JP3880962B2 - How to handle hazardous substances - Google Patents

Description

  The present invention relates to a method for treating hazardous substances that removes harmful substances contained in contaminated soil or industrial waste accumulated in a garbage disposal site or the like.

  Hazardous substances such as poisonous and deleterious substances are contained in contaminated soil or industrial waste accumulated in a garbage disposal site. Many of these contaminated soils or industrial wastes are generated during the period of high economic growth, and recently the impact on health, the impact on the next generation, etc. have been screamed.

  Therefore, due to changes in the social situation surrounding soil contamination, the momentum for countermeasures against soil contamination has increased, and the Soil Contamination Countermeasures Bill was approved by the Cabinet in February 2002, and the Soil Contamination Countermeasures Act was enforced on February 15, 2003. ing.

  Various methods for treating toxic substances have been developed to remove toxic substances contained in contaminated soil or industrial waste accumulated in garbage disposal sites.

By the way, volatile organic compounds (Volatile
Organic Compounds (VOC) has a high ability to dissolve oils and fats, and has properties such as being hard to be decomposed and being stable and difficult to burn as a chemical substance. Therefore, in the 1970s, it became popular in the industry as an ideal cleaning agent. Recently, however, it has been pointed out that volatile organic compounds (VOC) may cause headaches and dizziness due to inhalation, kidney damage or cancer. Volatile organic compounds (VOCs) cause air, water and groundwater pollution, and are also attracting attention as indoor air pollutants in houses, and the concept of TVOC (total hazardous substances) has also been proposed. For example, current decomposition techniques for volatile organic compounds include the groundwater pumping method and the soil gas suction method, and attempts have been made to reduce the concentration to below the environmental standard in a short period of time.

  Moreover, as a volatile organic compound (VOC), it is a compound which is easy to volatilize at normal temperature, and there exist various substances, such as trichloroethylene, trachlorethylene, formaldehyde, toluene, benzene, xylene. Also in the soil pollution countermeasure method mentioned above, the volatile organic compound mentioned above is the object of designated standard regulation.

  Next, a method for lowering the concentration of the volatile compound below the specified reference concentration will be described with an example.

Environmental Purification Technology 2003.9 Vol.2. NO.9 Pages 1 to 4 Environmental Purification Technology 2003.9 Vol.2. NO.9 pp. 25-26 Environmental Purification Technology 2003.9 Vol.2. NO.9 Pages 27-29 Environmental Purification Technology 2003.9 Vol.2. NO.9 Pages 30-32

  First, the anaerobic bio method will be described. This anaerobic biomethod is a method of adding nutrients such as organic substances (food additives), nitrogen, and phosphorus as nutrients to groundwater. According to this method, tetrachloroethylene and trichlorethylene are reduced to ethylene and ethane to be rendered harmless.

  However, the anaerobic biomethod is effective for the treatment of specific volatile organic compounds, but is not intended for the treatment of all volatile organic compounds.

  Next, there is an in-situ oxidative decomposition method. This in-situ oxidative decomposition method is intended for contaminated groundwater, and is an oxidative decomposition technology that uses an oxidation reaction by injecting an oxidizing agent such as carium permanganate into the contaminated groundwater. In this method, trichlorethylene is decomposed into carbon dioxide and oxide ions, and manganese dioxide is generated and stabilized.

  However, this method is effective for the treatment of trichlorethylene, but is not intended for the treatment of all volatile organic compounds.

  Next, there is an iron powder method. This method is a method in which special iron powder is added to and mixed with contaminated soil, dechlorinated by the reducing power of metallic iron, decomposed into harmless ethylene and ethane, and purified.

  This method is highly safe, but there is a possibility that the treatment of used iron powder will emerge as a new problem.

  There are also incineration methods and multi-barrier methods. However, the incineration method has a problem of generation of dioxins due to low temperature treatment, and the multi-barrier method is a groundwater countermeasure technology for complex contamination, and has a problem in terms of comprehensive measures.

  Recently, a hot soil method has been developed as an effective method. This method is intended for contaminated soil, in which water and quicklime are mixed in the contaminated soil, and volatile organic compounds are volatilely separated by heat of hydration reaction. Here, the hydration reaction refers to a phenomenon in which a volatile organic compound and water undergo an exothermic reaction and the temperature rises to about 70 to 90 ° C. The optimum amount of hot soil added is 20% in terms of soil ratio. The volatile organic compound separated by volatilization is captured by adsorption treatment with activated carbon or the like. In this case, it is allowed to stand for 24 hours in a tent isolated from the external environment.

