FIELD EVALUATION OF ULTRASOUND ENHANCEMENT OF PERMEABLE TREATMENT WALLS. AAMOD S. SONAWANE MAJOR ADVISER: Dr. REINHART

Transcription

1 FIELD EVALUATION OF ULTRASOUND ENHANCEMENT OF PERMEABLE TREATMENT WALLS AAMOD S. SONAWANE MAJOR ADVISER: Dr. REINHART

2 Outline Objective Introduction Ultrasound Field Application of Ultrasound LC 34 PTW Performance Evaluation of LC 34 PTW Denver Federal Center PTW

3 Outline (Continued) Conclusion Recommendations

4 Objective To Demonstrate the Application of Ultrasound Energy to Field Sites.

5 Introduction Chlorinated Compounds Previous Technologies Used for Remediation PTWs Problems Associated with PTWs Methods to Restore Iron Effectiveness Ultrasound

6 Ultrasound Periodic Stress Waves Cavitation and Streaming Phenomena Effects of Ultrasound Various Applications of Ultrasound Ultrasonic Cleaning

7 Ultrasound Equipment Omni Directional Probe Telsonic Radial Transmission Two Resonators with Frequencies 25-kHz and 40-kHz Compact and Portable Transducer Radiation Tube (Varied Lengths- 75 cm to 172cm) Generator Connection

8 Field Application of Ultrasound Launch Complex 34, Cape Canaveral Air Force Station Use: Saturn Rockets Launches from 1959 through Contamination: Trichloroethylene (TCE) Used to Clean Saturn Rockets and Parts

9 Field Implementation of Ultrasonic Unit 122 cm Direction of Groundwater Flow 36 cm to 54 cm Note: Not to scale 10.2 cm Diameter Sonication Well 9

10 Field Implementation of Ultrasonic Unit Generator Cable Well Casing Generator Cable Top of Transducer Welded Brackets Welded Bracket Well Casing TOP VIEW Note: Not to Scale 10

11 Schematic Diagram of LC 34 PTW

12 US Application

13 Effectiveness of Ultrasound Application 30 Minutes and 90 Minutes of Ultrasound Application Use of Two Resonators with Frequencies 25-kHz and 40-kHz Drilling Core Samples Kinetic Studies

14 Testing the Reactivity of Iron by Use of Bag Experiments 1.0 L Tedlar Bags 0.5 L Native Groundwater Deoxygenate Water Add Iron to the Bag (Pre or Post Ultrasound) Spike with TCE

15 Field Sonication Results Variables:Time and US Frequency Relative Depth Shallow m. Intermediate m. Deep m. 30 min at 40 khz 90 min at 40 khz 30 min at 25 khz 90 min at 25 khz Percentage Improvement of Half-Life Compared to Unsonicated Samples

16 Performance Evaluation of LC 34 PTW- TCE Average Upstream TCE Concentration: 1.5 mg/l TCE Concentration Inside the Wall: Non- Detectable TCE Concentration Downstream of the Wall: Non-Detectable

17 Performance Evaluation of LC 34 PTW- Trans-DCE Average Upstream Trans-DCE Concentration: 0.9 mg/l. Inside the Wall,Trans-DCE Reached Non- Detectable level after 400 Days. Downstream of the Wall, Trans-DCE Reached Non-Detectable level after 600 Days.

18 Performance Evaluation of LC 34 PTW- 1,1 DCE Non-Detectable Concentrations of 1,1 DCE Upstream or Downstream of the Wall Inside the Wall, 1,1 DCE Reached Non- Detectable level after 700 Days.

19 Performance Evaluation of LC 34 PTW- Cis-DCE Upstream Cis-DCE Concentration: 36 mg/l Inside Wall Concentration: Below MCL Downstream Wells Non-Detectable Except MW-3 MW-3 Concentration Declining from 2 mg/l to 0.24 mg/l, But still above MCL. No Specific Reason can be attributed to this Behavior.

