Relation of reactive solute-transport parameters to basic soil properties

Abstract

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 parametersvelocity of transport (V), dispersion coefficient (D), dispersivity (), 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 (), 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) ( 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,  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 poresize distribution index, n. V, D and P were positively correlated with soil pH, while R and  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.

Field‐scale measurements of soil physico‐chemical profiles of the Potohar region in the Indus basin of Pakistan

“…This supports irrigation management, groundwater recharge and ecoservices (Blasko, 2011; Issaca & Ashraf, 2017). Therefore, insight into profile infiltration and soil physico‐chemical characteristics is key to sustainable soil and water resource management and allied studies (da Silva et al, 2020; Dai et al, 2019; Dharumarajan et al, 2021; Mojid et al, 2018; Nemes, 2011; Poggio et al, 2021; Wimalasiri et al, 2020).…”

Pedo-transfer functions with multiple linear regressions to predict solute-transport parameters

“…Sub-samples from the sampled soils were analyzed for particle size distribution, gradation, pH and organic carbon (OC) by employing standard methods. Details of soil sampling and analysis of the samples are reported in Mojid et al (2018). The procedures of solute-transport experiments are described here in brief.…”

“…Regression technique is widely used to determine the relationship between predictors and predictands because of its simplicity. It can use linear regressions or nonlinear regressions depending on the expected relationship among the variables (Mojid et al, 2018). The advantage of regression analysis is that it is straightforward to carry out and easy to employ.…”

Characterization and Study of Dominated Alluvial Soil Profile of Mirzapur in Indo-Gangetic Plain (IGPs) of India

“…It also provides adequate information in terms of landform, natural vegetation as well as characteristics of soils which can be utilized for land resources management and development [10]. The alluvium deposit of both old and new types by the two great rivers of India, the Ganga and the Yamuna are found in this region, only the southern uplands, touching the Vindhya hills are not covered by such deposits [11][12][13][14][15][16][17][18][19][20]. Sandstone, shale, conglomerate and limestone are found in the Sun Valley region of Mirzapur.…”