Compuestos orgánicos volátiles en la interfase entre la zona saturada y la zona no saturada (SUIR) de un acuífero costero

摘要: Three VOC field profiles were obtained over a period of 13 months with passive multilayer sampler (MLS) from monitoring well located in the VOC- contaminated sandy phreatic Coastal Plain aquifer Israel Tel Aviv area. The presented here are unique that they span both saturated and unsaturated zones, through saturated-unsaturated interfase region (SUIR), represent concentrations single borehole unprecedented vertical detail. In groundwater just below water table, major contaminant, trichloroethylene (TCE), was present (260,000 Pg/L-water) approaching its aqueous solubility, zone above (124,000 Pg/L-air) close to vapor pressure. Other contaminants detected high included tetrachloroethylene (PCE), cis-1,2-dichloroethylene (cis- 1,2-DCE) 1,1-dichloroethylene (1,1-DCE), all at levels as several thousands Pg/L. three profiles, TCE PCE greatest decreased increasing distance table into zones. Temporal variations maximal ranging 44,000 124,000 Pg/L-air also observed between profiles. Concentration trends for two DCE isomers opposite PCE; i.e., these compounds (cis-1,2-DCE 1,1-DCE) increase concentration table. diffusion sampling characteristic MLS makes it possible obtain unmixed samples such that, example, differences great 24,000 Pg TCE/L- air can be measured consecutive only 6 cm apart zone. detail is compared other methods. Vertical utmost importance interphase regions, where content zones varies significantly depth, time space. data by this method SUIR allows one