POTENTIAL LIMITATIONS AND DRAWBACKSSmartStripping® applicability depends on contamination characteristics and on site geology and
hydrogeology. The technology can present limitation in low permeability soils and especially in stratified
and/or heterogeneous ones and i t is not recommended for confined aquifers.
STATE OF DEVELOPMENT AND PROCESS STANDARDISATIONPrevious case studies showed the effectiveness of the process on sites contaminated by petroleum
fractions. Moreover, the technology is under a process of standardisation and simulation through on-
site and lab scale demonstration to replicate the proposed solution and to clarify the limitations of the
stripping process for sites contaminated by chlorinated compounds. A numerical model using the finite
elements method (ABAQUS, CFX-ANSYS) is being developed to describe the processes occurring
in the saturated and unsaturated zones: stripping and vapor extraction. Furthermore, MATLAB is being
used for the simulation of the breakthrough curves for the adsorption of contaminants onto the granular
activated carbon filters. The goal of the developed model is to identify and analyze the main parameters
affecting the performance of the technology (air flow, injection pressure, soil characteristics and
hydrogeological properties of the site, etc.) in order to optimize the zone of influence of the remediation
technology. First results have already been used to redesign the SmartStripping® wells in order to
improve their efficiency. At the end of the project, the model will be an optimized tool for properly
designing the SmartStripping® technology in each particular site. This is, to determine the number
of SmartStripping® wells, their distribution over the space and the operation parameters (i.e. depth,
air flow etc.) to efficiently remediate a contaminated site.
ENVIRONMENTAL IMPACTS
The diagram below shows the schematic direct impacts of the technology to the environment: for each
300 Kg of extracted contaminant 30.000 cubic meter of groundwater are cleaned and NOT extracted
from groundwater and NOT released to superficial water or sewage.
INTRODUCTIONThe issue of contaminated groundwater remediation was addressed by minimizing the costs and the
time required to start up and complete the remediation and by optimizing the removal of the
contaminants. From attempts to solve these topics the SmartStripping® technology is born from the
need to start the “Misure di Messa in Sicurezza d'emergenza” and / or remediation without the need
to wait for the administrative authorisations for the discharge of water in sewer or superficial water
or air emission into the atmosphere. SmartStripping® combines a fast installation, a significant
reduction of environmental impacts with a high efficiency in removing volatile organic compounds
from groundwater.
FIELD OF APPLICATIONThe groundwater remediation technology called SmartStripping®, in compliance to Italian D.Lgs.
152/2006, is an innovative process for groundwater on-site remediation that reduces concentrations
of Volatile Organic Compounds (VOC) and semi-VOC which are produced by chlorinated compounds
(Tetrachloroethylene, triclhoroethylene, dichloroethylene, Viniyl Chloride) and petroleum fractions
(Benzene, Ethylbenzene, Styrene, Toluene and Xylene: BESTX, and Methyl tert-butyl ether: MTBE),
which are adsorbed into the unsaturated zone and dissolved in groundwater at industrial and civil
sites and especially at sites with underground storage tanks.
The system is suitable for use in permeable subsoils, unsaturated (vadose zone) and saturated
(groundwater) with a groundwater level between 1 and 10 meters deep under the ground level surface.
PRINCIPLE OF THE INNOVATIVE TECHNOLOGYThe process can be defined as an innovative combination of Air Sparging (AS) and Soil Vapor
Extraction (SVE): groundwater remediation occurs by enabling a transfer of contaminants from a
saturated zone (groundwater) to an unsaturated zone (vadose) by blowing heated air from existing
wells, which then enables groundwater stripping from the aquifer. The stripping allows the separation
of VOC and sVOC from groundwater that vent up to the unsaturated zone which is under a continuous
vacuum status, whereby the soil vapour is extracted. Vapours are treated with granular activated
carbon (GAC) adsorption filters before being re-injected into the groundwater to start the stripping
process again, through a continuous closed air-cycle system.
