Diesel Adsorption to PVC and Iron During Contaminated Water Flow and Flushing Tests.
Diesel Adsorption to PVC and Iron During Contaminated
Water Flow and Flushing Tests.
Kedzierski, M. A.
NISTIR 7520; 52 p. June 2008.
diesel fuel; absorption; polyvinyl chloride; iron; water
flow; contamination; fluorescence; thickness;
uncertainity; toluene; tests
This paper presents an experimental and theoretical
study of aqueous diesel contamination and
decontamination of a polyvinyl chloride (PVC) surface
and an iron (Fe) surface. A test apparatus designed for
the purpose of studying adsorption of diesel from a
flowing dilute diesel/water mixture was used to measure
the mass of diesel adsorbed per unit surface area (the
excess surface density) and the bulk concentration of
the diesel in the flow using a fluorescence based
measurement technique. Both bulk composition and
the,excess surface density measurements were achieved
via a traverse of the fluorescent measurement probe
perpendicular to the test surface. The diesel
adsorption to each test surface was examined for three
different Reynolds numbers between zero and 7000.
Measurements for a given condition were made over a
period of approximately 200 h for a diesel mass fraction
of approximately 0.15% in tap water. For a Reynolds
number of approximately 7000, the largest excess layer
thickness was approximately 4.4 mm, which was measured
on a PVC surface. Averaging over all contaminating flow
rates and exposure times, the excess layer thickness on
the PVC surface was approximately 2.0 mm. Reynolds
number had little or no effect on the accumulation of
diesel on an iron surface, which was approximately 0.71
mm. The adsorbed diesel on the PVC and iron surfaces was
removed by flushing with tap water. Models to predict
excess layer thickness during flushing and contamination
were developed. The models predict flushing times to
within 7 h and predict the influence of pipe surface on