular weight of organic substances due to high hydrolyzability, some of the fibers and the like remain in the solid component without being solubilized, so that the object to be processed through hydrothermal treatment The fact is that the efficiency is reduced when the is used as a processing substrate for anaerobic digestion. For these reasons, it has been requested to operate hydrothermal treatment from the viewpoint of combined use with anaerobic digestion. In addition, there is a demand for diverting organic material-containing waste such as sewage sludge into fertilizer and reducing its production cost.

  In order to achieve at least a part of the problems described above, the present invention can be implemented as the following forms.

  (1) According to one form of this invention, the processing method of an organic substance containing waste is provided. This organic matter-containing waste treatment method includes a hydrothermal treatment step in which the organic matter-containing waste is hydrothermally treated in a treatment tank having a subcritical atmosphere with subcritical water vapor, and anaerobic digestion treatment substrate and anaerobic In the digestion tank for storing the digestion target waste to be digested, the hydrothermally treated liquid component obtained by solid-liquid separation of the organic matter-containing waste that has undergone the hydrothermal treatment is used as the treatment substrate. A digestion treatment step for storing the target waste together with the anaerobic digestion treatment in the digestion tank, the digestible waste subjected to the anaerobic digestion treatment, and the hydrothermally treated liquid component as the treatment substrate, And a final solid-liquid separation step for solid-liquid separation.

  The treatment method of organic matter-containing waste in the above form is a hydrothermally-treated liquid component obtained by subjecting organic matter-containing waste to hydrothermal treatment in a subcritical atmosphere and then subjected to solid-liquid separation, as a treatment substrate for anaerobic digestion treatment, Anaerobic digestion treatment of waste subject to digestion in digestion tank. The hydrothermally treated liquid component used as the treatment substrate is mixed with organic substances in a low-molecular state by hydrothermal treatment, so anaerobic digestion of organic substances by anaerobic bacteria proceeds rapidly, and accordingly Anaerobic digestion of waste to be digested by anaerobic bacteria will also proceed. Therefore, according to the organic substance-containing waste processing method of the above aspect, it is possible to shorten the period required for anaerobic digestion of the digestible waste. Moreover, in the processing method of the organic substance containing waste of said form, nitrogen is contained in an organic state or an inorganic state by having received the anaerobic digestion in the solid component solid-liquid-separated by the last solid-liquid separation process. Therefore, according to the method for treating organic matter-containing waste in the above-described form, the solid component that has been subjected to solid-liquid separation in the final solid-liquid separation step can be provided as solid compost of agricultural products. In addition, it is possible that the organic substance-containing waste to be treated is contaminated with radioactive substances, but when the organic substance-containing waste contaminated with radioactive substances is hydrothermally treated in a subcritical atmosphere, the radioactive substances are hydrothermally treated liquid components. include. Therefore, radioactive substances are reduced in the solid component obtained by hydrothermal treatment. Thereby, effective utilization of a solid component is attained.

  (2) In the organic matter-containing waste processing method of the above aspect, the organic matter-containing waste may be sewage sludge. In this way, sewage sludge can be anaerobically digested in a short period of time.

  (3) In the method for treating organic matter-containing waste according to any one of the above forms, the heavy metal contained in the hydrothermally-treated liquid component is solid-liquid separated from the hydrothermally-treated liquid component in the previous step of the digestion treatment step. The hydrothermally-treated liquid component from which the heavy metal has been separated may be sent to the digestion tank in the digestion process step. In this way, heavy metals can be used effectively and heavy metals are not mixed into the solid components separated by solid-liquid separation in the final solid-liquid separation process, improving the usefulness of solid compost and avoiding adverse effects on the human body. Can be achieved.

(4) In the processing method of the organic substance-containing waste any of the above, in the final solid-liquid separation step, the solid component obtained by solid-liquid separating the organic substance-containing waste receiving the hydrothermal treatment In addition, it is possible to perform solid-liquid separation by blending as a dehydrating aid in the solid-liquid separation of the waste to be digested that has undergone the anaerobic digestion treatment and the hydrothermally treated liquid component as the treatment substrate. Good. In this way, it is possible to effectively use the solid component obtained by the hydrothermal treatment.

  (5) According to the other form of this invention, the processing system of an organic substance containing waste is provided. This organic matter-containing waste treatment system has a treatment tank that is made into a subcritical atmosphere by subcritical water vapor, and the organic matter-containing waste charged in the treatment tank is hydrothermally treated in the treatment tank. A heat treatment apparatus, a liquid component obtained by solid-liquid separation of the organic matter-containing waste that has undergone the hydrothermal treatment, and a waste to be digested that is subject to anaerobic digestion treatment by anaerobic bacteria. A digestion tank for storing an anaerobic digestion treatment as a processing substrate, a digestion treatment mechanism for advancing the anaerobic digestion treatment in the digestion tank, the digestible waste subjected to the anaerobic digestion treatment, and the treatment A final solid-liquid separation mechanism for solid-liquid separation of the liquid component as a substrate. The effects described above can also be achieved by this type of organic matter-containing waste treatment system.

  The present invention can be realized in various forms, for example, in the form of a sewage treatment apparatus, a sewage treatment system, and the like.

