Remediation methods of polluted soils

Sakari Halmemies, DSc (Tech)

Classification of remediation methods on

_{(FRTR 2001)} base of activities

Grouping of remediation methods on base

of environment and technologies ⁽ ^{Visitt 6.0 1997)} 

Number of remediation methods and technologies: _ 371



Environment: _ 68 % soil, 32 % water



Technologies: _ _ 39 % biological 21 % physical _ 21 % thermal _ 19 % chemical Treatment Technologies _{(FRTR 2001)} Screening Matrix 

Applicability of different technologies can be checked from this matrix: Treatment technology profiles ^{(FRTR 2001)} 

Soil, Sediment, Bedrock and Sludge Treatment Technologies _

Biological Treatment _ Physical/Chemical Treatment _ Thermal Treatment _

Ground Water, Surface Water, and Leachate

Treatment Technologies _

Biological Treatment _ Physical/Chemical Treatment _ Containment

Soil, Sediment, Bedrock and Sludge Treatment

Technologies Biological Treatment ^{(FRTR 2001)}

 Bioventing,

In Situ

 Enhanced Bioremediation,

In Situ

 Phytoremediation,

In Situ

 Biopiles,

Ex Situ

 Composting,

Ex Situ

 Landfarming,

Ex Situ

 Slurry Phase,

Ex Situ

(FRTR 2001) Bioventing, in situ



Introduction:



Oxygen is delivered to contaminated unsaturated soils by forced air movement (either extraction or injection of air) to increase oxygen concentrations and stimulate biodegradation.

Typical bioventing system

(FRTR 2001)

Applicability, duration, limitations, costs _{(FRTR 2001)} Bioventing 

Applicability for pollutants _

petroleum hydrocarbons, nonchlorinated solvents, some pesticides, wood preservatives, and other organic _ chemicals.

Duration _

Medium to long-term technology. Cleanup ranges from a few months to several years.

 More detailed data _ Enhanced Bioremediation, in situ biostimulation, bioaugmentation, enhanced biodegradation (FRTR 2001)

 Introduction: _

The activity of naturally occurring microbes is stimulated by circulating water-based solutions through contaminated soils to enhance in situ biological degradation of organic contaminants or immobilization of inorganic contaminants.



Nutrients, oxygen, or other amendments may be used to enhance bioremediation and contaminant desorption from subsurface materials.

Typical Enhanced Bioremediation

_{(FRTR 2001)} system

Applicability, Enhanced Bioremediation

_{(FRTR 2001)}

duration, limitations, costs

 Applicability for pollutants _

petroleum hydrocarbons, solvents, pesticides, wood preservatives, and other organic chemicals

 Duration _

Long-term technology which may take several years for cleanup of a plume.

 More detailed data _ Phytoremediation, in situ vegetation-enhanced bioremediation

(FRTR 2001) 

Introduction: _

Phytoremediation is a process that uses plants to remove, transfer, stabilize, and destroy contaminants in soil and sediment. Contaminants may be either organic or inorganic.



The mechanisms of phytoremediation include enhanced rhizosphere biodegradation, phyto-extraction (also called phyto-accumulation), phyto-degradation, and phyto- stabilization.

Typical In Situ Phytoremediation

(FRTR 2001)

System http://www.frtr.gov/matrix2/section4/D01-4-3.html

Applicability, duration, Phytoremediation

(FRTR 2001) limitations, costs

 Applicability for pollutants _

metals, pesticides, solvents, explosives, crude oil, PAHs, and landfill leachates

 Duration _

Long-term technology which may take even decades for cleanup of a plume.

 More detailed data _ ex situ Biopiles,

(FRTR 2001) 

Introduction: _

Excavated soils are mixed with soil amendments and placed in aboveground enclosures.



It is an aerated static pile composting process in which compost is formed into piles and aerated with blowers or vacuum pumps.

