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Page 2 of 2 <br /> ozone concentrations of just over 01 mg/liter <br /> and contact time of 15 second at temperatures <br /> of 25 degrees C (77 degrees F) and 30 degrees <br /> C (86 degrees F) " Streptococcus fecal€s are <br /> much more easily destroyed At ozone <br /> concentrations of about 0 025 mg/liter, 99 99% <br /> inactivation is obtained in 20 seconds or less at <br /> both temperatures Viruses are more resistant <br /> than bacteria Poliovirus types I, 11 and 111 are <br /> inactivated by exposure to concentrations of <br /> dissolved ozone of 0 4 mg/liter over a four <br /> minute contact period <br /> Oxidation of Inorganics <br /> In the case of iron, manganese and the several <br /> arsenate or arsenate compounds, oxidation takes <br /> place very rapidly, leaving insoluble compounds <br /> which are easily removed by an activated carbon <br /> filter Sulfide ions are oxidized sequentially to <br /> sulfate ions, an innocuous substance The first <br /> stage of this oxidation is very rapid, quickly and <br /> efficiently removing any sulfurous odors Nitrite <br /> ions are oxidized to nitrate ions, which are stable <br /> and innocuous <br /> Oxidation of Organics <br /> Ozone if a very powerful agent in treating <br /> organic materials Organics are either natural <br /> (hum€c and fulvlc acids) or synthetic <br /> (detergents , pesticides) in nature Some <br /> organics react with ozone very rapidly to <br /> destruction, within minutes or even seconds <br /> (phenol, formic acid), whereas other react more <br /> slowly with ozone (hum€c, fulvic acids, several <br /> pesticides, trichloroethane, etc ) In some cases, <br /> organic materials are only partially oxidized with <br /> ozone A major advantage of partial oxidation of <br /> organic materials is that in becoming partially <br /> oxidized, the organic materials become much <br /> more polar than originally, producing complex <br /> insoluble materials which are removed by <br /> activated carbon filters <br /> *Ozone in Water Treatment Applications and Eng ineenng, 1991 printing Lewis <br /> publishers <br /> Hess Machine International <br /> PO Box 639, Ephrata, PA 17522-0539, USA <br /> Phone 800 735 HESS or 717 733 0005 <br /> Fax 717 733 2255 <br /> E-mail ozonea@hessmachine com <br /> ittp //www hessmachine com/how—ozone htm 11/10/2004 <br />