It is explanatory drawing which shows the whole structure of the waste disposal system 1000 as embodiment of this invention by block view. 1 is an explanatory diagram showing a schematic configuration of a hydrothermal treatment apparatus 100 included in a hydrothermal treatment block 1100. FIG. It is explanatory drawing which shows schematic structure of the aeration processing apparatus 300 contained in the aeration block 1200. It is explanatory drawing which shows schematic structure of the digestion processing apparatus 400 contained in the digestion block 1300. FIG. It is explanatory drawing which shows the outline | summary of the evaluation test of the aeration-processed detached liquid Be as a process substrate of anaerobic digestion process. It is a graph which shows the VS decomposition rate in sludge by the 5th day and the 10th day.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing the overall configuration of a waste treatment system 1000 as an embodiment of the present invention in a block view. As shown in the figure, the waste treatment system 1000 of this embodiment includes a hydrothermal treatment block 1100, a first solid-liquid separation mechanism 1150, an aeration block 1200, a second solid-liquid separation mechanism 1250, a digestion block 1300, A third solid-liquid separation mechanism 1350 is provided, and an organic matter-containing waste that is an object to be treated is treated while transferring a liquid component or a gas component between the blocks. This object to be treated is put into a hydrothermal treatment block 1100 and hydrothermally treated by a hydrothermal treatment apparatus 100 described later included in the hydrothermal treatment block 1100. The liquid component obtained through the hydrothermal treatment and the solid-liquid separation by the first solid-liquid separation mechanism 1150 is transferred to an after-mentioned aeration processing apparatus 300 included in the aeration block 1200. Hereinafter, the liquid component obtained through the hydrothermal treatment by the hydrothermal treatment apparatus 100 and the solid-liquid separation by the first solid-liquid separation mechanism 1150 will be referred to as the desorbed liquid.

  In the liquid component (desorbed liquid) transferred to the aeration treatment apparatus 300, heavy metals are removed as described later in the apparatus, and the liquid component (desorbed liquid) after the removal of heavy metals is included in the digestion block 1300 described later. To the digestion processing apparatus 400 via the second solid-liquid separation mechanism 1250. The liquid component (desorbed liquid) transferred to the digestion apparatus 400 is subjected to an anaerobic digestion process as will be described later. Hereinafter, the device configuration of each block will be described. 2 is an explanatory diagram showing a schematic configuration of the hydrothermal treatment apparatus 100 included in the hydrothermal treatment block 1100, FIG. 3 is an explanatory diagram showing a schematic configuration of the aeration processing apparatus 300 included in the aeration block 1200, and FIG. It is explanatory drawing which shows schematic structure of the digestion processing apparatus 400 contained.

  As shown in FIG. 2, the hydrothermal treatment block 1100 of this embodiment includes a hydrothermal treatment apparatus 100 and a water vapor supply system 140. The hydrothermal treatment 100 is a hydrothermal treatment apparatus that hydrothermally treats an object to be treated using water components and heat of water vapor, and includes a treatment tank 110, a waste input system 120, a treatment discharge system 130, and a control device. 200. The treatment tank 110 is a hollow treatment tank for hydrothermally treating organic-containing wastes such as sewage sludge and food residues as an object to be treated, and is a steel or stainless steel pot having pressure resistance and temperature resistance. It is. This processing tank 110 is provided with a workpiece inlet 111 and an outlet 112 above and below the kettle, and a plurality of stirring blades 113 are rotatably provided inside the kettle. The right side of the processing tank 110 in the drawing is a watertight / airtight type door, and this door is opened and closed during maintenance inspection in the pot.

  The stirring blade 113 extends from the rotating shaft of the motor 114 outside the processing tank 110 into the hook, rotates in the processing tank 110 as the motor 114 rotates, and has been put into the processing tank 110 to be processed. Stir things. As will be described later, since the inside of the treatment tank 110 is filled with water vapor at high temperature and high pressure, the stirring blade 113 rotates to agitate the object to be treated. A uniform heat transfer to the object to be processed while uniformly contacting the water vapor.

  The waste input system 120 includes an input path 121 that leads to the input port 111 of the treatment tank 110 until reaching the waste input hopper 128, and includes a first valve 122 and a second valve 123 in the path. An inter-valve path 124 is defined between the valves. Valve driving devices 125 and 126 are mounted on the first and second valves, respectively, and these valves are opened and closed by being driven under the control of the control device 200. That is, both the first and second valves are opened when the workpiece is charged, and in this valve state, the waste charging hopper 128 feeds the workpiece to the charging port 111 while conveying the workpiece. . Then, during the duration of the hydrothermal treatment, both valves are normally closed. Note that a pressure release valve 127 is attached to the inter-valve path 124, and the inter-valve path 124 is opened to the atmosphere by the open valve.

  The processed product discharge system 130 includes a discharge path 131 connected to the discharge port 112, and has a discharge valve 132 in the path. The discharge valve 132 opens and closes when the valve driving device 133 is driven under the control of the control device 200, opens when the processing of the object to be processed (hydrothermal treatment) is completed, and closes during the hydrothermal treatment. State. The processed product discharged from the discharge port 112, that is, the organic matter-containing waste subjected to the hydrothermal treatment, is transferred to the first solid-liquid separation mechanism 1150, and is separated into solid and liquid by the first solid-liquid separation mechanism 1150.

