Pollution Engineering - October 2008 - (Page 48)

Basic principle of operation In its most basic form, the technology utilizes a high-pressure arc of 50 microseconds, developed across heavy-duty, 2-cm diameter electrodes submerged in a liquid-filled confinement chamber. The energy source for this arc is provided by a common 480-VAC line power, which is conditioned and then stored in a pulseforming network (PFN). The energy is then transferred to the electrodes by means of high-current switches called ignitrons. The energy stored in the PFN typically has a physical volume of 240,000 cm3, which is transferred and compressed into an arc volume of approximately 0.03 cm3. Such a dramatic energy compression creates an extremely high-pressure plasma arc channel, which achieves a temperature of 25,000 Kelvin and a surface pressure of 106 atmospheres. A shock wave is launched off the plasma channel surface as an expanding spherical shell and traverses the entire treatment chamber volume in approxi- “ The system can effectively treat and disinfect any wastewater stream regardless of influent type. mately 300 microseconds. By properly configuring the chamber shape, the shock wave produces cavitation, with resulting ionization, free radicals, and hydrated electrons throughout the entire chamber volume. These species, along with the hard ultraviolet radiation that is emitted from the plasma arc, cause the destruction of bacteria and viruses, while the high-pressure gradient caused by the shock wave drops some marginally soluble compounds from the solution. In conjunction with a flocculant, the arc discharge modifies the electrical charge ” (zeta) potential of the suspended solids, causing them to coalesce, thereby facilitating their quick removal by a high-flux lamellar clarifier, which is located downstream from the pulser unit. The system can effectively treat and disinfect any wastewater stream regardless of influent type. The disinfection of even high-turbidity waste streams is accomplished due to the secondary effects (cavitation, ionization, etc.) produced by the extreme pressure wave launched from the plasma channel wall. Additionally, a literal bombardment of free electrons and other ionic species are also produced throughout the chamber volume. All of these produced effects result in aqueous waste streams being effectively treated in a short period of time. PE Richard A. Ayers is an inventor and technical director, Advanced Conversion Technologies Inc., Spring Valley, Calif. Tony Vivona, P.E. is a senior project manager for Jacobs Carter Burgess, Houston. Contact Tony at (713) 8032058 or Tony.Vivona@jacobs.com. • In Situ • Ex Situ • Soil Blending • Treatability Lab Contracting Company EXO TECH provides a full range of soil and groundwater remediation alternatives. EXO TECH specializes in chemical oxidation (ChemOx) remediation (in-situ/ex-situ) as well as bioremedial alternatives. www.exotechinc.com • 770.564.1444 48 Pollution Engineering OCTOBER2008 PLE10084Exotech.indd 1 9/12/08 1:24:22 PM 9/11/08 9:39:51 AM PLE10084Crom.indd 1 http://www.exotechinc.com http://www.cromaglass.com/ http://www.exotechinc.com

Table of Contents Feed for the Digital Edition of Pollution Engineering - October 2008

Pollution Engineering - October 2008 Contents The Editor’s Desk EnviroNews PE Events Legal Lookout Green Connections Clearing the Air Water for People There’s a New Show in Town Catching Wind for Clean Water Taking the Pressure off Blower Selection Pulsed Plasma Positive Redundancy Product Focus: Municipal Water Treatment Product Focus: Monitoring Equipment PE Products Classified Marketplace Advertisers Index State Rules

Pollution Engineering - October 2008

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