Remediation of CCl4
DNAPL at Spanish Site
Ian Ross Ph.D.,
FMC Environmental Solutions
Health and Safety
• Project Team wearing FMC baseball cap
• Logistics –flight times / taxi’s
• Hotel –exits, facilities, tapas, drinks
• Bus –entry exit / traffic
• On site –No entry into remediation area –remain at boundary
–Trip Hazards –uneven ground
Air Pollution Control
FMC offers SOx and NOx abatement product technologies for coal-fired plants.
Natronx, LLC, EnProveTM sodium sorbents are engineered to remove SO2, SO3, HCl and HF
from stack gases.
FMC’s patented PerNOxide™ technology, licensed from NASA, uses H2O2 to oxidize nitrogen
oxide (NO) and elemental mercury (Hg˚) in flue gas into forms that can be captured by flue-
gas scrubbing devices.
Soil and Groundwater Remediation
FMC’s Klozur® persulfate, Daramend® bioremediation technology, and the EHC® family
of integrated carbon & ZVI technologies, are available globally to provide cost effective
solutions for the remediation of contaminated soil, groundwater, and sediments.
Water Treatment
FMC VigorOx® peracetic acid is a safe and environmentally-benign biocide. FMC can work
directly with customers to understand their unique challenges and develop turnkey solutions
tailored to meet their specific treatment needs while ensuring compliance with individual
state regulations. Our proven water treatment applications include the wastewater and the
oil services industries.
59-01-EIT-DL
Presentation Outline
• FMC Environmental Solutions
• In Situ Chemical Oxidation and Surfactants
• Site History
• Project Overview
• Site Investigation
• Remediation Implementation • Results
What is In Situ Chemical Oxidation?
ISCO Basics
• Addition of Oxidants into the subsurface to facilitate the conversion of recalcitrant and toxic compounds to CO2 and H2O or less toxic / more biodegradable intermediates
• ISCO reduces contaminant mass through the oxidation process
• Suitable for saturated and/or vadose zone source and plume treatment
• Application generally via
– injection to aquifers
– soil mixing to more cohesive lithologies
• ISCO maybe combined with other techniques (e.g. enhanced or monitored natural attenuation)
Persulfate
Advantages
• Oxidation mechanisms via direct oxidation (relatively strong) and production of radicals (sulphate SO4˙ and hydroxyl OH˙)
• Thermodynamically very strong –can oxidise multiple organic compounds
• Does not produce gaseous breakdown products or significant heat
• Persist in the aquifer for multiple months
• Reaction rate and thus persistence can be controlled by activation method
• High aqueous solubility (>40%) for diffusion and advection –large ROI
• Can be activated over a wide range of geochemical conditions
• Can be mixed into unsaturated soils to destroy a wide range of target organics
• Ease of handling as oxidant is supplied as a granular solid
• Leaves residual sulfate in formation to stimulation biodegradation
Disadvantages
• Persulfate without activation is kinetically slow to react
• Corrosive / material compatibility
• Have to add an activator
Granular Persulfate
Chemistry and Stoichiometry
S2O8-2 + 2H+ + 2e- 2HSO4
-1
1. Direct Oxidation:
2 S2O8-2 + C2Cl4 + 4 H2O 2 CO2 + 4 Cl- + 4 H+ + 4 HSO4
-1
3 kg / kg
persulfate anion
PCE
2. Radical Formation:
However, persulfate anion kinetics are generally too slow for most contaminants. As a result, you
must activate persulfate to form the sulfate radical.
S2O8-2 + activator SO4•- + (SO4•- or SO4
-2)
• Activation produces a radical which is more powerful and kinetically fast
• Radicals propagate and stoichiometry is not possible.
• FMC always recommends using an activator
A stoichiometric equation can be derived e.g. for PCE
Klozur® Activated Persulfate
produces a radical which is more powerful and kinetically fast
FMC always recommends using an activator
proper activation method is based on contaminant, site lithology, and hydrogeology
Klozur® Persulfate Chemistry
S2O8-2 + activator SO4•- + (SO4•- or SO4
-2)
Heat Iron H2O2 High pH
Purchase of FMC’s Klozur® Persulfate includes rights to practice
the inventions covered by the patents in the purchase price of the product.
Sustainable Solution: Utilizes Hydroelectric Power
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Competitive Scope
volts
F2 3.0
OH• 2.7
SO4• 2.6
O3 2.4
S2O8-2 2.1
H2O2 1.8
MnO4- 1.7
HClO 1.6
Cl2 1.4
ClO2 1.3
ClO4- 1.4
stro
ng
er o
xid
ize
r
Fenton’s
•Treats wide range of contaminants
•Short subsurface lifetime
•Difficult to apply in reactive soils
Ozone
•Treats wide range of contaminants
•Short subsurface lifetime
•Limited use in saturated zone
Permanganate
•Treats limited range of contaminants
•Long subsurface lifetime
•Potential effects on hydrogeology
Klozur® Activated Persulfate
•Treats wide range of contaminants
•Sulfate radical forms slower than
the hydroxyl radical, allowing a larger
radius of influence
Higher the oxidation potential the stronger the oxidizer
59-01-EIT-DL
Klozur® Persulfate Activation Chemistry
Primary Methods to Activate Klozur® Persulfate
1. Heat
• Kinetically Fast (Reaction Kinetics with Contaminant)
• Capable of Destroying Wide Range of Contaminants
• Temperature Range: 35 – 45º C
[FeEDTA]
2. Metal Chelates
• Slower Reaction Kinetics (Extends Persulfate Lifetime in Subsurface)
• Capable of Destroying: Chlorinated Ethenes, BTEX, PAHs, MTBE
• Target in Groundwater: 150 - 500ppm soluble Fe
M+2
Chelant
59-01-EIT-DL
Klozur® Persulfate Activation Chemistry
3. Hydrogen Peroxide
• Kinetically Fast (Reaction Kinetics with Contaminant)
• Capable of Destroying Wide Range of Organics
• Benefit of two powerful radical species.