Typical Biopile System for Solid Phase

(FRTR 2001)

Bioremediation

(FRTR 2001)

Applicability, duration, limitations, costs

Biopile 

Applicability for pollutants _ nonhalogenated VOCs and fuel hydrocarbons.

 Duration _

Short-term technology. Duration of operation and maintenance may last a few weeks to several months

 More detailed data _

ex situ

Composting,

(FRTR 2001) 

Introduction: _

Contaminated soil is excavated and mixed with bulking agents and organic amendments such as wood chips, hay, manure, and vegetative (e.g., potato) wastes.



Proper amendment selection ensure adequate porosity and provides a balance of carbon and nitrogen to promote thermophilic, microbial activity.

Typical Windrow Composting Process (FRTR 2001) Composting (FRTR 2001)

Applicability, duration, limitations, costs 

Applicability for pollutants _ _ biodegradable organic compounds (incl. PAH)

Pilot and full-scale projects have demonstrated explosives

 Duration _

Duration of operation and maintenance may last to several months

 More detailed data _ ex situ Landfarming,

(FRTR 2001) 

Introduction: _

Contaminated soil, sediment, or sludge is excavated, applied into lined beds, and periodically turned over or tilled to aerate the waste.

Typical Landfarming Treatment Unit

(FRTR 2001)

Applicability, duration, Landfarming

(FRTR 2001) limitations, costs _

Applicability for pollutants _

petroleum hydrocarbons, diesel fuel, No. 2 and No. 6 fuel oils, JP-5, oily sludge, wood-preserving wastes (PCP and creosote), coke wastes, and certain pesticides.

 Duration _

Duration of operation and maintenance may last to many years

 More detailed data _

Slurry Phase Biological Treatment, (FRTR 2001) ex situ

 Introduction: _

An aqueous slurry is created by combining soil, sediment, or sludge with water and other additives.



The slurry is mixed to keep solids suspended and microorganisms in contact with the soil contaminants.



Upon completion of the process, the slurry is dewatered and the treated soil is disposed of.

_{(FRTR 2001)}

Typical Bioreactor Process

http://www.frtr.gov/matrix2/section4/D01-4-14.html

Slurry Phase Biological Treatment

(FRTR 2001)

Applicability, duration, limitations, costs 

Applicability for pollutants _

explosives, petroleum hydrocarbons, petrochemicals, solvents, pesticides, wood preservatives, and other organic chemicals

 Duration _ Short- to medium-term technology.

 More detailed data _

Soil, Sediment, Bedrock and Sludge Treatment

Technologies Physical/Chemical Treatment ^{(FRTR 2001)}

 Chemical Oxidation, In Situ _ Electrokinetic Separation, In Situ _ Fracturing, In and Ex Situ _ Soil Flushing, In Situ _ Soil Vapor Extraction, In Situ _ Solidification/Stabilization, In and Ex Situ _ Chemical Extraction, Ex Situ _ Chemical Reduction/Oxidation, Ex Situ _ Dehalogenation, Ex Situ _ Separation, Ex Situ _ Soil Washing, Ex Situ

(FRTR 2001) In Situ

Chemical Oxidation, 

Introduction:



Oxidation chemically converts hazardous contaminants to non-hazardous or less toxic compounds that are more stable, less mobile, and/or inert.



The oxidizing agents most commonly used are ozone, hydrogen peroxide, hypochlorites, chlorine,

Typical Chemical oxidation

_{(FRTR 2001)} system

Applicability, Chemical oxidation duration, limitations, costs (FRTR 2001) _

Applicability for pollutants _ many toxic organic chemicals, unsaturated aliphatic (e.g.,

trichloroethylene,TCE) and aromatic compounds (e.g.,

_ benzene)

Duration _ Medium to long-term technology. Cleanup ranges from a few _ months to several years.

