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I <br /> • <br />' The soil ozone demand was found to range from 450-750 mg 03/kg field moist soil As <br /> shown in Figure 2, the concentration of ozone decreased rapidly in the first 90 minutes <br /> for Replicate A The concentration in Replicate B was nearly identical to the <br /> concentration in the Control until about 180 minutes This was due to heterogeneity of <br /> the soil--in Replicate A, the soil dispersed within about 30 minutes, while the Replicate <br /> B soil dad not begin to disperse until about 120 minutes presumably due to a higher clay <br /> content The SOD of Replicate A (480-750 mg 03/kg soil) was therefore calculated for <br /> time points <_ 90 minutes, while SOD of Replicate B (360-450 mg 03/kg soil) was <br /> calculated for time points >_ 180 minutes and used time= 120 minutes as "time 0" <br /> These results are consistent with the ozone demand observed in the COC Removal test <br /> (Section 3 1 ) Based on the soil ozone demand and the GW demand calculated from the <br /> results in this section, the estimated ozone demand in the COC Removal test was 230-330 <br /> Ing 03 (160-180 mg due to GW and 72-150 mg due to soil) A dose 2,800 mg 03 (-10 <br /> ftimes the estimated requirement) was applied in 6 hours in the COC Removal test and <br /> resulted in complete removal of COCl (except acetone) from the aqueous phase Most <br /> of the excess 03 applied was unnecessary because most of the COCl were destroyed <br /> within the first hour (Up to 96% of each COC was volatilized in the first hour in the <br /> Nitrogen test Since the flowrate was the same in both the nitrogen and ozone test, a <br /> similar mass of each COC would have been volatilized in the ozone test if destruction did <br /> not occur However, the mass of COCl to the ozone test was very low indicating that <br /> COCs had been destroyed The ozone dose in the first hour was 450 mg 03 ) <br /> 8 <br /> Note Sample A sod dispersed rapidly Amount of Soil Added <br /> 7 Sample B did not disperse much until control(no soil) <br /> about 120 minutes <br /> -�-2 5 g sodlL Rep A <br /> 6 -W-2 5 g soWL Rep B <br /> `as <br /> 5 <br /> r 4 <br /> 0 <br /> 0 3 <br /> N <br /> 6 <br /> 0 50 100 150 200 250 300 350 <br /> Time,minutes <br /> Figure 2. Soil Oxidant Demand Test. <br /> PRIMA Environmental 12 Eva[of Ozone <br /> January 27,2005 ENSR-Unocal 5098 <br />