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Pii s0016-7037(02)00992-4 experimental investigations on the formation of excess air in quasi-saturated porous media (2001).
| Content Provider | CiteSeerX |
|---|---|
| Author | Kinzelbach, Wolfgang Kipfer, Rolf |
| Abstract | Abstract—The formation of an excess of dissolved gas (“excess air”) in quasi-saturated media was studied by analyzing and interpreting dissolved noble gas concentrations in laboratory column experiments. Using quartz sand filled columns of 1 m length, two different experimental designs were realized. In the first, groundwater recharge was simulated by a unidirectional vertical water flow through the columns. In the second, groundwater level fluctuations in an aquifer zone without active infiltration were reproduced by cyclic water level fluctuations in the columns. The reproducible generation of excess air under these defined, near natural conditions was successful. Partial or complete dissolution of air bubbles entrapped in the quartz sand could be identified as the mechanism responsible for the generation of excess air. Depending on the experimental design, supersaturation of the dissolved atmospheric noble gases ranging between 1.4 % Ne and 16.2 % Ne was found. The measured noble gas patterns were interpreted using inverse modeling and conceptual gas exchange models and were compared to results of numerical simulations of gas bubble dissolution in water filled soil columns. The gas composition in most of the samples resembles either unfractionated pure atmospheric excess air or is fractionated in accordance with closed-system equilibration between entrapped air and surrounding water. In addition to the amount of entrapped air, the hydrostatic pressure exerted on the entrapped air bubbles is the dominating parameter responsible for the total amount of |
| File Format | |
| Publisher Date | 2001-01-01 |
| Access Restriction | Open |
| Subject Keyword | Excess Air Pii S0016-7037 Quasi-saturated Porous Medium Experimental Investigation Quartz Sand Unfractionated Pure Atmospheric Excess Air Inverse Modeling Quasi-saturated Medium Cyclic Water Level Fluctuation Conceptual Gas Exchange Model Different Experimental Design Aquifer Zone Entrapped Air Gas Composition Air Bubble Active Infiltration Groundwater Recharge Groundwater Level Fluctuation Unidirectional Vertical Water Flow Experimental Design Reproducible Generation Noble Gas Concentration Dissolved Atmospheric Noble Gas Soil Column Laboratory Column Experiment Numerical Simulation Complete Dissolution Total Amount Gas Bubble Dissolution Entrapped Air Bubble Hydrostatic Pressure Natural Condition Measured Noble Gas Pattern Closed-system Equilibration |
| Content Type | Text |