More detailed data _ in situ Electrokinetic Separation, _ (FRTR 2001)

Introduction: _

The Electrokinetic Remediation (ER) process removes metals and organic contaminants from low permeability soil, mud, _ sludge, and marine dredging.

ER uses electrochemical and electrokinetic processes to _ desorb, and then remove, metals and polar organics.

This in situ soil processing technology is primarily a separation and removal technique for extracting contaminants from soils.

Typical In Situ Electrokinetic

_{(FRTR 2001)} Separation System

Applicability, Electrokinetic Separation duration, limitations, costs (FRTR 2001) _

Applicability for pollutants _

heavy metals, anions, and polar organics in soil, mud, _ sledge, and marine dredging

Duration _

Short to medium-term technology. Cleanup ranges from a few weeks to several months.

 More detailed data _

In Situ Fracturing, _{(FRTR 2001)}



Introduction:



Cracks are developed by fracturing beneath the surface in low permeability and over- consolidated sediments to open new passageways that increase the effectiveness of many in situ processes and enhance extraction efficiencies.

Typical Pneumatic Fracturing

_{(FRTR 2001)} Process

Applicability, duration, Fracturing limitations, costs (FRTR 2001) _

Applicability for pollutants _ Fracturing is applicable to the complete range of contaminant groups with no particular target group. The technology is _ used primarily to fracture silts, clays, shale, and bedrock.

Duration _ Normal operation employs a two-person crew, making 15 to 25 fractures per day with a fracture radius of 4 to 6 meters to a depth of 15 to 30 meters. For longer remediation programs,

refracturing efforts may be required at 6- to 12-month

_ intervals.

More detailed data _

In Situ Soil Flushing, _{(FRTR 2001)}



Introduction:



Water, or water containing an additive to enhance contaminant solubility, is applied to the soil or injected into the ground water to raise the water table into the contaminated soil zone.



Contaminants are leached into the ground water, which is then extracted and treated.

Typical Soil Flushing System

(FRTR 2001)

Applicability, duration, Soil Flushing limitations, costs (FRTR 2001)

 Applicability for pollutants _

inorganics including radioactive contaminants. The technology can be used to treat VOCs, SVOCs, fuels, and pesticides.

 Duration _

Short to medium-term technology. Cleanup ranges from a few weeks to several months.

 More detailed data _

In Situ Soil Vapor Extraction, _{(FRTR 2001)}



Introduction:



Vacuum is applied through extraction wells to create a pressure/concentration gradient that induces gas-phase volatiles to be removed from soil through extraction wells.



This technology also is known as in situ soil venting, in situ volatilization, enhanced volatilization, or soil vacuum extraction.

Typical In Situ Soil Vapor Extraction

_{(FRTR 2001)} System

Applicability, Soil Vapor Extraction, duration, limitations, costs (FRTR 2001)

 Applicability for pollutants _

The target contaminant groups for in situ SVE are VOCs and some fuels

 Duration _

The duration of operation and maintenance for in situ SVE is typically medium- to long-term.

 More detailed data _

In Situ Solidification/Stabilization, _{(FRTR 2001)}



Introduction:



Contaminants are physically bound or enclosed within a stabilized mass (solidification), or chemical reactions are induced between the stabilizing agent and contaminants to reduce their mobility (stabilization).

Typical In Situ Vitrification

_{(FRTR 2001)} System

Solidification/Stabilization,

Applicability, duration, limitations, costs (FRTR 2001)

 Applicability for pollutants _

The target contaminant group for in situ S/S is generally inorganics (including radionuclides).

 Duration _

The timeframe for in situ S/S is short- to medium-term, while in situ ISV process is typically short-term.

 More detailed data _

Ex Situ Chemical Extraction, _{(FRTR 2001)}



Introduction:



Waste contaminated soil and extractant are mixed in an extractor, thereby dissolving the contaminants.



The extracted solution is then placed in a separator, where the contaminants and extractant are separated for treatment and further use.



