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Air stripping of hydrocarbon‐contaminated soils: Investigation of mass transfer effects
Author(s) -
Karan Kunal,
Chakma Amitabha,
Mehrotra Anil K.
Publication year - 1995
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450730205
Subject(s) - mass transfer , desorption , adsorption , stripping (fiber) , hydrocarbon , chemistry , soil vapor extraction , contamination , soil water , interphase , particle (ecology) , analytical chemistry (journal) , environmental chemistry , materials science , chromatography , soil science , environmental science , environmental remediation , composite material , geology , organic chemistry , ecology , genetics , oceanography , biology
Bench‐scale experiments were carried out to simulate air stripping of soil contaminated with a semi‐volatile hydrocarbon, n ‐octane. The experiments were conducted in an 8‐cm diameter glass column, packed with two types of packings: glass beads to represent non‐adsorbing materials and soil particles to represent adsorbing materials. Effects of gas superficial velocity, particle size and soil organic matter on the column outlet concentration and temperature profile were studied. Nitrogen adsorption/desorption experiments were performed to establish the desorption characteristics of the soil sample. Additionally, a mathematical model is presented which treats the interphase contaminant transport as a mass transfer rate‐limited process. The predictions from the mathematical model are shown to be in good agreement with the experimental results. Most importantly, the numerical results show that, contrary to the common assumption of local equilibrium, the interphase contaminant transport (from the sorbed to the vapour phase and/or from the liquid to the vapour phase) is mass transfer controlled.