  The steam supply system 140 includes a steam supply source 141, a steam supply pipe 143 that reaches the processing tank 110, and an opening / closing valve 144 for the pipe. The steam supply source 141 includes a temperature raising / pressurizing device group 142, and the device group heats and applies steam to a temperature and pressure suitable for hydrothermal treatment in the treatment tank 110 (for example, a pressure of about 2 MPa at around 200 ° C.). Press. The temperature raising / pressurizing device group 142 for heating and pressurizing the steam is composed of a boiler, a steam superheater, a compressor, and the like. The temperature raising / pressurizing device group 142 is driven under the control of the control device 200 to generate the above-described high-temperature / high-pressure water vapor, and the water-vapor supply source 141 supplies the high-temperature / high-pressure water vapor to the vapor supply line 143. Then, the inside of the treatment tank 110 is continuously fed by pressure during the hydrothermal treatment. In FIG. 2, the steam supply line 143 is illustrated as a single line. However, in order to uniformly supply water vapor into the processing kettle, the steam supply line 143 is used as a branch pipe, and the tip of each branch officer is used. High-temperature and high-pressure steam is supplied into the treatment kettle. Therefore, the treatment tank 110 is quickly and completely filled with the high-temperature and high-pressure steam simultaneously ejected from the ejection holes corresponding to each of the plurality of branch pipes, and is made into a subcritical atmosphere with the subcritical steam. Hydrothermal treatment of organic waste. The hydrothermal treatment 100 includes a discharge system that releases the water vapor in the treatment kettle to the atmosphere after completion of the hydrothermal treatment, but is not directly related to the gist of the present invention, and thus illustration and description thereof are omitted.

  In addition, the hydrothermal treatment 100 includes three kettle temperature sensors 161 to 163 that detect the internal temperature of the treatment tank 110, and these sensors output detection signals to the control device 200. The first kettle temperature sensor 161 is attached to the upper inner wall of the processing tank 110 as shown in the figure, and detects the upper temperature in the kettle. The second kettle temperature sensor 162 is attached to the inner wall near the center of the treatment tank 110 and detects the temperature near the center in the kettle, that is, near the liquid surface of the liquid component in the kettle. The third pot temperature sensor 163 is attached to the bottom inner wall of the processing tank 110 and detects the temperature (liquid temperature) of the liquid component in the pot.

  The control device 200 performs overall control of the hydrothermal treatment 100 of this embodiment, and includes a CPU that executes logical operations, a ROM that stores programs and data, and a RAM that allows temporary reading and writing of data. Etc. It is comprised with the computer which has etc. Then, the control device 200 inputs detection signals from the various sensors described above, and according to such detection signals and operating condition setting parameters from an operation panel (not shown), the valve opening / closing control of the processing tank 110, the steam supply system 140, the drive control of the temperature raising and boosting device group 142 and the on-off valve 144, the drive control of the on-off valve 154 of the oxygen supply system 150, the drive control of the motor 114, and the like are executed, and the organic matter-containing waste is watered in a subcritical atmosphere Heat treatment.

  In the present embodiment, hydrothermal treatment is performed by the hydrothermal treatment apparatus 100 as sewage sludge treated at a sewage purification treatment facility of a local government as an organic matter-containing waste. At this time, the sewage sludge was gravity-concentrated mixed sludge mixed with the sludge of the first sedimentation basin and the final sedimentation basin of the sewage purification treatment facility to obtain a dewatered cake (sludge concentration 22%) after dewatering by a belt press. The dehydrated cake was subjected to primary hydrothermal treatment at 160 ° C. for 45 minutes, and then subjected to secondary hydrothermal treatment at 180 ° C. for 15 minutes.

  The first solid-liquid separation mechanism 1150 to which the organic matter-containing waste that has been subjected to the hydrothermal treatment from the hydrothermal treatment apparatus 100 described above is provided with a hydrothermal treatment solid-liquid separation apparatus 260. This hydrothermal treatment solid-liquid separation device 260 accepts the organic substance-containing waste that has undergone hydrothermal treatment from the treatment tank 110 through the opening of the discharge valve 132 of the discharge path 131 connected to the bottom of the treatment tank 110, and solid-liquid separates it. To do. In this case, the opening control of the discharge valve 132 is performed by the control device 200 in accordance with the end timing of the primary and secondary hydrothermal treatment. Then, the hydrothermal solid-liquid separation device 260 supplies the solid component obtained through the solid-liquid separation of the organic substance-containing waste that has been hydrothermally treated to a third solid-liquid separation mechanism 1350 (see FIG. 1) described later. It discharges (transfers) from the solid component discharge pipe 264 through the opening control. Further, the hydrothermal solid-liquid separation device 260 is a liquid component (desorbed liquid) obtained through the solid-liquid separation of the organic matter-containing waste that has been subjected to the hydrothermal treatment, which will be described later in the aeration block 1200 via the transfer pipe 266. It is transferred to 300 (specifically, its processing vessel 302). This transfer is performed at a predetermined timing by a pump 268 that is controlled by the aeration control device 330.

  As shown in FIG. 3, the aeration block 1200 of the present embodiment includes an aeration processing device 300 and a boiler device 380. The aeration processing apparatus 300 includes a hollow sealed processing container 302, a gas aeration mechanism 304, a hydrogen sulfide gas preliminary tank 306, an aeration pipe 308, a stirring device 310, and an aeration control apparatus 330. The processing vessel 302 is connected to the transfer pipe 266 of the hydrothermal treatment solid / liquid separation device 260 in the first solid / liquid separation mechanism 1150. Then, a liquid component (hereinafter, referred to as a desorbed liquid We) separated by the first solid-liquid separation mechanism 1150 after being subjected to hydrothermal treatment by the hydrothermal treatment apparatus 100 is transferred to the processing vessel 302. It is transferred through the pipe 266, and the processing vessel 302 stores this desorbed liquid We.