  However, since the hot soil method uses a hydration reaction, there is a problem that heat generation caused by the reaction must be solved and secondary pollution and the like are caused. This hot soil method is effective in dealing with contaminated soil because it involves a hydration reaction, but it is difficult to apply when new problems arise when reaction heat is applied, such as industrial waste. In some cases.

  It is an object of the present invention to provide a method for treating harmful substances that can be easily reduced to a concentration below the environmental standard in a short time and can suppress the generation of secondary pollutants. It is.

  In order to achieve the above-mentioned object, the hazardous substance processing method according to the present invention includes a cleaning process for cleaning contaminants such as contaminated soil and contaminated industrial waste, and a harmful substance separated from the contaminants through the cleaning process, It has a separation step of separating based on light weight of specific gravity with a specific gravity of water as a threshold, and a trap step of trapping harmful substances separated in the separation step. Here, hazardous substances include substances that are subject to designated regulations under the VOC and Soil Contamination Countermeasures Law.

  According to the present invention, in the cleaning process, the pollutant is cleaned, and then the harmful substance separated from the pollutant through the cleaning process is separated based on the light weight of the specific gravity using the specific gravity of water as a threshold value.

  Next, in the trap step, the harmful substances separated in the separation step are trapped.

  Therefore, according to the present invention, by washing in the washing step, harmful substances can be classified and removed from the contaminants based on the light weight of the specific gravity using the specific gravity of water as a threshold value. Furthermore, since harmful substances are classified using the specific gravity of water as a threshold, it is possible to appropriately treat each classified harmful substance.

  Moreover, since harmful substances are trapped using the specific gravity of water as a threshold, all harmful substances contained in contaminated soil and industrial waste can be treated.

  Moreover, in this invention, it can be set as the structure which includes the process of collect | recovering the clean substance from which the harmful substance was isolate | separated as a material for reproduction | regeneration.

  Therefore, according to the present invention, the washed soil and the washed industrial waste from which harmful substances have been separated are recovered as recycling materials, so that these materials can be used effectively. Moreover, even if the collected soil and industrial waste are recycled, the environment is not affected.

  In the present invention, when separating harmful substances lighter than the specific gravity of water, the contaminated soil and contaminated industrial waste are aerated by bringing clean air into contact with the contaminated soil and contaminated industrial waste being washed. In addition, gas-liquid separation from the washing water is possible.

  Further, in the present invention, when separating harmful substances heavier than the specific gravity of water, the hazardous substances heavier than the specific gravity of water are dissolved in the washing water washing the pollutants, and the washing water is recovered. Can be separated from contaminants.

  Therefore, according to the present invention, generation of heat of hydration reaction can be prevented, and problems associated with the exothermic phenomenon do not occur. In addition, it is possible to separate harmful substances with a simple configuration, such as contact aeration of clean air to contaminated soil and contaminated industrial waste, or dissolving hazardous substances with a specific gravity heavier than the specific gravity of water in washing water. Cost can be greatly reduced. Volatile organic compounds with a specific gravity lighter than that of water can be separated by washing contaminated soil and contaminated industrial waste. Furthermore, the volatile organic compound having a specific gravity lighter than the specific gravity of water can be more efficiently gas-liquid separated by bringing the clean soil into contact with the contaminated soil and contaminated industrial waste being washed and aeration.

  In this case, it is possible to trap the harmful substance dissolved in the washing water in the ultrafilter by press-fitting the washing water in which the harmful substance having a specific gravity heavier than water is dissolved into the ultrafilter.

  Therefore, according to the present invention, harmful substances dissolved in the washing water can be easily trapped, and the running cost can be greatly reduced.

  In this case, the hazardous substance is rendered harmless by incineration of the ultrafilter that traps the harmful substance having a specific gravity heavier than that of water.

  Therefore, according to the present invention, the trapped harmful substance can be easily and safely treated by incineration of the ultrafilter that traps the harmful substance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a processing system for carrying out the hazardous substance processing method of the present invention includes a drilling device 1, a sealed watering system device 2, and an ultrafiltration membrane device 3 as an ultrafilter. It is configured.

  The excavator 1 excavates contaminated soil and contaminated industrial waste 4, and conveys the contaminated soil and contaminated industrial waste 4 to the sealed watering system device 2 by a belt conveyor 5. Hereinafter, substances to be treated such as contaminated soil and contaminated industrial waste 4 are referred to as contaminants.