Two main types of extraction are Acid Extraction, Solvent Extraction

Typical Chemical extraction

_{(FRTR 2001)} System

http://www.frtr.gov/matrix2/section4/D01-4-15.html

Applicability, Chemical extraction

, _ duration, limitations, costs (FRTR 2001) Applicability for pollutants _

primarily organic contaminants such as PCBs, VOCs, halogenated solvents, and petroleum wastes.

 Duration _

The duration of operations and maintenance for chemical extraction is medium-term.

 More detailed data _ Chemical Reduction/Oxidation, _{(FRTR 2001)} Ex Situ

 Introduction: _

Reduction/oxidation chemically converts hazardous contaminants to non-hazardous or less toxic compounds that are more stable, less mobile, and/or inert.



The oxidizing agents most commonly used are ozone, hydrogen peroxide, hypochlorites, chlorine, and chlorine dioxide. Typical Chemical _{(FRTR 2001)} Reduction/Oxidation Process http://www.frtr.gov/matrix2/section4/D01-4-16.html

Chemical Reduction/Oxidation , _

Applicability, duration, limitations, costs (FRTR 2001)

Applicability for pollutants _

Mainly for inorganics, but also effect against nonhalogenated VOCs and SVOCs, fuel hydrocarbons, and pesticides.

 Duration _ a short- to medium-term technology.

 More detailed data _ Dehalogenation, _{(FRTR 2001)} Ex Situ

 Introduction: _

Reagents are added to soils contaminated with halogenated organics.



The dehalogenation process is achieved by either the replacement of the halogen molecules or the decomposition and partial volatilization of the contaminants.

Typical BCD Dehalogenation

_{(FRTR 2001)} Process

Applicability, duration, Dehalogenation, limitations, costs (FRTR 2001)

 Applicability for pollutants _

halogenated SVOCs and pesticides

 Duration _

a short- to medium-term process

 More detailed data _ Separation, _{(FRTR 2001)} Ex Situ

 Introduction: _

Separation techniques concentrate contaminated solids through physical and chemical means.



These processes seek to detach contaminants from their medium (i.e., the soil, sand, and/or binding material that contains them).

Typical Gravity Separation

_{(FRTR 2001)} System http://www.frtr.gov/matrix2/section4/D01-4-18.html

Separation ,

Applicability, duration, limitations, costs (FRTR 2001) _ Applicability for pollutants _

SVOCs, fuels, and inorganics (including radionuclides)

 Duration _

a short-term process

 More detailed data _

Soil Washing, _{(FRTR 2001)} Ex Situ

 Introduction: _

Contaminants sorbed onto fine soil particles are separated from bulk soil in an aqueous-based system on the basis of particle size.



The wash water may be augmented with a basic leaching agent, surfactant, pH adjustment, or chelating agent to help remove organics and heavy metals. Typical Soil Washing Process ^{(FRTR 2001)} http://www.frtr.gov/matrix2/section4/D01-4-19.html

Applicability, duration, Soil Washing

, limitations, costs (FRTR 2001)

 Applicability for pollutants _

SVOCs, fuels, and heavy metals

 Duration _

typically short- to medium-term

 More detailed data _ Solidification/Stabilization, _{(FRTR 2001)} Ex Situ

 Introduction: _

stabilization Process Flow Diagram

http://www.frtr.gov/matrix2/section4/D01-4-21.html

, Applicability, Solidification/ stabilization _ duration, limitations, costs (FRTR 2001)

Applicability for pollutants _

The target contaminant group for ex situ S/S is inorganics, including radionuclides

 Duration _

Typical ex situ S/S is a short- to medium-term technology

 More detailed data _

Soil, Sediment, Bedrock and Sludge Treatment

Technologies Thermal Treatment ^{(FRTR 2001)}

 Thermal Treatment,

In Situ

 Hot Gas Decontamination,

Ex Situ

 Incineration,

Ex Situ

 Pyrolysis,

Ex Situ



Thermal Desorption, Ex Situ

(FRTR 2001) In Situ

Thermal Treatment ,

 Introduction: _

Steam/hot air injection or electrical resistance/electromagnetic/fiber optic/radio frequency heating is used to increase the volatilization rate of semi-volatiles and facilitate extraction.