  The gas aeration mechanism 304 is connected to a digestion tank 402 of a digestion processing apparatus 400 described later via a gas discharge pipe 422. The gas aeration mechanism 304 guides a gas (digestion process gas Sg described later) transferred from the digestion tank 402 via the gas discharge pipe 422 to the aeration pipe 308 extending to the bottom of the process container 302, so that the bottom of the process container Then, the digestion processing gas Sg is brought into contact with the desorption liquid We stored in the processing container 302. The aeration amount and duration of the digestion processing gas Sg at this time are determined according to the amount of the desorbed liquid We transferred from the hydrothermal treatment apparatus 100 to the processing container 302 and stored in the container. In addition, the gas aeration mechanism 304 includes a sensor 305 that detects the gas amount of the digestion process gas Sg transferred from the gas discharge pipe 422 and the hydrogen sulfide gas amount (hydrogen sulfide concentration) contained in the gas, and the sensor Depending on the output, it works as follows. If the amount of hydrogen sulfide gas contained in the digestion process gas Sg is less than the specified gas quantity from the sensor output, or if the gas amount of the digestion process gas Sg itself is less than the specified gas quantity, the gas aeration mechanism 304 Under the control of 330, the hydrogen sulfide gas stored in the hydrogen sulfide gas preliminary tank 306 is guided to the aeration pipe 308 through the gas pipe line 307. The above-mentioned prescribed gas amount that determines the introduction of hydrogen sulfide gas from the hydrogen sulfide gas preliminary tank 306 is determined according to the liquid amount of the desorption liquid We described above.

  The boiler device 380 communicates with the upper part of the liquid level of the processing container 302 via the gas introduction pipe 382, and sucks gas from the upper part of the liquid level of the processing container 302 through the suction rotation of the gas suction fan 384. The gas at the top of the liquid level in the processing container 302 is a digestion processing gas Sg that is aerated from the bottom of the processing container 302 and floats on the detachment liquid We and is released from the liquid level. A biogas produced by anaerobic digestion, which contains a combustible gas such as methane. Therefore, the boiler apparatus 380 burns the sucked digestion process gas Sg and propagates the combustion heat to the water vapor supply source 141 of the hydrothermal treatment apparatus 100, thereby generating a subcritical atmosphere in the treatment tank 110 of the hydrothermal treatment apparatus 100. Used for expression or maintenance. In this case, the rotation control of the gas suction fan 384 is performed by the aeration control device 330 according to the timing of starting the aeration of the digestion process gas Sg. Note that if the boiler device 380 comes close to the water vapor supply source 141, the propagation efficiency of combustion heat increases, so the boiler device 380 may be an accessory device of the water vapor supply source 141.

  The aeration control device 330 is configured as a computer having a CPU, a ROM, and a RAM for executing logical operations, and comprehensively controls the aeration processing device 300, the post-aeration solid-liquid separation device 360, and the boiler device 380. In other words, the aeration control device 330 receives the input of various switches (not shown) and the sensor 305, performs aeration by the gas aeration mechanism 304 described above, replenishment of hydrogen sulfide gas, valve opening / closing of each pipe line, and hydrothermal treatment. The overall control of the transfer of the desorbing liquid We from the apparatus 100, the driving of the stirring device 310, and the like is performed. When the aeration control device 330 aerates the digestion process gas Sg for a predetermined duration, the aeration control unit 330 controls the valve 364 of the post-aeration solid-liquid separation device 360 to process the desorbed liquid We after aeration. The container 302 is discharged (transferred) to the second solid-liquid separation mechanism 1250 (see FIG. 1).

  The second solid-liquid separation mechanism 1250 to which the desorbed liquid We after aeration is transferred from the aeration processing apparatus 300 described above includes a post-aeration solid-liquid separation apparatus 360. This post-aeration solid-liquid separation device 360 communicates with the bottom of the processing container 302 via the introduction pipe 362, receives the detachment liquid We from the processing container 302 through the opening of the valve 364, and aggregates the detachment liquid We. Use solid-liquid separation using a method or filtration equipment. In this case, the opening control of the valve 364 is performed by the aeration control device 330 in accordance with the end timing of the aeration of the digestion process gas Sg. Then, the post-aeration solid-liquid separation device 360 discharges the solid component obtained through the solid-liquid separation of the desorbed liquid We from the solid component discharge pipe 370 through the opening control of the valve 372. In addition, the post-aeration solid-liquid separation device 360 uses a liquid component (hereinafter, aeration-treated desorption solution Be) obtained through solid-liquid separation of the desorption solution We via a transfer pipe 366 and a digestion treatment device 400 (described later). Specifically, it is transferred to the digester (402). This transfer is performed at a predetermined timing by the pump 368 under the control of the aeration control device 330.