PREVIOUS APPLICATIONS OF THE TECHNOLOGYThe technology effectiveness was observed in some on-site pilot plants operating in Italy mainly
contaminated by petroleum fractions. Case studies allow to outline important issues, problems
encountered, lessons learned, solutions identified and remediation results.
The table below shows the remediation results after the application of the SmartStripping technology
in two sites. The following graph shows the comparison between the remediation results obtained in
a monitoring well in Site 2 by SmartStripping and P&T active in different period of time.
ADVANTAGES, REMEDIATION COSTS AND DURATIONThe process differs from other technologies (Pump & Treat, Air Sparging, Soil Vapor Extraction/Air
Sparging) as it is a green remediation process without any contaminant expulsion to the atmosphere,
surface water or sewage networks; in addition the remediation results are achieved quickly. During
remediation, water is not extracted from the groundwater and no substances (air or water) are released
into the environment.
The costs to achieve groundwater remediation by this new technology for site owners are competitive:
in the order of 1/5 compared to Pump & Treat costs. Also the startup time of the remediation is
competitive because, before installation, SmartStripping® doesn't need the authorisation Authorities
for water and gas discharge to the environment; this particularity reduces the intervention time.
The optimisation of the technology started
in December 2011 through funding
received from the European Commission
under the program Eco Innovation
(http://ec.europa.eu/environment/eco-
innovation/about/index_en.htm). Eco
Innovation is a financial project for the
development of innovative and eco-
friendly technologies that could contribute
to sustainability development by reducing
Environmental impacts.
Figure 2 – Pump & Treat compared to Smart Stripping application results in a monitoring well (Site 2); It could be seen that in P&Tactive period contaminants concentration hadn't decreased while, after one years of application, Smart Stripping strongly reducedconcentration of contaminant in groundwater, in particular of MTBE .
SMART-STRIPPING® Emission free groundwater remediation technology
Caridei F., Pagano M., Mosangini C.B., R. Verri - LA152 srl, Via Don Minzoni 11, 40121 Bologna, Italy - email: [email protected], tel: +390517457013, fax: +390513762637.
Jubany I., Marti V., M. Calderer.- Fundació CTM Centre Tecnològic Manresa Av. De les Bases de Manresa 1 - 08242 Manresa BCN, Spain, email: [email protected]
Saipem for Innovation, Remtech 19-21 September, 2012 Ferrara
zone of influence
groundwater level
Smart-Stripping® well
Activecarbon
filter
ground levelsampling S
sampling
Controlpanel
Activecarbon
filter
sampling S
sampling
Treated air pipes
Contaminated air pipe
Air flow
LEGEND
Muff screwed orsettled to central
pipe of the packer
ømm6x4
Blower pipe
Pipe to inflatethe packer
Operatingtwine
Operatingpipe
Air output
PACKER
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
giu-06 set-06 dic-06 mar-07 giu-07 set-07 dic-07 mar-08 giu-08 set-08 dic-08 mar-09
Piombo tetraetile Benzene Etilbenzene Stirene Toluene Idr. totali (n-esano) MTBE Xilene
Smart-Stripping®Pump & Treat
Co
nce
ntr
atio
n in
gro
un
dw
ate
r m
on
ito
rin
g w
ell
(ug
/l)
COSTS COMPETITIVE: 1/5 COMPARED TO P&T COSTS
VENTILATION OF UNDERGROUND IMPROVE NATURALDEGRADATION OF CONTAMINANTS
EASY INSTALLATION, MINIMAL DISTURBANCE TO SITEOPERATIONS
WATER TREATMENT (PHREATIC ZONE)
SOIL TREATMENT (VADOSE ZONE)
TREATED WATER IS NOT DISCHARGED TO SURFACE WATEROR INTO SEWERS
THE VOC ESTRACTED ARE NOT RELEASED INTO THEATMOSPHERE AFTER TREATMENT
LOW COST MAINTENANCE
LOW PRODUCTION OF WASTE
NO NEED FOR AUTHORISATIONS FOR WATER DISCHARGEAFTER TREATMENT
NO NEED FOR AUTHORISATION FOR GAS DISCHARGEAFTER TREATMENT
USE OF EXISTING WELLS FOR REMEDIATION
SHORT TREATMENT TIMES
DescriptionSmart
Stripping P&T AS SVE/AS
No.a. No.a.