Typical Six-Phase Soil Heating

_{(FRTR 2001)} System.

, Applicability, duration, limitations, Soil Heating costs (FRTR 2001)

 Applicability for pollutants _

SVOCs and VOCs

 Duration _

Thermally enhanced SVE is normally a short- to medium-term technology

 More detailed data _

(FRTR Ex Situ

Hot Gas Decontamination ,

2001) 

Introduction: _

The process involves raising the temperature of the contaminated equipment or material for a specified period of time.



The gas effluent from the material is treated in an afterburner system to destroy all volatilized contaminants. Typical Process Flow Diagram for Hot Gas

Decontamination of Explosives Contaminated

_{(FRTR 2001)} Equipment

Applicability, Hot Gas Decontamination, _ duration, limitations, costs (FRTR 2001)

Applicability for pollutants _

explosive items, such as mines and shells, being demilitarized (after removal of explosives) or scrap material contaminated with explosives.

 Duration _

a short-term technology

 More detailed data _

Incineration, Ex Situ

(FRTR 2001) 

Introduction: _ High temperatures, 870-1,200 °C, are used to combust (in the presence of oxygen) organic constituents in hazardous wastes.



Different types of combustion processes 

Circulating Bed Combustor (CBC) _ Fluidized Bed _ Infrared Combustion _ Rotary Kilns

Typical Mobile/Transportable

_{(FRTR 2001)} Incineration Process http://www.frtr.gov/matrix2/section4/D01-4-23.html

Applicability, duration, limitations, Incineration

, _ costs (FRTR 2001) Applicability for pollutants _

explosives and hazardous wastes, particularly chlorinated hydrocarbons, PCBs, and dioxins.

 Duration _

incineration technology ranges from short- to long-term

 More detailed data _

(FRTR 2001) Ex Situ

Pyrolysis ,

 Introduction: _

Chemical decomposition is induced in organic materials by heat in the absence of oxygen.



Organic materials are transformed into gaseous components and a solid residue (coke) containing fixed carbon and ash. Typical Pyrolysis Process ^{(FRTR 2001)} http://www.frtr.gov/matrix2/section4/D01-4-25.html

Pyrolysis ,

Applicability, duration, limitations, costs (FRTR 2001) _ Applicability for pollutants _

SVOCs and pesticides

 Duration _

incineration technology ranges from short- to long-term

 More detailed data _

(FRTR 2001) Ex Situ

Thermal Desorption ,

 Introduction: _

Wastes are heated to volatilize water and organic _ contaminants.

A carrier gas or vacuum system transports volatilized water and organics to the gas treatment _ system.

High Temperature Thermal Desorption (HTTD) _ _ 320 – 560 °C

Low Temperature Thermal Desorption (LTTD)

_ 90 – 320 °C

Typical High Temperature Thermal

_{(FRTR 2001)} desorption Process http://www.frtr.gov/matrix2/section4/D01-4-26a.html

Applicability, duration, Thermal desorption

, limitations, costs (FRTR 2001)

 Applicability for pollutants _

SVOCs, PAHs, PCBs, and pesticides

 Duration _

short-term technolgy

 More detailed data _

Ground Water, Surface Water, and Leachate

Biological Treatment ^{(FRTR 2001)} 

Enhanced Bioremediation,

In Situ

 Monitored Natural Attenuation,

In Situ

 Phytoremediation,

In Situ

 Bioreactors,

Ex Situ

 Constructed Wetlands,

Ex Situ

In Situ Enhanced Bioremediation, (FRTR 2001)

 Introduction: _

The rate of bioremediation of organic contaminants by microbes is enhanced by increasing the concentration of electron acceptors and nutrients in ground water, surface water, and leachate.



