JP2005238141A - Apparatus for clarifying contaminated soil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify equipment configuration, to reduce treatment cost and to increase clarification precission in an apparatus for clarifying contaminated soil. <P>SOLUTION: A feed pump 17 and a feed pipeline 18 for feeding a solvent are provided and further a discharge pump 20 and a discharge pipeline 21 for discharging an extraction solvent are provided at a cleaning tank 11 in which the contaminated soil is charged and then which can be closed. A solvent purifying apparatus 27 having active carbon tanks 31, 32 for adsorbing and removing harmful organic substances from the extraction solvent discharged from the cleaning tank 11 through the discharge pipeline 21, is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a contaminated soil purification apparatus for purifying soil contaminated with harmful organic substances such as oil, PCB, and dioxin.

  In recent years, there has been an increase in soil and groundwater contaminated with chemical substances that cannot be naturally decomposed due to soil contamination of domestic wastewater, wastewater from factories, offices, etc., and soil contamination of factory sites. As a result, it has a serious impact on the soil environment as an ecosystem and social infrastructure. Therefore, as a technique for purifying PCB, dioxin, heavy metals such as mercury and lead, and cyanides from such contaminated soil and groundwater, there is a technique described in Patent Document 1 below, for example.

  In the technology described in Patent Document 1 below, contaminated soil containing harmful substances is mixed and stirred with a solvent in a washing tank to separate the harmful substances attached to the contaminated soil and extract containing the harmful substances. While the solvent is separated from the harmful substances by the evaporator in the solvent refining equipment, the purified soil is dried and returned to the environment as purified soil.

JP 2000-334249 A

  In the technique described in the above-mentioned Patent Document 1, the extraction solvent containing the harmful substance by purifying the contaminated soil separates the solvent and the harmful substance by the evaporator of the solvent refining equipment. However, this evaporator heats the extraction solvent supplied in the container with a heat source such as a boiler and takes out the solvent as a gas while concentrating and processing harmful substances. Therefore, there is a problem that a large space for installing a container, a boiler, and the like is required, and equipment costs and fuel costs increase. In addition, when the extraction solvent is heated and evaporated with an evaporator, a part of harmful substances such as PCB may be mixed in the generated solvent vapor, and there is a problem that solvent purification cannot be performed with high accuracy.

  This invention solves such a problem, and it aims at providing the purification apparatus of the contaminated soil which aimed at the simplification of an installation, reduction of processing cost, and the improvement of purification processing precision.

  In order to solve the above-mentioned problems, a contaminated soil purification apparatus according to a first aspect of the present invention includes a cleaning tank that can be sealed by introducing contaminated soil, and a solvent supply / discharge system that supplies and discharges the solvent to and from the cleaning tank. And solvent refining means for adsorbing and removing harmful substances from the extraction solvent discharged from the washing tank by the solvent supply / discharge means.

  According to a second aspect of the present invention, there is provided an apparatus for purifying contaminated soil, wherein the solvent purification means is an adsorbent tank filled with an adsorbent having a predetermined particle diameter.

  A contaminated soil purification apparatus according to a third invention is characterized in that, in the second invention, there is provided an adsorbent regeneration means for regenerating the adsorbent that has been used and deteriorated by the solvent purification means.

  According to a fourth aspect of the present invention, there is provided the apparatus for purifying contaminated soil, wherein the adsorbent regeneration means regenerates the adsorbent by being filled with the adsorbent and supplied with the regenerant. And a regenerant purification means for purifying the regenerant used in the adsorbent regeneration means.

  According to a fifth aspect of the present invention, there is provided a contaminated soil purification apparatus according to the first aspect, wherein the fine particle removing means removes the fine particles from the extraction solvent discharged from the washing tank by the solvent supply / discharge means upstream of the solvent purification means. Is provided.

  According to a sixth aspect of the present invention, there is provided a purification apparatus for contaminated soil according to the first aspect, wherein the solvent refining means is formed by connecting a plurality of solvent refining tanks in parallel via a switching valve to a solvent discharge path. The solvent refining tank can be switched by operating the switching valve in accordance with the degree of purification of the solvent in the refining tank.

  According to a seventh aspect of the present invention, there is provided a purification apparatus for contaminated soil according to the first aspect, wherein water is extracted from the extraction solvent discharged from the washing tank by the solvent supply / discharge means or the purified solvent from which harmful substances have been removed by the solvent purification means. And a dehydrating means for separating the water.

  According to an eighth aspect of the present invention, there is provided a purification apparatus for contaminated soil according to the first aspect, wherein the solvent refining means separates harmful substances by subjecting the extraction solvent discharged from the washing tank to distillation by the solvent supply / discharge means. It comprises distillation means and adsorption means provided on the downstream side of the distillation means for adsorbing and removing harmful substances from the extraction solvent.

  According to a ninth aspect of the present invention, there is provided a purification apparatus for contaminated soil according to the first aspect, wherein the solvent supply / discharge means has a circulation means for returning the extracted solvent discharged from the cleaning tank back to the cleaning tank. The means is provided in a solvent circulation path of the circulation means.

  According to a tenth aspect of the present invention, there is provided a purification apparatus for contaminated soil according to the ninth aspect, wherein the solvent refining means separates harmful substances by subjecting the extraction solvent discharged from the washing layer to distillation, and the washing An adsorption means for adsorbing and removing harmful substances from the extraction solvent discharged from the bed is provided in parallel with the solvent circulation path, and the distillation means and the adsorption means are switched according to the degree of contamination of the extraction solvent. It is possible to do this.

  According to the contaminated soil purification apparatus according to the first invention, the solvent supply / discharge means for supplying and discharging the solvent is provided to the cleaning tank that can be sealed by introducing the contaminated soil. Since the solvent purification means that adsorbs and removes harmful substances from the extraction solvent discharged from the cleaning layer is provided, the apparatus can be made compact because the organic substances in the extraction solvent are adsorbed and removed to purify the solvent. The facility cost and fuel cost can be reduced, and the refining accuracy of solvent refining can be improved.

  According to the contaminated soil purification apparatus of the second invention, since the solvent purification means is an adsorbent tank filled with an adsorbent having a predetermined particle size, the apparatus does not require a large space such as a distillation facility. Can be made compact, and equipment costs and fuel costs can be reduced.

  According to the dyed soil purifying apparatus according to the third aspect of the invention, since the adsorbent regeneration means for regenerating the deteriorated adsorbent used by the solvent purification means is provided, the deteriorated adsorbent is regenerated and recycled. The material cost can be greatly reduced.

  According to the contaminated soil purification apparatus according to the fourth invention, the adsorbent regeneration means regenerates the adsorbent by being filled with the adsorbent and supplied with the regenerant. The adsorbent regeneration means Since the regenerant purification means for purifying the regenerant used in the above is provided, the cost required for the regeneration of the adsorbent can be suppressed.

