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Water Treatment Using Ultrasound-Induced Cavitation

Water Treatment Using Ultrasound-Induced Cavitation. Michael Anderson Mechanical Engineering Center for Intelligent Systems Research Greg Möller Food Science and Toxicology. Experts consider options over sources of city water Associated Press, September 20, 2004

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Water Treatment Using Ultrasound-Induced Cavitation

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  1. Water Treatment Using Ultrasound-Induced Cavitation Michael Anderson Mechanical Engineering Center for Intelligent Systems Research Greg Möller Food Science and Toxicology UI ECE Research Colloqiuim

  2. Experts consider options over sources of city water Associated Press, September 20, 2004 TWIN FALLS, Idaho – After years of drought and a declining Snake River Aquifer, experts are not ruling out any local lakes or even wastewater plant effluent as a source of city water. Just five years ago, Twin Falls thought it had accumulated enough water sources to last for 50 years. Considering that diminishing supply, the city now finds itself pretty much starting over. But since the first plan was devised, rounding up that water has become more complicated. The federal government recently said Twin Falls must lower naturally occurring arsenic levels in about 40 percent of its supply. A committee is looking at a number of sources for water along the Snake River Canyon, including Devil's Corral, Rock Creek, seepage tunnels and wastewater treatment plant effluent. It's also working with state officials to change the use of certain water rights to purchase them. UI ECE Research Colloqiuim

  3. Problem Statement • Water quality and quantity is vitally linked to public health, environmental quality and economic opportunity. • Many communities are now “development limited” due to limited water supply and limited wastewater discharge opportunity. • New science suggests bioactive substances in human wastewater and other discharges are a direct threat. UI ECE Research Colloqiuim

  4. Disinfection Clarifiers Secondary Aeration Primary Settling Solids Digestion Pump & Screen NPDES Permit to Pollute UI ECE Research Colloqiuim

  5. Challenges • Pharmaceuticals, endocrine disrupting substances, personal care products, and various pesticides and herbicides are found in many natural waters. • Wastewater discharge and non-point source pollution. • Micropollutants, PPCPs, PhAS, Biocidals. • Concern about environmental and public health impact of these substances. • Need for better science and technology. • Disposal and treatment options. • Detection of chemicals and biological impacts. • Green science and engineering. UI ECE Research Colloqiuim

  6. Example: Antibiotic Soap • Triclosan, the common antiseptic, was found in 57.6% of the United States water resources surveyed (USGS). • A broad-spectrum antibacterial - antimicrobial agent classified as a Class III drug by the FDA. • Bacteriostatic activity against a wide range of bacteria has lead to popular use in: • Personal care products, cosmetics, anti- microbial creams, acne treatment, lotions and hand soaps, plastics, polymers and textiles. • Linked to estrogenic effectsin fish. UI ECE Research Colloqiuim

  7. Micropollutants in U.S. Waters • USGS study tested U.S. waters for 95 chemicals ranging from perfumes to antidepressants. • Of 139 streams tested, 80% had at least one of the chemicals and 50% had seven or more. • Continual introduction  “persistence”. • Threat to water reuse and to “captive” aquatic biota. UI ECE Research Colloqiuim

  8. Excretion • When we take medication, our bodies excrete the active chemicals with as much as 90% of the ingested drug still in a potent form. UI ECE Research Colloqiuim

  9. Estradiol Endocrine Disrupters • Chemicals which interfere with endocrine system function. • Endocrine system consists of glands and the hormones they produce. • Pituitary, thyroid, and adrenal glands, the female ovaries and male testes. UI ECE Research Colloqiuim

  10. Male-to-Female Sex Reversal • Salmon: “a high incidence (84%) of a genetic marker for the Y chromosome in phenotypic females sampled from the wild... It appears likely that female salmon with a male genotype have been sex reversed, creating the potential for an abnormal YY genotype in the wild that would produce all-male offspring and alter sex ratios significantly.” • High Incidence of a Male-Specific Genetic Marker in Phenotypic Female Chinook Salmon from the Columbia River. Nagler, JJ; Bouma, J; Thorgaard, GH; Dauble, DD Environmental Health Perspectives. Vol. 109, no. 1, pp. 67-69. Jan 2001 UI ECE Research Colloqiuim

