Oxygenated gasoline release in the unsaturated zone, Part 2: Downgradient transport of ethanol and hydrocarbons.

摘要: In the event of a gasoline spill containing oxygenated compounds such as ethanol and MTBE, it is important to consider impacts these might have on subsurface contamination. One main concerns commonly associated with that decrease biodegradation aromatic hydrocarbon compounds, leading an increase in dissolved plume lengths. The first part this study (Part 1) showed when infiltrates unsaturated zone, likely partition be retained zone pore water. 2), controlled field test combined two-dimensional laboratory three-dimensional numerical modelling investigate how retention affects downgradient behaviour compounds. Ethanol transport was extremely limited. appearance wells delayed concentrations were lower than would expected based equilibrium dissolution. Oscillations water table resulted minor flushing ethanol, but its effect could still perceived groundwater from source zone. partitioning reduced mass fraction within NAPL thus reducing anticipated impact fate A conceptual simulation indicated potential ethanol-induced benzene length after 20 years 136% 40% considered.