  According to the contaminated soil purification apparatus of the fifth invention, since the particulate removing means for removing particulates from the extraction solvent discharged from the washing layer by the solvent supply / discharge means is provided upstream of the solvent purification means, After removing the soil fine particles, the harmful substances in the extraction solvent are adsorbed and removed, and the adsorption and removal efficiency of the harmful substances can be improved.

  According to the contaminated soil purification apparatus according to the sixth aspect of the invention, the solvent refining means comprises a plurality of solvent refining tanks connected in parallel to the solvent discharge path via the switching valve, and the solvent purification by the solvent refining tank. Since the solvent refining tank can be switched by operating the switching valve according to the degree, the extraction solvent can be continuously purified by sequentially switching and using a plurality of solvent refining tanks. Purification efficiency can be improved.

  According to the purification apparatus for contaminated soil according to the seventh invention, there is provided a dehydrating means for separating water from the extraction solvent discharged from the cleaning layer by the solvent supply / discharge means or the purified solvent from which harmful substances have been removed by the solvent purification means. Therefore, solvent purification can be performed with high accuracy by removing water from the solvent by the dehydrating means, and a decrease in the ability to extract harmful substances from the contaminated soil by the solvent can be prevented.

  According to the apparatus for purifying contaminated soil according to the eighth invention, as a solvent refining means, a distillation means for separating an toxic substance by subjecting an extraction solvent discharged from a washing layer to a distillation process by a solvent supply / discharge means; Since the adsorption means for adsorbing and removing harmful substances from the extraction solvent is provided on the downstream side, harmful organic substances remaining in the adsorption solvent are removed after removing harmful organic substances in the extraction solvent by distillation means. Since the solvent is purified by adsorption removal, toxic substances are roughly separated and finished, so that solvent purification can be performed with high accuracy, preventing premature deterioration of the adsorption means, and reducing the solvent purification cost. Can be reduced.

  According to the contaminated soil purification apparatus of the ninth invention, the solvent supply / discharge means is provided with a circulation means for returning the extracted solvent discharged from the washing tank to the washing tank again, and the solvent purification path is provided in the solvent circulation path of the circulation means. Since the means is provided, the apparatus can be made compact, and the equipment cost and fuel cost can be reduced.

  According to the contaminated soil purification apparatus of the tenth invention, the solvent refining means is a distillation means for separating the harmful substance by distilling the extraction solvent discharged from the washing layer, and the extraction solvent discharged from the washing layer. The adsorption means for adsorbing and removing harmful substances from the solvent is provided in parallel with the solvent circulation path, and the distillation means and the adsorption means can be switched according to the degree of contamination of the extraction solvent. Accordingly, by selectively using the distillation unit and the adsorption unit, extraction solvent purification can be performed with high accuracy and early deterioration of the adsorption unit can be prevented.

  Embodiments of a contaminated soil purification apparatus according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments.

  FIG. 1 shows a schematic configuration of a contaminated soil purification apparatus according to the first embodiment.

  In the contaminated soil purification apparatus of the first embodiment, as shown in FIG. 1, a cleaning tank 11 for carrying out purification treatment by introducing contaminated soil is portable, and a large number of cleaning tanks 11 are treated with contaminated soil. Transport it to a place for use. The washing tank 11 is composed of a tank main body and a lid that can be attached to and detached from the tank main body and seals the soil. Solvent supply ports are formed in the upper and lower parts of the tank main body, and a solvent drain is formed in the lower part. An exit is formed. Moreover, the filtration filter 12 is provided in the inside of the washing tank 11, and the soil thrown into the inside does not flow outside. And the contaminated soil can be input into this washing tank 11 by the contaminated soil input device 13.

  The tank unit 14 has a purified solvent tank 15 and a discharged solvent tank 16. The purified solvent tank 15 stores a solvent for extracting harmful organic substances (for example, oil, PCB, dioxin, etc.) contained in the contaminated soil, and has a supply pipe 18 having a purified solvent supply pump 17. It is connected to the washing tank 11 via On the other hand, the discharge solvent tank 16 stores a solvent containing an organic substance extracted from the contaminated soil in the cleaning tank 11, and is cleaned through a discharge pipe 21 having an operation valve 19 and an extraction solvent discharge pump 20. It is connected to the tank 11. A circulation pipe 24 having an operation valve 22 and a circulation pump 23 is connected between the supply pipe 18 and the discharge pipe 21. In this case, the solvent supply / discharge means of the present invention is constituted by the supply pipe 18 and the discharge pipe 21.

  Therefore, when the purified solvent pump 17 is driven with the operation valves 19 and 22 closed, the solvent in the purified solvent tank 15 can be supplied to the cleaning tank 11 via the supply pipe 18. When the extraction solvent discharge pump 20 is opened and the extraction solvent discharge pump 20 is driven, the extraction solvent in the cleaning tank 11 can be discharged to the discharge solvent tank 16 through the discharge pipe 21. On the other hand, when the circulation pump 23 is driven in a state where the operation valve 19 is closed and the operation valve 22 is opened, the solvent can be circulated to and discharged from the cleaning tank 11 through the circulation pipe 24.

  The discharge pipe 21 is equipped with a concentration sensor 25 for detecting the concentration of harmful organic substances contained in the extraction solvent. In this case, a plurality of highly accurate concentrations are detected according to the types of harmful organic substances. It is desirable to arrange the sensors.

  The purification unit 26 removes the organic substance from the extraction solvent discharged from the cleaning tank 11 and stored in the discharge solvent tank 16 and purifies the organic substance by sucking the gas in the cleaning tank 11. A drying device 28 is provided for removing the remaining solvent and drying the removed soil.

  This solvent refining device 27 includes a strainer (fine particle removing means) 29 for removing coarse particles or fine particles such as sand, an oil strainer 30 for removing fats and oils, and two activated carbon tanks provided in parallel to adsorb and remove harmful substances. (Solvent refining tanks) 31 and 32. The discharged solvent tank 16 and the strainer 29 are connected by a transfer pipe 34 having a transfer pump 33. Further, the strainer 29 and the oil strainer 30 are connected by a connecting pipe 35, and the oil strainer 30 and each activated carbon tank 31, 32 are connected by a connecting pipe 37 having a three-way valve (switching valve) 36. Further, the activated carbon tanks 31 and 32 and the purified solvent tank 15 are connected by a return pipe 38. Concentration sensors 39 and 40 for detecting the concentration of minute harmful substances contained in the purified solvent are mounted on the outlet side of the activated carbon tanks 31 and 32 in the return pipe 38. In addition, an organic material processing device (storage tank, processing device) 42 is connected to the strainer 29 and the oil strainer 30 through an organic material discharge pipe 41.