In this case, it is desirable to perform chemical continuous wall treatment in order to prevent the contaminants from diffusing. In this chemical continuous wall treatment, as shown in FIGS. 4 and 5, the pollutant 4 is physically surrounded by the continuous wall 6 and does not flow out of the continuous wall 6 or is chemically trapped and rendered harmless. It is processing to do. Specifically, for example, graphite (bamboo charcoal, charcoal) or the like is finely pulverized with a ball mill to form highly penetrating carbon with enhanced adsorption capacity. Alternatively, activated carbon or a chemical neutralizing agent (for example, quick lime) is used instead of or mixed with the highly osmotic carbon. As this chemical neutralizer, a mixture or mixture of ultrafine iron powder and / or carbon powder, calcium-based material (such as quicklime and calcium, shell fossil and calcium carbonate), shirasu (volcanic product), etc. A solution can be used.

  On the other hand, continuous vertical holes 7 are formed on all sides of the region where the contaminant 4 is present. As shown in FIG. 5, the lower end portion of the vertical hole 7 is drilled to a depth that reaches the impermeable layer 8. The reason is that the impermeable layer 8 prevents the harmful substance separated from the pollutant 4 from entering the groundwater and entering the groundwater, so that the harmful substance expands laterally along the impermeable layer 8. This is to prevent the chemical continuous wall 6.

  The highly penetrating carbon, activated carbon or chemical neutralizing agent is mixed with biodegradable plastic that does not impair the natural environment, and the mixture is poured into the vertical hole 4 and cured to form the chemical continuous wall 6. The boundary part of the contaminant 4 is isolated from the clean soil by the chemical continuous wall 6. Here, as the biodegradable plastic, a compound obtained by mixing starch and / or polyvinyl alcohol with polyethylene or polypropylene can be used.

The chemical continuous wall 6 prevents the contaminant 4 from diffusing and contacts the contaminant 4 to trap harmful substances by the high-permeation carbon or activated carbon contained in the chemical continuous wall 6 or chemically. Detoxify with neutralizer.

  The sealed watering system device 2 has a sealed space, and air-permeable conveyors 9a and 9b are installed sideways in the sealed space 2a. The conveyors 9a and 9b are arranged in a plurality of stages in the vertical direction. Then, the contaminant 4 is laterally fed, for example, from the left to the right by the upper conveyor 9a, and dropped and conveyed to the lower conveyor 9b at the feed end. The lower conveyor 9b laterally feeds the contaminants sent from the upper conveyor 9a in the horizontal direction, for example, from the right to the left. By repeating these operations, the combination of the upper conveyor 9a and the lower conveyor 9b transports the pollutant 4 from the upper side to the lower side while laterally feeding the contaminants 4. These conveyors 9a and 9b have a slat-like structure in which the conveyor surface supporting the contaminant 4 allows cleaning water to pass therethrough and supports the contaminant 4.

  In the present invention, harmful substances contained in the pollutant 4 are separated on the basis of light weight of specific gravity with the specific gravity of water as a threshold value. First, a case where a harmful substance having a specific gravity heavier than that of water is separated will be described. Hazardous substances with a specific gravity heavier than that of water exist in a dissolved state in water. In order to separate harmful substances having a specific gravity heavier than the specific gravity of water using this property, when the pollutant 4 is laterally fed by the upper and lower conveyors 9a and 9b, clean water (river water) or The groundwater is pumped, and the pollutant 4 that has been laterally fed by the conveyors 9a and 9b is sprayed from the sprinkling nozzle 10a to wash the pollutant 4. Hazardous substances with a specific gravity heavier than the specific gravity of water are washed away from the contaminants 4 under the pressure of the washing water, and fall to the bottom of the sealed space 2a in a state dissolved in the washing water after washing. Therefore, by washing the pollutant 4 with the washing water, harmful substances having a specific gravity heavier than that of water can be separated from the pollutant 4.

  In order to trap a harmful substance having a specific gravity heavier than the specific gravity of water in the next step, the washing water 11 from which the pollutant 4 has been washed is captured in the capture tank 12 in the sealed space 2a. The capture tank 12 is disposed at the bottom of the sealed space 2a. Then, the cleaning water after cleaning the contaminants 4 is collected and captured in the capturing tank 12.

