In Situ Determination of the Rate of Unassisted Degradation of Saturated-Zone Hydrocarbon Contamination

摘要: Abstract A method to measure the in situ degradation rate of dissolved hydrocarbon contamination has been developed and applied at two locations a field site. The uses rates downward diffusion oxygen upward carbon dioxide through unsaturated zone, as calculated from vertical soil-gas concentration gradients, combined with stoichiometry obtain mass per water table surface area time. Values 0.385 gram m2 day 0.52 (based upon data) 0.056 0.12 were site fuel contamination. This result lower values ground-air concentrations is consistent significant fraction produced being lost aqueous phase. Based single-stage equilibrium phase-transfer model, gas/water volume ratios 0.02 0.2 for capillary fri...