  Therefore, when the transfer pump 33 is driven and the extraction solvent in the discharged solvent tank 16 is sent to the solvent purification device 27 through the transfer pipe 34, first, solid matter such as soil fine particles contained in the extraction solvent is removed by the strainer 29. Next, the oil and fat is removed by the oil strainer 30. Then, the organic substances such as PCB and dioxin in the extraction solvent are adsorbed and removed by the activated carbon tanks 31 and 32, and the purified solvent can be returned to the purified solvent tank 15 through the return pipe 38.

  At this time, the extraction solvent is supplied only to, for example, the activated carbon tank 31 by the operation of the three-way valve 36, where harmful substances are adsorbed and removed, and the concentration sensor 39 detects the concentration of minute harmful substances contained in the purified solvent. doing. Since the degree of purification of the activated carbon tank 31 deteriorates due to a long-term solvent purification treatment, when the concentration of harmful substances contained in the purification solvent exceeds the reference concentration, the three-way valve 36 is operated to switch the supply destination, and the extraction solvent is activated carbon. It supplies to the tank 32 and is made to process. Note that the soil particles removed by the strainer 29 and the fats and oils removed by the oil strainer 30 are attached with harmful substances, and therefore are sent to the organic substance processing device 42 through the organic substance discharge pipe 41, where they are stored and stored for detoxification. Can be processed.

  Moreover, since the activated carbon (adsorbent) filled in the activated carbon tanks 31 and 32 is deteriorated by long-term use and the adsorption capacity is reduced, an adsorbent regeneration device 43 that regenerates the deteriorated activated carbon, A regenerant purification device 44 that purifies the regenerant used in the adsorbent regenerator 43 is provided. The adsorbent regenerator 43 fills a cleaning container with a regenerant such as hexane or toluene, puts activated carbon that has deteriorated by adsorbing harmful substances therein, and immerses the adsorbed harmful substances in the activated carbon. It is possible to recycle it by desorbing it. In addition, the regenerant purification device 44 uses the adsorbent regenerator 43 to distill the regenerant containing harmful substances desorbed from the activated carbon, thereby separating the regenerator and moisture from the regenerant and recycling the regenerant. The separated harmful substance and moisture are sent to the organic substance processing apparatus 42 (details will be described later).

  Therefore, when the activated carbon used in the activated carbon tank 31 adsorbs and deteriorates a predetermined amount of harmful substances, the activated carbon tank 31 to be used is switched to another activated carbon tank 32, and the deteriorated activated carbon in the activated carbon tank 31 is replaced with the adsorbent regeneration device. Send to 43. In this adsorbent regenerator 43, the deteriorated activated carbon is immersed in a cleaning container filled with the regenerant for a predetermined period to desorb the adsorbed harmful substances, and the regenerated activated carbon is returned to the activated carbon tank 31 again. Use for recycling. The harmful substances desorbed from the activated carbon are sent to the regenerant purification device 44, where the regenerant containing the harmful substances is distilled to separate the harmful substances and moisture from the regenerant and regenerate the regenerated agent. Is returned to the regenerant adsorbent regenerator 43 for recycling, and harmful organic substances and the like separated from the regenerant by the regenerant purifier 44 are sent to the organic substance treatment device 42 where they are stored and stored harmlessly. (Details will be described later).

  The drying device 28 includes a knockout pot 45 that takes in the gas containing the solvent (mist) discharged from the cleaning tank 11 and separates the mist contained therein, a heat exchanger 46 that cools the gas, and activated carbon that adsorbs the solvent vapor. It consists of a tower 47 and a blower 48. The cleaning tank 11 is connected to the knockout pot 45 through a gas discharge pipe 49, and the activated carbon tower 47 (blower 48) is connected to the cleaning tank 11 through a gas supply pipe 50. The knockout pot 45 and the heat exchanger 46 are connected to the discharged solvent tank 16 via a return pipe 52 having a solvent return pump 51.

  Therefore, when the blower 48 is operated to suck the gas in the cleaning tank 11, the solvent mist contained in the knockout pot 45 is separated, and the gas is cooled by the heat exchanger 46 so that the solvent vapor becomes liquid. The solvent purified by the activated carbon tower 47 and supplied to the washing tank 11 and remaining in the washing tank 11 can be evaporated and removed from the soil.

  Further, as the utility unit 53, a boiler unit 54, a cooling unit 55, a compressor unit 56, and the like are provided. The boiler unit 54 is for heating the gas supplied to the cleaning tank 11 as necessary. The cooling unit 55 cools the gas discharged from the cleaning tank 11 by the heat exchanger 46 and condenses the solvent vapor. The compressor unit 56 is for operating various pumps.

  In addition, the solvent for extracting harmful organic substances such as oil, PCB, dioxin, etc. contained in the contaminated soil shall be investigated in advance to determine the content and concentration of the harmful substances contained in the contaminated soil. It is necessary to set the type accordingly. In this case, hydrophilic solvents such as alcohols and acetone are suitable as the solvent.

  A contaminated soil purification method using the contaminated soil purification apparatus according to the present embodiment will be described. In this case, the state of contamination at the site where the soil is treated will be investigated in advance, necessary equipment and treatment agents will be prepared, various devices will be transported and assembled, and purification facilities will be installed. Then, the number of cleaning tanks 11 is set according to the size of the treatment site, the amount of contaminated soil to be purified, etc., and the contaminated soil is purified in parallel, or in series according to the degree of purification. Install and perform various tasks.

  When various facilities for purifying the contaminated soil are installed at the treatment site, the contaminated soil input device 13 is activated, the contaminated soil is conveyed by a belt conveyor (not shown), and the contaminated soil is washed from the tip of the belt conveyor. It is put into the tank 11. When the contaminated soil is introduced into the washing tank 11 by the contaminated soil feeding device 13, the pile height of the contaminated soil which is introduced into the washing tank 11 by various sensors and changes as needed, and the contaminated soil which is introduced into the washing tank 11 Measure the weight of the container to obtain the optimum stacking height.

  Thus, when the contaminated soil of the optimal stacking height is put into the washing tank 11, the cover is fixed to the tank main body, the contaminated soil is sealed, and the harmful substance purification treatment work is started. First, with the operation valves 19 and 22 of the cleaning tank 11 closed, the solvent of the purified solvent tank 15 is supplied by the purified solvent pump 17 through the supply pipe 18 until the contaminated soil is immersed in the cleaning tank 11.

  When a predetermined amount of solvent is introduced into the washing tank 11 in this way, the purified solvent pump 17 is stopped, while the operation valve 22 is opened to operate the circulation pump 23 and the solvent is washed through the circulation pipe 24. By circulating in the tank 11 for a predetermined time, extraction of organic substances contained in the contaminated soil, that is, oil, PCB, and dioxin can be promoted.