  Next, the case where gas-liquid separation of harmful substances having a specific gravity lighter than that of water, particularly volatile organic compounds, will be described. Hazardous substances with a specific gravity lighter than the specific gravity of water are volatile and thus have the property of staying in the air or rising by an air stream. In order to trap harmful substances having a specific gravity lighter than that of water using this property, clean air is forcibly sent into the sealed space 2a by the blower 13. And the harmful substance contained in the pollutant 4 currently wash | cleaned is gas-liquid-separated by making the sent air contact the pollutant 4 on conveyor 9a, 9b and aeration. . In this case, aeration by the blower 13 may be omitted when gas-liquid separation is possible by carrying out the conveyance by the conveyors 9a and 9b and washing by spraying water without performing the aeration by the blower 13.

The case of trapping hazardous substances with a specific gravity lighter than the specific gravity of water will be described. Hazardous substances, particularly volatile organic compounds, separated from the pollutant 4 by gas and liquid rise in the sealed space 2a and stay in the upper space in the sealed space 2a. Therefore, the VOC adsorption tower 14 is installed in the upper part of the sealed space 2a. The VOC adsorption tower 14 traps harmful substances separated from gas and liquid, particularly volatile organic compounds. Also, clean air after trapping volatile organic compounds is released into the atmosphere. Here, the trapped volatile organic compounds include benzene and the like.

  A primary filter 16 (secondary filter 17 if necessary) is installed on the protruding side of the recovery tank 12 in the sealed space 2a. The washing water after washing the pollutant 4 is passed through the primary filter 16 so as to trap sandstone and grain sand contained in the washing water. In addition, as shown in FIG. 3, the soil passing through the primary filter 16 may be trapped by the secondary filter 17 and recovered as regenerated soil.

The case of trapping harmful substances with a specific gravity heavier than that of water will be described. A harmful substance having a specific gravity heavier than the specific gravity of water exists in the recovery tank 12 in a state of being dissolved in water due to the specific gravity difference. Moreover, since dichloromethane, dichloroethylene, and tetrachloroethylene are insoluble in water, they are mixed in the wash water and exist in the recovery tank 12. Focusing on this state, it is possible to separate the wash water into reclaimed waste water and harmful substances by filtering the wash water. Therefore, in order to trap harmful substances having a specific gravity heavier than that of water, the ultrafiltration membrane device 3 is used as an ultrafilter.

  The ultrafiltration membrane device 3 includes a supply tank 3a, a recovery tank 3b, and an ultrafiltration membrane body 3c. The supply tank 3a is a receiving tank that receives the wash water supplied by filtering from the capture tank 12. The collection tank 3b is a tank that collects the washing water that has passed without being filtered by the ultrafiltration membrane body 3c and returns the washing water to the supply tank 3a.

  The ultrafiltration membrane body 3c is installed in a water channel 3d formed between the supply tank 3a and the recovery tank 3b, and traps harmful substances having a specific gravity heavier than the specific gravity of water contained in the wash water. . Specifically, as shown in FIG. 2, the ultrafiltration membrane body 3c is formed in a structure in which tubular filter structures 8 are bundled in parallel (see FIG. 1). As shown in FIG. 2, each filter structure 8 is formed in a structure in which a tubular ultrafiltration membrane 8b is covered inside a porous pressure-resistant support tube 8a, and does not have a housing. Since the filter structure 8 has a structure without a housing, maintenance and inspection are easy, and the structure is simple and the cost is low. The number of tubular filter structures 8 bundled in parallel is not limited to the number shown in FIG.

The ultrafiltration membrane 8b used in the embodiment has a tubular shape with an inner diameter of about 9 mm, and the washing water is filtered under a pressure of about 1 to 5 kg / cm ² . Moreover, the molecular weight of the ultrafiltration membrane 8b is 40,000 daltons (dalton = M / W), and traps harmful substances having a specific gravity heavier than that of water. For example, polysulfone is used as the material of the filtration membrane 8b, and is excellent in heat resistance, acid resistance, alkali resistance, and mechanical properties. When the water pressure is applied to the washing water in the supply tank 3a and the washing water is sent to the ultrafiltration membrane body 3c, the washing water is press-fitted into the porous pressure-resistant support tube 8a, and from the hole 8c of the support tube 8a. Extruded out of the tube. When the cleaning water is pushed out of the support tube 8a, the harmful substances 15 in the cleaning water are trapped in the filtration membrane 8b. Wash water that has passed through the filtration membrane 8b and is pushed out of the support tube 8a is collected and discharged as reclaimed waste water. In this case, the wash water containing the harmful substance 15 that has not permeated through the filtration membrane 8b is recovered in the recovery tank 3b and then returned to the supply tank 3a. By repeating this, the harmful substance 15 is trapped in the filtration membrane 8b. Here, harmful substances to be trapped include volatile organic compounds such as trichlorethylene, tetrachloroethylene (all of which include components with a specific gravity of around 1.5 to 1.6), lead, hexavalent chromium, cadmium, mercury, cyanide, Arsenic, dichloromethane, dichloroethylene and the like are included.

