Solute-transport
parameters are needed to assess the pollution risks of soil and groundwater
resources. A reliable estimate of these parameters from easily measurable soil
properties is therefore important. So, the correlations of the transport
parameters for one metalloid compound (NaAsO2), six heavy metal
compounds (Cd(NO3)2, Pb(NO3)2,
Ni(NO3)2, ZnCl2, CuSO4 and Co(NO3)2),
two pesticides (cartap and carbendazim) and one inert salt (CaCl2)
with some basic properties of eight agricultural soils of Bangladesh were
investigated. The purpose of this study was to generate information for
development of non-parametric pedo-transfer functions for reactive solute
transport through soils. The transport experiments with the solutes were done
in repacked soil columns under unsaturated steady-state water flow conditions.
The major solute-transport parameters – velocity of transport (V), dispersion coefficient (D), dispersivity (l),
retardation factor (R) and Peclet
number (P) – were determined by
analysing solute breakthrough curves (BTCs). The basic soil properties
pertinent to solute transport: clay content, median grain diameter (D50),
pore-size distribution index (n),
bulk density (r), organic carbon content
(C) and pH were determined. The associations of the solute-transport parameters
with these soil properties were investigated and evaluated. Both the solute
dispersivity and retardation factor increased significantly (p<0.05) (l
linearly and R following power law)
with the increase in soil clay content. Dispersivity significantly decreased
with the increase in median grain diameter following power law. The V, D,
l and P values were weakly and negatively
correlated with the soil bulk density. Retardation factor, R, was moderately and positively correlated with the ratio of clay
content to organic carbon content. Dispersivity decreased but P increased, both significantly, with
increasing pore-size distribution index, n.
V, D and P were positively
correlated with soil pH, while R and l were
negatively correlated with it. The correlation of the solute-transport
parameters with soil properties being significant (p < 0.05), in most cases,
provides strong possibility of predicting solute-transport parameters from the
basic soil properties through the development of pedo-transfer functions.
Reactive solutes transport parameters soil pH pore-size distribution
Birincil Dil | İngilizce |
---|---|
Bölüm | Articles |
Yazarlar | |
Yayımlanma Tarihi | 1 Ekim 2018 |
Yayımlandığı Sayı | Yıl 2018 Cilt: 7 Sayı: 4 |