No.a.
No.a. No.a.
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30.000 mc of water arecontained in aphreaticzone (porosity of 0,30)with a surface of 20.000square meters and agroundwater thicness of5 m.
phreatic zone
vadose zone
contaminated air
clean air
groundwater level
ACTIVATED
CARBONS
FILTER
(CAG)
DIRECTIMPACTS(ON SITE)
air flow OUT
air flow IN
contaminats concentration ingroundwater: 10.000 µg/l
600 Kg ActivatedCarbon absortioncapacity of 50%
One 600 Kg CAG retain300 Kg of contaminatstherefore 30.000 mc ofg r o u n d w a t e r a r et r e a t e d w i t h o u treleases to superficialwater or sewage.
phreatic zoneporosity 0,30
5 m
20.000
vadose zone
Location North Italy
Site 1: dismissed petrol refinery
Duration
N. SmartStripping® wells
N. monitoring wells
N. gas probe
about 16 months
6
6
3
Distance monitoring – remediation wells
Medium groundwater depth
Aquifer thickness
Type of pollutants
Start concentration (µg/l)
Final Concentration (µg/l)
between 2,5 and 5,5 m
10 m from surface
5 m
Aromatic HydrocarbonsTotal Hydrocarbons
16.000 Benzene20.000 Total hydrocarbons
1 Benzene<350 Tot. hydrocarbons
Central Italy
Site 2: operating gas station
1 years
2
4
4
between 10 and 12 m
1,5 m from surface
5,5 m
MTBE, BTEX,Total Hydrocarbons
2.000 Total hydrocarbons6.000 MTBE100 BTEX
46 Total hydrocarbons72 MTBE<0,23 BTEX
Description
LA152 SRL
POTENTIAL LIMITATIONS AND DRAWBACKSSmartStripping® applicability depends on contamination characteristics and on site geology and
hydrogeology. The technology can present limitation in low permeability soils and especially in stratified
and/or heterogeneous ones and i t is not recommended for confined aquifers.
STATE OF DEVELOPMENT AND PROCESS STANDARDISATIONPrevious case studies showed the effectiveness of the process on sites contaminated by petroleum
fractions. Moreover, the technology is under a process of standardisation and simulation through on-
site and lab scale demonstration to replicate the proposed solution and to clarify the limitations of the
stripping process for sites contaminated by chlorinated compounds. A numerical model using the finite
elements method (ABAQUS, CFX-ANSYS) is being developed to describe the processes occurring
in the saturated and unsaturated zones: stripping and vapor extraction. Furthermore, MATLAB is being
used for the simulation of the breakthrough curves for the adsorption of contaminants onto the granular
activated carbon filters. The goal of the developed model is to identify and analyze the main parameters
affecting the performance of the technology (air flow, injection pressure, soil characteristics and
hydrogeological properties of the site, etc.) in order to optimize the zone of influence of the remediation
technology. First results have already been used to redesign the SmartStripping® wells in order to
improve their efficiency. At the end of the project, the model will be an optimized tool for properly
designing the SmartStripping® technology in each particular site. This is, to determine the number
of SmartStripping® wells, their distribution over the space and the operation parameters (i.e. depth,
air flow etc.) to efficiently remediate a contaminated site.
ENVIRONMENTAL IMPACTS
The diagram below shows the schematic direct impacts of the technology to the environment: for each
300 Kg of extracted contaminant 30.000 cubic meter of groundwater are cleaned and NOT extracted
from groundwater and NOT released to superficial water or sewage.
FELSILAB