  The aeration treatment process in the aeration treatment apparatus 300 is executed simultaneously in batches in parallel with the completion of the hydrothermal treatment in the hydrothermal treatment apparatus 100 shown in FIG. 2, and the hydrothermal treatment apparatus 100 in the previous batch is executed. The desorption liquid We that has undergone hydrothermal treatment is treated. Since the desorbing liquid We subjected to the aeration of the digestion gas Sg is obtained from the organic matter-containing waste that has been subjected to hydrothermal treatment, the heavy metal contained in the organic matter-containing waste (sewage sludge), for example, iron Lead, gold, platinum, silver, copper, chromium, cadmium, mercury, zinc, arsenic, manganese, cobalt, nickel, molybdenum, tungsten, tin, etc. are dissolved. And the digestion process gas Sg to be aerated contains hydrogen sulfide because it is obtained by an anaerobic digestion process in the digestion processing apparatus 400 described later. Therefore, by aeration of the digestion gas Sg in the aeration treatment apparatus 300, the heavy metal dissolved in the desorption liquid We changes to metal sulfide by contact with hydrogen sulfide, and after solidification as a metal sulfide, a solid-liquid separation apparatus Solid-liquid separation is performed at 360 and discharged as a solid component. The discharged heavy metal can be reused using metal separation equipment.

  As shown in FIG. 4, the digestion block 1300 of this embodiment includes a digestion processing device 400 and a gas pressure feeding device 420. The digestion processing apparatus 400 includes a hollow sealed digestion tank 402, a stirring device 404, and a digestion control device 430. The digestion processing apparatus 400 maintains the inside of the digestion tank 402 anaerobically and makes the inside of the digestion tank a growth environment for various anaerobic bacteria such as anaerobic methane fermentation bacteria. The digestion processing apparatus 400 continuously maintains the anaerobic digestion treatment by these anaerobic bacteria in the digestion tank 402 by appropriately supplementing the digestion tank 402 with a carrier carrying such anaerobic bacteria. The digester tank 402 is connected to the post-aeration solid / liquid separation device 360 (see FIG. 3) in the second solid / liquid separation mechanism 1250 via a transfer pipe 366. In the digestion tank 402, the aeration-treated desorbed liquid Be that has been subjected to aeration of the digestion process gas Sg in the aeration treatment apparatus 300 and then solid-liquid separated in the post-aeration solid-liquid separation apparatus 360 is transferred to the transfer pipe 366. The digestion tank 402 stores this aerated desorbed liquid Be as a processing substrate for anaerobic digestion. In addition, treated sludge (seed sludge) is introduced into the digestion tank 402 through opening and closing of a lid 405 that can be liquid-tightly opened and closed, and this treated sludge is subjected to anaerobic digestion treatment (waste for digestion). ). In the present embodiment, the treated sludge (seed sludge) that is a digestion treatment target in the intermediate temperature digestion tank in the sewage purification treatment facility of the local government is the target of the anaerobic digestion treatment in the digestion tank 402. The treated sludge (seed sludge) at this time may be a non-dehydrated sludge or a semi-solid dehydrated cake that has undergone gravity concentration and belt press. In the case of non-dehydrated sludge, the lid 405 may be provided at the top of the digestion tank 402. That is, the digestion processing apparatus 400 stores the aerated desorbed liquid Be as a processing substrate for the anaerobic digestion process and the treated sludge (seed sludge) to be subjected to the anaerobic digestion process in the digestion tank 402, and this digestion. An anaerobic digestion process is advanced in the tank 402. By doing so, the digestion processing apparatus 400 biodegrades the organic components contained in the treated sludge (seed sludge) and the aeration-treated desorption liquid Be, and as a result of the decomposition, the digestion-treated gas Sg is aerated and desorbed. The liquid Be is discharged from the liquid surface.

  The gas pressure feeding device 420 communicates with the liquid surface upper part of the digestion tank 402 via the gas discharge pipe 422, and sucks gas from the liquid surface upper part of the digestion tank 402 through the suction rotation of the gas suction fan 424. The gas above the liquid level in the digestion tank 402 is generated as a result of biodegradation of the organic components contained in the aerated desorbed liquid Be by an anaerobic digestion process. This digestion process gas Sg is a biogas generated by an anaerobic digestion process, and contains hydrogen sulfide in addition to a combustible gas such as methane. Then, the gas pressure feeding device 420 transfers all of the digestion processing gas Sg, which is a hydrogen sulfide-containing biogas, to the gas aeration mechanism 304 (see FIG. 3) of the aeration processing apparatus 300. In this case, the rotation control of the gas suction fan 424 is performed by the digestion control device 430 according to the progress of the anaerobic digestion process in the digestion tank 402. It should be noted that the transfer of the digestion process gas Sg to the gas aeration mechanism 304 by the gas pressure feeding device 420 may be a part of the transfer of the gas, and the untransferred digestion process gas Sg is aerated. You may make it send to the boiler apparatus 380 of the apparatus 300. FIG.

  The digestion control device 430 is configured as a computer having a CPU for executing logical operations, a ROM, and a RAM, and comprehensively controls the digestion processing device 400, the post-digestion solid-liquid separation device 410, and the gas pressure feeding device 420. That is, the digestion control device 430 controls the driving of the stirring device 404, the post-digestion solid-liquid separation device 410, and the like in addition to driving valves and fans in each pipeline while receiving inputs from various switches and sensors (not shown). . And if this digestion processing apparatus 400 continues an anaerobic digestion process over predetermined | prescribed duration, it will control valve opening 413 of the solid-liquid separation apparatus 410 after a digestion process, and the digested liquid after anaerobic digestion process will be carried out. Is discharged (transferred) to the third solid-liquid separation mechanism 1350 (see FIG. 1).