Oxygen is the main electron acceptor for aerobic bioremediation.



Nitrate serves as an alternative electron acceptor under anoxic conditions Typical Oxygen-Enhanced Bioremediation

System for Contaminated Ground water with Air

_{(FRTR 2001)} Sparging

Applicability, duration, Enhanced Bioremediation, _ limitations, costs (FRTR 2001)

Applicability for pollutants _

nonhalogenated VOCs, nonhalogenated SVOCs, and fuels

 Duration _

long-term technologies, which may take several years for plume clean-up

 More detailed data _

In Situ Monitored Natural Attenuation, (FRTR 2001)

 Introduction: _

Natural subsurface processes—such as dilution, volatilization, biodegradation, adsorption, and chemical reactions with subsurface materials—are allowed to reduce contaminant concentrations to acceptable levels.

Typical Monitoring Well Construction

_{(FRTR 2001)} Diagram http://www.frtr.gov/matrix2/section4/D01-4-32.html

Monitored Natural Attenuation , _

Applicability, duration, limitations, costs (FRTR 2001)

Applicability for pollutants _

VOCs and SVOCs and fuel hydrocarbons, maybe also halogenated VOCs

 Duration _

long-term technologies, which may take several years

 More detailed data _

In Situ ,

Phytoremediation (FRTR 2001)

 Introduction: _

Phytoremediation is a set of processes that uses plants to remove, transfer, stabilize and destroy organic/inorganic contamination in ground water, surface water, and leachate.

Typical In Situ Phytoremediation

_{(FRTR 2001)} System http://www.frtr.gov/matrix2/section4/D01-4-33.html

Applicability, duration, Phytoremediation, _ limitations, costs (FRTR 2001)

Applicability for pollutants _

organic contaminants from surface water, ground water, leachate, and municipal and industrial wastewater

 Duration _

Long-term technology which may take even decades for cleanup of a plume.

 More detailed data _

Ex Situ ,

Bioreactors (FRTR 2001)

 Introduction: _

Contaminants in extracted ground water are put into contact with microorganisms in attached or suspended growth biological reactors.



In suspended systems, such as activated sludge, contaminated ground water is circulated in an aeration basin.



In attached systems, such as rotating biological contractors and trickling filters, microorganisms are established on an inert support matrix.

Typical Rotating Biological Contactor

_{(FRTR 2001)} (RBC) http://www.frtr.gov/matrix2/section4/D01-4-42.html

Applicability, duration, ,

Bioreactors _ limitations, costs (FRTR 2001) Applicability for pollutants _

SVOCs, fuel hydrocarbons, and any biodegradable organic material

 Duration _

Bioreactors are a long-term technology. The process may take up to several years.

 More detailed data _

Ex Situ ,

Constructed Wetland (FRTR 2001)

 Introduction: _

The constructed wetlands-based treatment technology uses natural geochemical and biological processes inherent in an artificial wetland ecosystem to accumulate and remove metals, explosives, and other contaminants from influent waters.



The process can use a filtration or degradation process.

_{(FRTR 2001)}

Typical Constructed Wetlands System

http://www.frtr.gov/matrix2/section4/D01-4-43.html

Applicability, duration, Constructed Wetland, _ limitations, costs (FRTR 2001)

Applicability for pollutants _

organic matter; nutrients, such as nitrogen and phosphorus; and suspended sediments

 Duration _

Wetland treatment is a long-term technology intended to operate continously for years.

