Soil and Groundwater Contamination Survey and Countermeasure Technologies

Category of Tchnology	Treatment	Treatment of Excavated Soil
Media	Soil
Contaminants	Heavy Metal (Cd, Pb, As, Hg, Se, etc)
	Applied (Demonstrated) Substances	Pb, Zn, Hg
Scope	Concentration Range
	Hydrogeological Conditions	-	-
	Chemical Soil Properties	Difficult for low melting point soil
	Other Remarks	Applicable for complex contamination with organic materials
Technology Description	Classification	Separation
	Status	Under Demonstration Soil and Groundwater Countermeasure Test Study (Performed 1993)
	Outline of Technology	Volatile heavy metals are removed from contaminated soil by vaporization in a rotary kiln, which is heated with fuel and air at the temperature of 1000 to 1100°C.  Non volatile heavy metals also change to insoluble oxide by heating.  Treated soil is cooled rapidly or gradually.  Exhaust gas is cleaned by alkali solution and electrostatic precipitator.
	Required Pre- and Post-treatment	Heavy metals in exhaust gas should be removed and treated appropriately.
	Enhance Effectiveness through Combination
	Case History	A contaminated soil with high concentration of Zn, Hg, and soluble Pb is treated.  Rapidly cooled soil has met the soil environmental quality standard through elution test in pH 7.
	Application Examples
	Limitations	Properties of Treated Soil are considerably changed.  Physical properties don’t meet the construction material standard, though it meets soil environmental quality standard.  Treated soil can only goes to landfill.
	Properties of Treated Soil	Possibility of Change in Properties
Schematic Flow Process	Thermal Treatment System of Contaminated Soil
Applicability	In Situ Applicability	Not Possible
	Ground Structures	-
	Required Excavation	Excavated soil is treated (To be applied to excavated soil)
	Groundwater Extraction
	Required Space	-
	Operational Time
	Installation Time
	Maintenance and Control Requirements
	Additional Remarks
Secondary Impacts to Environment	Secondary Treatment Required?	Effluent Water Treatment    Off-gas Treatment
	Effects on Living Environment	Noise
	Additives	Air Others (Fuel)
	Possibility of Contaminant Spreading	None
	Secondary By-products	Depends on coexisting materials

• Understanding the Contamination Survey and Countermeasure Technology Description Sheet
• Where to make contact

Soil Environment Management Division, Water Environment Department, Environmental Management Bureau, Ministry of Environment
Tel: +81-3-5521-8319
E-mail: MOE@env.go.jp