Soil and Groundwater Contamination Survey and Countermeasure Technologies
| Category of Tchnology | Survey | In Situ Extraction Technology | |
| Media | Soil Gas | ||
| Contaminants |
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| Applied (Demonstrated) Substances | Volatile Chlorinated Organic Compounds | ||
| Scope | Concentration Range | equivalent to 1 ppbv in concentration | |
| Hydrogeological Conditions |
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| Chemical Soil Properties | |||
| Other Remarks | Soil gas distribution in soil is comparatively expressed by ion-counts obtained from mass spectroscopic analysis | ||
| Technology Description | Classification | ||
| Status |
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| Outline of Technology | Activated carbon is glued on the end of ferro-magneticwires inserted into bore hole of approximately 30cm in depth for 2 to 3 weeks. Wires in the glass tube exposed in soil gas are retrieved and the soil gas desorped by heating is analyzed by mass spectroscopy. | ||
| Required Pre- and Post-treatment | |||
| Enhance Effectiveness through Combination | Linear survey method, to which the soil-gas method is applied, for surveying the plume containing contaminated groundwater and for searching the contaminant source. | ||
| Case History | Because the positioning of collectors in boreholes does not require long time, it may averagely be possible to finish the positioning within a day or two at sites. For the adsorption and analysis, it will take much longer time. It is possible to detect pollutants 50-100m apart from the origin of contamination in the soil gas investigation. | ||
| Application Examples | It can be used in wider range of soil gas concentration in detection survey of contamination source or in industrial property survey. | ||
| Limitations | Longer time required in adsorption period and in mass analysis to obtain ion count distribution. | ||
| Properties of Treated Soil |
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| Schematic Flow Process | 
Gas Collector Setup for CA/ED/MS |
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| Applicability | In Situ Applicability | Possible | |
| Ground Structures | Applicable even if Ground Structures are Present * | ||
| Required Excavation | Gas collectors to be put in bore holes of in 15cmφ x 30cm depth. | ||
| Groundwater Extraction | None | ||
| Required Space | 1-2 m2 | ||
| Operational Time |
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| Installation Time | Gas collectors to be placed for 2 to 3 weeks before MS analysis. | ||
| Maintenance and Control Requirements |
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| Additional Remarks | * Drill cutter is necessary for concrete floor. | ||
| Secondary Impacts to Environment | Secondary Treatment Required? |
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| Effects on Living Environment | |||
| Additives |
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| Possibility of Contaminant Spreading | None | ||
| Secondary By-products |
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Soil Environment Management Division, Water Environment Department, Environmental Management Bureau, Ministry of Environment
Tel: +81-3-5521-8319
E-mail: MOE@env.go.jp
