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The ozone demand of the soil will be estimated by adding a small amount of soil to <br /> ozone-saturated water, then measuring the concentration of ozone over time using the <br /> ' indigo method. A control in which no soil is added will also be performed. Each test will <br /> be conducted in duplicate and two soil amounts will be used, giving a total of six ozone <br /> consumption curves for soil. The soil ozone demand (SOD,j is taken to be the <br /> ' difference in ozone consumption in the presence and absence of site material. It was <br /> calculated according to the equation <br /> ' SODO, _ {[03 Consumed].,troi—[03 Consumed].;i)x V/M EON 4 <br /> Where: <br /> ' SOD = soil oxidant demand in mg 03 consumed/g soil <br /> [03 Consumed]wnb, = change in 03 concentration in the absence of soil in mg/L <br /> ' [03 Consumed]sojj = change in 03 concentration in the presence of soil in mg/L <br /> V= volume of ozonated water in L <br /> M = mass of soil in g <br /> ' The ozone demand of the groundwater will be estimated by adding a small <br /> amount of groundwater to ozone-saturated water, then measuring the residual <br /> ' ozone concentration over time using the indigo method. A control in which <br /> ozone-demand-free water rather than groundwater is used will also be run. Each <br /> test will be conducted in duplicate and two amounts of GW will be tested, giving a <br /> ' total of 6 ozone-consumption curves. The GW ozone demand (GWOD.) is taken <br /> to be the difference in ozone consumption in the presence and absence of GW. It <br /> will be calculated according to the equation <br /> ' GWODo�_ {[03 Consumed].ntroj— [03 Consumed]w;,) x VtotNcW EON 5 <br /> ' Where: <br /> GWOD,, = GW oxidant demand in mg 03 consumed/L GW <br /> ' [03 Consumed].ntrol = change in 03 concentration in the absence of GW in mg/L <br /> [03 Consume&jj = change in 03 concentration in the presence of GW in mg/L <br /> Vtot= total volume of solution (ozonated water+ GW) in L <br /> VFW = volume of GW in L <br /> Task 3 - Confirmation of Contaminant Removal <br /> To confirm that COCs are removed and estimate the amount of removal due to <br /> destruction versus volatilization, batch tests will be conducted. Groundwater (GW) and <br /> soil will be sparged with either air or ozone as shown in Table 3. GW and soil will be <br /> placed in a closed reactor fitted with a gas dispersion tube and vent for off-gases then <br /> sparged at a flowrate of 500 mL/min for 6-8 hours. Off-gases from 0-30 minutes and <br /> 31-60 minutes will be collected in Tedlar bags, then analyzed for TPH-g, BTEX, MTBE, <br /> acetone and TBA to determine whether CDCs volatilized. (Note that it is not possible to <br /> collect all of the off-gases due to the large volume expected.) At the end of the test, the <br /> aqueous phase will also be analyzed for CDCs and potential by-products (as listed in <br />