Diesel Fuel Contaminated Water Treatment by Sonication: a Potential 20-Minute Sump and Stormwater Remedy

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Diesel Fuel Contaminated Water Treatment by
Sonication a Potential 20-Minute Sump and
Stormwater Remedy

• Presented by
• Roxanne Bessette, E.I.
• Co-author
• Dr. Robert W. Peters, P.E.
• UAB Department of Civil, Construction, and
  Environmental Engineering
• Presented at the 2007 Alabama Water Resources
  Conference, Orange Beach, AL, September 5-7, 2007.

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Situation Diesel Usage Diesel Spills
Receiving Waters Impacted
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Current Treatment Gravity Phase Separation
and Mechanical Recovery
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Limitations of Current Treatment

• Cannot handle large spills rapidly
• Cannot handle peak storm flows of the
  Southeastern U.S.
• Minimal removal at lt100mg/L, NPDES OG discharge
  limit is usually 15 mg/L and
• Overflow must be sent to local POTW at a per
  gallon service charge (!).

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Sonochemical Treatment Unique Aspects

• Organic compounds rapidly oxidized (seconds to
  minutes)
• Rapid emulsification of immiscible liquids
  (seconds)
• Extreme conditions on the micro-scale with
  ambient bulk solution conditions

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Acoustically Induced Cavitation
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Cavitation Quick Overview

• Microbubble is spherical at first and then
  shrinks rapidly
• Microbubble formed near solid surface yielding an
  asymmetric implosion expelling a 400 kph liquid
  jet
• The jet develops opposite the solid surface and
  moves towards it
• Implosion heats gases to 5,500ºC
• Pressure 500-1000 atm at collapsing interface
• Microbubble shown is 150 µm can be much larger
  depending on kHz

Source Suslick, Scientific American Feb 1989
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Acoustical Cavitation Micro High Energy
Rapidly Quenched

• In less than a µs, implosion energy causes
• Ionization
• N2 ? NOx ? NO2-
• Radical Creation
• O2 and H2O ? OH?
• Luminescence
• Visible and UV
• Pressures of 500 atm
• Temperatures of
• 5,500oC for gases
• 2,100oC for immediately surrounding liquid

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Bench-Scale Treatment Method
Experimental Conditions

• Initial Off Road No. 2 Diesel Fuel Concentration
  
• 195 mg/L
• Volume Treated
• 100 mL
• Sonicator Frequency
• 20 kHz
• Sonicator Max Power Output
• 950 W

Sonication Equipment Branson 910 BC Power
Supply and 902 J Converter
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Bench-Scale Treatment Method
Experimental Matrix
Rep Time Sonicated (min) Time Sonicated (min) Time Sonicated (min) Time Sonicated (min) Time Sonicated (min) Time Sonicated (min) Time Sonicated (min) Time Sonicated (min) Time Sonicated (min) Time Sonicated (min)
1 CV 0 2 5 5DUP 5MS 10 20 IB Meth BlK
2 CV 0 2 5 5DUP 10 10MS 20 IB Meth BlK
3 CV 0 2 5 5DUP 5MS 10 20 IB Meth BlK
CV Calibration Verification DUP Duplicate
Sample MSMatrix Spike IBInstrument Blank
Meth BlkMethod Blank
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Bench-Scale Analytical Method
Sample Preparation by SW846 3510C Separatory
Funnel Liquid to Liquid Extraction
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Bench-Scale Analytical Method
Sample Analysis by SW846 8015B Nonhalogenated
Organics Using GC/FID
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Bench-Scale Diesel Sump Water Treatment Results
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Electrical Energy per Mass of Contaminate Removed
(kWh/kg)
where P Power, (kW) t treatment time,
(min) V Volume of Treated Solution, (L)
Ci Initial Contaminate Concentration, (mg/L)
Cf Final Contaminate Concentration, (mg/L)
93 removal of No. 2 Diesel Fuel requires
8,203.8 kWh/kg (0.0082 kWh/mg) This number is
approximately 3-4 fold greater than the TCE and
CCl4 sonication energy requirements found by
Peters, et al. (2005) Paper presented at the
15th Annual AEHS Meeting and West Coast
Conference on Soils, Sediments, and Water, San
Diego, CA.
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Published Sonochemical Degradation Rates of
Various Organic Compounds(Reality Check)
Compound Sonication Condition k (min 1) (Mass Transfer Rate Constant) Source
2,4,6-trinitrotoluene (TNT) 20kHz 0.0010 M.R. Hoffmann et al., Ultrasonics Sonochemistry 3 (1996) S163-S172
Carbon Tetrachloride 20 kHz, 130W 0.1980 M.R. Hoffmann et al., Ultrasonics Sonochemistry 3 (1996) S163-S172
2-Chlorophenol 20 kHz, 96W 0.0002 Ku et al., Water Res. 31 (1997) 929-935
Anthracene (PAH) 20kHz, 600W 1.5660 Z. Laughrey et al., Ultrasonics Sonochemistry 8 (2001) 353-357
Phenanthrene (PAH) 20kHz, 600W 0.6600 Z. Laughrey et al., Ultrasonics Sonochemistry 8 (2001) 353-357
Pyrene (PAH) 20kHz, 600W 0.6240 Z. Laughrey et al., Ultrasonics Sonochemistry 8 (2001) 353-357
Styrene (Hydrocarbon) 520kHz, 14.6W 0.0622 De Visscher et al., J. Phys. Chem., 100 No.28 (1996)
Ethylbenzene (Hydrocarbon) 520kHz, 14.6W 0.0446 De Visscher et al., J. Phys. Chem., 100 No.28 (1996)
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Removal Efficiencies Comparison
Belt Strippers (common current technology)

OG mg/L 10,000 200 100 15
Oil/water removal efficiency per API 90 50 Minimal Common NPDES Discharge Limit
DRO is a subgroup of OG Removal time frame
commonly on the order of hours to days
Sonication (proposed technology)
198 mg/L No.2 Off-road Diesel 95 removed ?10
mg/L in 20 min
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Bench-Scale Diesel Sump Water Treatment
Conclusions

• Sonochemical Treatment Potential
• Rapid treatment to handle storm event runoff
  (minutes vs. days)
• Exceeds gravity separation treatment efficiency
  by 45
• 0.002 kWh/mg removal energy requirement for
  200mg/L initial concentration
• Tested conditions achieves NPDES discharge
  standard of 15 mg/L

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Acknowledgements

• Dr. Robert W. Peters, P.E.
• for opportunities and encouragement
• UAB Department of Civil, Construction,
• and Environmental Engineering
• -for research facilities support
• Sound Environmental Practice LLC
• -for funding

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Thanks for this opportunity.Questions?