  11. HypospadiasIncomplete Masculinization of the Reproductive Tract • Paulozzi LJ, Erickson JD, Jackson RJ. 1997. Hypospadias trends in two U.S. surveillance systems. Pediatrics 100:831-834. • Paulozzi LJ 1999. International trends in rates of hypospadias and cryptorchidism. Environmental Health Perspectives 107:297-302. • Gray, LE, C Wolf, C Lambright, P Mann, M Price, RL Cooper and J Ostby. 1999. Administration of potentially antiandrogenic pesticides (procymidone, linuron, iprodione, chlozolinate, p,p'-DDE, and ketoconazole) and toxic substances (dibutyl- and diethylhexyl phthalate, PCB 169, and ethane dimethane sulphonate) during sexual differentiation produces diverse profiles of reproductive malformations in the male rat. Toxicology and Industrial Health. 15:94-118. UI ECE Research Colloqiuim

  12. Cavitation • Oscillating pressure field (ultrasonic) or fluctuating pressure in shear layer of water jets (hydrodynamic) cause pre-existing microscopic bubble nuclei to grow explosively and then collapse violently. UI ECE Research Colloqiuim

  13. Simulated Cavitation Bubble Dynamics • Sequence from high speed film of ~1cm cavitation bubble collapse. • Note formation of high speed re-entrant jet (3,4) 1 2 UI ECE Research Colloqiuim 4 3

  14. Pressure Field Associated with Bubble Collapse Cavitational activity is directly proportional to the number density of particles present in the medium (Madanshetty and Apfel, 1991). UI ECE Research Colloqiuim

  15. Ultrasonic Water Treatment: How Does It Work? • Acoustic waves in water can resonantly vibrate gas bubbles • Resonant vibration can result in violent bubble collapse, causing temperatures and pressures as high as 5000K and 1700atm • High pressures and temperatures cause chemical reactions among the gas in the bubble and water vapor, one of them the dissolution of water into H● and OH● (free radicals). • Free radicals diffuse into the water and oxidize harmful chemicals. UI ECE Research Colloqiuim

  16. How Hot? New York Times, “Tiny Bubbles Implode With the Heat of a Star”, March 15 2005 UI ECE Research Colloqiuim

  17. Sonochemistry • Free radicals are formed as a result of the cavitation microbubbles which are created during the negative pressure period of sound waves • Acoustic vs hydrodynamic • Dissolved gas & nucleation sites needed • Ozone • Milder operating conditions • Lower T, P UI ECE Research Colloqiuim

  18. Postulated Reaction Mechanisms and Locations • Within bubble. • Hydroxyl and other radical attack in gas phase. • Pyrolysis in gas phase. • Ion reactions. • At or near bubble surface in liquid. • Hydroxyl and other radical attack in liquid phase. • Formation and reaction with supercritical water. • In bulk liquid solution. • Hydroxyl and other radicals attack in liquid phase. • Intermediate reactions and reaction products. UI ECE Research Colloqiuim

  19. Mechanism of Cavitation OxidationAdvanced oxidation process • Water dissociates under extreme physical conditions generated at cavitation bubble collapse. • Calculated up to ~5-10,000°K and 500-1200 atm (sec lifetime). • Forms free radicals: H2O  H + OH H + H H2 OH + OH H2O2 OH + ORGANIC  CO2 + H2O + … UI ECE Research Colloqiuim

  20. Higher Frequency UltrasonicsMegasonics ~1MHz • Current research is finding that for oxidations higher frequencies may lead to higher reaction rates. • More, smaller, faster collapsing bubbles • Less OH radical recombination? UI ECE Research Colloqiuim

  21. Rayleigh-Plesset Equation UI ECE Research Colloqiuim

  22. Resonance Frequencies Air Bubbles in Water UI ECE Research Colloqiuim

  23. Moderate Vibration Source: Leighton, “The Acoustic Bubble”, Academic Press, 1994 Ro= 2 mm, fo=1.7 kHz f = 10 kHz PA= 2.4 bar = 0.27 MPa UI ECE Research Colloqiuim

