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 SCALE (m): 0 20 40  4-9 m: sandy clay 10  9-12 m: clay  Pre-ISCO pump & treat for 6 years

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) D esign P arameter E valuation (dosage refinement) 1. Pilot field application (dosage refinement) 2. Full-scale field application 3.

Oxidant Screening/Selection Volts (1) Oxidant Fluorine (F) 3.0 Hydroxyl Radical (OH• ) 2.7 Sulfate Radical (SO4• ) 2.6 Ozone (O 3 ) 2.4 Sulfate (S 2 O 8 -2 ) 2.1 Hydrogen Peroxide (H 2 O 2 ) 1.8 Permanganate (MnO 4 - ) 1.7 Chlorine (Cl 2 ) 1.4 (1) = Provided by FMC Corporation

Activating Sodium Persulfate Activation methods for sodium persulfate:  Presence of transition metal  Heat (> 40 o C)  Hydrogen peroxide (H 2 O 2 )  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 190 Temperature ( 0 F) 170 150 130 110 90 70 50 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Monitoring Well Days CleanOX App. Well

Laboratory Treatability Test ISCO is not solely stochiometric o Total oxidant demand (TOD) is determined via o predictive empirical modeling and laboratory testing Oxidant demand and viability confirmed via parallel o oxidant formulation treatability tests Treatability test objectives include: o 1. determine reactivity of the site media 2. select the optimum reagent formulation 3. observe adverse reactions, if any

Chemical Safety Oxidant properties 0  reactive with most metals Flammability  highly acidic (pH < 2) 1 1  requires careful handling/use Reactivity Health Chemical Storage:  stored in cool/dry area  injection solution homogenized in vented, chemically compatible vessels

Application Metrics  Target treatment Area: 2,000 m 2  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)

5 levels of flow control 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 Pre-ISCO PCE PCE Post-ISCO (9/2009) (4/2010) PCE Reduction Well (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 1 st application Average: 62%  Area reduced  2,000 m 2 (~½ acre) to 200 m 2 (~2,000 ft 2 )

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