 More detailed data _

Ground Water, Surface Water, and

Physical/Chemical Treatment _{(FRTR 2001)} 

Leachate

In Situ 

In Situ

Passive/Reactive Treatment Walls,

In Situ 

In-Well Air Stripping,

In Situ 

Hydrofracturing,

Thermal Treatment,

Bioslurping,

In Situ 

Air Sparging,

In Situ 

Directional Wells,

In Situ 

Chemical Oxidation,

In Situ 

Dual Phase Extraction,

In Situ Air Sparging, (FRTR 2001)

 Introduction: _

Air is injected into saturated matrices to remove contaminants through volatilization. Typical Air Sparging System ^{(FRTR 2001)}

Air Sparging ,

Applicability, duration, limitations, costs ^{(FRTR 2001)} _ Applicability for pollutants _

VOCs and fuels

 Duration _

a medium to long duration which may last, generally, up to a few years _

 More detailed data _

In Situ _{(FRTR 2001)} Bioslurping, 

Introduction: _

Deep well injection is a liquid waste disposal technology.



This alternative uses injection wells to place treated or untreated liquid waste into geologic formations that have no potential to allow migration of contaminants into potential potable water aquifers.

_{(FRTR 2001)}

Typical Deep Well Injection System

http://www.frtr.gov/matrix2/section4/D01-4-54.html

Applicability, duration, ,

Bioslurping _{(FRTR 2001)} limitations, costs

 Applicability for pollutants _

VOCs, SVOCs, fuels, explosives, and pesticides

 Duration _

no data

 More detailed data _

In Situ Chemical Oxidation

, (FRTR 2001)

 Introduction: _

Oxidation chemically converts hazardous contaminants to non-hazardous or less toxic compounds that are more stable, less mobile, and/or inert.



The oxidizing agents most commonly used are ozone, hydrogen peroxide, hypochlorites, chlorine, and chlorine dioxide.

Typical Chemical Oxidation

(FRTR 2001)

System

Applicability, Chemical Oxidation

, (FRTR 2001) _ duration, limitations, costs

Applicability for pollutants _

many toxic organic chemicals, unsaturated aliphatic (e.g., trichloroethylene,TCE) and aromatic compounds (e.g., benzene)

 Duration _

Medium to long-term technology. Cleanup ranges from a few months to several years.

 More detailed data _

In Situ Directional Wells, (FRTR 2001)

 Introduction: _

Drilling techniques are used to position wells horizontally, or at an angle, to reach contaminants not accessible by direct vertical drilling.



Directional drilling may be used to enhance other in-situ or in-well technologies such as ground water pumping, bioventing, SVE, soil flushing, and in-well air stripping.

Typical Diagram of In Situ Air

Stripping with Horizontal Wells

(FRTR 2001)

Applicability, Directional Wells

, (FRTR 2001) duration, limitations, costs

 Applicability for pollutants _

no particular target group

 Duration _

no data

 More detailed data _

In Situ Dual Phase Extraction, (FRTR 2001)

 Introduction: _

A high vacuum system is applied to simultaneously remove various combinations of contaminated ground water, separate-phase petroleum product, and hydrocarbon vapor from the subsurface.

Typical Dual Phase Extraction

(EPA 1996)

Schematic

Applicability, Dual Phase Extraction _{(FRTR 2001)} , duration, limitations, costs

 Applicability for pollutants _

VOCs and fuels (e.g., LNAPLs)

 Duration _ Medium to long-term technology.

 More detailed data _

In Situ ,

Thermal Treatment (FRTR 2001)

 Introduction: _

Steam is forced into an aquifer through injection wells to vaporize volatile and semivolatile contaminants.



Vaporized components rise to the unsaturated zone where they are removed by vacuum extraction and then treated.

Subsurface Development

(FRTR 2001)

Process

Applicability, Thermal Treatment

, (FRTR 2001) _ duration, limitations, costs

Applicability for pollutants _

SVOCs and fuels

 Duration _

typically short to medium duration, lasting a few weeks to several months

 More detailed data _

In Situ ,

Hydrofracturing (FRTR 2001)

 Introduction: _

Injection of pressurized water through wells cracks low permeability and over- consolidated sediments.