  When oil, PCB, or dioxin contained in the contaminated soil is extracted by circulating and discharging the solvent to the washing tank 11 for a predetermined time, the operation valve 22 is closed and the circulation pump 23 is stopped, while the operation valve 19 is opened. The extraction solvent discharge pump 20 is operated, and the extraction solvent in each cleaning tank 11 is discharged to the discharge solvent tank 16 through the discharge pipe 21. Then, in the same manner as described above, a new solvent in the purified solvent tank 15 is supplied to the cleaning tank 11, and the organic substance is extracted by circulating and discharging for a predetermined time. The concentration sensor 25 measures the concentrations of oil, PCB, and dioxin in the discharged solvent while performing this cleaning operation for several cycles set in advance. And when the measured value of this concentration sensor 25 becomes less than a predetermined value set in advance, it is assumed that the residual amount of the organic substance contained in the soil of the washing tank 11 becomes less than the reference value determined by the official method, Finish the cleaning operation.

  When harmful organic substances are removed from the soil in the washing tank 11, next, all the solvent in the washing tank 11 is discharged to the discharge solvent tank 16, and then the blower 48 is operated to gas in the washing tank 11. , The solvent remaining in the soil in the washing tank 11 is evaporated and discharged together with the gas to dry the soil. Then, the exhausted gas is allowed to collide with the partition wall in the knockout pot 45 to separate the mist of the solvent, and by cooling with the heat exchanger 46, the solvent vapor is condensed, and further the gaseous state contained in the gas The solvent is adsorbed by the activated carbon tower 47. Then, the residual solvent removed by the knockout pot 45 and the heat exchanger 46 is returned to the discharged solvent tank 16 through the return pipe 52 by the solvent return pump 51.

  In parallel with the operation of removing harmful organic substances from the contaminated soil in the washing tank 11 in this way, the solvent purification apparatus 27 refines the solvent from which organic substances such as oil, PCB, and dioxin have been extracted. I do. That is, the extracted solvent in the discharged solvent tank 16 is sent to the solvent purifier 27 by the transfer pump 33 through the transfer pipe 34, the soil particles are removed from the extracted solvent by the strainer 29, and then the oil and fat are removed by the oil strainer 30. Then, the activated carbon tanks 31 and 32 adsorb and remove organic substances such as PCB and dioxin in the extraction solvent.

  At this time, the extraction solvent is supplied to the activated carbon tank 31 by the operation of the three-way valve 36, and harmful substances are adsorbed and removed. The activated carbon tank 31 is deteriorated, and the minute harmful substance contained in the purified solvent detected by the concentration sensor 39 is used. When the concentration of the substance exceeds the reference value, the extraction solvent is supplied to the activated carbon tank 32 by the three-way valve 36 and processed. Then, while the activated carbon tank 32 is treating the extraction solvent, the activated carbon deteriorated in the activated carbon tank 31 is sent to the adsorbent regenerator 43 to regenerate by desorbing harmful substances from the deteriorated activated carbon. Is returned to the activated carbon tank 31 for recycling. In addition, the regenerant purification device 44 can distill the regenerant containing harmful substances desorbed from the activated carbon by the adsorbent regenerator 43, separate the harmful substances and moisture from the regenerant, and recycle the regenerant. (Details will be described later).

  The soil particles and fats and oils removed from the extraction solvent by the strainers 29 and 30 contain harmful organic substances, which are sent to the organic substance treatment device 42 through the organic substance discharge pipe 41, where they are detoxified. . Further, harmful substances and moisture removed from the regenerant by the regenerant purification apparatus 44 are also sent to the organic substance treatment apparatus 42 where they are detoxified. In this case, the oil is incinerated and the PCB is hydrothermally decomposed.

  When harmful organic substances are separated and removed from the contaminated soil in the washing tank 11 by the purification treatment of the contaminated soil described above, the washing tank 11 is opened, the internal purified soil is discharged, and it can be returned to the natural world for reuse. It becomes.

  As described above, in the present embodiment, the supply pump 17 and the supply pipe 18 for supplying the solvent are provided to the cleaning tank 11 that can be sealed with the contaminated soil, and the discharge pump 20 and the discharge for discharging the extraction solvent are provided. A pipe 21 is provided, and a solvent purifier 27 having activated carbon tanks 31 and 32 for adsorbing and removing harmful organic substances contained in the extraction solvent discharged from the washing tank 11 through the discharge pipe 21 is provided.

  Therefore, the activated carbon tanks 31 and 32 adsorb and remove harmful organic substances in the extraction solvent to purify the solvent. Therefore, the apparatus can be made compact, and a large space such as a distillation facility is not required. Costs and fuel costs can be reduced. In addition, in the activated carbon tanks 31 and 32, harmful substances in the extraction solvent are surely adsorbed and removed, so that the purified solvent is hardly mixed with harmful substances such as PCB, and the solvent purification can be performed with high accuracy. it can.

  In addition, the activated carbon tanks 31 and 32 are arranged in parallel in the solvent refining device 27, the deterioration state of the used activated carbon tank is determined according to the concentration of minute harmful substances contained in the purified solvent, and the activated carbon used. The tank is switched. Accordingly, the extraction solvent can be continuously purified, and the solvent purification efficiency can be improved.

  When the activated carbon filled in the activated carbon tanks 31 and 32 is deteriorated, the adsorbent regeneration device 43 that regenerates the deteriorated activated carbon and the regeneration that purifies the regenerant used in the adsorbent regeneration device 43. An agent purification device 44 is provided. Therefore, activated carbon and a regenerative agent can be recycled and material costs can be greatly reduced.

  Here, the adsorbent regeneration device 43 and the regenerant purification device 44 will be described in more detail with reference to FIG.

  As shown in FIG. 2, a boiler 74 is connected to an adsorbent regeneration device 43 to which deteriorated activated carbon (adsorbent) is transferred and filled, and regeneration is performed via a supply pipe 123 having a regenerant supply pump 122. The agent tank 105 is connected. The adsorbent regenerator 43 is connected to the regenerant purifier 44 via a regenerant discharge pipe 124 and is connected to the desorption solvent tank 102 via a desorption solvent pipe 129 having a desorption solvent condenser 101. The desorption solvent tank 102 is connected to the regenerant purification device 44 via a pipe 130 having a desorption solvent pump 121.

  The regenerant purification device 44 is connected to a three-way valve 115 via an evaporating solvent pipe 125 having an evaporating solvent condenser 103. The three-way valve 115 is connected to the regenerant tank 105 through a pipe 126 and is connected to the exhaust solvent tank 16. In addition, the regenerant purification device 44 is connected to the organic matter processing device 42 through a residual liquid pipe 128.

  A temperature sensor 104 for detecting the temperature of the evaporated solvent is attached to the evaporated solvent pipe 125, and the three-way valve 115 is automatically switched based on information from the temperature sensor 104. Yes.