  The ultrafiltration membrane body 3c is replaced with a new one when the trapping amount of the harmful substance 15 is increased and the filtration capacity is lowered. The replaced old ultrafiltration membrane body 3c is incinerated to detoxify the harmful substance 15. In addition, although the ultrafiltration membrane apparatus 3 equipped with the ultrafiltration membrane body shown in FIG. 2 was used as an ultrafilter, it is not limited to this. Any filtering means capable of trapping harmful substances having a specific gravity heavier than that of water can be used as an ultrafilter.

  Next, a method for treating harmful substances using the system shown in FIG. 1 will be described. The method for treating harmful substances according to the present invention basically includes a washing process for washing the pollutant 4, and a harmful substance separated from the soil and the industrial waste 4 through the washing process, with a specific gravity of water as a threshold. And a trapping step for trapping harmful substances separated in the separation step. Next, the processing content in each process is demonstrated concretely based on FIGS. 1-3.

(Washing step S1)
As shown in FIG. 1, excavate contaminated soil and industrial waste contaminated with harmful substances such as VOC (see FIG. 3). Here, since VOC is a compound that volatilizes at room temperature, it is necessary to be careful when excavating. For example, it is desirable to isolate a portion to be excavated with a sheet or mat that adsorbs VOCs. In this case, as shown in FIGS. 4 and 5, in order to prevent the contaminant 4 from diffusing, the contaminant 4 is physically surrounded by the continuous wall 6 and does not flow out of the continuous wall 6 or Is chemically trapped and detoxified (see FIG. 3).

  The excavated contaminated soil and industrial waste 4 are conveyed to the sealed watering system 2 by the conveyor 5.

  The pollutant 4 carried into the sealed watering system 2 is laterally fed, for example, from the left to the right by the upper conveyor 9a, and dropped and conveyed to the lower conveyor 9b at the feed end. The pollutant 4 transferred to the lower conveyor 9b is laterally fed, for example, from right to left. By repeating these operations, the combination of the upper conveyor 9a and the lower conveyor 9b transports the pollutant 4 from the upper side to the lower side while laterally feeding the contaminants 4.

  When the pollutant 4 is laterally fed by the upper and lower conveyors 9a and 9b, clean water (river water) or groundwater is pumped by the pumping pump 10, and the water spray nozzle is applied to the pollutant 4 being fed laterally by the conveyors 9a and 9b. Water is sprayed from 10a, and the contaminant 4 is washed. Further, the washed soil and the washed industrial waste 4a from which the harmful substances have been removed are collected as recycling materials (see FIG. 1).

(Separation step S2)
When the pollutant 4 is laterally fed by the upper and lower conveyors 9a and 9b, that is, the operation performed in the above-described washing step S1, the washing water pressure is applied to the pollutant 4 that is laterally fed by the conveyors 9a and 9b. As a result of the cleaning operation, the cleaning water 11 containing harmful substances having a specific gravity heavier than the specific gravity of the water washed away from the contaminant 4 is captured in the capture tank 12 in the sealed space 2a. Thereby, the harmful substance having a specific gravity heavier than that of water is separated from the pollutant 4 (see FIG. 3).

  In conjunction with the above operation, clean air is forcibly sent into the sealed space 2 by the blower 13 when the contaminant 4 is laterally fed by the upper and lower conveyors 9a and 9b. The harmful air contained in the cleaned pollutant 4 is separated into gas and liquid by contacting the pollutant 4 on the conveyors 9a and 9b and aerating it. Thereby, the harmful substance having a specific gravity lighter than the specific gravity of water is separated from the pollutant 4 (see FIG. 3).

(Trap process S3)
Hazardous substances, particularly volatile organic compounds, separated from the pollutant 4 by gas and liquid rise in the sealed space 2a and stay in the upper space in the sealed space 2a. The VOC adsorption tower 14 traps the gas-liquid separated harmful substances, particularly volatile organic compounds. The clean air after trapping the volatile organic compound by the VOC adsorption tower 14 is released into the atmosphere (see FIG. 3).

  The cleaning water recovered in the recovery tank 12 installed in the sealed space 2a and after cleaning the pollutant 4 is passed through the primary filter 16 to trap sandstone and grain sand contained in the cleaning water. . The cleaning water after the trap is carried into the supply tank 3a of the ultrafiltration membrane device 3 (see FIG. 1).