20 Performance Evaluation of LC 34 PTW- Cis-DCE 2.5 Concentration (mg/l) Days since Wall Installation MW-1 MW-2 MW-3

21 Performance Evaluation of LC Probable Reasons 34 PTW- Cis-DCE Groundwater Flow Around the Wall Cis-DCE Concentration Declining due to Dilution with Treated Groundwater Zone of High Contaminant Concentrations

22 Performance Evaluation of LC 34 PTW- VC Upstream VC Concentration Increased to 4.5 mg/l Inside wall: Lower Concentrations, Reached Non-Detectable level after 780 Days. Downstream Wells: Non-Detectable Except MW-3. MW-3 Concentrations Increased over Time to 2 mg/l.

23 Performance Evaluation of LC 34 PTW- VC 2.5 Concentration (mg/l) Days since Wall Installation MW-1 MW-2 MW-3

24 Performance Evaluation of LC 34 PTW- OW Concentration (mg/l) Days since Wall Installation VC cis-dce

25 Performance Evaluation of LC 34- MW-3 Higher Concentrations of Cis-DCE and VC Break Through of VC. Zone of High Contaminant Concentrations. Less Iron Content in the Wall in front of MW-3 Flow around the Wall. Proper Investigative Studies.

26 Denver Federal Center- PTW Site Description Ultrasound Application Drilling Core Samples Kinetic Studies

27 Site Description Funnel and Gate System: 4 Gates Contaminants of Concern: TCE, 1,1 DCE, TCA, 1,1 DCA Gate 2 Selected for Study. 1,1 DCE Downstream Concentrations Attributed to Loss of Reactivity of Iron

28 Site Description

29 Ultrasound Application Use of Two Resonators with Frequencies 25-kHz and 40-kHz. Installation of 10-cm Ultrasound Access Tubes 90 Minutes of Ultrasound Application

30 Ultrasound Access Tubes Location

31 Ultrasound Application

32 Pre- and Post- Ultrasound Samples Angled Geoprobe Sample Collection Samples Preserved in an Anaerobic Environment. Drilling Core Samples

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35 Kinetic Studies 1.0 L Tedlar Bags 0.3 L Native Groundwater Deoxygenate Water Add Iron to the Bag (pre or post ultrasound) Control Samples Spike with TCE

36 Effect of Ultrasound Application Access Tube Depth of the Sample (m) Specific t 1/2 Ultrasound Treatment % Change in Half-life 25-kHz (UAT-1) NO YES kHz (UAT-2) NO YES kHz NO NO YES 40

37 Conclusion- LC 34 PTW All Inside Wells and Downstream Wells have Reached MCL with the Exception of MW-3 MW-3 Behavior is a Mystery. Ultrasound Application Increased Reactivity of Iron Higher Sonication Period: More Effective 25-kHz Resonator Proved more Effective than 40-kHz Resonator.

38 Conclusion: DFC PTW 25-kHz Resonator: 64-73% Decrease in Half-life for TCE Degradation 40-kHz Resonator: 40% Decrease in Halflife for TCE Degradation Similar Results as those for NASA PTW. Groundwater Analysis after Ultrasound Treatment: Declination of 1,1 DCE Concentration in Downstream Well.

39 Conclusion Results from Both the Sites Indicate that Ultrasound effectively removes Corrosion Products and Precipitates, Increasing the Reactivity of Iron.

40 Recommendations Installation of Two Monitoring Wells at LC-34. One Well between MW-1 and MW- 2. Second Well in front of MW-3, close to the Wall. Screen Level should be 5-7m. Ultrasound Application to Entire Wall Vertical Geoprobe Sampling. Iron Samples should be Maintained in Anaerobic Environment

41 Recommendations Monitoring of Wells near Ultrasound Access Tubes Should be Continued. More Kinetic Studies on Iron Collected from DFC PTW. Next Potential Study: Determination of Interval between Ultrasound Applications to Field Sites.

42 Acknowledgement Dr. Reinhart Dr. Clausen Dr. Geiger Dr. Randall Dr. Jackie Quinn Christina Clausen