• Typical Concentration Ratio: 5:1, moles peroxide : mole persulfate
4. High pH / Alkaline Activation
• Kinetically Fast (Reaction Kinetics with Contaminant)
• Capable of Destroying Wide Range of Organics
• pH between 10.5 – 12 (maintained while the Klozur is present)
• Pre-treatment titration is needed to determine the soil’s natural pH
resistance
S2O8-2 + H2O2 → 2SO4• + 2OH•
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Klozur® Activated Persulfate
Chlorinated Solvents
PCE, TCE, DCE
TCA, DCA
Vinyl chloride
Carbon tetrachloride
Chloroform
Chloroethane
Chloromethane
Dichloropropane
Trichloropropane
Methylene chloride
TPH
BTEX
GRO
DRO
ORO
creosote
Oxygenates
MTBE
TBA
Chlorobenzenes
Chlorobenzene
Dichlorobenzene
trichlorobenzene
Phenols
phenol
Pentachlorophenol
nitrophenol
Freons
Pesticides
DDT
Chlordane
Heptachlor
Lindane
Toxaphene
MCPA
Bromoxynil
PAHs
Anthracene
Benzopyrene
Styrene
Naphthalene
Pyrene
Chrysene
trimethylbenzene
Others
Carbon disulfide
PFOS / PFOA
Aniline
PVA
TNT / DNT
1,4 Dioxane
Examples of Contaminants Destroyed by Klozur Persulfate
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Oxidation State Examples
C C
Cl H
Cl Cl
PCE = +2
C C
Cl Cl
Cl Cl
C C
Cl Cl
Cl Cl
+
+ +
+
-
- -
-
C C
Cl H
Cl Cl
+
+ +
-
- -
+
-
Cl
C
Cl
Cl Cl
+
-
+ +
+
Cl
C
Cl
Cl Cl
-
- -
TCE = +1 / +2 CCl4 = +4
H
C
H
H H
H
C
H
H H
CH4 = -4
- -
-
-
+ +
+ +
Klozur® Activated Persulfate Application Methods
Direct push
Fixed well
In situ soil mixing
Ex situ soil mixing
Forming a persulfate solution
Fixed wells
Direct push rig In situ mixing 59-01-EIT-DL
Technology Background: S-ISCO®
Surfactant-enhanced In Situ Chemical Oxidation
www.verutek.com
• VeruSOL desorbs & emulsifies NAPL/sorbed
contaminants o Brings into aqueous phase
• Activators generate free-radicals o Sulfate radicals (SO4•
- or SO4-2)
o Hydroxyl radicals (OH∙)
• Free radicals oxidize aqueous-phase contaminants
• Primawave Pressure-Pulsing Injection Enhancement • Wavefront Technology Solutions US Inc
VeruSOL®
Biodegradable,
Plant-based Surfactant
&
Co-solvent Mixtures
Free Radical
Oxidant Systems
Safe, Permanent
Source
Destruction
Remedial Technologies for In Situ Treatment
Less Hydrophobic
• Ethanol
• Acetone
• MTBE
• Methylene chloride
• Vinyl chloride
• Ketones
• 1,2 DCA
• Chloroform
Hydrophobic
• Diesel & gasoline
• BTEX; benzene, xylene, toluene, ethyl benzene
• Naphthalene
• Chlorinated solvents; PCE, TCE
• Heating oil
• Nitrophenol
• Often found at fueling/petro stations, manufacturing sites
Very Hydrophobic
• PAHs; acenapthene, anthracene, benzo(a) pyrene, benzo (b) flouranthene
• Heavy fuel; # 6 oil
• Often found at creosote, gas works or MGP sites
When to Use Surfactant
• S-ISCO with VeruSOL & alkaline-
activated persulfate destroyed 96%
SVOCs and 99% PAHs in 28 days
• VeruSOL-3 increased solubility up to 29x
0
100
200
300
400
500
600
700
800
0 2 5 10 25
Co
nce
ntr
atio
n (m
g/L
)
VeruSOL-3 Concentration (g/L)
Solubility Enhancement with VeruSOL-3: VOC & SVOC Concentration vs Surfactant Concentration
SVOCs
VOCs
0
50
100
150
200
250
300
350
400
NONE Alkaline Activated Persulfate (100 g/L, pH>12)
Conc
entr
atio
n (m
g/kg
)
Column Condition
Day 28: Concentrations of Total SVOCs & PAHs
SVOCs (mg/kg)
PAHs (mg/kg)
www.verutek.com
Remedial Design: Typical Treatability Study
S-ISCO incorporates VeruSOL– plant-based & biodegradable surfactant/co-solvent mixtures into oxidation systems to address bound & NAPL contamination (Figure A).