  When water pressure is applied to the cleaning water in the supply tank 3a and the cleaning water is sent to the ultrafiltration membrane body 3c, the cleaning water is pressed into the porous pressure-resistant support tube 8a, and the tube is passed through the hole 8c of the support tube 8a. Extruded outside. When the washing water is pushed out of the support pipe 8a, the harmful substance 15 in the washing water is trapped in the filtration membrane 8b (see FIG. 2). Wash water that has passed through the filtration membrane 8 and is pushed out of the support tube 8a is collected and discharged as reclaimed waste water. In this case, the wash water containing the harmful substance 15 that has not permeated through the filtration membrane 8b is recovered in the recovery tank 3b and then returned to the supply tank 3a. By repeating this, the harmful substance 15 is trapped in the filtration membrane 8b (see FIG. 2).

  The ultrafiltration membrane body 3c is replaced with a new one when the trapping amount of the harmful substance 15 is increased and the filtration capacity is lowered. The replaced old ultrafiltration membrane body 3c is incinerated to detoxify the harmful substance 15.

  As described above, according to the present invention, the specific gravity of water is used as a threshold, harmful substances having a specific gravity lighter than the specific gravity of water are gas-liquid separated, and harmful substances with a specific gravity heavier than the specific gravity of water are limited. Because it is trapped by the outer filter, it is possible to reliably handle almost noxious substances that cause pollution.

  Furthermore, since the toxic substances are separated by washing with water and a trap with an ultra filter, toxic substances can be effectively captured with a simple configuration.

It is a block diagram which shows the system for enforcing the processing method of the harmful substance which concerns on this invention. It is sectional drawing which shows the ultra filter used for the processing method of the hazardous | toxic substance based on this invention. 3 is a flowchart showing a hazardous substance processing method according to the present invention. It is a top view which shows the installation state of the chemical continuous wall used for this invention. It is a longitudinal cross-sectional view which shows the installation state of the chemical continuous wall used for this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Excavation device 2 Sealed watering system device 3 Ultrafiltration membrane device 3c Ultrafiltration membrane body 4 Contaminant (contaminated soil, contaminated industrial waste, etc.)
10a Watering nozzle 13 Blower 14 VOC adsorption tower

Claims (1)

A chemical continuous wall treatment process that surrounds the contaminant with a continuous wall and prevents diffusion of the contaminant;
A cleaning step of taking the contaminant surrounded by the continuous wall into a sealed space and cleaning the contaminant with cleaning water in the sealed space;
A separation step of separating harmful substances separated by washing in the sealed space based on light weight of specific gravity with a specific gravity of water as a threshold;
A trap process for capturing and processing harmful substances that are lighter than the specific gravity of water;
A recovery process for recovering harmful substances heavier than the specific gravity of water in the sealed space ;
A filter trap step of trapping the harmful substance mixed in the cleaning water into the ultrafilter by press-fitting the cleaning water into the ultrafilter;
In one sealed space, each process in the cleaning step, the separation step, the trap step and the recovery step is continuously performed,
In the chemical continuous treatment step, a high-permeation carbon or activated carbon contained in the continuous wall is used to trap harmful substances or neutralize with a neutralizing agent,
In the washing step, the contaminants treated in the chemical continuous wall treatment step are washed with washing water while being transported from the upper side to the lower side while being laterally fed by a conveyor arranged in a plurality of stages vertically in the sealed space. Process
In the separation step, when cleaning the pollutant transported from the upper side to the lower side while being laterally fed in the sealed space with cleaning water, clean air is brought into contact with the pollutant and aerated, thereby causing harmful substances. , With a specific gravity of water as a threshold, a process for gas-liquid separation based on the light weight of the specific gravity,
In the trap step, a harmful substance containing VOC that is lighter than the specific gravity of water separated by aeration and volatilizes at room temperature is captured in the sealed space, and a volatile organic compound is trapped in a VOC adsorption tower.
In the recovery step, using the air permeability of the conveyor, a harmful substance heavier than the specific gravity of water is collected in the recovery tank of the sealed space together with the cleaning water,
In the filter trap step, pressure is applied to the harmful substances collected in the collection tank, and filtration is performed with an ultrafiltration membrane having a divided molecular weight of 40,000 daltons, thereby performing a process of trapping harmful substances heavier than the specific gravity of water. A method for treating harmful substances characterized by the above.

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