Vapor Phase Remediation Technologies Conference

GROUND WATER SAMPLING • WATER LEVEL & PRESSURE • WATER SAMPLE FILTRATION • GROUND WATER REMEDIATION • GEOPHYSICAL MEASUREMENTS

The Nielsen Environmental Field School, Inc.
2012 North American Environmental Field Conference & Exposition

VAPOR PHASE
REMEDIATION TECHNOLOGIES

2650 East 40th Avenue • Denver, Colorado 80205 • www.geotechenv.com


Agenda
• Introductions
• Vapor Intrusion Overview
• Vapor Phase Remediation Technologies
• Vapor Extraction
• Air Sparging



John Scripter
Technical Sales

JohnS@GeotechEnv.com
603.654.6840



Geotech Corporate Headquarters
Denver, Colorado USA

…a world leader in environmental technology,
manufacturing and product training since 1978.
www.GeotechEnv.com


In addition to corporate
headquarters and its
European office in
Barcelona, Spain, Geotech
operates 5 service centers
in the United States.
Texas North Carolina

Michigan Vermont Florida



an environmental industry
products leader since 1978

partners with federal, state,
local and international
government agencies

over 20,000 private sector
clients worldwide

distribution in 72 countries

provides products and product
training to colleges, universities
and technical schools around the globe



Audience Introductions
• Name
• Company name
• Experience with vapor phase remediation



What is Vapor Intrusion



The Facts About Vapor Intrusion
• 100,000 contaminated sites in US
in 2002*
• Contamination sources vary
• Problems associated with VI
– Health problems
– Decline in property values
– Liability for property owners

* Source: The National Research Council


Some Methods of Vapor Phase
Remediation
• Bioremediation
• Venting
• Bioventing
• Chemical Oxidation
• Excavation
• Dual Phase Extraction



Henry’s Law
At a given
temperature,
the mass of a
gas dissolved in
a liquid is proportional to
the pressure of the gas
acting on the liquid.



What Happens When Boiling Eggs?
• To vaporize
contaminants
– Increase temperature
– Decrease pressure



Lower Pressure and Energy Required
Melting Boiling
Molecular State at
Point Point
Formula 25oC
Name (oC) (oC)
methane CH4 -183 -164 Gas
ethane C2H6 -183 -89 Gas
propane C3H8 -190 -42 Gas
butane C4H10 -138 -0.5 Gas
pentane C5H12 -130 36 Gas
hexane C6H14 -95 69 Gas
heptane C7H16 -91 98 Gas
octane C8H18 -57 125 Gas
nonane C9H20 -51 151 Liquid
decane C10H22 -30 174 Liquid
undecane C11H24 -25 196 Liquid
dodecane C12H26 -10 216 Liquid
eicosane C20H42 37 343 Liquid
triacontane C30H62 66 450 solid



What is Soil Vapor Extraction ?
Soil Vapor Extraction (SVE) extracts contaminants for the
subsurface soil in a vapor form. Therefore , SVE systems
are designed to remove contaminants that have a
tendency to volatilize or evaporate easily such as volatile
organic compounds (VOC’s) and some semi-volatile
organic compounds ( SVOC’s) beneath the ground surface
in the unsaturated zone IE: Vadose zone. By applying a
vacuum through a series of underground wells,
contaminants are pulled to the surface as vapor or gas.



Soil Vapor Extraction (SVE)
• Extracts contaminants from
the subsurface soil in a vapor
form
• Only works on contaminants
which volatilize (or evaporate)
easily
• Vacuum through underground
wells
• Contaminants pulled to
surface as vapor or gas
• Will not remove heavy oils,
metals, PCB’s or dioxins



Soil Vapor Extraction
Applicability
The target contaminants group for in situ SVE are VOC’s and some
fuels. The technology is typically applicable only to volatile
compounds with a Henry’s law constant greater than 0.01 or a vapor
pressure greater than 0.5 mm Hg ( 0.02 inches Hg) Other factors,
such as moisture content, organic content, and air permeability of the
soil, will affect the SVE’s effectiveness. In situ SVE will not remove
heavy oils, metals, PCB’s, or dioxins.

Because the process involves a continuous flow of air through the
soil, however, it often promotes the in situ biodegradation of low-
volatility organic compounds that may be present.