  In such an adsorbent regenerator 43, the activated valves 111, 112, and 114 are closed after the activated carbon tanks 31 and 32 are filled with activated carbon (adsorbent) that has been used to purify the extraction solvent and adsorbs harmful substances. When the regenerant supply pump 122 is driven with the operation valve 113 opened, the regenerant in the regenerant tank 105 is supplied through the supply pipe 123. When the activated carbon (adsorbent) in the adsorbent regenerator 43 is completely immersed in the regenerant, the regenerant supply pump 122 is stopped and the operation valve 113 is closed so that the activated carbon (adsorbent) is regenerated with the regenerant. When immersed for a predetermined period, harmful substances adsorbed on the activated carbon (adsorbent) are desorbed from the activated carbon (adsorbent).

  After the activated carbon (adsorbent) is immersed in the regenerative agent for a predetermined period in this way, the operation valve 114 is opened, and the regenerative agent (in addition to harmful substances, which is filled in the adsorbent regeneration device 43 is used for soil washing. The solvent is contained in a small amount) but is sent to the regenerant purifier 44.

  By repeating the filling, dipping and holding operations of the regenerant into the adsorbent regenerator 43, harmful substances adsorbed on the activated carbon (adsorbent) are completely desorbed from the activated carbon (adsorbent). can do.

  Next, a desorption operation for completely removing the regenerant remaining in the activated carbon (adsorbent) is performed. After opening the operation valve 112 with the operation valves 113 and 114 closed, the operation valve 111 is opened and steam is supplied from the boiler 74. By allowing the steam to flow through the activated carbon (adsorbent) for a predetermined period, the activated carbon (adsorbent) is heated and the regenerant is desorbed and discharged from the desorption solvent pipe 129 together with the steam.

  The discharged mixed gas of steam and regenerant (including a small amount of soil cleaning solvent and harmful substances) is condensed and liquefied by the desorption solvent condenser 101 and sent to the desorption solvent tank 102. By this operation, the regenerant remaining in the activated carbon (adsorbent) is completely desorbed and removed from the activated carbon (adsorbent), and the regeneration of the activated carbon (adsorbent) is completed. Then, by driving the desorption solvent pump 121, the desorbed regenerant is fed to the regenerant purification device 44 via the pipe 130.

  As described above, the harmful substance discharged from the adsorbent regenerator 43, the regenerator, the solvent used for soil cleaning, the condensed water of the desorbed steam, etc., during the regeneration operation of the activated carbon (adsorbent) Collected in 44. When steam is supplied from the boiler 74 to heat the regenerant purification device 44, components having low boiling points are sequentially evaporated and sent to the evaporating solvent condenser 103 via the evaporating solvent piping 125.

  Since the boiling point of the soil cleaning solvent and the regenerant is different, the temperature sensor 104 detects the temperature of the evaporating solvent and switches the three-way valve 115 to collect the regenerant in the regeneration tank 105 via the pipe 126 and The cleaning solvent can be recovered to the discharge solvent tank 16 via 127.

  Note that the condensed water of the steam injected into the adsorbent regenerator 43 also flows into the regenerant purifier 44 via the desorption solvent tank 102. When water forms an azeotrope due to the physical properties of the cleaning solvent and the regenerant, the water flows into the tanks 105 and 16 through the pipes 126 and 127 in the form of a mixture. In such a case, water and the cleaning solvent or the regenerant can be separated by appropriately applying a method utilizing various physical properties such as stationary specific gravity separation or distillation.

  After the evaporation operation in the regenerant purification device 44, the harmful substance having a high boiling point remains as an evaporation residue (partly including water etc.). It can be fed to the organic substance processing device 42.

  Here, the test example performed in order to confirm the reproduction | regeneration effect of activated carbon (adsorbent) by an adsorbent reproduction | regeneration apparatus is demonstrated.

  First, an extraction solvent containing water and harmful substances (composition: acetone 85 wt%, water 15 wt%, PCB (KC-300) 60 mg / liter) is passed through an activated carbon tank filled with activated carbon (adsorbent), The time-dependent change of the PCB concentration in the extraction solvent after passing was measured. The result is shown in FIG.

  As can be seen from FIG. 3, in the initial stage of liquid flow, activated carbon (adsorbent) has a sufficient adsorption capacity, and therefore PCB hardly remains in the extracted solvent after purification. However, as the passing time elapses, the amount of PCB adsorbed on the activated carbon (adsorbent) gradually increases, and the adsorptive capacity of the activated carbon (adsorbent) gradually decreases. In this test example, PCB began to be detected in the purified extraction solvent after a purification process of more than 10 hours.

  And refinement | purification processing is complete | finished when the PCB density | concentration in the refined extraction solvent becomes a predetermined value. The end time of this purification process is detected by a concentration sensor attached to the outlet of the activated carbon tank (because the time during which the purification process can be performed varies depending on the PCB concentration in the extraction solvent, the amount of activated carbon (adsorbent), etc.). .

  Next, all the extraction solvent in the activated carbon tank was discharged, and the activated carbon (adsorbent) was regenerated as follows.

  The activated carbon (adsorbent) purified from the extraction solvent is filled in the adsorbent regenerator 44, toluene (regenerant) is injected into the adsorbent regenerator 44, and the activated carbon (adsorbent) is added. After immersing in toluene (regenerant) for a predetermined time, toluene (regenerant) is discharged, and the concentration of PCB remaining in the activated carbon (adsorbent) is measured. By repeating this operation, changes in the PCB concentration in the activated carbon (adsorbent) were examined. The result is shown in FIG.

  As can be seen from FIG. 4, the PCB concentration in the activated carbon (adsorbent) decreases each time immersion cleaning is repeated, and the PCB concentration in the activated carbon (adsorbent) is predetermined by repeating several times (in this example, 4 times). It was confirmed that the activated carbon (adsorbent) can be regenerated.

  Here, the number of immersion cleaning required for regeneration of the activated carbon (adsorbent) is the PCB concentration in the activated carbon (adsorbent) before regeneration, the physical properties of the regenerant, and the PCB that is adsorbed together with the PCB on the activated carbon (adsorbent). Since it varies depending on the components and concentrations of harmful substances, fats and oils other than the above, when performing the adsorbent regeneration process at an actual site, it is preferable to obtain the optimal regeneration operation conditions in advance.

  In addition, in the said example, it was the case of the batch system which repeatedly immerses and wash | cleans with a regenerant, However, The same result is obtained also when supplying a regenerant continuously to an activated carbon tank and carrying out liquid washing. Furthermore, although toluene was used as a regenerant, similar results can be obtained even with a solvent having high PCB solubility, such as hexane, methylene chloride, and the like.

  In the present embodiment, the deteriorated activated carbon is regenerated with a regenerant such as hexane or toluene, but the present invention is not limited to this. For example, a steam regeneration method that desorbs harmful substances attached by circulating steam through activated carbon without using a regenerative agent, and harmful substances attached by heating activated carbon in a vacuum state without using a regenerant. It is also possible to apply a heat regeneration method for desorption. In this case, desorbed harmful substances can be liquefied by distillation or cooling and recovered in a high concentration state, thereby contributing to a reduction in waste.

