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: cm@ecosurvey.it, 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: irene.jubany@ctm.com.es

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

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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