Design Considerations
• Soil that has high percentage of fines and a
high degree of saturation will require higher
vacuums
• Large screen intervals are required in
extraction wells with highly variable
permeability's or stratification, which may
result in uneven delivery of gas flow from
contaminated regions



Design Considerations (continued)
• Soil that has high organic content or is extremely dry
has a high sorption capacity for VOC’s, which reduce
removal rates
• SVE is not effective in the saturated zone; however,
lowering the water table can expose more of the
contaminated zone to the SVE ( LNAPLS)
• Exhaust air from the in situ SVE system may require
treatment
• Residual liquids may require treatment or disposal



Data Needs
• Depth and areal extent of contamination
• Concentration of contaminants
• Depth to water table
• Soil type and properties e.g., structure, texture,
permeability, moisture content
• Pilot study: to determine radius of influence, flow
rate, optimal vacuum and contaminant mass
removal rates



Limitations
Factors that may limit the applicability and effectiveness
of the process include:
• Soil that has high percentage of fines and a high degree
of saturation will require higher vacuums ( $$$$$) and
/ or hinder on the system the operation
• Large screen intervals are required in extraction wells
with highly variable permeability's or stratification,
which otherwise may result in uneven delivery of gas
flow from contaminated regions.



Limitations (continued)
• Soil that has high organic content or is extremely dry
has a high sorption capacity for VOC’s, which reduce
removal rates.
• SVE is note effective in the saturated zone; however,
lowering the water table can expose more of the
contaminated zone to the SVE ( LNAPLS)
• Exhaust air from the in situ SVE system may require
treatment ($$$$)
• Residual liquids may require treatment or disposal(
$$$$)



First Thing -Establish CFM
What are you measuring?
• CFM is a CFM .. Or is it ?

• SCFM, ACFM, ICFM… What does it mean ?



SCFM
Definition of SCFM– the term SCFM stands for Standard
Cubic Feet Per Minute. It is referenced to a pre-specified
atmospheric pressure, temperature, and relative
humidity.

SCFM is referenced to 14.7 PSIA, 68 degrees F, and 0%
relative humidity.

By specifying these parameters, the mass flow of
compressed air and gas is clearly defined.



ACFM
Definition of ACFM– the term ACFM stands for Actual Cubic Feet Per
Minute.

The ACFM is dependent on actual site conditions: PSIA,
temperature, relative humidity.

By specifying these parameters, the mass flow of compressed air
and gas is defined on actual site conditions.

The larger the difference between site conditions and SCF conditions,
the larger the difference between SCF and ACF.



ICFM
Definition of ICFM– the term ICFM stands for Inlet Cubic Feet Per Minute.

The ICFM is dependent on the amount of air flow that enter in through the
air filter on the equipment

Vacuum blowers / Pressure Blower manufacturer usually rated at SCFM
conditions ….. BUT WHEN ARE YOU REALLY AT THOSE CONDITIONS ??

QUESTION: When you are measuring CFM, are you correcting for the
location conditions or are you assuming it is SCFM because the meters says
it reads in SCFM ?



BAROMETRIC PRESSURE
vs. ALTITUDE
FEET PSIA IN HG
0 (sea level) 14.70 29.92
1000 14.16 28.86
2000 13.66 27.82
3000 13.16 26.81
4000 12.68 25.85
5000 12.22 24.89
6000 11.77 23.98
7000 11.33 23.09
8000 10.91 22.22
9000 10.50 21.38
10000 10.10 20.58



Several blower options available depending on flow and vacuum
requirements….including Centrifugal Fans, Regenerative, Rotary Lobe
IE: Positive Displacement, Rotary Vane, Rotary Claw, Liquid Ring (Dual
Phase – Multi-Phase Extraction {MPE} )

CONFIGURATIONS AVAILABLE
• Compact skid mounted designs
• Trailer Mounted and Enclosures available
• Complete systems including knockout drums, effluent pumps,
temperature and vacuum switches, and controls



Soil Vapor Extraction “Rule of Thumb”
Blower Sizing Application
Blower CFM INHGG
Equipment Flow Range Vacuum Range
Centrifugal Fan 400-1500 1-3
Regenerative 20- 300 2-7
Rotary Lobe 50- 1000 5-15
Rotary Vane 5- 50 5- 28
Rotary Claw 30- 1000 5- 28
Liquid Ring 20- 1000 15- 28



• Compact skid mounted
designs
• Trailer Mounted and
Enclosures available
• Complete systems including
knockout drums, effluent
pumps, temperature and
vacuum switches, and controls
• A surface liner or clay cap
gives control over the path of
airflow.



Centrifugal Fan
Vacuum Application



Regenerative SVE in enclosure



Rotary Lobe
Vacuum Application



Rotary Vane
Vacuum application



Rotary Claw SVE Skid



Liquid Ring System
Vacuum Application for Multi- Phase



What is Air Sparging?
Since SVE cannot remove contaminants in the
saturated zone that lies below the water table,
Air Sparging technology pushes air into the
saturated zone to help flush (bubble) the
contaminants up into the unsaturated zone
where the SVE extraction wells can remove
them.