  Specifically, in the case of a steam regeneration method for desorbing the harmful substances attached by circulating steam from the boiler to the activated carbon, the desorption solvent condenser 101 and the desorption solvent tank 102 are used. Harmful substances can be separated by collecting the condensed water and re-evaporating the condensed water using the regenerant purification device 44. The separated harmful substances are sent to the hazardous substance processing apparatus 42 for processing. In the case of a method of regenerating by heating activated carbon with a high-temperature gas in a vacuum state, the desorption solvent condenser 101 has a gas cooling structure (addition of a solid collecting function), so that activated carbon (adsorption of harmful substances) is obtained. Can be desorbed and collected from the agent.

  In the present embodiment, the adsorbent regeneration device 43 and the regenerant purification device 44 are provided separately from the solvent purification device 27, but may be incorporated inside. For example, the regenerant is circulated and supplied to the used one of the activated carbon tanks 31 and 32 of the solvent purifier 27 to regenerate the activated carbon. At the same time, the used regenerant is circulated to the regenerant purifier. It is also possible to purify by flowing.

  That is, the activated carbon (adsorbent) deteriorated in the activated carbon tanks 31 and 32 is sent to the adsorbent regenerator 43, the harmful substances are desorbed from the deteriorated activated carbon and regenerated, and the regenerated activated carbon is returned to the activated carbon tanks 31 and 32. It is also possible to recycle the activated carbon, or to incorporate an adsorbent regenerator inside the activated carbon tank and supply the regenerant to the activated carbon tank where the activated carbon has deteriorated to regenerate the activated carbon.

  The incorporation of the adsorbent regenerator inside the activated carbon tank as described above can be implemented not only in this embodiment but also in each of the following embodiments.

  FIG. 5 shows a schematic configuration of the contaminated soil purification apparatus according to the second embodiment, FIG. 6 shows a schematic configuration of the contaminated soil purification apparatus according to the third embodiment, and FIG. 7 shows a contaminated soil purification apparatus according to the fourth embodiment. FIG. 8 shows a schematic configuration of a contaminated soil purification apparatus according to the fifth embodiment. In addition, the same code | symbol is attached | subjected to the member which has the same function as what was demonstrated in embodiment mentioned above, and the overlapping description is abbreviate | omitted.

  In the contaminated soil purification apparatus of the second embodiment, as shown in FIG. 5, the solvent purification apparatus 61 includes a strainer 29 that removes soil particles from the extraction solvent, an oil strainer 30 that removes fats and oils, and harmful organic substances. Is composed of an activated carbon tank (solvent refining tank) 62 for adsorbing and removing water and a dehydrating device 63 for removing water. The discharged solvent tank 16 and the strainer 29 are connected by a transfer pipe 34 having a transfer pump 33, and the strainer 29, the oil strainer 30, the activated carbon tank 62, and the dehydrator 63 are connected by connection pipes 35, 64, and 65, respectively. The dehydrator 63 and the purified solvent tank 15 are connected by a return pipe 38.

  The activated carbon tank 62 has the same configuration as the activated carbon tanks 31 and 32 of the first embodiment, and adsorbs and removes harmful organic substances contained therein by circulating an extraction solvent through the activated carbon filled therein. . In addition, when the solvent extracts harmful substances contained in the contaminated soil, the moisture in the soil is also extracted, so the dehydrator 63 removes the moisture contained in the solvent purified in the activated carbon tank 62. Therefore, a dehydrating agent supply device 66 that circulates and supplies the dehydrating agent to the dehydrating tank is provided. In this case, as the dehydrating agent, anhydrous sodium sulfate or an ion exchange agent is preferable.

  Accordingly, when the transfer pump 33 is driven and the extraction solvent in the discharged solvent tank 16 is sent to the solvent purification device 61 through the transfer pipe 34, first, the soil particles are removed from the extraction solvent by the strainer 29, and then the oil strainer 30. The oil and fat is removed by this. Then, organic substances such as PCB and dioxin in the extraction solvent are adsorbed and removed by the activated carbon tank 62, and subsequently, water in the purified solvent is removed by the dehydrator 66, and the purified solvent is purified through the return pipe 38. It is returned to the solvent tank 15.

  In this case, as in the first embodiment, a plurality of activated carbon tanks may be connected to the oil strainer 30 via a three-way valve, and the activated carbon tanks may be sequentially replaced according to the degree of deterioration of the activated carbon. Then, an adsorbent regeneration device that regenerates the deteriorated activated carbon tank 62 or a regeneration agent purification device that purifies the regeneration agent may be provided.

  The dehydrating device 63 is not limited to the one that supplies the dehydrating agent to the solvent and removes the water. For example, the solvent may be dehydrated by using a distillation apparatus, and if it is a distillation facility for dehydration treatment, it can be made compact. In addition, although the dehydrating device 63 is provided on the downstream side of the activated carbon tank 62, it may be provided on the upstream side, and the extraction solvent may be dehydrated before the harmful substances are purified.

  Thus, in the contaminated soil purification apparatus of the second embodiment, the activated carbon tank 62 that adsorbs and removes harmful organic substances to the solvent purifier 61 and the dehydrator 63 that removes moisture are provided. Therefore, since the activated carbon tank 62 adsorbs and removes harmful organic substances in the extraction solvent to purify the solvent, the apparatus can be made compact to reduce equipment costs and fuel costs, and the dehydrator 63 can remove moisture from the purified solvent. By removing, solvent refining can be performed with high accuracy, and a decrease in the ability to extract harmful substances from the contaminated soil due to the solvent can be prevented.

  In the contaminated soil purification apparatus of the third embodiment, as shown in FIG. 6, the solvent purification apparatus 71 includes a strainer 29 that removes soil particles from the extraction solvent, an oil strainer 30 that removes fats and oils, and harmful organic substances. Is composed of a distillation apparatus (solvent purification means) 72 and an activated carbon tank (solvent purification means) 73, and a boiler 74 is connected to the distillation apparatus 72. The discharged solvent tank 16 and the strainer 29 are connected by a transfer pipe 34 having a transfer pump 33, and the strainer 29, the oil strainer 30, the distillation apparatus 72, and the activated carbon tank 73 are connected by connection pipes 35, 75, and 76, respectively. The activated carbon tank 73 and the purified solvent tank 15 are connected by a return pipe 38.

  The distillation apparatus 72 heats and boils the extraction solvent to take out only the solvent from the harmful substances, and the activated carbon tank 73 allows the solvent from which the harmful substances have been separated by the distillation apparatus 72 to flow through the activated carbon, thereby remaining. It absorbs and removes minute harmful substances.

