The performance of 10 deterministic one-dimensional dynamic pesticide leaching models with different complexity was evaluated using data collected on a humic sandy soil with a shallow ground water table in the Netherlands. Both mechanistic models, based on the solution of the governing ̄ow equations (the Richards equation for soil water and the convection dispersion equation for solute ̄ow) and...

Understanding the major controls on water flow and solute transport at the hillslope scale remains a major topic of research despite numerous hillslope experiments at different sites around the world. For example, the influence of lateral preferential flow due to pipes or macropores in the subsurface flow is still unresolved. Experiments show the often paradoxical finding of fast entry of event...

subsurface drainage systems are used to control the depth of the water table and to reduce or prevent soil salinity. water flow in these systems is described by the boussinesq equation, and the advection-dispersion equation coupled with the boussinesq equation is used to study the solute transport. the objective of this study was to propose a finite difference solution of the advection-dispersi...

ated with soil type, vadose zone flow and transport processes are also affected by such external factors as tillage Vadose zone flow and transport processes are known to be strongly practices. For example, Petersen et al. (1999, 2001) affected by both soil structure and soil texture. We conducted a field experiment to explore the impact of heterogeneity in soil structure showed that surface til...

hanced transport has been clearly documented in batch and column studies (Chiou et al., 1986; Dunnivant et The apparent enhanced transport of soil-applied atrazine following al., 1992; Enfield et al., 1989; Hassett and Anderson, irrigation of treated effluents has been hypothesized to be from com1982; Hutchins et al., 1985; Kan and Tomson, 1990; plexation of atrazine with effluent-borne dissolv...

Sulfonamide antibiotics are a commonly used group of compounds in animal husbandry. They are excreted with manure, which is collected in a storage lagoon in certain types of confined animal feeding operations. Flood irrigation of forage fields with this liquid manure creates the potential risk of groundwater contamination in areas with shallow groundwater levels. We tested the hypothesis that-i...

A finite-element approach was formulated, aimed at enabling an integrated study of mechanical and biochemical factors that control the functional development of tissue engineered constructs. A nonlinear biphasic displacement-velocity-pressure description was combined with adjective and diffusive solute transport, uptake and biosynthesis. To illustrate the approach we focused on the synthesis an...

Peritoneal solute transport increases with time on treatment in a proportion of peritoneal dialysis (PD) patients, contributing to ultrafiltration failure. Continuous exposure of the peritoneum to hypertonic glucose solutions results in morphologic damage that may have a causative role in changes in peritoneal function. The purpose of this analysis was to establish whether increased exposure to...