Air Sparging
• The process of blowing air directly into the ground
water.
• As the bubbles rise, the contaminants are removed
from the groundwater by physical contact with the air
(i.e., stripping).
• Air and contaminants are carried up into the
unsaturated zone (i.e., soil).
• As the contaminants move into the soil, a soil vapor
extraction system is usually used to remove vapors.



Air Sparging
Applicability & Limitations
For Air Sparging to be successful, the soil in the saturated zone must
be loose enough to allow injected air to readily escape up into the
unsaturated zone. Sites where coarse grained soil, sand, gravel are
good candidates. Tight clays and poor permeable soil only inhibit the
effectiveness of this technology. You can spend a lot of money on
electricity and accomplish very little when the soil are not conducive
for Air Sparging technology.

As with SVE, the added benefit of Air Sparging is that it provides an
oxygen source which helps stimulate aerobic biodegradation.



Before you can size an Air Sparge
Blower – Do a pilot test
• As with the SVE pilot, you will need to know just
how much air flow and PSIG will be required to
push the air into the formation.
• Also when incorporating the technology with an
SVE system how much is enough ? Too much ?
• Rule of thumb: size the Air Sparge unit air flow
at 1/3rd to 1/5th of the SVE system air flow. You
will want to be able to capture the vapors and not
allow for off-site migration.



Air Sparging an Example
• Easier at warmer
temperatures.
• Effected by moisture,
organics, air permeability of
the soil.
• Ineffective for heavy oils,
metals, PCB’s or dioxins.
• Enhances biodegradation of
low-volatility organic
compounds.
• Principles based on Henry’s
Law.



Air Sparge Blowers
Several blower options available depending on flow
and pressure requirements

Configurations Available
• Compact skid mounted designs
• Trailer Mounted and Enclosures available
• Complete systems to work in conjunction with an
SVE System



Air Sparge “Rule of Thumb”
Blower Sizing Application
Blower CFM PSIG
Equipment Flow Range Pressure Range

Regenerative 20- 300 <4
Rotary Lobe 50- 1000 1-15
Rotary Vane 5- 50 1- 20
Rotary Claw 50- 350 5- 30
Rotary Screw 20- 200 +30- 150



Regenerative



Rotary Lobe



Rotary Vane



Rotary Vane
(Dual System)



Rotary Claw
Pressure Application



Rotary Screw



For Example:
SV and Sparge Together

Vadose Zone

Graphic Source: Environmental Geoscience Environmental Science in the 21st Century Textbook by Robert Stewart



Carbon Treatment
• May be required to treat the off-
gas.
• 100 lb up to 20,000 lb vessels
available
• Reactivated carbon, virgin carbon,
coconut shell media and other
types of media available
depending on your application
• Low pressure and high pressure
units
• 50 lb bags for media replacement
available



Carbon Treatment
• Liquid Phase vessels
• 100 lb up to 20000 lb vessels available
• Reactivated carbon, virgin carbon, coconut
shell media and other types of media available
• Low pressure and high pressure units
• 50 lb bags for media replacement available



Liquid Phase Carbon Vessels



Carbon Treatment
• Vapor Phase vessels
• 100 lb up to 20000 lb vessels available
• Reactivated carbon, virgin carbon, coconut
shell media and other types of media available
• Low pressure and high pressure units
• 50 lb bags for media replacement available



Vapor Phase Carbon Vessels



Plume Eater
• Soils are flushed with oxygenated
groundwater
• Pulls from the groundwater surface and re-
injects, oxygenated water deep in the
formation, creating convection currents
• Accelerates bio-remediation
• Maximum efficiency with minimal power
• No sub-surface moving parts
• Works in a variety of soil types
• No net change in groundwater volume
• Options available for use with other gases
• In Situ Technology – No re-injection permits
or water treatment extraction required,
water never leaves the subsurface



Summary
• Get proper data
• Choose right blower for your application
• Geotech can help in the discussion
• Let’s get coffee



Many companies can provide the
equipment
to keep these industries within
environmentally acceptable standards

… but Geotech provides more than that.



…your partner in
creating the
environmentally
safe planet
of the future!


Vapor Phase Remediation Technologies Conference

Recommended

Recommended

More Related Content

Viewers also liked

Viewers also liked (6)

Similar to Vapor Phase Remediation Technologies Conference

Similar to Vapor Phase Remediation Technologies Conference (13)

More from Signarama Dtc

More from Signarama Dtc (6)

Vapor Phase Remediation Technologies Conference