  24. Stable Cavitation Ro= 0.10 mm, fo 10 kHz f = 10 kHz PA= 2.4 bar = 0.24 MPa Source: Leighton, “The Acoustic Bubble”, Academic Press, 1994 UI ECE Research Colloqiuim

  25. Stable Cavitation Made by Tom Matula, Applied Physics Laboratory, University of Washington, available on Wikipedia UI ECE Research Colloqiuim

  26. Transient Cavitation Ro= 60 m Ro= 50 m f = 10 kHz PA = 0.24 MPa Ro= 10 m Ro= 1 m Source: Leighton, “The Acoustic Bubble”, Academic Press, 1994 UI ECE Research Colloqiuim

  27. Spectra for Stable and Transient Cavitation Source: Frohly, et al., JASA, 108(5), 2012-2020, 2000 UI ECE Research Colloqiuim

  28. Spectra for Stable and Transient Cavitation Source: Frohly, et al., JASA, 108(5), 2012-2020, 2000 UI ECE Research Colloqiuim

  29. Spectra for Stable and Transient Cavitation Source: Frohly, et al., JASA, 108(5), 2012-2020, 2000 UI ECE Research Colloqiuim

  30. Effect of Pressure Amplitude on Acoustic Cavitation UI ECE Research Colloqiuim

  31. State of the Art- Water Treatment Source: Destaillats, et al., “Ind. Eng. Chem. Res., 40, pp. 3855-3860, 2001 3096 J/Liter for ½ “removal” MO @ 67 W/Liter UI ECE Research Colloqiuim

  32. Diffusion of Ultrasound in Tube Reactor Total Length of Tube = 120 cm Tube Diameter = 9 cm UI ECE Research Colloqiuim

  33. Copper Backing Collimator to Diffuse Ultrasound UI ECE Research Colloqiuim

  34. Pilot Scale Flow Ultrasonic Cavitation5 Cell Apparatus and FilterRadiator Design UI ECE Research Colloqiuim

  35. High Achievable Energy Densities UI ECE Research Colloqiuim

  36. Luminol Chemi-Lumeniscence UI ECE Research Colloqiuim

  37. Ultrasound Distribution 100% Drive= 100 Watts = 15.1 W/Liter 70% Drive = 43 Watts Length of Tube = 55 cm Measurement 15 cm from transducer UI ECE Research Colloqiuim

  38. Spectra at Low Power UI ECE Research Colloqiuim

  39. Spectra at High Power UI ECE Research Colloqiuim

  40. Test Reactor Sonochemical Measurements Diameter = 7.5 cm Length = 27 cm Volume = 1.2 Liter 0.7 MPa at 95 Watts Typical = 80 Watts/Liter UI ECE Research Colloqiuim

  41. Relative Oxidizing Strength UI ECE Research Colloqiuim

  42. Redox Potential: 18 MΩ-cm Water UI ECE Research Colloqiuim

  43. Fe2+/Mn2+ Oxidation UI ECE Research Colloqiuim

  44. Potassium Iodide UI ECE Research Colloqiuim

  45. Potassium Iodide UI ECE Research Colloqiuim

  46. Potassium Iodide 3096 J/Liter for ½ “removal” MO @ 67 W/Liter UI ECE Research Colloqiuim

  47. Indigo Carmine Dye Bleaching UI ECE Research Colloqiuim

  48. Observations/Conclusions • 0.7 MPa achieved at 15 W/Liter in 3.5 Liter volume. • Sonochemical activity caused by stable cavitation. Potential for increased performance with transient cavitation. • At 0.7 MPa and 56 W/Liter, measured 6180 J/Liter for t1/2 KI in 1 Liter volume (possibility for 15 W/Liter with tube reactor). • Compares with unknown pressure, 67 Watt/Liter, 3096 J/Liter for t1/2 MO in 45 Liter volume. UI ECE Research Colloqiuim

  49. UI Intellectual Property • Parabolic transducer source (6,818,128) • Radiator tube reactor array (6,911,153) • Biphasic/triphasic US/ozone/metal-oxide catalytic water filter (patent pending) UI ECE Research Colloqiuim

  50. UI ECE Research Colloqiuim

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