A laboratory desert dust generator using vibration on a soil sample:
mineralogical and compositional study
Abstract
A laboratory study was carried out using a vibrating system (SyGAVib) to
produce particles from four soils collected in the central Tunisian
region around Sfax. The aim of this device is to mimic dust emission by
natural wind erosion. Using compositional analysis, the dust produced
was compared to: dust generated in a wind tunnel by the same soils, fine
sieved and original bulk soils, and naturally occurring aerosol samples
collected in the same area. The relative quartz content strongly
decreases from bulk to fine soils, and again from fine soils to both
wind tunnel and vibration generated aerosols. Compositional data
analysis (CoDA) clearly shows: a silica dilution effect in bulk soils,
and that if silica is removed from the composition, the elemental
compositions of fine soils and generated aerosols are similar but differ
from bulk soils. Both aerosol generation methods produce material with
chemical compositions that are also close to those measured in
field-sampled aerosols, and the fine soil composition is much closer to
that of field and laboratory aerosols than to the parent soil. Aerosols
generated from soils in the laboratory, either using a vibrating system
or a wind tunnel, can be used as surrogates of the particles collected
directly in the field.