• VeruSOL increases the solubility of contaminants that have normally low solubility (e.g
NAPLs), making them available for oxidative destruction.
Volume: 1.4 m3 Surface area: 20 m2 Volume: 1.4 m3 Emulsion Diameter: 1 millimeter Surface area: 8,495 m2 Approximately 2.5 orders of magnitude higher
Volume: 1.4 m3 Emulsion Diameter: 1 micrometer Surface area: 8,499,978 m2
Approximately 5 orders of magnitude higher
Emulsification and Surface Area
10’
0.5’
10’
Emulsions increase interface area between oxidant and contaminant by several orders of magnitude
Groundwater
NAPL
Products Made at the Site
May 8, 2013
May 8, 2013
• Facility closed • Land held on Leasehold basis –handback in progress • Remediation required as part of process to return land • Elevated concentrations of CCl4 (>540 mg/L) and DNAPL droplets observed plus other chlorinated VOC’s • Geology comprises fine sands to approx. 45m where clay layer exists • Groundwater shallow (3 m bgl), saline water (intrusion at 30m bgl) • Negligible hydraulic gradient • VOC’s at elevated concentrations at depth (40-45m) • Investigations indicate point source • Remediation focussed on mass removal (DNAPL) • After thorough technical review of all available remedial techniques surfactant enhanced in situ chemical oxidation was chosen • Klozur® persulfate with NaOH activation and Verusol were both injected to the DNAPL source zone • Concentrations of cVOC’s were depleted by >98% in the main DNAPL zone within 3 months • Negligible increases in cVOC’s were observed in surrounding monitoring wells • Further groundwater monitoring is ongoing
Project Outline
Site Investigation
May 8, 2013
• Site Investigations to depth performed using differing drilling techniques:
• Water flush • Air flush • Core recovery
• Source Area Defined • Limited spatial area, • Defined deep source
• High natural organic matter (high Foc) • Black anaerobic water • Chloride from saline intrusion • DNAPL at depth-comprised >90% of contaminant mass
Geology
May 8, 2013
Unit A. Concrete Slab
Unit B. Clayey Made ground
Unit C. Brown sand with silt
Unit D. Black Siliceas Sands
Unit E. Sands interbedded with organic silts
Unit F. Black organic silts
Legend
Cross Section
May 8, 2013
Unit A. Concrete Slab
Unit B. Clayey Made ground
Unit C. Brown sand with silt
Unit D. Black Siliceas Sands
Unit E. Sands interbedded with organic silts
Unit F. Black organic silts
May 8, 2013
Laboratory Work
May 8, 2013
• Laboratory Tests performed using site soil and groundwater • Soil Oxidant Demand determined • Treatment efficacy confirmed
• Persulfate activation methods tested • Kinetics of oxidation with increasing oxidant concentrations
• Aquifer pH buffering capacity evaluated
Lab Results
May 8, 2013
Site Work
May 8, 2013
Infrastructure
May 8, 2013
Well cleaning
Liquid Silicates from
manufacturing plant
May 8, 2013
Persulfate distribution
May 8, 2013
Results
May 8, 2013
• Injection of alkaline activated Klozur persulfate (65 tons) and Verusol to wells Fac2 and Cas6c • cVOC concentration decreases observed in all wells screened across deeper area • Electrical conductivity increases observed as a result of oxidant • cVOC’s in groundwater from Fac2 decreased by 98% in 3 months • cVOC’s in groundwater from remaining deep wells decreased by 87% in 3 months • Further groundwater monitoring ongoing
May 8, 2013
Results
May 8, 2013
Results
May 8, 2013
Summary
• Remediation required as part of process to return land • Elevated concentrations of CCl4 (>540 mg/L) and DNAPL droplets observed plus other chlorinated VOC’s •VOC’s at elevated concentrations at depth (40-45m) • Investigations indicate point source • Remediation focussed on mass removal (DNAPL) • Klozur® persulfate with NaOH activation and Verusol were both injected to the DNAPL source zone • Concentrations of cVOC’s were depleted by >98% in the main DNAPL zone within 3 months • Further groundwater monitoring is ongoing
Questions?
Our remediation chemistries have had a positive impact in the communities in which we live and do business. We believe sustainability demands the use of the right chemistry - building on sustainable innovation, operations, and business practices - as we seek to grow and improve the quality of people’s lives everywhere. The use of hydropower in our manufacturing process contributes significantly to our sustainability initiative; having one of the lowest carbon footprints in the environmental market for chemical remediation technologies.
Ian Ross Ph.D.
Technical / Business Manager EMEA
FMC Environmental Solutions
Phone: +44 (0)7855745531
www.environmental.fmc.com
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