  The third solid-liquid separation mechanism 1350 to which the anaerobic digested digested liquid is transferred from the digestion processing apparatus 400 includes a post-digestion solid-liquid separation apparatus 410. This post-digestion solid-liquid separation device 410 communicates with the bottom of the digestion tank 402 via the introduction tube 412, receives the digested liquid that has been subjected to the anaerobic digestion treatment from the digestion tank 402 through the opening of the valve 413, and The liquid is subjected to solid-liquid separation using an agglomeration method or a filtration device. In this case, the opening control of the valve 413 is performed by the digestion control device 430 according to the progress of the anaerobic digestion process in the digestion tank 402. Further, the post-digestion solid-liquid separation device 410 receives the solid component obtained through the first solid-liquid separation mechanism 1150 from the organic substance-containing waste subjected to the hydrothermal treatment in the hydrothermal treatment device 100, and receives this solid component. Is reused as a dehydration aid during solid-liquid separation. Then, the post-digestion solid-liquid separation device 410 discharges the solid component obtained through the solid-liquid separation of the digested liquid that has been subjected to the anaerobic digestion process from the solid component discharge pipe 414 through the opening control of the valve 415. Further, the post-digestion solid-liquid separation device 410 discharges the liquid component (processed liquid component) obtained through the solid-liquid separation of the digested liquid that has been subjected to the anaerobic digestion process through the discharge pipe 416. The discharge of the solid component and the liquid component that has been processed is performed at a predetermined timing by the valve 413 and the valve 417 that are controlled by the digestion control device 430.

  Even in the anaerobic digestion process in the digestion apparatus 400, the batch is executed simultaneously in parallel with the completion of the hydrothermal process in the hydrothermal apparatus 100 shown in FIG. The desorption liquid We that has been subjected to the hydrothermal treatment of the hydrothermal treatment apparatus 100 is treated. The digestion liquid that is subjected to the anaerobic digestion process in the digestion processing apparatus 400 contains almost no heavy metal since the heavy metal has already been removed by the aeration process of the previous aeration process apparatus 300. Therefore, the solid component and the liquid component obtained by solid-liquid separation of the digested liquid after the anaerobic digestion treatment by the solid-liquid separation device 410 after the digestion treatment are both substantially free of heavy metals.

  Next, evaluation of the aeration-treated desorbed liquid Be used as a processing substrate for anaerobic digestion processing in the anaerobic digestion process in the digestion processing apparatus 400 will be described. 5 is an explanatory diagram showing an overview of the evaluation test of the aeration-treated detachment liquid Be as a treatment substrate of the anaerobic digestion treatment. An experimental apparatus E shown in FIG. 5 is an apparatus simulating the digestion processing apparatus 400 described above, and a plurality of hollow sealed vials Ev are prepared, and one treated vial (species) is contained in one vial Ev. Sludge: Digested sludge in a medium-temperature digestion tank in a municipal sewage purification facility and aeration-treated desorbed liquid Be (sample K1) are placed, and the above-mentioned treated sludge (seed sludge) is placed in another vial Ev. ) And sludge to be hydrothermally treated in the hydrothermal treatment apparatus 100 (hydrothermally treated sludge: sample K2). Then, each vial Ev containing the treated sludge (seed sludge) and the sample was kept at 38 ° C. in a thermostatic bath and subjected to a digestion test for 5 days and 10 days. In this case, the load was adjusted so that the VS amount of each sample was 0.4 times the VS (Volatile Solids) amount of the seed sludge and adjusted to 500 mL with water. And the gas collection bag was connected to the vial bottle Ev, and the gas collected in the gas collection bag on the 5th day and the 10th day was analyzed. Hydrothermal treatment sludge as a treatment substrate for treated sludge (seed sludge) even in the vial Ev containing the aerated desorbed liquid Be (sample K1) as a treatment substrate for treated sludge (seed sludge) Even in the vial Ev containing (Sample K2), generation of digestion treatment gas Sg, which is a biogas, accompanying the progress of anaerobic digestion treatment by anaerobic bacteria was observed. And it was confirmed that methane gas is contained in this digestion process gas Sg.

  Moreover, the VS decomposition | disassembly rate in the sludge of each said vial bottle Ev was measured on the 5th day and the 10th day. FIG. 6 is a graph showing the VS decomposition rate in sludge on the 5th and 10th days. From this graph, a high VS decomposition rate was obtained from the fifth day in the vial Ev in which the aerated desorbed liquid Be (sample K1) was added as a treatment substrate to the treated sludge (seed sludge). From this, it was found that the aeration-treated desorption liquid Be is a high-quality treatment substrate for the treatment sludge (seed sludge).