  Accordingly, when the transfer pump 33 is driven and the extraction solvent in the discharged solvent tank 16 is sent to the solvent purification device 71 through the transfer pipe 34, first, the soil particles are removed from the extraction solvent by the strainer 29, and then the oil strainer 30. The oil and fat is removed by this. Then, the harmful substance contained in the extraction solvent is removed by the distillation apparatus 72, the minute harmful substance remaining in the solvent purified by the distillation apparatus 72 is adsorbed and removed by the activated carbon tank 73, and the purified solvent is returned. It is returned to the purified solvent tank 15 through the pipe 38.

  In this case, as in the first embodiment, a plurality of activated carbon tanks are connected to the oil strainer 30 via a three-way valve, or an adsorbent regeneration device that regenerates deteriorated activated carbon, or a regenerant purification that purifies the regenerant. An apparatus may be provided. Further, as in the second embodiment, a dehydrator may be provided on the upstream side or the downstream side of the activated carbon tank 73.

  Thus, in the contaminated soil purification apparatus of the third embodiment, the distillation apparatus 72 and the activated carbon tank 73 for adsorbing and removing harmful organic substances to the solvent purification apparatus 71 are provided in series. Therefore, the harmful organic substances in the extraction solvent are first removed by the distillation apparatus 72, and then the harmful organic substances remaining in the solvent are adsorbed and removed by the activated carbon tank 73 to purify the solvent. Since the toxic substances are roughly separated in 72 and finished and separated in the activated carbon tank 73, the solvent purification can be performed with high accuracy, the early deterioration of the activated carbon in the activated carbon tank 73 can be prevented, and the solvent purification cost can be reduced. it can.

  In the contaminated soil purification apparatus of the fourth embodiment, as shown in FIG. 7, a supply pipe 18 having a purified solvent supply pump 17 is connected to the cleaning tank 11 from the purified solvent tank 15, and an operation valve 19. The exhaust solvent tank 16 is connected through a discharge pipe 21 having an extraction solvent discharge pump 20. A circulation pipe 24 having an operation valve 22 and a circulation pump 23 is connected between the supply pipe 17 and the discharge pipe 21. The supply tank 18, the discharge pipe 21, and the circulation pipe 24 constitute solvent circulation means for the cleaning tank 11, and a solvent purification device 81 is provided here.

  The solvent refining device 81 includes a filter 82 that removes soil fine particles from the extraction solvent, and two activated carbon tanks (solvent refining tanks) 83 and 84 that adsorb and remove harmful organic substances. And the filter 82 and each activated carbon tank 83,84 are connected by the connection piping 86 which has the three-way valve (switching valve) 85, and the minute harmful substance contained in a refinement | purification solvent is on the exit side of each activated carbon tank 83,84. Concentration sensors 87 and 88 for detecting the density of each are mounted.

  Therefore, when a predetermined amount of contaminated soil is introduced into the cleaning tank 11 and sealed, the solvent of the purified solvent tank 15 is supplied to the cleaning tank 11 through the supply pipe 18 by the purified solvent pump 17. When a predetermined amount of solvent is introduced into the cleaning tank 11, the purified solvent pump 17 is stopped, the operation valve 22 is opened, and the circulation pump 23 is operated, so that the solvent is cleaned via the circulation pipe 24. 11 is circulated for a predetermined time to extract and purify harmful organic substances contained in the contaminated soil, and at the same time, the extraction solvent is always purified by the solvent purifier 81.

  That is, in this solvent refining device 81, soil fine particles are removed from the extraction solvent by the filter 82, and supplied to, for example, the activated carbon tank 83 by the operation of the three-way valve 85, where harmful substances are adsorbed and removed, and the concentration sensor 87. Detects the concentration of minute harmful substances contained in the purified solvent. When the activated carbon in the activated carbon tank 31 deteriorates due to long-term use and the concentration of harmful substances in the purified solvent detected by the concentration sensor 87 exceeds the reference concentration, the three-way valve 85 is operated to switch the supply destination and extract The solvent is supplied to the activated carbon tank 84 for processing.

  In this case, as in the first embodiment, an adsorbent regeneration device that regenerates deteriorated activated carbon or a regenerant purification device that purifies the regenerant may be provided. In addition, as in the second embodiment, a dehydrator may be provided on the upstream side or the downstream side of the activated carbon tanks 83 and 84. Furthermore, you may provide a distillation apparatus in the upstream of activated carbon tank 83,84 like 3rd Embodiment.

  Thus, in the purification apparatus of contaminated soil of 4th Embodiment, the circulation system path (the supply piping 18, the discharge piping 21, and the circulation piping 24) which circulates a solvent is provided with respect to the septic tank 11, and solvent is here. A purifier 81 is provided, and the solvent purifier 81 is constituted by activated carbon tanks 83 and 84. Therefore, by providing the solvent refining device 81 directly in the solvent supply / discharge path for the cleaning tank 11, the apparatus can be made compact, equipment costs and fuel costs can be reduced, and the activated carbon tank In 83 and 84, since harmful substances in the extraction solvent are reliably adsorbed and removed, harmful substances such as PCB are hardly mixed in the purified solvent, and the solvent purification can be performed with high accuracy.

  In the contaminated soil purification apparatus of the fifth embodiment, as shown in FIG. 8, a solvent circulation means is constituted by a supply pipe 18, a discharge pipe 21, and a circulation pipe 24 for the cleaning tank 11, and solvent purification is performed here. A device 91 is provided. The solvent refining device 91 includes a filter 92 for removing soil fine particles, a distillation device (solvent refining means) 94 having a boiler 93, and an activated carbon tank (solvent refining means) 95. The filter 92, the distilling device 94, The activated carbon tank 95 is connected by a connecting pipe 97 having a three-way valve (switching valve) 96, and a concentration sensor 98 for detecting the concentration of harmful substances contained in the extraction solvent is attached to the outlet side of the cleaning tank 11. .

  Therefore, when the solvent is circulated through the supply pipe 18, the discharge pipe 21 and the circulation pipe 24 with respect to the contaminated soil in the cleaning tank 11, harmful organic substances contained in the contaminated soil are extracted and purified by the solvent. At the same time, the extraction solvent is purified by the solvent purification device 91 at all times.

  That is, in this solvent refining device 91, soil fine particles are removed from the extraction solvent by the filter 92, and by operating the three-way valve 96, first, it is supplied to the distillation device 94 where toxic substances are removed, and the concentration sensor 98 is It detects the concentration of harmful substances contained in the extraction solvent. Then, when the purification of the contaminated soil in the washing tank 11 progresses and the harmful substances contained in the extraction solvent are reduced, and the concentration of the harmful substances in the extraction solvent detected by the concentration sensor 98 falls below a predetermined concentration, the three-way valve 96 To switch the supply destination. The activated carbon tank 95 adsorbs and removes harmful substances remaining from the supplied extraction solvent.

