| Vol. 4 (1992) | |||
- Ausbreitungsverhalten von leichtflüchtigen
Chlorkohlenwasserstoffen (LCKW) in der ungesättigten Zone.
[Behavior of Volatile Hydrocarbons in the Unsaturated Zone]
Straub, Johannes (1992), 119 p., 48 Fig., 31 Tab.
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Abstracts
Ausbreitungsverhalten von leichtflüchtigen Chlorkohlenwasserstoffen
(LCKW) in der ungesättigten Zone.
[Behavior of Volatile Hydrocarbons in the Unsaturated Zone]
Johannes Straub
Abstract: This paper presents the transport and fate of volatile hydrocarbons
as trichloroethylene and tetrachloroethylene in the unsaturated zone.
The behavior of organic pollutants in this compartment is determined by
many physical and chemical processes. Batch experiments have been conducted
to measure partition coefficients between the solid, liquid and vapor
phase. Column experiments have been performed to determine the gaseous
diffusion coefficients in relation to moisture contents in unsaturated
systems. Quaternary fluvioglacial and tertiary sediments with different
specific surfaces areas and different contents of organic carbon have
been used in all experiments. The transport of dissolved hydrocarbons
during the column experiments has been monitored with suction cups, made
of porous ceramic, steel or teflon. Problems in sampling the seepage water
consist in the fact that the substances are adsorbed at the suction cups
and are degassing in the sample bottle. Sorption coefficients have been
determined by laboratory experiments. An apparatus has been constructed,
which a closed system prevent degassing by collecting the sample in a
gastight glassiringe. To illustrate the volatile pollutant behavior, contaminant
transport has been calculated with a given analytical model. This model
incorporates the effects of volatilization, leaching and degradation to
describe the major pathways of soil applied organic chemicals as a function
of environmental variables and soil conditions.
Paper language: german; german abstract
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