  In the processing method of the organic matter-containing waste according to the present embodiment described above, first, the sewage sludge as the organic matter-containing waste is sub-critical atmosphere in the treatment tank 110 (see FIG. 2) of the hydrothermal treatment apparatus 100 in the hydrothermal treatment block 1100. Hydrothermal treatment in Thereafter, the desorption liquid We obtained by solid-liquid separation from the organic matter-containing waste (sewage sludge) subjected to hydrothermal treatment by the first solid-liquid separation mechanism 1150 is subjected to an aeration process in the aeration block 1200, and then a digestion block 1300. As a processing substrate for anaerobic digestion processing in the digestion processing apparatus 400 of FIG. In addition, the organic matter-containing waste processing method according to the present embodiment stores the sewage sludge (digestion target waste), which is an organic matter-containing waste, together with the desorption liquid We in the digestion tank 402 and performs anaerobic digestion treatment. The desorption liquid We used as the treatment substrate is mixed with organic substances in a low molecular state by hydrothermal treatment, so that the anaerobic digestion of the organic substances by anaerobic bacteria proceeds promptly, and the organic substances are Anaerobic digestion of anaerobic bacteria in sewage sludge (digestible waste), which is a waste product, will also proceed. This is also inferred from the graph in FIG. Therefore, according to the organic substance containing waste processing method by the waste processing system 1000 of this embodiment, the period required for anaerobic digestion of the sewage sludge (digestion target waste) which is the organic substance containing waste can be shortened. Moreover, in the digestion processing apparatus 400, since the support | carrier which carried | supported the anaerobic bacteria is additionally injected into the digestion tank 402, the period required for the anaerobic digestion of the sewage sludge (digest object waste) which is an organic substance containing waste can be shortened further. . As a result, according to the organic substance-containing waste treatment method of the present embodiment, hydrothermal treatment using subcritical water vapor can be used in combination with anaerobic digestion treatment.

  In the organic matter-containing waste processing method of the present embodiment, the third solid-liquid separation mechanism 1350 performs solid-liquid separation on the digested liquid that has been subjected to the anaerobic digestion processing in the digestion processing apparatus 400 in the digestion block 1300. The solid component thus obtained contains nitrogen in an organic or inorganic state due to anaerobic digestion. Therefore, according to the organic matter-containing waste processing method of the present embodiment, the solid components separated by the third solid-liquid separation mechanism 1350 can be beneficially used as nitrogen-containing solid compost.

  In the processing method for organic matter-containing waste according to this embodiment, prior to the anaerobic digestion process in the digestion processing apparatus 400 in the digestion block 1300, the hydrothermally treated desorbed liquid We is sulfided in the aeration process apparatus 300 in the aeration block 1200. Treated with hydrogen gas. And the organic substance containing waste processing method of this embodiment solid-liquid-separates the heavy metal contained in the hydrothermally-treated desorbed liquid We from the hydrothermally-treated desorbed liquid We by hydrogen sulfide gas aeration, and the heavy metal is separated. The hydrothermally treated detachment liquid We is fed into the digestion tank 402 of the digestion apparatus 400. Therefore, according to the organic matter-containing waste processing method of the present embodiment, the heavy metal which is the solid component separated by the second solid-liquid separation mechanism 1250 after the aeration process in the aeration block 1200 is recovered and effectively used. Can be achieved. In addition to this, according to the organic matter-containing waste processing method of the present embodiment, the solid component separated by solid-liquid separation in the third solid-liquid separation mechanism 1350 is not mixed with heavy metal, so that the usefulness as solid compost is increased. It can be increased and adverse effects on the human body can be avoided. Moreover, since the liquid component solid-liquid separated by the third solid-liquid separation mechanism 1350 is not mixed with heavy metal, this liquid component can be used as liquid compost.

  The organic matter-containing waste treatment method of the present embodiment solid-liquid separates the organic matter-containing waste (sewage sludge) that has been hydrothermally treated by the hydrothermal treatment apparatus 100 in the hydrothermal treatment block 1100 using the first solid-liquid separation mechanism 1150. In the solid-liquid separation of the obtained solid component from the treated sludge that is the waste to be digested that has undergone the anaerobic digestion process in the digestion processing unit 400 in the digestion block 1300 and the aeration-treated desorbed liquid Be as the processing substrate. As a dehydration aid, the solid-liquid separation is performed by blending into the third solid-liquid separation mechanism 1350. If it carries out like this, the solid component obtained by the hydrothermal treatment can be used effectively.

  The present invention is not limited to the above-described embodiment, and can be realized with various configurations without departing from the spirit of the present invention. For example, the technical features of the embodiments corresponding to the technical features in each embodiment described in the summary section of the invention are intended to solve part or all of the above-described problems, or part of the above-described effects. Or, in order to achieve the whole, it is possible to replace or combine as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

  In the waste treatment system 1000 of the above-described embodiment, the hydrothermal treatment apparatus 100 that does not have a solid-liquid separation function is used. However, solid-liquid separation is performed by compression dehydration or centrifugal separation using a rotational centrifugal force as disclosed in Patent Document 1. It is good also as a hydrothermal processing apparatus which aims at.

  In the above-described waste treatment system 1000 of the present embodiment, the hydrothermal treatment apparatus 100 hydrothermally treats sewage sludge as organic matter-containing waste, but the livestock manure and food residue are hydrothermally treated by the hydrothermal treatment apparatus 100. The liquid component (hydrothermally treated desorption liquid We) may be used in the digestion block 1300 as a treatment substrate.

  In the above-described waste treatment system 1000 according to the present embodiment, the organic matter-containing waste contaminated with the radioactive material may be hydrothermally treated by the hydrothermal treatment apparatus 100. By doing so, the radioactive material that has contaminated the organic matter-containing waste is included in the hydrothermally treated liquid component during the hydrothermal treatment of the organic matter-containing waste in the subcritical atmosphere. Therefore, the solid component obtained by the solid-liquid separation after the hydrothermal treatment is decontaminated by reducing the radioactive substance, so that the solid component can be effectively used. In this case, the decontaminated solid component is used as a mixture to landfill soil, and the liquid component is subjected to anaerobic digestion to recover energy. On top of that, wastewater (digested liquid) after anaerobic digestion is stored by transporting it to an intermediate storage place for radioactive materials, or by adsorbing radioactive materials in wastewater to radioactive materials adsorbents such as zeolite. Only radioactive material adsorbents can be stored.