  Thus, in the contaminated soil purification apparatus of the fifth embodiment, a circulation system path (a supply pipe 18, a discharge pipe 21, and a circulation pipe 24) for circulating the solvent is provided in the septic tank 11. A purification device 91 is provided, and the solvent purification device 91 is configured by disposing a distillation device 94 and an activated carbon tank 95 in parallel. Therefore, by providing the solvent refining device 91 directly in the solvent supply / discharge path for the cleaning tank 11, the device can be made compact, the equipment cost and the fuel cost can be reduced, and the extraction solvent can be reduced. Since the distillation apparatus 94 is used when the concentration of harmful substances contained in is high, and the activated carbon tank 95 is used when the concentration of harmful substances decreases, the solvent purification can be performed with high accuracy and the early deterioration of the activated carbon tank 95 is prevented. be able to.

  In each of the above-described embodiments, the soil is purified by extracting a harmful organic substance such as oil, PCB, dioxin and the like contained in the contaminated soil with a solvent. However, mercury, lead, etc. contained in the contaminated soil An apparatus for dissolving and extracting or decomposing and cleaning harmful inorganic substances such as heavy metals and cyanides with a cleaning liquid may be used in combination. In this case, water, an alkaline liquid, and an acidic liquid are suitable as the cleaning liquid.

  Further, in each of the above-described embodiments, a hydrophilic solvent (for example, alcohol) is used as the solvent. However, a ketone or the like can be used as the hydrophilic solvent, and a hydrophilic solvent can be used as the solvent. Hydrocarbons, aromatics, etc. can be used as the hydrophobic solvent. In addition, using this hydrophilic solvent (alcohol, ketone, etc.) and hydrophobic solvent (hydrocarbons, aromatics, etc.), dehydrated water in contaminated soil in a water-containing state with a hydrophilic solvent, and then organic substances In contrast, harmful organic substances contained in contaminated soil may be extracted and removed with a hydrophobic solvent having a high extraction / dissolution capacity, and inorganic substances may be dissolved and decomposed with a cleaning agent to be removed. In this case, the processing time can be shortened by using a mixed solvent in which a hydrophilic solvent and a hydrophobic solvent are mixed. Further, the structure of the cleaning tank 11 described above is not limited to the above-described embodiments.

  The contaminated soil purification apparatus according to the present invention can purify soil contaminated with harmful organic substances such as oil, PCB, dioxin, etc. easily and accurately at low cost, and is therefore extremely useful for industrial use. be able to.

It is a schematic block diagram of the purification apparatus of the contaminated soil which concerns on 1st Embodiment of this invention. 1 is a schematic configuration diagram of an adsorbent regeneration device and a regeneration agent purification device according to a first embodiment of the present invention. It is a graph showing the extraction solvent refinement | purification test result of the activated carbon tank which concerns on 1st Embodiment of this invention. It is a graph showing the adsorbent reproduction | regeneration test result of the adsorbent reproduction | regeneration apparatus which concerns on 1st Embodiment of this invention. It is a schematic block diagram of the purification apparatus of the contaminated soil which concerns on 2nd Embodiment of this invention. It is a schematic block diagram of the purification apparatus of the contaminated soil which concerns on 3rd Embodiment of this invention. It is a schematic block diagram of the purification apparatus of the contaminated soil which concerns on 4th Embodiment of this invention. It is a schematic block diagram of the purification apparatus of the contaminated soil which concerns on 5th Embodiment of this invention.

Explanation of symbols

11 Washing tank 15 Purified solvent tank 16 Discharged solvent tank 18 Supply piping (solvent supply / discharge means)
21 Discharge piping (solvent supply / discharge means)
24 Circulation piping (solvent circulation means)
26 Purification unit 27, 36, 61, 71, 81, 91 Solvent refining device 28 Drying device 31, 32, 62, 73, 83, 84, 95 Activated carbon tank 36, 85, 96 Three-way valve (switching valve)
39, 40, 87, 88, 98 Concentration sensor 42 Organic substance processing device 43 Adsorbent regeneration device 44 Regeneration agent purification device 63 Dehydration device 66 Dehydration agent supply device 72, 94 Distillation device 74 Boiler 101 Desorption solvent condenser 102 Desorption solvent tank 103 Evaporative solvent condenser 104 Temperature sensor 105 Regenerant tank 115 Three-way valve (switching valve)

Claims (10)

A cleaning tank that can be sealed with contaminated soil,
Solvent supply / discharge means for supplying and discharging the solvent to and from the cleaning tank;
Solvent purification means for adsorbing and removing harmful substances from the extraction solvent discharged from the washing tank by the solvent supply / discharge means. In claim 1,
The apparatus for purifying contaminated soil, wherein the solvent purification means is an adsorbent tank filled with an adsorbent having a predetermined particle diameter. In claim 2,
An apparatus for purifying contaminated soil, comprising adsorbent regeneration means for regenerating the adsorbent that has deteriorated by being used by the solvent purification means. In claim 3,
The adsorbent regeneration means is for regenerating the adsorbent by being filled with the adsorbent and being supplied with the regenerant.
The apparatus for purifying contaminated soil is characterized by comprising regenerant purification means for purifying the regenerant used in the adsorbent regeneration means. In claim 1,
An apparatus for purifying contaminated soil, characterized in that fine particle removal means for removing fine particles from the extraction solvent discharged from the washing tank by the solvent supply / discharge means is provided upstream of the solvent purification means. In claim 1,
The solvent refining means is configured by connecting a plurality of solvent refining tanks in parallel to a solvent discharge path via a switching valve, and operating the switching valve according to the degree of purification of the solvent by the solvent refining tank. A device for purifying contaminated soil, characterized in that the solvent refining tank can be switched. In claim 1,
An apparatus for purifying contaminated soil, comprising dehydrating means for separating water from the extraction solvent discharged from the washing tank by the solvent supply / discharge means or the purified solvent from which harmful substances have been removed by the solvent purification means. . In claim 1,
The solvent purification means,
A distillation means for separating the harmful substance by distillation treatment of the extraction solvent discharged from the washing tank by the solvent supply and discharge means;
An apparatus for purifying contaminated soil, comprising: an adsorption means provided on the downstream side of the distillation means for adsorbing and removing harmful substances from the extraction solvent. In claim 1,
The solvent supply / discharge means has a circulation means for returning the extraction solvent discharged from the cleaning tank to the cleaning tank again,
The apparatus for purifying contaminated soil, wherein the solvent purification means is provided in a solvent circulation path of the circulation means. In claim 9,
The solvent purification means,
A distillation means for separating the harmful substances by subjecting the extraction solvent discharged from the washing layer to a distillation treatment;
An adsorbing means for adsorbing and removing harmful substances from the extraction solvent discharged from the washing layer, in parallel with the solvent circulation path, and depending on the degree of contamination of the extraction solvent, the distillation means and the adsorbing means, A device for purifying contaminated soil, characterized in that it can be switched.

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