Cracks are filled with porous media that serve as substrates for bioremediation or to improve pumping efficiency.

Typical Sequence of Operations for

_{(FRTR 2001)} Creating Hydraulic Fractures

Applicability, Hydrofracturing

, (FRTR 2001) duration, limitations, costs

 Applicability for pollutants _

a wide range of contaminant groups with no particular target group

 Duration _

no data

 More detailed data _

In Situ ,

In-Well Air Stripping (FRTR 2001) _

Introduction: _

Air is injected into a double screened well, lifting the water _ in the well and forcing it out the upper screen.

Simultaneously, additional water is drawn in the lower _ screen.

Once in the well, some of the VOCs in the contaminated ground water are transferred from the dissolved phase to _ the vapor phase by air bubbles.

The contaminated air rises in the well to the water surface where vapors are drawn off and treated by a soil vapor extraction system.

Typical UVB Vacuum Vapor

_{(FRTR 2001)} Extraction Diagram

Applicability, In-Well Air Stripping, _{(FRTR 2001)} duration, limitations, costs

 Applicability for pollutants _ halogenated VOCs, SVOCs, and fuels

 Duration _

no data

 More detailed data _ Passive/Reactive Treatment (FRTR 2001)

In Situ Walls,

 Introduction: _

These barriers allow the passage of water while causing the degradation or removal of contaminants.



Different types of walls: _ _ Funnel and Gate Iron Treatment Wall

Typical Passive Treatment

_{(FRTR 2001)} Wall (Cross-Section) http://www.frtr.gov/matrix2/section4/D01-4-41.html

Passive/Reactive Treatment Applicability, duration, limitations, costs _{(FRTR 2001)} Walls,

 Applicability for pollutants _

VOCs, SVOCs, and inorganics

 Duration _

generally intended for long-term operation to control migration of contaminants in ground water.

 More detailed data _

Ground Water, Surface Water, and

Leachate Containment

(FRTR 2001) 

Physical Barriers 

Deep Well Injection

(FRTR 2001) Physical Barriers,

 Introduction: _

These subsurface barriers consist of vertically excavated trenches filled with slurry.



The slurry, usually a mixture of bentonite and water, hydraulically shores the trench to prevent collapse and retards ground water flow.

Typical Keyed-In Slurry Wall

_{(FRTR 2001)} (Cross-Section)

http://www.frtr.gov/matrix2/section4/D01-4-53.html

, Applicability, duration, Physical Barriers _{(FRTR 2001)} _ limitations, costs

Applicability for pollutants _

Slurry walls contain the ground water itself, thus treating no particular target group of contaminants

 Duration _

no data

 More detailed data _

(FRTR 2001) Deep Well Injection,

 Introduction: _

Deep well injection is a liquid waste disposal technology.



Typical Deep Well Injection

_{(FRTR 2001)} System

http://www.frtr.gov/matrix2/section4/D01-4-54.html

, Applicability, Deep Well Injection _{(FRTR 2001)} duration, limitations, costs

 Applicability for pollutants _

VOCs, SVOCs, fuels, explosives, and pesticides

 Duration _

no data

 More detailed data _ Sources _ _{Research and Development. EPA/600/R-93/028.} _{EPA 1993. Decision-Support Software for Soil Vapor Extraction Technology Application: HyperVentilate. Cincinnati, OH: Office of} _  _{EPA 1996. A Citizen’s Guide to Soil Vapor Extraction and Air Sparging. Solid Waste and Emergency Response (5102G). EPA 542-} _{Transfer Committee. EPA/542/B-94/013.} _{EPA 1994. Remediation Technologies Screening Matrix and Reference Guide. Second Edition. DOD Environmental Technology} _{F-96-008 April 1996.} _ _{Navvac, Naval Facilities Engineering Command} Visitt 6.0 1997, Vendor Information System for Innovative Treatment Technologies, EPA Form 542-R-97-006

Remediation methods of polluted soils