Nonaqueous phase liquid transport and cleanup: 2. Experimental studies

Abstract

An analysis of the movement of nonaqueous liquids such as organic solvents and gasoline in part 1 (Hunt et al., this issue) showed that separate phase liquids are not completely displaced by groundwater flow under typical pumping conditions and that removal of the compounds by dissolution is mass transfer limited. Steam displacement was proposed as a more efficient cleanup strategy for separate phase organic liquids present in porous media. This paper presents the results of a series of laboratory sand column experiments designed to confirm the theoretical analyses presented in part 1 (Hunt et al., this issue). Experiments with trichloroethylene, a benzene‐toluene mixture, and a commercial gasoline, showed that water flow at rates as high as 15 m d−1 could not displace the separate phase liquids when present in a sand matrix in quantities corresponding to a column average saturation of 2.5%. Steam injection, on the other hand, displaced the contaminants as a separate phase just ahead of the steam front, producing a concentrated, small‐volume waste stream. Analysis of the laboratory data consisting of pressure gradients, temperature profiles, and water flow velocities shows that the laboratory results are consistent with the theoretical predictions. Moreover, computations of energy requirements show that steam displacement of separate phase contaminants is economically attractive.

Universality of AC conductivity: Random site-energy model with Fermi statistics

“…We also conclude that we do not appear to find any dependence of the form ⍀ ͑d−1͒/2 , as predicted by percolation-based theories. 29 On the other hand, such a dependence would not be easily observable in systems with variable-range hopping, since it would require very low frequencies. 42 …”

“…Nevertheless, it is in this regime where differences between theoretical predictions from effective-medium theories by Ganter and Schirmacher, 28 ͑ ͒ = ͑0͒͑1+⍀ d/2 ͒, and from percolation-based theories by Hunt, 29 ͑…”

Influence of Water Table Fluctuations on Formation of Retained and Trapped Light Petroleum Products

“…J.R. Hunt и его со-авторы [Hunt et al, 1988] исследовали ме-ханизм переноса отдельных капель ЛНП. Они сделали вывод, что подъем УГВ не сдвигает отдельных капель в ненасыщен-ной зоне.…”

“…Этим мы подтверждаем вывод, сделанный J.R. Hunt и др. [Hunt et al, 1988], что природный подъем УГВ не сдвигает от-дельных капель ЛНП в ЗА.…”

“…Этим мы подтвердили вывод, сделанный J.R. Hunt и др. [Hunt et al, 1988], что природный подъем УГВ не сдви-гает отдельных капель ЛНП в ЗА, а защем-ляет их. Условием выноса ЛНП из порового пространства является превышение капил-лярного числа над числом Бонда (см.…”