Co-Authors Isaac Aboulafia PE Doug Carvel PE Larry Rader PG - - PowerPoint PPT Presentation

CHLORINATED SOLVENT REMEDIATION IN BRAZIL VIA IN-SITU CHEMICAL OXIDATION

Rich Cartwright PE, CHMM*, CPIM*

Co-Authors

 Isaac Aboulafia PE  Doug Carvel PE  Larry Rader PG

Facility Overview

 Active manufacturing of pots/pans  Historical release of tetrachloroethylene (PCE)  PCE affected nearby drinking water wells  Two affected zones

 4-9 m: sandy clay  9-12 m: clay

 Pre-ISCO pump

& treat for 6 years

SCALE (m): 10 40 20

ISCO Technical Challenges

 Pressure & temperature control  Vertical contaminant migration  Chemical storage and safety  Operational interruptions

International Challenges (Brazil or otherwise…)

 Safety culture  Lack of ISCO experience  Chemical handling  Language, hand signals, etc.  Units of measure  Logistics for equipment & chemicals

ISCO Process

 Oxidant and reagent screening  Continuous dosage refinement

Oxidant demand empirical modeling (initial dosage determination)

1.

Design Parameter Evaluation (dosage refinement)

2.

Pilot field application (dosage refinement)

3.

Full-scale field application

Oxidant Screening/Selection

Oxidant Fluorine (F) Hydroxyl Radical (OH• ) Sulfate Radical (SO4• ) Ozone (O3 ) Sulfate (S2O8

• 2 )

Hydrogen Peroxide (H2O2 ) Permanganate (MnO4

• )

Chlorine (Cl2 ) Volts(1) 3.0 2.7 2.6 2.4 2.1 1.8 1.7 1.4

(1) = Provided by FMC Corporation

Activating Sodium Persulfate

Activation methods for sodium persulfate:

 Presence of transition metal  Heat (> 40oC)  Hydrogen peroxide (H2O2)  Alkaline conditions (high pH)

Catalyzed hydrogen peroxide (CHP) uses synergistic activation via 3 of the 4 activation methods:

• 1. presence of transition metal
• 2. heat
• 3. hydrogen peroxide

ISCO Temperature Trend

Temperature Trends

50 70 90 110 130 150 170 190 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Days Temperature ( 0F)

Monitoring Well CleanOX App. Well

Laboratory Treatability Test

• ISCO is not solely stochiometric
• Total oxidant demand (TOD) is determined via

predictive empirical modeling and laboratory testing

• Oxidant demand and viability confirmed via parallel
• xidant formulation treatability tests
• Treatability test objectives include:

1. determine reactivity of the site media 2. select the optimum reagent formulation 3.

• bserve adverse reactions, if any

Oxidant properties

 reactive with most metals  highly acidic (pH < 2)  requires careful handling/use

Chemical Storage:

 stored in cool/dry area  injection solution homogenized in vented,

chemically compatible vessels

Chemical Safety

Flammability

Health

1 1

Reactivity

Application Metrics

 Target treatment Area: 2,000 m2  38 injection wells total

 16 multi-level injection  22 single-level injection

 1,500 m of hose  30 tons of chemicals applied  10 days of reagent application

Application Well Coverage (ROI)

Flow Control

5 levels of flow control

Reagent Distribution Manifolds

Treatment Area

Pressure Monitoring and Flow Control

Monitoring/Thermocouples

Results

 10 days of safe injection  75% reduction in contaminant mass  Area reduced

 2,000 m2 (~½ acre) to 200 m2 (~2,000 ft2)

Well Pre-ISCO PCE (9/2009) PCE Post-ISCO (4/2010) PCE Reduction (ug/L) (ug/L) (ug/L) % MW-14 1,200 ND 1,200 100% MW-15 12,330 3,552 8,778 71% MN-10 34,105 8,875 25,230 74% MW-19 50 45 5 10% MW-25 10,553 4,373 6,180 59% MW-26 3,950 3,489 461 12% MW-27 3,950 1,092 2,858 72% MW-28 493 591 (98)

• 20%

MW-29 9 ND 9 100% =Treatment goal met after 1st application Average: 62%

www.mecx.net

Rich Cartwright, PE, CHMM*, CPIM* 713 . 412-9697 Richard.Cartwright@mecx.net MECX, LP 3203 Audley St Houston, Texas 77098

Questions