Effect of rate of water table rise on LNAPL entrapment in uniform and well-graded sands.

摘要

Vertical water table movement is liable to trap part of any tight non-aqueous phase liquid (LNAPL) present within the vicinity of capillary fringe and water table in contaminated aquifers. Due to toxicity and low dissolution of LNAPLs in water, the trapped component could be a long-term groundwater contamination source. This present work experimentally investigated and modeled the influence of rate of water table rise on the entrapment of Saudi Arabian light crude oil in natural uniform and blended well-graded sands. Series of laboratory column tests were conducted to simulate a rising water table at several rise rates and the subsequent entrapment of the LNAPL for range of initial water saturations between 0--71%; from which macroscopic quantitative measurements of trapped LNAPL saturation were performed after attainment of quasi-static equilibrium.; The experimental results apparently show that, at high rate of water table rise, in addition to initial water saturation, the entrapment of LNAPL is also significantly influenced by the rate of the water table rise. (Abstract shortened by UMI.)