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27 October 2005 <br /> AGE-NC Project No. 96-0235 <br /> Page 4 of 11 <br /> TPH(g) hydrocarbons were diminished by >-90% in the soil by day 5 of ozonation. Individual <br /> hydrocarbon compounds decreased by 10-100x in both 8260 and 8020 soil analyses. TPH(g) <br /> hydrocarbons in the aquifer water phase increased— 30x after ozonation. This is probably simple <br /> mass transfer from the soil to water phase due to the oxidative loss of organic sorption sites in the <br /> soil. A decrease of 317 mg/kg TPH(g) occurred in the soil, with an increase of 2.7 mg/L in the <br /> aquifer water. Looking at the reaction vessel soil and water as though it comprised a section of the <br /> subsurface being ozonated, there was a 340/(33+3) or a 94% decrease in TPH(g) after 5 days, <br /> indicating that ozonation is an effective means of decomposing hydrocarbons. MTBE was `absent' <br /> from the Initial (and Final) soil presumably due to its high water solubility; MTBE decreased from <br /> 91 to <5 ppb in the aquifer water due to ozonation. <br /> The amount of hydrocarbon lost to purging by ozone was negligible compared to that oxidized by <br /> ozone,as evidenced by the"Ozone degassed front and back samples".As expected,simple purging <br /> alone, using a much higher gas to soil ratio in a U-shaped purge and trap sparge vessel, was <br /> completely effective. <br /> 1200 ppb acetone and 360 ppb MEK were observed in the Final water(but not Final soil) sample <br /> and small amounts of MEK were found in the front and back organic liquid traps downstream from <br /> the sample reaction vessel.The trace benzene found in the liquid traps may be an artifact of the tygon <br /> tubing used to connect them to the ozone destroying cartridges. Our lab has observed trace benzene <br /> arising from the degassing of tygon tubing in the past.Trace amounts of acetone and MEK were also <br /> found in the"N2 Sparged Sample".This discourages their description as ozonation by-products and <br /> their explanation remains unresolved. Acetone is ambient laboratory contaminant,but MEK is not. <br /> Acetone's diffusion through Teflon tubing, induced by flowing gas on the receiving side, with its <br /> partial breakdown to MEK is a possible explanation. <br /> Metals: Major AND Trace Elements <br /> Water <br /> The Initial water contained a fairly high sediment content, 1-3%,but the Final Water had negligible <br /> to low sediment,and the sediment content and precipitation reactions are believed to be responsible V <br /> for some difficulties in reconciling some metals data.This led to our reliance on"Total Recoverable" <br /> metals (TRM) values, for which data trends were clear. <br /> TRM determinations for the Initial and Final aquifer water were performed as follows. The Initial <br /> water including its suspended sediment was acidified with—2%HNO3 and remained in contact for <br /> a minimum of 16 hours.The aliquot of water withdrawn from the reaction vessel for the Final water <br /> was treated similarly. This is equivalent to "Total Recoverable Metals" as described by the EPA <br /> in method 200.8. This procedure was used because it was found that the amount of time that the <br /> water stood unpreserved prior to filtering and preserving dramatically affected the recovered <br /> �.. "dissolved" metals content. <br /> Advanced GeoEnvironmental,Inc. <br />