DESCRIPTION OF SYMBOLS 100 ... Hydrothermal treatment 110 ... Processing tank 111 ... Input port 112 ... Discharge port 113 ... Stirrer blade 114 ... Motor 120 ... Waste input system 121 ... Input path 122 ... First valve 123 ... Second valve 124 ... Inter-valve path 125 DESCRIPTION OF SYMBOLS ... Valve drive device 127 ... Pressure release valve 128 ... Waste input hopper 130 ... Processed material discharge system 131 ... Discharge path 132 ... Discharge valve 133 ... Valve drive device 140 ... Water vapor supply system 141 ... Water vapor supply source 142 ... Temperature rising pressure increase device Group 143 ... Steam supply line 144 ... Open / close valve 150 ... Oxygen supply system 154 ... Open / close valve 161 ... First pot temperature sensor 162 ... Second pot temperature sensor 163 ... Third pot temperature sensor 200 ... Control device 260 ... Hydrothermal solid-liquid separator 262 ... Valve 264 ... Solid component discharge pipe 266 ... Transfer pipe 26 DESCRIPTION OF SYMBOLS ... Pump 300 ... Aeration processing apparatus 302 ... Processing container 304 ... Gas aeration mechanism 305 ... Sensor 306 ... Hydrogen sulfide gas preliminary tank 307 ... Gas pipe line 308 ... Aeration pipe 310 ... Stirrer 330 ... Aeration control apparatus 360 ... Solid liquid after aeration Separation device 362 ... introduction pipe 364 ... valve 366 ... transfer pipe 368 ... pump 370 ... solid component discharge pipe 372 ... valve 380 ... boiler equipment 382 ... gas introduction pipe 384 ... gas suction fan 400 ... digestion treatment device 402 ... digestion tank 404 ... Stirrer 405 ... Lid 410 ... Solid-liquid separator after digestion 412 ... Inlet tube 413 ... Valve 414 ... Solid component discharge tube 415 ... Valve 416 ... Discharge tube 417 ... Valve 420 ... Gas pumping device 422 ... Gas release tube 424 ... Gas suction fan 430 ... Digestion control device 1000 ... Waste treatment system 1100 ... Hydrothermal treatment block 1150 ... First solid-liquid separation mechanism 1200 ... Aeration block 1250 ... Second solid-liquid separation mechanism 1300 ... Digestion block 1350 ... Third solid-liquid separation mechanism E ... Experimental equipment Ev ... Vial bottle Sg ... Digestion treatment gas

Claims (4)

A method for treating organic matter-containing waste,
A hydrothermal treatment step of hydrothermally treating the organic matter-containing waste in a treatment tank having a subcritical atmosphere with subcritical water vapor;
Hydrothermal treatment obtained by solid-liquid separation of the organic matter-containing waste subjected to the hydrothermal treatment in a digestion tank for storing the treatment substrate of the anaerobic digestion treatment and the waste subject to the anaerobic digestion treatment A digestion treatment step of storing a spent liquid component as the treatment substrate together with the waste to be digested, and subjecting to the anaerobic digestion treatment in the digestion tank;
A final solid-liquid separation step for solid-liquid separation of the waste to be digested that has undergone the anaerobic digestion treatment and the hydrothermally treated liquid component as the treatment substrate;
In the previous step of the digestion treatment step, the heavy metal contained in the hydrothermally treated liquid component is solid-liquid separated from the hydrothermally treated liquid component, and the hydrothermally treated liquid component from which the heavy metal has been separated is separated from the digestion treatment step. The processing method of the organic matter containing waste sent to the said digester.   The method for treating organic matter-containing waste according to claim 1, wherein the organic matter-containing waste is sewage sludge. It is a processing method of the organic matter containing waste according to claim 1 or 2,
In the final solid-liquid separation step,
Solid components obtained by solid-liquid separation of the organic matter-containing waste subjected to the hydrothermal treatment, the digestible waste subjected to the anaerobic digestion treatment, and the hydrothermally treated liquid component as the treatment substrate, A method for treating organic matter-containing waste, in which solid-liquid separation is performed by mixing as a dehydrating aid during solid-liquid separation. A method for treating organic matter-containing waste,
A hydrothermal treatment step of hydrothermally treating the organic matter-containing waste in a treatment tank having a subcritical atmosphere with subcritical water vapor;
Hydrothermal treatment obtained by solid-liquid separation of the organic matter-containing waste subjected to the hydrothermal treatment in a digestion tank for storing the treatment substrate of the anaerobic digestion treatment and the waste subject to the anaerobic digestion treatment A digestion treatment step of storing a spent liquid component as the treatment substrate together with the waste to be digested, and subjecting to the anaerobic digestion treatment in the digestion tank;
A final solid-liquid separation step for solid-liquid separation of the waste to be digested that has undergone the anaerobic digestion treatment and the hydrothermally treated liquid component as the treatment substrate;
In the final solid-liquid separation step,
Solid components obtained by solid-liquid separation of the organic matter-containing waste subjected to the hydrothermal treatment, the digestible waste subjected to the anaerobic digestion treatment, and the hydrothermally treated liquid component as the treatment substrate, A method for treating organic matter-containing waste, in which solid-liquid separation is performed by mixing as a dehydrating aid during solid-liquid separation.

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